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First International Palaeontological Congress! ABSTRACTS No. 68

Edited by Glenn A. Brock & John A. Talent

Geological Society of Australia

Geological Society of Australia, Abstracts Number 68 First International Palaeontological Congress (IPC2002) 6-10 July, 2002, Macquarie University, N.S.W., Australia Editors: Glenn A. Brock & John A. Talent

IPC2002 Organising Committee: John A. Talent, Ruth Mawson, Brian McGowran, Michael Archer, Anne Musser, Barry Webby, Ian Percival, Glenn Brock, Peter Molloy, Andrew Simpson, Theresa Winchester-Seeto, Tony Wright, Clinton Foster, Peter Cockle, George Wilson, Margaret Anderson, David Mathieson, Warwick Try, Margaret McFarlane, James Valentine, John Paterson & Luke Strotz

ISSN 0729 011X © Geological Society of Australia Incorporated, 2002

Preferred citation for papers in this volume: Abdelghany, O. 2002. Late Eocene biostratigraphy (Cribrohantkenina inflata Zone, P16) of the Buraimi-AI Ain area, western side of the Northern Oman Mountains, U.A.E. - Oman border zone. IPC2002, Geological Society of Australia, Abstracts 68, 3. Material published here may be freely copied for library, educational or research purposes, but replication of any part requires written permission from the Geological Society of Australia, as well as appropriate acknowledgement. Copies of this publication may be obtained from: Geological Society of Australia Incorporated Suite 706, 301 George Street Sydney NSW 2000 Australia

TAXONOMIC/NOMENCLATURAL DISCLAIMER: This publication is not deemed valid for taxonomic or nomenclatural purposes (see ICZN, 4th Edition, 1999) Logo Design: Alan Lam & John Talent Cover Design: Dean Oliver Graphics.

Printed by: McPherson's Printing Group: www.mcphersons.com.au

Foreword The onset of a new millennium has moved many scientific organisations and individuals to evaluate accomplishments of the past and to seek new and fruitful directions of enquiry. Many scientists, palaeontologists included, feel that their particular areas of research are under threat in what they see as disturbingly changing times. Perhaps this situation is "the norm". We should not be surprised if the palaeontologies, along with other sciences, are always doing battle with clever economic and social systems quick to exploit or sidestep the implications of the new data and new theories they and other sciences bring forward. Palaeontologists are prone to lament the decrease in numbers of university departments offering courses in their discipline and feel themselves to be under-appreciated handmaids of geology sensu lato, but stratigraphy, sedimentology, regional mapping and classical petrology, long taken for granted as core areas for training geologists, are all under pressure and in decline in tertiary institutions and geological surveys around the globe. But the same phenomenon is occurring in other disciplines; taxonomy per se has disappeared from most departments of zoology and botany, and university after university is abandoning the teaching of classical physics. Granted, these areas or disciplines are not always taught inspiringly, but, in the case of palaeontology, without precise taxonomy (too time-consuming for most students in the Internet age), any exercise in high-precision stratigraphic alignments, palaeobiogeography or palaeoecologic analysis is prone to produce flawed if not disastrous results. Increasingly strong and beneficial linkages are nevertheless developing between the palaeontologies and other areas of science, especially with the biological sciences, but also with chemistry (notably isotope chemostratigraphy) and archaeology. The palaeontologies find it easier than most areas of science to reach into the public domain. It is important that we capitalize on this too! Generation of an umbrella group, the International Palaeontological Association (IPA), for the many palaeontological societies worldwide goes back to the 16th International Geological Congress (1933, Washington), but it remained an essentially passive organisation within the International Union of Geological Sciences until the 1960s when, due especially to the energies of Marius Lecompte (Brussels), it gained effectiveness as an organization. The first major initiative of IP A was to publish scientific material of highest quality and of general interest to palaeontologists, biologists and stratigraphers. Paleobiology, integrating the study of fossil organisms with modern biology, has always been central to this enterprise, as have been phylogeny of higher taxonomic units, broad-scale palaeobiogeography and analysis of biologic and environmental events, always with an emphasis on providing information for large groups of earth and biological sciences. IPA (through the Lethaia Foundation, Oslo) publishes the periodical Lethaia (since 1968) and the series of monographs, Fossils and Strata, all renowned for sustained editorial excellence. IPA has published the Directory of Palaeontologists of the World (5th edition, 1989, now web-based) and Fossils of the World: an International Guide (1989). For many years, IPA has had a significant role in providing seed-money to help international research groups mount international meetings Mounting international palaeontological congresses at regular intervals is a new initiative for IPA. The first of these, IPC-2002, being held in Sydney, brings together more than 400 palaeontologists from 35 nations. IPA is grateful to the Vice-Chancellor of Macquarie University, Prof. Di Yerbury, for sustained interest and numerous courtesies that have greatly facilitated mounting IPC-2002 at Macquarie, important among which have been the art exhibition, Palaeographia, in the Vice-Chancellor's Gallery. The staff of the Gallery

zestfully and imaginatively collaborated in amassing appropriate art pieces for this exhibition. We are grateful to our joint-host, the Australian Museum, and to the National Opal Collection for hosting two evenings during the Congress. The business manager of the Geological Society of Australia, Misha Frankel, and the treasurer of the Association of Australasian Palaeontologists, Tim Munson, provided much advice on, inter alia, recent and labyrinthine changes to Australian taxation law. Much appreciated has been the sustained enthusiasm of colleagues who organised the broad spectrum of pre-, mid- and post congress excursions in Australia and New Zealand (11 major excursions, 4 one-day excursions and 5 half-day excursions: all viable), the 24 symposia and other congress events, and Macquarie University Centre for Ecostratigraphy and Paleobiology (MUCEP) people (staff, research associates, students and friends) who organised the technical program, and skilfully managed registrations, finances, accommodation (displays, transport and publicity, dealt with deluges of requests for personalised invitations, and organised the associated programs for science teachers and for accompanying persons. Numerous friends provided accommodation for the overflow of participants. The logo and wine labels are the work of artist friends Alan Lam and Dean Oliver for the former, and John Wolseley for the latter. We are profoundly grateful to IP A for their faith in IPC-2002 and MUCEP by readily undertaking to publish four volumes of papers from the IPC-2002, three in Fossils and Strata, one in Lethaia. Several other stand-alone publications will result from the Congress; we are indebted to those (mainly symposium convenors) who have undertaken to edit these tomes. IPC-2002 is dedicated to demonstrating that the palaeontologies are not only alive but burgeoning as new and ever more exciting linkages develop across an increasingly broad spectrum of the sciences. Most importantly, this gathering provides a unique opportunity for dialogue, for sharing information about positive and innovative programs that are helping expand the boundaries of our science, and giving the palaeontologies greater cultural significance. We feel sure that IPC-2002 will help develop a momentum that will advance our science in the new millenium. John A. Talent Professor of Earth and Planetary Sciences, Macquarie University President, International Palaeontological Association Convenor, First International Palaeontological Congress (IPC2002)

IPC 2002

Oral Presentations

IPC2002 Oral Presentations PLENARY LECTURE PALAEONTOLOGY AND KINDRED SCIENCES FACE ANOTHER CENTURY Tat'vana N. KOREN VSEGEI, Sredniy Prospekt 74, St Petersburg 199026, Russia; tkoren@mail.wplus.net Following fragmentation of the Soviet Union, the venerable VSEGEI, the research wing of the former Soviet Ministry of Geology passed through difficult times, but it seemed that things were getting better, that the worst period (including long delays in receiving salaries) had passed. On the basis of imaginative projects, it had become possible once again to employ young scientists, though not in great numbers. There were thus prospects for re-inventing the foremost research geological institution in Russia. The role of palaeontologists in providing the tightest possible ages for stratigraphic units and thus contributing importantly to the legends of new map sheets being produced by the Ministry was appreciated, and viewed as a pivotal activity in an organization with the greatest diversity of mapping initiatives globally— and renowned for the quality and quantity of maps produced. But times have changed. In keeping with the global trends towards reduction in scientific expertise, towards introduction of layers of management staffed by managers (with little or no scientific training or appreciation of basic science), and retraction from mapping initiatives (unless funded primarily by outside bodies), VSEGEI and many regional branches of the Ministry of Geology are again facing difficult times and, by extension, so are their groups concerned with palaeontology and stratigraphy. The soft-rock areas of the earth sciences, palaeontology included, are not expensive. For this reason they may seem to be unsophisticated and therefore prime targets for excision in cost-cutting exercises. But it is precisely because palaeontologists are inexpensive, returning value for every dollar spent, that their labours, perceptively directed, are eminently worthy of increased support. Opportunities for obtaining funding for research are extremely limited. A vast amount of energy is being devoted by VSEGEI scientists to generation and submission of numerous applications to national and foreign funding bodies. This activity has become the prime activity of most scientists, though the filling in of evermore-comprehensive forms generated by the new managerial class (the "bean-counters") consumes huge amounts of time that would be better spent on research in the laboratory or in the field. Sadly, this has become a global phenomenon without any apparent signs of recovery. Because the majority of earth scientists in Russia are curiosity-driven and inclined to optimism, the effect on morale of this downward spiral has been less devastating than might be at first imagined, but it has been devastating nonetheless. How can palaeontology and kindred sciences go forward? There must be more fanfare about how our particular skills still provide the highest levels of precision as regards relative ages, and how these skills, imaginatively applied, can greatly improve knowledge of the contexts within which mineral exploration often takes. We all know this, but are disappointed when our peers take our labours for granted. We have been expecting too much! We are too passive, too inclined to lurk in the shade. Clearly we need to increase our relevance at all levels of society by establishing increasingly visionary linkages to other areas of science, especially outside the earth sciences domains. That the International Palaeontological Association has opted for increased autonomy by launching regular international congresses bodes well for the future of palaeontology and kindred sciences.

IPC2002 Oral Presentations

LATE EOCENE BIOSTRATIGRAPHY (CRIBROHANTKENINA INFLATA ZONE, P16) OF THE BURAIMI-AL AIN AREA, WESTERN SIDE OF THE NORTHERN OMAN MOUNTAINS, U.A.E. OMAN BORDER ZONE Osman ABDELGHANY Geology Dept., Faculty of Science, United Arab Emirates University, P.O. Box 17551, AlAin, Abu Dhabi, U.A.E. [Osman.Abdelghany@uaeu.ac.ae]. The Late Eocene Cribrohantkenina inflata (Howe) and the homogenous biozone (PI6) are recorded for the first time from Jabal Qatar, along the U.A.E.-Oman border, near A1 Ain area, Abu Dhabi. A correlation is proposed between this (PI6) stratigraphic horizon and the Tle6 unit of Hunting (1979) of the Dammam Formation, which crops out on the western limbs of the Jabal Hafit and Jabal Malaqet anticlines, south and east, respectively, of A1 Ain city. The occurrence of the Cribrohantkenina inflata species and its associated forms permits the division of the Upper Eocene of Jabal Qatar into three planktonic foraminiferal zones (PI 5, P16, P17) of Blow (1969).

MAASTRICHTIAN FORAMINIFERA FROM THE WESTERN SIDE OF THE NORTHERN OMAN MOUNTAINS, UNITED ARAB EMIRATES Osman ABDELGHANY1, Ahmed Aly ISMAIL2, & Mohamed BOUKHARY2 1 Geology Department, Faculty of Science, United Arab Emirates University, Al Ain, P.O.Box 17551, United Arab Emirates; [Osman.abdelghany@uaeu.ac.ae]; 2 Geology Department, Faculty of Science, Ain Shams University, Cairo, Egypt; [aaismail@asunet.shams.edu. eg; boukhary@hotmail.com]. A precise correlation of the Maastrichtian sections from the western side of the Northern Oman Mountains: Jabals Qarn El Barr, Al Aqaba and Malaqet of the United Arab Emirates; and Jabal El Rawdah of the Sultanate of Oman, reveals two distinct facies based on microfaunal assemblages. The former is an open marine facies at Qarn El Barr section, yielding numerous planktonic foraminiferal species describing three planktonic zones: Globotruncana aegyptiaca (Early Maastrichtian), Gansserina gansseri (Middle Maastrichtian) and Abathomphalus mayaroensis (Late Maastrichtian). During Maastrichtian time, this open marine facies passed laterally into a shallow marine one which is characterized by larger foraminiferal species: Lepidorbitoides socialis, Siderolites calcitrapoides, Omphalocyclus macroporous, Orbitoides media and Sulcoperculina sp. This facies is well developed in Jabal Al Aqaba, Jabal El Rawdah and Jabal Malaqet sections.

BIODIVERSIFICATION OF ORDOVICIAN CHITINOZOANS FROM LAURENTIA, BALTICA AND NORTH GONDWANA Ai'cha ACHAB1, Florentin PARIS2, Jaak Nolvak3 & Esther ASSELIN4 1,4 Centre geoscientifique de Quebec, C.P 7500, Sainte-Foy, Quebec, G1V4C7, Canada; 2GeosciencesRennes, UMR 6118 du CNRS, Universite de Rennes 1, 35042 Rennes-cedex, France;3 Tallinn Technical University, Institute of Geology, EE -10143 Tallinn, Estonia. Ordovician chitinozoans are well known from Laurentia, Baltica and North Gondwana where they have been used to establish well-defined regional biozonations. Information on chitinozoan assemblages from these palaeoplates has also allowed for the documentation of faunal relationships between these regions as well as changes that have occurred at high, intermediate and low latitudes during the Ordovician. In the context of the IGCP 410 project, a global Ordovician chitinozoan database has been constructed integrating the regional datasets. This database contains information on more than 10,000 fossiliferous samples with a worldwide distribution yielding 56 genera and 289 species of chitinozoans. North Gondwana, Baltica and Laurentia contributed more than 2/3 of the data of the global database: North Gondwana provided information on 1415 productive samples and 126 species; Baltica contributed more than 4500 samples and 96 species and Laurentian 1391 fossiliferous samples and 144 species. With the exception of the Upper Ordovician of Laurentia, Ordovician chitinozoan diversity is usually moderate in all three regions with values ranging from 10 to 30 species per time-slice. However, chitinozoan abundance shows important variations according to latitude. It is greater in high-latitude regions (North Gondwana), where it may reach several thousand specimens per gram of rock, and lower in low-latitude

IPC2002 Oral Presentations regions (Laurentia) where more productive samples have yielded not more than a few hundred specimens per gram of rock. Latitudinal Ordovician chitinozoan provincialism is reflected in the faunas of the three palaeoplates as shown by distinct differences in regional biozonations. This distinctiveness is also expressed in the form of regional biodiversity curves. The signals expressed by the curves are not synchronous. For instance, the first occurrence of chitinozoans in North Gondwana and Baltica has been documented in the lower Tremadoc, but only in the lower Arenig in Laurentia. Similarly, greater diversity is recorded in the upper Darriwilian of North Gondwana, whereas in Baltica it occurs in an interval spanning the upper Darriwilian-lower Caradoc. In Laurentia the peak is observed in the upper Caradoc. The distinctiveness of the regional microfaunas can also be expressed in terms of common species. Of 390 known Ordovician species, only 21 are shared by the three palaeoplates. However, in the same period, from 36 to 38 species have been recorded from two palaeoplates. It is during the Darriwilian and lower Caradoc that chitinozoans from Baltica are recognised in North Gondwana microfaunas and during the Late Ordovician that Baltica and Laurentia share the greater number of common species. This suggests that more open communication between Gondwana and Baltica and closer relationships between Baltica and Laurentia prevailed during these epochs. These epochs correspond to increased chitinozoan diversity. Despite these differences, some points are common to the three regions. A strong correlation exists between the diversity and the available data curves. In the three palaeoplates pulses in diversity and in origination rate are recorded in the Darriwilian. It is also worth noting that chitinozoan diversity starts declining in the upper Caradoc with the minimum level reached in the upper Ashgill. This observation implies that the chitinozoan microfauna was under environmental pressures since the Caradoc, and that the Late Ordovician glaciation provided the final stroke for the weakened chitinozoan populations.

VENTASTEGA CURONICA AND THE CONTINUING PROBLEM OF DEVONIAN TETRAPOD PHYLOGENY Per Erik AHLBERG Department of Palaeontology, the Natural History Museum, Cromwell Rd., London SW7 5BD, UK; [pea@nhm. ac. ukj. Although many new Devonian tetrapods have been discovered in recent years, phylogenetic studies of these earliest limbed vertebrates continue to focus predominantly on the Famennian genera Ichthyostega and Acanthostega from East Greenland. This is not surprising, as these two genera are known from virtually complete skeletons, whereas the others are at best fragmentary (Tulerpeton, Ventastega, Elginerpeton), and at worst (Obruchevichthys, Metaxygnathus, Densignathus, Hynerpetori) known only from isolated elements. Ventastega, Elginerpeton, Obruchevichthys, Metaxygnathus and Densignathus are represented by whole or partial mandibular rami with preserved dentitions; Ventastega is additionally known from semi-articulated cranial and pectoral girdle material, Elginerpeton from fragmentary pectoral and pelvic girdles, a humerus, a femur and a tibia. It is now generally agreed that all Devonian tetrapods, with the possible exception of Tulerpeton, are members of the stem group. This naturally directs attention to the question of what light they can cast on the evolution of the crown-group character complement. Furthermore, there is no clear evidence that any of them are uniquely related to each other, with the possible exception of Elginerpeton and Obruchevichthys which may be sister taxa. Because of these factors, recent phylogenetic analyses have tended to view the Devonian tetrapod genera as a series of separate plesions, and have focused on the ordering of these plesions relative to the crown group. Most of these analyses have placed Ichthyostega crownward to Acanthostega, based on its possession of an olecranon process, large ribs, and several other characters. All of the fragmentary Devonian tetrapods except Tulerpeton have been placed below Acanthostega and Ichthyostega in the stem group; this principally reflects their possession of coronoid fangs, unlike Acanthostega, Ichthyostega and more crownward tetrapods. Among these fragmentary genera, Ventastega, Metaxygnathus and Densignathus share some characteristics of uncertain polarity, such as a splint-like and loosely attached dentary, with Acanthostega. On the other hand, Elginerpeton (the earliest known tetrapod) shares postcranial characteristics (ventrally placed radial facet; shape of ilium; presence of iliac canal) with Ichthyostega. A recently discovered partial skull and braincase of Ventastega adds greatly to our knowledge of this taxon and further underscores its similarity to Acanthostega. In particular, the morphology of the basipterygoid process and prootic region prove to be almost identical in the two genera - and closely comparable to post-Devonian tetrapods. By contrast, work in progress on Ichthyostega (in collaboration with J.A. Clack and H. Blom) has revealed a more fish-like basipterygoid process and an otoccipital which, while strikingly autapomorphic, appears fundamentally to be the most primitive of any known tetrapod. These discoveries substantially increase the amount of character incongruity, not just between Ichthyostega and

IPC2002 Oral Presentations Acanthostega (each of which now has some uniquely primitive characters), but among the more fragmentary forms (where Ventastega resembles Acanthostega, Elginerpeton resembles Ichthyostega, but both Ventastega and Elginerpeton retain primitive dental characters that are lost in the other two). Clearly, homoplasy was more prevalent among these early tetrapods than has previously been recognised. Several alternative tree topologies now seem possible, with substantially different implications for character polarity and the evolution of the tetrapod character complex. It will not be easy to resolve this problem: most of the Devonian tetrapods remain too poorly known to provide a clear phylogenetic signal, and because of the morphological magnitude of the fish-tetrapod transition it is difficult to establish detailed character polarities through outgroup comparison with Panderichthys or 'osteolepiforms'. Future discoveries will hopefully remedy these deficiencies. For the present, it is important to keep an open mind and not too readily dismiss suboptimal tree topologies.

TRACE FOSSILS FROM PALAEOZOIC OF SPITI BASIN AND EARLY CAMBRIAN TALS OF THE KROL BELT, NW HIMALAYAS, INDIA A.D. AHLUWALIA. O.N. BHARGAVA and Sandeep S. WALIA DST Project, Centre of Advanced Study in Geology, Panjab University, Chandigarh, India 160014; [adahl@pu. ac. in; geoadahluwalia@hotmail. com]. The Palaeozoic succession of the Spiti valley (Kunzam La, Thango, Takche, Muth, and Lipak, Po and Kuling Formations) and Early Cambrian Tal Group of the Krol belt have yielded important ichnofossils of geological and palaeoecological value. This oral presentation illustrates some unique preservations from the Tals discovered recently as well as providing a quick overview of ichnofossils from the Palaeozoics of Spiti. In the Tethys Himalaya, the Palaeozoic succession beginning with Cambrian Kunzam La Formation yielded Phycodes, Plagiogmus and Rusophycus of Early Cambrian age in the Parahio and Pin River sections and Phycodes pedum, Diplichnites, Planolites and Skolithos in the Kunzam La section. The Thango Formation has yielded, inter alia, Phycodes sp., P. circinatum, P. palmatum, Skolithos, Planolites, Sinusites, Arenicolites, Teichichnus. Rusophycus, Rouaultia, Monomorphicnus, Isopodichnus, Bifungites, Spirifungites and Spiriphycus in the Kinnaur area and the Pin valley. The marine trace fossils clinch discussion about possible fluvial origin of the Thango debated in recent years. The Takche Formation contains Arenicolites, Arthrophycus, Chondrites, Planolites, Skolithos and Rusophycus. From the Muth Formation are known Planolites, Palaeophycus tuhularis, Arenicolites, Skolithos and arthropod trackways. The Lipak Formation, conformably overlying the Muth, has quartzites in the lower part with a surface of omission in the Takche area displaying a superb dipslope and spectacular preservation of mega-burrows oriented across, oblique and even diagonal to the bedding. Close to the famous Tabo Monastery in the Spiti Valley, the Po Formation has plant beds with root mats which can be confused with skolithos. Just above the layer bearing rhacopterids is a bed full of Skolithos filled with ferruginous materials. Other trace fossils known in Po Formation include Asteriacites, Aulichnites, Phycodes, Planolites and Rusophycus. Zoophycos occurs nicely in the black shales of the Gungri Formation close to the Attargoo bridge and opposite the Pin-Spiti confluence. The Early Cambrian Tal Group has yielded the earliest burrows in the "Earthy Siltstone" in the KantiMishwa and Kandi-Koti Dhiman sections in Nigali Dhar Syncline below the volcaniclastic horizon. In the Mussoorie Syncline, near Kaphlani on the Mussoorie Masrana road, one of us (ADA) has found spectacularly preserved Taphrehlminthopsis circularis in a 2m x 2m dip-slope slab of micaceous mudstone. Other trace fossils recorded in the Tal group include Arenicolites, Rusophycus, Cruziana, Dimorphicnus, Monomorphicnus, Planolites, Diplichnite and Helminthopsis. The Lesser Himalaya does not have Palaeozoic rocks intermediate in age between the Tal Group and the Early Permain); the latter has not produced an ichnofauna.

BIOGEOGRAPHIC PATTERNS OF EVOLUTION AND EXTINCTION AMONG NEOGENE CORBULIDAE OF TROPICAL AMERICA Laurie C. ANDERSON1 & Peter D. ROOPNARINE2 ! Dept. of Geology and Geophysics, Louisiana State University, Baton Rouge, LA 70803 USA; 2Dept. of Invertebrate Zoology & Geology, California Academy of Sciences, San Francisco, CA 94118. Corbulid bivalves are ubiquitous and often abundant members of late Mesozoic and Cenozoic faunas from tropical to warm temperate regions of the world. Corbulids were important members of Neogene palaeocommunities in tropical America, and underwent significant morphologic evolution, speciation, and

IPC2002 Oral Presentations extinction in this region during the Neogene. We conducted phylogenetic analyses on corbulid genera and subgenera (subsequently referred to as genera) found in the tropical American Neogene to begin to elucidate their evolutionary and biogeographic history. Both composite taxa and exemplar species were used in the analyses, and for composite taxa (8 of the 12 genera), we included, when possible, specimens of the type species as well as those from a geologically old and a geologically young species of that genus. All characters used were conchological and described aspects of external ornament, valve shape, hinge, pallial line and sinus, and adductor muscle scars. Many characters were multistate and because corbulids are inequivalved, any trait that differed between valves in at least on genus was coded as two characters. We ran analyses on two matrices: one of 79 characters and the other of 76. The two matrices differ only in that 5 characters concerning comarginal ribs are combined into 2 characters in the 76-character data set. Comarginal ribs are absent in either the left or both valves of several genera, and, therefore, characters describing aspects of ribs had to be coded as missing for these taxa, although the characters are not present rather than not observed. In one set of analyses, characters were given equal weight. For a second set of analyses, characters were weighted according to their consistency indices (CI). Characters were treated as unordered and were polarized using Corbula as an outgroup. Analyses were conducted using branch and bound searches and maximum parsimony. Character state transformations were determined using accelerated transformation (ACCTRAN). We used Bremer decay indices (Bremer, 1994) to compare the robustness of cladogram nodes. For analyses where characters were equally weighted, both matrices produced one most parsimonious tree with the same topology. For the 79-character matrix tree length =235 steps, the CI = 0.5885, and the retention index (RI) = 0.5592. The 76-character matrix yielded slightly better tree statistics (tree length = 230 steps, CI = 0.6063, RI = 0.5735). When characters were weighted according to their Cis, tree topology did not change. Bremer decay indices indicate relatively robust cladogram nodes for both matrices. The larger (79character) matrix has higher Bremer support values for most nodes, although the two matrices differ only in a few characters. Based on Bremer decay values, basal nodes are less well supported than the crown group nodes in the cladograms. The cladogram resulting from our analyses agrees well with the fossil record. Only one ghost lineage (Panamicorbula) is required. Panamicorbula is a rare genus and, therefore, it is not surprising that the stratigraphic position of this taxon may not be congruent with it phylogenetic position. These results indicate that tropical American corbulids are not monophyletic. Biotic interchange with other provinces (Europe/Africa, western Pacific) must have occurred, and taxa from these regions need to be examined to fully elucidate the relationships among major clades. Nonetheless, tropical American corbulids include two endemic crown groups that, with a number of other genera, first appear in the region in the Miocene. This large proportion of first appearances is correlated with an expansion in morphospace (both shape and size) in Caryocorbula and with a divergence in oceanographic conditions between the eastern Pacific and Caribbean. Further, subsequent loss of genera (via extirpation or true extinction) from the western Atlantic is associated with a decline in Caryocorbula morphospace, and Plio-Pleistocene environmental amelioration in the tropical western Atlantic. Clades extirpated from the western Atlantic (but that survive today elsewhere in the eastern Atlantic or eastern Pacific) were limited to in the southern Caribbean Gatunian Province. Bothrocorbula s.s., which was endemic to the subtropical Caloosahatchian Province, underwent global extinction in the Pleistocene. Finally, no genera are endemic to tropical America today and except for Juliacorbula, surviving genera (Caryocorbula and Varicorbula) had broad Pliocene geographic ranges that extended to the eastern Atlantic. ICHNOFOSSILS FROM THE EARLY CARBONIFEROUS OF THE MANSFIELD BASIN, VICTORIA, AND THEIR PALAEOENVIRONMENTAL INTERPRETATION H.L.E. ANSELL & N.W. ARCHBOLD School ofEcology and Environment, Deakin University, Melbourne Campus, 221 Burwood Hwy, Burwood 3125, Victoria, Australia. The first diverse collection of ichnofossils from the Early Carboniferous terrestrial deposits of the Devil's Plain Formation, Mansfield Basin, Victoria, has been studied in order to define palaeoenvironments of deposition. The ichnofossils have been preserved in the upward fining Mansfield Group - the Devil's Plain Formation (VandenBerg & Hendrickx 1995). Most of the Devil's Plain Formation is composed of red or drab carbonaceous overbank mudstones, and approximately 10-15% drab ferruginous feldspathic and lithic finegrained sandstones arranged in thin fining-upwards cycles, and has been interpreted as being deposited in fine-grained meandering fluvial and flood plain settings. The Mansfield group of the Mansfield basin consists of Late Devonian to Early Carboniferous age sedimentary sequences, which, unconformably lie upon lower Palaeozoic rocks. The Mansfield Basin was

IPC2002 Oral Presentations formed as part of the Mount Howitt Province, (part of the Palaeozoic Lachlan Fold Belt) when Early and Middle Devonian phases of tectonic activity stabilised and uplifted south-eastern Victoria. Previous studies of the palaeontology of the Devil's Plain Formation have yielded plant fossils (Sphenopteris sp.), fish fossils (Long 1988; Woodward 1906), a problematic ichnofossil and probable annelid burrows. Trace fossils of the Devil's Plain Formation have not previously been studied in detail. Palaeoenvironmental analysis of the new Bridge Creek site has been derived from inferred ichnofossil behaviour, and assemblage studies combined with sedimentological data. Ichnofacies of the Bridge Creek site have been classified according to Bromley's (1996) scheme. The predominant solid vertical burrows {Arenicolites isp., Skolithos verticalis, and Trichichnus isp.,) in full relief with an erosional top, are characteristic of the Arenicolites ichnofacies. They were formed within rapidly deposited rippled looseground fine sandstone within a levee deposit, indicating a reletively high energy environment. The association of Cruziana problematical Diplichnites triassicus, Kouphichnium isp., Palaeophycus striatus, Planolites annularis, Planolites beverleyensis, Protichnites octonotatus, Protovirgularia dichotoma, Rusophycus carbonarius, and Strobilorhaphe pusilla, are characteristic of the Rusophycus ichnofacies, the most diverse ichnofacies of Bridge Creek. These ichnofossils are preserved in semirelief, in cohesive siltstone with variable patches of softground siltstone, indicative of a low energy floodplain environment. The most abundant ichnofossil assemblage - Rusophycus carbonarius, and Palaeophycus tubularis are characteristic of the Scoyenia ichnofacies. The burrows are predominantly cubichnial with some Palaeophycus tubularis in full relief, and are preserved in levee/floodplain deposits of a higher energy than the Rusophycus ichnofacies Udichnia (fish trace fossils) and vertebrate trackways both formed upon low angled rippled siltstone indicate a calm shallow water environment. The vertebrate trackways range in scale and width, are relatively broad, and are interpreted as being formed by inefficient to fairly efficient walkers subaqueously. BROMLEY, R. G., 1996. Trace Fossils: Biology, taphonomy and application. London, Chapman and Hall. LONG, J. A., 1988. New palaeoniscoid fishes from the Late Devonian and Early Carboniferous of Victoria. Memoir of the Association of Australasian Palaeontologists 7: 1-64, 50 figs. VANDENBERG, A . H . M . , WILLMAN, C.E., HENDRICKX, M . , BUSH, M . D . , a n d SANDS, B . C . , 1995. T h e g e o l o g y a n d p r o s p e c t i v i t y o f the

1993 Mount Wellington Airborne Survey area: Geological Survey of Victoria Victorian Initiative for Minerals & Petroleum Report 2. Melbourne, Crown (State of Victoria) Department of Agriculture, Energy & Minerals, Geological Survey of Victoria: 1-165, 89 fig, 18 tbl. WOODWARD, A.S., 1906. On a Carboniferous fish fauna from the Mansfield district, Victoria. Memoirs of the National Museum of Victoria 1: 1-32, 3 figs., 11 pi.

THE EARLY PERMIAN MACROFAUNA OF THE DUGADDA-SATPULI- RATHWARDAB AREA OF THE GARHWAL SYNFORM, LESSER HIMALAYA, INDIA Neil W. ARCHBOLD1, John A. TALENT2 & R.S. CHATURVEDI3 School of Ecology and Environment, Melbourne Campus, Deakin University, Burwood 3125, Victoria, Australia fnarchie@deakin.edu.aaj; 2MUCEP, Earth and Planetary Sciences, Macquarie University 2109, NSW, Australia [jtalent@laurel.ocs.mq.edu.au]; s"Kamal Kutir", Dr Baijnath Rd, Lucknow, India. Extensive collections of an Early Permian fauna from the Sil Formation (= inter alia, "Volcanic Breccia" of Middlemiss, 1885, "Bijni Tectonic Unit of Shanker and Ganesan, 1972, and "Jogira Member" of the Tal Formation of Valdiya, 1980) of the Garhwal Lesser Himalaya, were made by JAT and RSC in 1970-1972 following discovery of fenestellid bryozoans by R.K Arora of the University of Roorkee. The fossils, from numerous localities in the Dugadda-Satpuli- Rathwardab area on both flanks of the Garhwal Synform, were first reported by Chaturvedi and Talent (1971, 1972). Subsequent to this discovery, personnel from various organisations hurried to the area, made collections from one or two poorly defined or even bogus localities, and produced manuscripts in which elements of the fauna were cursorily described and the significance of the faunas too hastily asserted. Each subsequent report made new assertions and a concatenation of stratigraphic and palaeontologic confusion resulted regarding what was essentially a fairly simple story, though in a technically complicated area with generally poor exposures. The first descriptions were fenestellid bryozoans (Ganesan, 1972), followed by Paleogene molluscs incorrectly asserted to be from the Sila Formation and attributed a Late Triassic-Early Cretaceous age (Maithani (1972), Paleogene algae and foraminifers, and random sections through oolites misidentified as Permian fusulinids (Kalia, 1974, 1976; Tewari 1978), scolecodonts [derivation dubious] asserted to be Devonian in age (Tewari, Kachroo and Gupta, 1976), Permian spores (Gupta and Visscher, 1980) now presumed because of metamorphic grade in the Rathwardab-Dugadda-Satpuli area to have been based on "far travelled" samples [possibly from one of the Gondwana sequences of Peninsular India], and a larger fauna of generally poorly preserved and/or sheared brachiopods and molluscs from a spurious locality near Dugadda (Waterhouse and Gupta, 1978;

IPC2002 Oral Presentations Gupta, 1983; cf. Talent et al., 1988, Talent, 1995) apparently misappropriated from collections made by Panjab University research student J. Singh. This and other brachiopod-mollusk reports from the area were evaluated by Archbold and Singh (1993) who, incidentally, had a new small collection at their disposal. The pre-1980 reports on microfossils supposedly from the Sila Formation/"Bijni Tectonic Unit" have been evaluated by Bhatia (1980) and argued to have been based on material from occurrences of the Maastrichtian/Danian Bansi Limestone. The macrofossils from the Sila Formation are preserved in variably tectonised, splintery shales, siltstones and very fine sandstones of a dark grey colour when fresh weathering to brown/buff. Carbonate has been leached from the sediments resulting in fossils being preserved as internal and external moulds showing fine details. The large collections made by JAT and RSC permit us to describe in detail the variability of the species, taking into account the tectonised nature of the preservation. The fauna includes Tivertonia sp. nov., Coronalosia blijniensis Waterhouse and Gupta, Costatumulus sp. nov., Trigonotreta sp. nov., Lamniplica? sp. and fragments of streptorhynchids, Deltopecten sp., Etheripecten? sp., Streblopteria sp., Megadesmus sp. and Peruvispira sp. The chonetid Tivertonia is a widespread Gondwanan genus known from the Late Sakmarian of the eastern and western Himalaya, the early Artinskian of eastern Australia and the Asselian of Argentina. Coronalosia is known from the Late Sakmarian and Aktastinian of Western Australia and the Asselian of Argentina. Costatumulus is a widespread Gondwanan genus known from the Asselian to the Artinskian. The Trigonotreta species is close to early Sakmarian (Tastubian) species known from eastern Australia (the Beckers Formation, Cranky Corner Basin, NSW) and the Permian glacigenic sequences of Victoria. Lamniplica ioccurs in the fauna of the Tastubian Bap Formation of Peninsular India. The age of the fauna is assessed as being Early Sakmarian (Tastubian), according with earlier estimates of age (Waterhouse and Gupta 1978; Archbold 1982; Archbold and Singh 1993. The new assessment of the fauna has reduced the number of species reported and has demonstrated that the fauna is an important constituent of the Permian record in the Himalaya.

K/T VERTEBRATE EXTINCTION AND SURVIVAL: DISPELLING MYTHS AND TESTING THEORIES J. David ARCHIBALD Dept. of Biology, San Diego State Univ., San Diego, CA 92182-4614 USA; [darchibald@sunstroke.sdsu.edu]. A number of myths surround the K/T extinctions. One myth is that we have a global record of dinosaur extinction. There is a reasonably good record for all of the L. Cretaceous, but at the K/T boundary we have only western North America. Sites in South America, India, and China may provide new records. A second myth is that the number of species of dinosaurs held constant or even increased during the last 10 million years of the Cretaceous. We have more dinosaur species known from within the last 5 million years of the L. Cretaceous, but this is related to having far more specimens and sites (Dodson, 1991). A more biologically meaningful way is to compare ecologically similar dinosaur faunas - the 75 Myr old Judith River fauna and the 65Myr old Hell Creek fauna. There was a drop of some 13 dinosaur genera (40%) from the older to younger dinosaur fauna. It is the more common families, ceratopsids and hadrosaurids, rather than the rarer saurischians that disappeared. Thus this decline is real, not an artifact. A third myth is that we know what happened to the number of dinosaur species and individuals near the boundary. The record is too poor to tell the rate of turnover leading up to the K/T boundary. Sloan et al. (1986) suggested a decline in dinosaurs leading up to the boundary based upon numbers of dinosaur teeth. It is now believed that these dinosaur teeth are reworked. Sheehan et al. (1992) used several statistical measures to argue that there is no evidence of a decline in dinosaurs leading up to the boundary. A reanalysis of this study (Hurlbert and Archibald, 1995) showed these statistical tests were incapable of determining if the number of dinosaur taxa stayed constant, decreased, or increased approaching the K/T boundary. The only well documented vertebrate record across the K/T boundary is from the Western Interior, North America. When artifacts of taxonomy (pseudoextinctions), ecology (local extirpations), and preservation (errors caused by rare species) are taken into account, 57 of 107 species (49%) survived this boundary (Archibald, 1996). This is only a 10% lower level than for intervals of time just before and after the K/T boundary. Further, if the 20 rare species disappearances are actually survivals rather than extinctions, survival could rise to as high as 67% (72 of 107 species). Thus, true survival levels for vertebrate species are between 49 and 67% at the K/T boundary, with 49% most likely closer to being correct. Extinction is not uniform across the K/T boundary for the 12 major taxonomic groups of vertebrates (elasmobranchs, actinopterygians, lissamphibians, multituberculates, placentals, marsupials, turtles, lizards, champsosaurs, crocodilians, ornithischians, saurischians). It is concentrated in just five groups

IPC2002 Oral Presentations (elasmobranchs, marsupials, lizards, ornithischians, saurischians), each with 70% or more extinction. These five groups account for 41 of 55 (or 75%) of the K/T vertebrate species extinctions. Asteroid impact and massive volcanism (including global fire, sharp temperature decrease, acid rain) correctly predict only five of 12 turnover patterns (survivals or extinctions) for 12 major vertebrate groups across the K/T boundary, while marine regression and habitat fragmentation correctly predict 11 of 12 (Archibald, 1996). With marine regression / habitat fragmentation the following occur: sharks and relatives disappear from the Western Interior as close contacts with oceanic waters are lost; marsupials decline with introductions of potential placental competitors crossing newly formed land bridges; both ornithischians and saurischians sharply decline as coastal habitats are fragmented and reduced. Only the decline of lizards caused by an increase in wetter habitats, is not predicted by marine regression. The coincidence of global marine regression, a large impact, and massive volcanism near the K/T boundary marks a cacophonous time in earth history. Results of the above study eliminate at least impacts and massive volcanism as sole causes of K/T vertebrate extinctions. Separately these causes are not sufficient to explain vertebrate extinctions, but combined with global regressions, they explain the patterns of faunal (and floral) turnover at the K/T boundary. Support of the National Science Foundation and National Geographic Society is gratefully acknowledged. ARCHIBALD, J.D. 1996. Dinosaur Extinction and the End of an Era: What the Fossils Say. New York Columbia University Press, 237pp DODSON, P. M. 1991. Maastrichtian dinosaurs. GSA Abstracts with Programs 23(5): 184-185. HURLBERT. S, and ARCHIBALD, J.D. 1995. No evidence of sudden (or gradual) dinosaur extinction at the K/T boundary. Geology 23, 881-884. SHEEHAN, P.M. et al. 1991. Sudden extinction of the dinosaurs: Latest Cretaceous, upper Great Plains, U.S.A. Science 254, 835-839 SLOAN, R.E. et al. 1986. Gradual dinosaur extinction and simultaneous ungulate radiation in the Hell Creek Formation. Science 234, 1173-1175.

RELATIONSHIPS, BIOGEOGRAPHY, AND THE TIMING OF THE ORIGIN OF MAJOR CLADES OF EUTHERIA J. David ARCHIBALD Department of Biology, San Diego State Univ., San Diego, CA 92182-4614, USA. Extant eutherian mammals and their most recent common ancestor constitute the crown group Placentalia. This taxon plus all extinct taxa that share a more recent common ancestor with placentals than they do with Metatheria (including marsupials) constitute Eutheria (Rougier et al. 1998). Both fossil and molecular research have indicated new eutherian relationships, new aspects of eutherian biogeography, and new assessments of the timings of origins of various clades within Eutheria. There is an impression that considerable disagreements exist between fossils and molecules regarding placental relationships, yet molecular data (e.g. Murphy et al. 2001) support the monophyly of 16 of 18 traditionally recognized placental orders (McKenna and Bell, 1997). The exceptions to this are Artiodactyla and Insectivora. In addition, the slightly revised superordinal clades Archonta, Ferungulata, Glires, and Paenungulata are also supported by molecular data. A notable difference is the recognition of the superordinal clade Afrotheria, which was not suspected using fossil data (e.g. Murphy et al. 2001). In regard to eutherian biogeography, neither molecules nor fossils offer strong evidence for the early distribution of eutherians (e.g. Murphy et al. 2001); however, phylogenetic analyses using fossils (Luo et al. 2002) reject eutherians in Australia (Rich et al. 1997) during the Cretaceous. Using a parsimony argument and rejecting the idea that the "greatest diversity equals center of origin," it appears that Eutheria most likely originated in Laurasia, first budding off the superordinal afrothere clade to Africa and then a xenarthran clade to South America. Laurasiatheria then arose in Laurasia. Turning to the timings of origins within Eutheria, fossil evidence argues that the earliest eutherians are from well over 120mya (Ji et al., in press), the oldest placentals are between 85-90mya (superordinal clades) (Archibald et al. 2001), and the diversification of extant placental ordinal clades occurred about 65mya. Molecular evidence has eutherians originating over 130mya (e.g., Springer 1997), superordinal appearances over lOOmya (Murphy et al. 2001), and in some cases diversification of extant placental ordinal clades over lOOmya (e.g., Springer, 1997). Such ancient ordinal diversifications are artifacts of the assumption of a molecular clock during the greatest reorganization of land vertebrates that occurred 65mya with the extinction of dinosaurs; three studies using the fossil record indicate ordinal diversification occurred about 65mya (Alroy, 1999; Foote et al, 1999; Archibald and Deutschman, 2001). Support of the National Science Foundation and National Geographic Society is gratefully acknowledged. ALROY, J. (1999). The fossil record of North American mammals: Evidence for a Paleocene evolutionary radiation. Systematic Biology 48, 107-118.

IPC2002 Oral Presentations ARCHIBALD, J.D. and DEUTSCHMAN, D. 2001. Quantitative analysis of the timing of origin of extant placental orders. Journal of Mammal Evolution 8, 107-124. ARCHIBALD, J.D., AVERIANOV, A.O. & EKDALE, E.G. 2001. Late Cretaceous relatives of rabbits, rodents, and other placental mammals.

Nature 414, 62-65

FOOTE, M., HUNTER, J.P. JANIS, C.M. and SEPKOSKI, J.J., Jr. (1999). Evolutionary and preservational constraints on origins of biologic groups: divergence times of eutherian mammals. Science 283, 1310-1314. Jl, Q., Luo, Z., YUAN, C., WIBLE, J.R., ZHANG, J. & GEORGI, J.A. in press. The earliest Eutherian mammal. Nature. Luo, Z., KIELAN-JAWOROWSKA, Z., and CLFELLL, R.L. 2002. In quest for a phylogeny of Mesozoic mammals. Acta Palaeontologica

Polonica 47, 1-78.

MCKENNA, M.C., and BELL, S.K. (1997). Classification of Mammals Above the Species Level. Columbia University Press, New York. MURPHY, W.J., EIZIRIK, E., O'BRIEN, S.J., MADSEN, O., SCALLY, M. DOUADY, C.J., TEELING, E., RYDER, O. A., STANHOPE, M.J., DE JONG, W.W., and SPRINGER, M.S. 2001. Resolution of the early placental mammal radiation using Bayesian phylogenetics. Science

294, 2348-2351.

RICH, T.H., VICKERS-RICH, P., CONSTANTINE, T.A., FLANNERY, T., KOOL, L., and VAN KLAVEREN, N. (1997). A tribosphenic mammal from the Mesozoic of Australia. Science 278, 1438-1442. ROUGIER, G.W., WIBLE, J.R., NOVACEK, M.J. (1998). Implications of Deltatheridium specimens for early marsupial history. Nature 396,

459-463.

SPRINGER, M.S. (1997). Molecular clocks and the timing of the placental and marsupial radiations in relation to the Cretaceous-Tertiary

boundary. Journal of Mammalian Evloution 4, 285-302.

EARLY CARBONIFEROUS (TOURNAISIAN) CONODONT FAUNAS FROM EASTERN AND NORTHERN IRAN A.R. ASHOURI Azad Islamic University of Mashhad, Mashhad, Iran Conodont-bearing Tournasian successions have been discriminated in the Shishtu Formation in the Tabas region of E Iran and in the upper part of the Khoshyeilagh Formation in N Iran (Ahmadzadeh 1971; Weddige 1984; Ashouri 1990; 2001a, 2001b & in press; Yazdi 1996, 1999). The conodont fauna of the Shishtu Formation has been investigated in its type section in the Ozback-Kuh Mountains (Ruttner et al. 1960's) and in its reference section at Howz-e-Dorah in the southern Shotori Range (Stocklin et al. 1965). In both areas two subformations (Shishtu 1 and Shishtu 2) have been discriminated, divided by a distinctive black shale unit (the Mush Horizon). The Tournaisian horizons are in the Shishtu 2 where the sequences are less than 50 m thick. The uppermost 30 m of the Khoshyeilagh Formation in its type section (Bozorgnia 1973; Brice et al 1978; Ashouri 1994) in the eastern Alborz has produced 28 species and subspecies of Polygnathus, Pseudopolygnathus, Bispathodus, Protognathodus, Siphonodella, Gnathodus, Doliognathus, Scaliognathus and Dollymae. A new species of Pseudopolygnathus is proposed. The bouckaerti and anchoralis-latus conodont zone has been recognized in the Khoshyeilagh area, the anchoralis - latus and texanus conodont zones in the Howz-e-Dorah area and Ozback-kuh Mountains. ASHOURI, A-R., 1990. Devonian and Carboniferous conodont faunas from Iran. Ph. D. thesis, University of Hull. ASHOURI, A-R., 1994. The stratigraphical position of Member 1 and Member 6 of the Khoshyeilagh Formation based on conodont

faunas and introducing three conodont zones from Member 6. Geosciences. Geol. Surv. Iran. 4 (in Persian).

ASHOURI, A-R., 2001a. Frasnian-Tournaisian conodonts from the Shishtu Formation, Shotori Range, eastern Iran. Cour. Forsch.-Inst.

Senck., Frankfurt am Main.

ASHOURI, A-R., 2001b. Late Devonian-Early Carboniferous conodonts from the Ozbak-Kuh, eastern Iran. Cour. Forsch.-Inst. Senck.,

Frankfurt am Main. ASHOURI, A-R., in press. Middle Devonian - Early Carboniferous conodont fauna from the Khoshyeilagh Formation, Alborz Mountains, north Iran. BOZORGNIA, F. 1973. Paleozoic foraminiferal biostratigraphy of central and east Alborz Mountains, Iran. Nat. Iran Oil Comp. 4. BRICE, D., JENNY, J., STAMFLI, G. & BIGEY, F. 1978. Le Devonian de 1 Elbourz oriental: Straigraphie, paleontology (brachiopod et bryozoaire) paleogeographies. Riv. Ital. Paleont. 84. RUTTNER, A., NABAVI, M.H. & ALAVI, M. (early 1960's) Geology of the Ozbak-Kuh Mountains, Tabas area, East Iran. Geol. Surv. Iran (unpub. rept) STOCKLIN. J., EFTEKHARNEJAD, J. & HUSHMAND-ZADEH, A. 1965. Geology of the Shotori Range, Tabas area. Rept. Geol. Surv. Iran, 3. WEDDIGE, K. 1984. Zur Stratigraphie and Palaeogeographie des Devons und Carbons von N/E Iran. Senck. Leth., 52. YAZDI, M. 1996. Late Devonian Carboniferous Conodont biostrarigraphy of the Tabas area, eastern Iran. Ph. D. thesis, Macquarie University, Sydney. YAZDI, M. 1999. Late Devonian-Carboniferous conodonts from eastern Iran. Riv. Ital. Paleont. 105, 167-200.

THE TAGHANIC BIOTIC EVENTS (MIDDLE DEVONIAN) IN THE TYPE AREA: NORTHERN APPALACHIAN BASIN: RELATIONS TO TECTONICS AND EUSTASY Gordon C. BAIRD , Carlton E, BRETT & Jocelyn SESSA 1

IPC2002 Oral Presentations !

Dept. of Geosciences, S.U.N.Y. Fredonia, Fredonia, NY, 14063 [Gordon.Baird@fredonia.edu]; 2Dept. of Geology, University of Cincinnati, 500 Geology/Physics Bldg., Cincinnati, OH 45221-0013 [Carlton. Brett@uc. edu]. The late Givetian Taghanic Bioevent(s) have emerged recently as among the major marine faunal changes of the Devonian with global extinctions, perhaps rivaling those of the better known Frasnian-Famennian mass extinctions. However, the detailed pattern of these events, their timing, relative intensity and relationship to physical events have remained poorly understood in the type area in eastern North America. The "Taghanic Event" takes its name from bioevents recorded in the Tully Limestone-Geneseo formations at Taughannock (Taghanic) Falls in central New York State. The Tully Limestone (late Givetian/Taghanic Stage: MiddleUpper varcus zones) records episodes of relative (eustatic?) sea level fluctuation coupled with tectonic flexure and differential basin subsidence. Recent detailed correlation of the Tully and its thick siliciclastic equivalents in east-central New York State and central Pennsylvania has led to recognition of three unconformities that divide the Tully interval into three fourth-order depositional sequences. In very localized areas of the central New York and central Pennsylvania the lower Tully exhibits a nearly conformable contact with the underlying Windom Member of the Moscow Formation (Hamilton Group). Upper Hamilton and lower Tully facies generally represent a range of mid-shelf to dysoxic basin environments, rather than shallow near shore settings. Moreover, the horizon of an abrupt incursion of the unique lower Tully (Hypothyridina) fauna and temporary partial outage of the diverse, long-standing Hamilton fauna ("Lower Tully bioevent") is identified in both shelf and basin settings. This incursion of Old World Realm taxa occurred within a longer interval of modest highstand during latest Hamilton and early Tully deposition. A mid-Tully sequence boundary signals an erosional lowstand event, followed by major transgression recorded by deposition of the Taughannock Falls Bed interval and its equivalents. The lower Tully fauna survived this regression into the lower part of the succeeding sequence (upper part of the Carpenters Falls Bed and Smyrna Bed). The Taughannock Falls highstand was characterized by major regional flexural downwarping of areas bordering the Tully shelf and by rapid filling of the trough with sediments. The upper-middle Tully highstand was followed by a major regression event that produced a widespread disconformity that post-dated the flexural event. This lowstand was followed by a deepening upwardsuccession of units marking a full spectrum of facies from shallow, inner shelf deposits (Bellona Coral Bed) to anoxic black shale facies of the Geneseo Member; we believe that this transgression marks the true onset of the Taghanic onlap event, not the base of the Tully.. The regionally thin, post-disconformity, deposits of the Bellona Bed and coeval West Brook Shale saw a dramatic return of the diverse Hamilton fauna with conspicuous absence of lower Tully fauna taxa. This return of old endemics ("Upper Tully bioevent") appears to have started in mid- or late highstand facies of the Taughannock Falls Bed interval, but is most evident in shallow water deposits overlying the regional disconformity. Transgressive deposits of the uppermost Tully (Moravia Bed, Fillmore Glen Beds) record a decrease in benthic diversity of residual Hamilton taxa, most likely reflecting the onset of dysoxia and finally anoxia within the study area. The evolutionary fate of the Hamilton biota, is partly obscured by this facies change, but many Hamilton taxa appear to have become extinct, at least in the Appalachian Basin coincident with deepening to a maximum flooding surface at the base of the Geneseo Shale; the succeeding highstand (IIA) coincides with the hermanni-cristatus conodont Zone. Hence, there are three distinct episodes of faunal overturn that may be termed "Taghanic Bioevents." The lower and middle Tully biotic events, occurring late in the Middle varcus Zone, are significant faunal overturns that may correspond to crises seen elsewhere. However, we argue that the final elimination of the long-standing Hamilton biotas and community types (termination of an ecological-evolutionary subunit) during the Upper varcus Zone represents the main Taghanic Bioevent It is noteworthy that each of these faunal events is associated with an interval of highstand and widespread dysoxic-anoxic conditions as well as local tectonic-flexural events in the foreland basin.

THERE IS NO COMMON CAUSE FOR ALL MASS EXTINCTIONS Richard K. BAMBACH Botanical Museum, Harvard University, 26 Oxford Street, Cambridge, Massachusetts, 02138, USA. The end-Ordovician, Late Devonian, end-Permian, end-Triassic and end-Cretaceous precipitous decreases in marine diversity have traditionally been called "the big five mass extinctions." In recent years there has been considerable speculation that these events (and some smaller peaks of extinction) might share a common cause. Apparent periodicity of peaks of extinction over the last 260 million years led to the speculation that astronomical forcing might be involved in extinction events and the statistical similarity between the distribution of magnitudes of extinction and the sizes of known impact craters (but without any demonstration of a time-correlative link between crater size or age and the amount of extinction) produced

IPC2002 Oral Presentations the suggestion that impacts might be the sole cause of extinction. Others have argued that a correlation of extinction events with the time of eruption of plateau basalts implicates mantle-plume volcanism as a causal agent in most extinction events. Also, global refrigeration has been advocated as the primary cause of most major extinctions. However, comparison of the major intervals of diversity loss suggests each event was unique and there is little reason to believe they were all caused by the same mechanism. (1) Differences in rates of origination and extinction from one event to another, (2) differences in the length of time associated with different times of diversity decrease, (3) differences in the pattern of timing of events of diversity loss, (4) differences in the severity of diversity loss among different taxa (selectivity) in different events, (5) differences in the longterm consequences of diversity loss following different events, and (6) differences in global features typifying different times combine to demonstrate that each of the "big five" diversity decreases in the marine realm had different fundamental properties. The losses of diversity in two of the "big five" events (the Late Devonian and end-Triassic) are primarily because of reduced origination rather than elevated extinction, making them more "mass depletions" than mass extinctions. The diversity loss associated with the later Devonian actually occurred in a number of episodes, often affecting different taxa, spread throughout the Middle as well as Late Devonian. Although some of these events clearly have elevated extinction associated with them, the Devonian was also a time of major biotic change on land as well as a time of great taxonomic turnover in the oceans. Such changes must also have had an impact on the biota. The Triassic diversity decrease(s) is/are still generally poorly understood. The end-Permian and end-Cretaceous diversity decreases were both extinction driven events of short duration, with single major pulses of extinction. However, the selectivity of diversity decrease among different taxa was entirely different in the two events, implying that entirely different kill mechanisms were involved in the two great era-bounding extinctions. The impact that left the Chicxulub crater has been implicated as the trigger event that induced the end-Cretaceous extinction, but no similar evidence is yet established for the initiation of the Permian catastrophe. The end-Ordovician event was a multi-phase process affecting marine shelf biotas. It is clearly associated stratigraphically with eustatic sea-level changes associated with the climatic changes influenced by the Ashgillian glaciation in Gondwana, the first glacial event since the Late Proterozoic. Such features are not associated with the other major diversity decreases. Even if several of these diversity decreases were forced by similar events the physical and biological circumstances that amplified these ecological stresses did so in different ways.

PALAEOBATHYMETRY OF THE EARLY CRETACEOUS BASIN OF THE MOUNTAIN CRIMEA: INTEGRATED DATA FROM AMMONITES, TRACE FOSSILS AND FOSSIL ASSEMBLAGES ~ Evgenii J. BARABOSHKIN & Kristina V. ENSON Z Dept. Regional Geology & Earth History, Geological Faculty, f Moscow State University, 119992, Moscow, Leninskie r Gory[barabosh@geolmsu.ru]. The early Cretaceous history of the Mountain Crimea marine Z basin demonstrates its gradual deepening during the Valanginianearly Hauterivian and in the late Albian, rapid deepening during the latest early Hauterivian-Aptian, abruptly interrupted by the uplift and folding event in the latest Aptian-early Albian - (Baraboshkin, 2001). To quantify estimation of the bathymetry of the basin and the nature of the sea level signal, an integrated study ;; of the Lower Cretaceous succession of the Kacha-Bodrak Rivers r watershed was carried out. The analysis included several aspects: (1) Calculating siphonal and septal strength indices of £ representatives of ammonite families Phylloceratidae, I Lytoceratidae, Tetragonitidae, Desmocerat-idae, Hoploceratidae, ;; Holcodiscidae and Crioceatitinae, and also Cymatoceratidae - (Nautilida) based on a technique of Hewitt & Westermann (1986, r 1987, 1988, 1990, etc.). A total of 95 samples were analysed.. 1 Data obtained indicate the critical depth of destruction of the ™ shells. Most of the analysed ammonites had nectobenthic mode of life and, hence, the measurements reflect the depth of the basin. r Calculated depths of the studied part of the basin increased in the - early Cretaceous: Valanginian and late Albian: 50-150 m; early

IPC2002 Oral Presentations Hauterivian: 200-300 m; late Hauterivian-early Barremian: 300-400 m; late Barremian-Middle Aptian: 400-500 m (Fig.). (2). Analysis of Valanginian-lower Hauterivian and uppermost Albian ichnotaxa has revealed the prevalence of three main types of Crustolithida: Thalassinoides Ehrenberg, 1944; Ophiomorpha Lundgren, 1891; Skolithos Haldeman, 1840 of the Skolithos littoral-sublittoral ichofacies. Their presence accords with other results. (3). Analysis of the ratio of ecological position for the various groups of macrofauna (mollusks, brachiopods, echinoderms, crustaceans, corals) is in accord with other data. (4). Facial analysis of sections also confirms the tendency to gradual expansion and deepening of the basin, even within the studied area where depths differ. During the Valanginian-early Hauterivian, terrigenous sedimentation in the basin took place under littoral-sublittoral conditions. During the late Hauterivian-early Barremian the basin subsided greatly and Ammonitico Rosso facies formed in areas of pelagic uplift. Clay deposition took place during the late Barremian-Aptian in deep pelagic depressions with weak water circulation. Comparison of the calculated sea level curve with the global eustatic curve (de Graciansky et al., 1998, see Fig.) shows that the rates of a deepening of the Mountain Crimea basin ("the regional factor") were similar in the Valanginian-early Hauterivian; and much greater than eustatic rise during the late HauterivianAptian. The most probable explanation is local tectonic activity. The authors are grateful to the Russian Foundation for Basic Research (grants 00-05-64738, 01-05-64641, 01-05-64642) for financial support.

EARLY APTIAN BLACK SHALE DEPOSITION ON THE RUSSIAN PLATFORM: BIOTIC EVIDENCE OF CLIMATIC CHANGES Evgenii J. BARABOSHKIN1, Sofia B. SMIRNOVA1, Filippo BIAGIANTI2 & Ekaterina A. SCHERBININA3 Geological Faculty, Moscow State University, 119992, Leninskie Gory, Moscow, Russia, [barabosh@geol.msu.ru]; 2Facolta di Scienze Matematiche, Fisiche e Naturali, Istituto di Geologia dell Universita di Urbino, Campus Scientiftco, 1-61029 Urbino, Italy;3Geological Institution, Russian Academy of Sciences, 109117, Pyzhevskyi pereulok 7, Moscow, Russia, [shcherbi@inran.msk.su]. One of the major early Aptian events on the Russian Platform (RP) Basin was formation of the black shale horizon covering more than 150,000 km2 during the Deshayesites volgensis ammonite Zone (Baraboshkin, 2001; Mikhailova & Baraboshkin, 2001) - equivalent to the D.forbesi Zone of NW Europe. Its onset can be correlated with the OASE-la anoxic event and coincides with opening of the sea/strait connection between the sub-boreal RP Basin and Tethys. Muddy sedimentation had prevailed in the basin from the end of the Barremian. Deepening during the early Aptian is reflected in prevalence of pelagic heteromorph ammonites in the assemblages. Recent integrated study of macrofauna and microflora from the lower Aptian provides evidence of climatic control on black shale formation. Palynomorphs demonstrate that since the late Hauterivian the RP basin was in a zone of Sub-boreal climate with temperate annual temperatures. The black shale interval, however, is marked by short-term warming. This is indicated by increasing content of Cheirolepidiaceae (up to 16 %) in palynospectra and by relative abundance of calcareous nannoplankton: Rhagodiscus angustus, R. splendens and R. asper. That humidity of the climate increased simultaneously is reflected in decrease of Schizaeaceae and increase of Gleicheiniaceae, though the moisture-preferring spores (e.g. Sphagnumsporites and Foraminisporites) are present in small quantities. The content of Disaccites pollens falls significantly before formation of black shale—as a result of the epicontinental basin extension. The event is marked by very significant increase in green algae: up to 60-70% in palynospectra with dominance of the genus Pterospermella (up to 93%). This clearly indicates very significant freshening of the surface water and suggests stratification of the water column. This is very important in explaining development of anoxic conditions in the basin. The amount of oceanic forms of dinocysts (Pterodinium and Impagidinium) remains practically constant (about 20 %) through the interval. The fresh water influx caused a lowering in nutrients and, as a consequence, a lowered number of species. The Pridiniales/Gonyaulacales ratio in a black shale interval (and higher) increases slightly (to 25%). Lower diversity of calcareous nannoplankton also indicates slightly oligotrophic conditions. The quantity of neritic dinocyst species is practically constant, but their diversity falls (from 40-30 to 20%) in the black shale interval. The quantity of littoral species is reduced from 30% down to 10%. It indicates more or less stable open neritic conditions through the interval. The macrofauna of the black shales is represented mainly by nektobenthic and (lesser) nektoplanctonic ammonites and a few species of highly tolerant bivalves (Paleotaxodonta and Inoceramidae). This shows presence of a normal salinity water mass with concurrent dysoxic to anoxic bottom conditions. Massextinctions of juvenile ammonites may reflect rapid freshening of surface water due to precipitation.

IPC2002 Oral Presentations Interpretation of the data presented in this study can be summarized as follows: The black shale formation occurred in outer neritic conditions in a temperate humid climate. Periodic fresh water influx (with decreased mixing) slightly limited productivity and caused stratification of the water column leading to accumulation of organic matter under anoxic conditions. It seems that periods of freshening/normal salinity environments alternated during this time—possibly indicating monsoonal climate. The authors are grateful to the Russian Foundation for Basic Research (grants 00-05-64738, 01-05-64641, 01-05-64642) for financial support.

MICROBIAL-INDUCED STRUCTURES IN FOSSIL COLD-SEEP CARBONATES Roberto BARBIERI1, Barbara CAVALAZZI1, Frances WESTALL2, and Gian Gabriele ORI3 1 Dipartimento di Scienze della Terra e Geoambientali, Universita di Bologna, Bologna, Italy [barbieri@geomin.unibo.it]; 2Centre de Biophysique Moleculaire, CNRS, Orleans, France [westall@cnrsorleans.fr]; 3IRSPS, Universita d'Annunzio, Pescara, Italy [ggori@irsps.unich.it]. Geological products variously related to chemosynthetic processes are characterized by a wealth of conditions that are controlled by the microbial activity and their interactions with the ambient fluids. Microorganisms can therefore be considered a unifying element linking the present-day chemosynthetic ecosystems with those developed in Phanerozoic and Precambrian times. Environmental conditions hosting chemosynthetic-based ecosystems are characterized by fast (venting) and slow (seepage) expulsion of fluids, especially carbon dioxide, methane and hydrogen sulphide, that abound on Earth since the Archean, even during its prebiotic phase. The interplay between type of sediment and cold fluid emissions to the sea floor establish a microenvironmental chemistry which select processes and biological agents, and the mineral precipitation. Authigenic minerals play a dominant role in the development of cold-seep bodies and for granting the preservation of the biogenic structures. The delivery to the fossil record of the microbial communities depends on a number of conditions, especially on their capability of early mineral replacement. The bodies investigated include i) the Miocene and Pliocene-aged, methane and hydrogen sulphidederived, carbonate blocks and lenses cropping out in the Apennine range and Sicily (Italy); ii) the Devonianaged conical mounds (kess-kess) of Anti-Atlas (Morocco), whose origin (hydrothermal or cold seep-related) is still disputed;.iii) a Silurian-aged carbonate body of Middle Atlas (Morocco), which represents the most ancient known cold seep-interpreted (hydrocarbon-based) carbonate construction. Unless altered by heavy recrystallization processes, cold-seep bodies can preserve microbial-derived fossils in isotopically (carbon)-light carbonate groundmass and cavity/conduit-filling structures. Paragenetic sequences, leading to different mineral phases, developed in both aerobic and anaerobic conditions. In Miocene/Pliocene carbonate bodies, direct evidences of fossil microbes include i) dark filamentous networks interpreted as giant, H2S oxidizing Beggiatoa-like bacteria, arranged in 1-4 mm thick microbial mat, similar to those described from present-day sites of hydrocarbon seepage; ii) clusters of coccoid and rod-shaped bacterial colonies from strongly 13C depleted, yellow calcite phases derived from anaerobic bacterial oxidation of methane. In the Palaeozoic carbonate bodies a number of structures, potentially generated by microbial activity, are present and include microtufts, ferruginous crusts, rims, perforation and microbioturbation fillings, and microstromatolites. In the Silurian-aged chemosynthetic body, deposited in oxygen-poor and shallow water conditions, a three-dimensional alveolar network made up of iron oxide (hematite) has been described in the mudstone facies. This network is interpreted as the original organic (microbial) framework in which early mineral (hematite) replacement has permitted an excellent preservation of such a complex structure. We consider as modern analogues of this ancient structure mats of filamentous bacteria described off central Peru and identified as colonies of the sulfur-oxidizing Beggiatoa; whereas fossil analogues are probably the stromatolites of the Miocene-aged Monterey Formation, California. Depending on the different organization of the alveoli, these hematite-rich microbial structures have acted as loci for micrite precipitation, but they have also determined the formation of condensed structures, such as ferruginous crusts and the microstromatolites.

PROXY RECORDS IN SKELETAL MATERIALS: A VERY SHORT INTRODUCTION D.J. BARNES and J.M. LOUGH Australian Institute of Marine Science, PMB 3, Mail Centre, Townville Qld 4810, Australia [d. barnes@aims.gov. au; j. lough@aims.gov. au].

IPC2002 Oral Presentations The world's climate varies over a range of time scales and shows major variations over the many scales between decades and geological ages. Instrumental records are mostly less than 100 years long. In the last 50 years, or so, this gap has begun to be filled by proxy environmental records. Certain geological, biological and physical processes create proxy environmental records. Alterations in such proxy records over geological time scales can provide astronomical information. Tree rings, ice-cores and documents have provided much information about past environments. Users of such information, as opposed to its creators, have identified common features amongst useful, high-resolution proxy records. (1) Preservation of information about past environmental conditions that allows the record to be dated to the year. (2) The information can be recovered and interpreted as environmental variation. (3) The reliability of the record can be tested and, hopefully, cross-checked, allowing development of principals and procedures for routine recovery of environmental information. Tree rings are the best established, longest and most important of all proxy records. Research on tree rings has provided a model against which environmental reconstructions from other proxy sources can be judged. Skeletal materials containing proxy records include mollusc shells, barnacle plates and, pushing the definition of skeletal, polychaete jaws and fish otoliths. Corals have provided the most used skeletal material for recovery of proxy records. Skeletons of massive corals contain an annual density banding pattern that allows dating of records and they have several other features that give them the potential to be wonderful proxy environmental recorders. Research to recover environmental information from coral skeletons began in the early 1930s with the work of T.Y.H. Ma, which lasted for 3 decades. Much of this work was dismissed in the 1950s and 60s. However, there may now a need to re-examine his findings because some of his basic tenets are lately proving correct. The next major research effort was prompted by S.K. Runcorn in the 1960s. He saw the potential of daily, monthly and annual signals apparently preserved in the epithecae of fossil corals to provide information about the history of the earth-moon system. It was the discovery of annual density bands in the skeletons of massive corals in the early 1970s that gave rise to a massive increase in research. Annual density bands were immediately likened to annual tree rings and it was thought that corals would quickly provide the same fabulous information about oceans and seas that tree rings were then providing about terrestrial environments. There is now an extensive literature that indicates that coral skeletons are excellent archives of environmental information and contain a more diverse range of information than any other proxy recorder. This wide range has caused problems since it has been possible for researchers to move to new records before tying down earlier ones to the satisfaction of climatologists and other potential users of recovered information. Apparently contradictory research, and a lack of a mechanistic understanding of how the records are formed, has bothered such potential users, as has a lack of data showing the reliability of recovered information. In general, potential coral records have been recognised because they met requirement (1). However, in most cases, those records that met requirement (2) have not met requirement (3). Work over the past several years has begun to overcome these deficiencies.

THE ORDOVICIAN EARTH SYSYEM: PHYSICAL-CHEMICAL-TECTONIC CONTROLS ON THE MARINE BIOTA Christopher R. BARNES School of Earth and Ocean Sciences, University of Victoria, P.O. Box 3055, Victoria, BC V8W 3P6, Canada [crbarnes@uvic. ca]. Despite much progress on several fronts in recent years, many of the intriguing questions remain on the nature and evolution of the Earth System during the Ordovician Period. The late phases of Rodinia breakup and Gondwana assembly of the Neoproterozoic and early Cambrian were followed by continental dispersal and some further reassembly (Baltica to Laurentia). Much uncertainty remains on the paloegeographic positions of many peri-Gondwana terranes, which is critical for establishing the role of key gateways that impacted the climate system. The high level of volcanic activity is expressed especially in the occurrences of extensive ash-falls across much of the Iapetus Ocean and its borderlands (Arenigian-Caradocian) and voluminous volcanics (Darriwilian-Caradocian) in the New Brunswick Appalachians, both types of occurrences being possibly the largest single events in the Phanerozoic. These may be related to a mantle superplume event in the middle Ordovician for which there are several lines of supporting evidence (high sea levels, black shales, strontium isotope excursion, lack of magnetic reversals). The Ordovician is a remarkable time in the evolution of life, notably with the replacement of the Cambrian Evolutionary Fauna by the radiation of the Palaeozoic Evolutionary Fauna in the early-mid Ordovician. Despite a rapid five-fold increase in biodiversity, there was a sharp plateau in diversity in the late Ordovician until a rapid collapse with the terminal Ordovician mass extinction. This resulted in a halving of diversity at the generic level. The

IPC2002 Oral Presentations recovery phase in the latest Ordovician through the Llandovery took about 5-9 million years and saw the initial appearance and rise of lacustrine and terrestrial biotas. The controls and precise processes involved in these Ordovician bioevents are not well understood. New geochemical and isotopic data and modelling have improved interpretations of the changing palaeoceanography and palaeoclimatology, especially those from greenhouse to icehouse conditions in the late Ordovician-early Silurian and the apparent paradox of a glaciation during times of up to 16X C0 . More quantitative values are needed for atmospheric C0 and 0 levels and oceanic nutrient values. There is likely a strong correlation between increased water vapour and greenhouse climates with the most extensive epeiric seas in the Phanerozoic, and a close linkage between transgressive/regressive cycles and climate and faunal change. The detailed interrelationship between faunal and eustatic change has been established using conodont biostratigraphy and community analysis along several platform-shelfbreak-slope-basin transects around the northern margin of Laurentia. 2

SEQUENCE STRATIGRAPHY OF MIDDLE DEVONIAN (GIVETIAN) NEAR-SHORE/PARALIC FACIES, EASTERN NEW YORK STATE: STRATIGRAPHIC CONTEXT OF THE WORLD'S OLDEST FOSSILIZED FOREST Alexander J. BARTHOLOMEW , Carlton E. BRETT , Gordon C. BAIRD University of Cincinnati, Geology Dept., [sil078@hotmail.comj; SUNY Fredonia. 1

The upper Middle Devonian (Givetian) Hamilton Group of New York State stretches from the shores of Lake Erie in the west to the Catskill Front in the east, encompassing facies deposited in deep, anoxic, basin to shallow, storm-dominated shelf and continental flood plain settings. The Moscow Formation, the uppermost unit of the Hamilton Group, is subdivided into six and one-half small-scale packages representing high-order cycles of sea level oscillation. The large scale cycles have previously been correlated across the basin, with some variation, from Lake Erie in the west to near Hamilton in the east. Recent detailed tracing of marker beds has demonstrated that even small-scale cycles can be correlated over 100 km. farther eastward to Milford and Schenevus, Otsego Co., Summit, western Schoharie Co., and eventually to outcrops within the Schoharie Valley. Along this transect, the section thickens from about 75 m. to 175 m. and facies change rapidly, recording changes from distal shelf to shallow shelf, shoreface, and finally, estuarine-fluvial environments. Despite these changes, general patterns of sea level oscillation cycles can be discerned even in the eastern-most, paralic outcrops. Dark shale horizons of western, basinal sections correlate with shaly, marine tounges that onlap marginal marine sands. Correlation of small-scale cycles within the Moscow Formation has also elucidated the stratigraphic position of four different levels of the famous "Gilboa Forest" Lagerstatten. Exposed in 1869 after flooding along the Schoharie Creek, stumps of the progymnosperm Eospermatopteris ("Dawn-Seed-Fern" of Goldring) represent the oldest fossilized forest deposit in the world. Eospermatopteris trees were buried in life position by massive sands, rotted, and the portions encased by the sand were filled-in to form molds. The stumps occur at the boundaries of the small-scale sea level cycles, i.e. transgressive surfaces within the middle and upper Moscow Formation. ENVIRONMENTS AND BIOFACIES IN THE DEVONIAN PELAGIC REALM R. Thomas BECKER Geologisch-Palaontologisches Institut, Westfalische Wilhelms-Universitat, Corrensstr. 24, D-48149 Munster, Germany, [rbecker@uni-muenster.de]. The reconstruction of Palaeozoic pelagic ecosystems is hampered by a number of factors which make actualistic comparisons difficult. Apart from strongly tectonised, metamorphosed and more or less unfossiliferous ophiolites, there are no remains of the large Devonian oceans (Palaeotethys, Panthalassia). All identified pelagic environments were part of extensive outer epicontinental shelf areas which included some deeper troughs in technically active zones. Due to the lack of continental ice sheets, the global sea level was very high, giving very wide and deep open marine settings along the craton margins. Another important aspect is the fact that Devonian pelagic organisms mostly belong to extinct major clades. There is very poor knowledge of the open marine primary producers which probably included unfossilized cyanobacteria and algae. Dominating plankton groups were entomozoid ostracods, various tentaculite orders (Tentaculitida, Dacryoconarida, Homoctenida) and, locally, the extinct albaillellid and entactinariid Radiolaria. Vast areas are thought to have been strongly oligotrophia resulting in thick, completely unfossiliferous shale sequences, especially of flysch basins. Blooms of phytoplankton, such as prasinophytes, Chitinozoa, and acritarchs, were

IPC2002 Oral Presentations often connected with short-term global eutrophication events which led to the deposition of hypoxic beds (black shales and limestones). The pelagic nekton consisted of ammonoids, nautiloids, conodonts, and, probably, of rarely preserved Scyphozoa. Diverse fish faunas preferred nearshore and shallow to marginal marine settings but there were a few exceptional pelagic event beds and inter-reefal basins (e.g., yielding the famous Gogo fauna). Devonian pelagic environments can be classified using both the pelagic and the mostly low-diverse benthic fauna. Typical outer shelf benthic assemblages are characterized by small-eyed to blind trilobites, rhynchonellids, smooth terebratulids, small-sized orthids, subordinate chonetids, nuculoid bivalves, thinshelled Pteriomorpha (Buchiola, Guerichia, Loxopteria, Praecardium, etc.), small Archaeogastropoda (e.g., Naticopsis), subordinate bellerophontids, various ostracods, solitary deep-water Rugosa, specialized crinoids, and, occasionally, auloporid Tabulata. An idealized biofacies succession from neritic areas to deeper basins can be roughly characterized as follows: 1. dysphotic hemipelagic carbonates and shales, still with diverse benthos (e.g., spiriferids, atrypids, large-eyed trilobites, diverse gastropods and echinoderms), 2. hemipelagic hypoxic basins, 3. allochthonous crinoidal limestones with low-diverse benthos and nekton, 4. condensed cephalopod limestones with (following the bathymetric gradient) moderately to low-diverse benthos, 5. deepwater stromatolites and mudmounds, growing during times of extreme sediment starvation, 6. nodular limestones and shales with diverse nekton and poor benthos, 7. hypoxic intrashelf basins with few lowoxygen tolerant benthic specialists, occassionally including radiolarites, 7. eupelagic, oxygenated, deeper marine entomozoid and styliolinid shales with very poor benthos, 8. mostly unfossiliferous red, green and grey shales of deep basins and troughs (radiolarites in some regions). Proximal to distal reefal debris, including mass flows and calcareous turbidites, as well as clastic lowstand wedges may be intercalated. Event beds typically show mass occurences of single groups: Chitinozoa, styliolinids, homoctenids, specialized brachiopods ("pumilios", inarticulates), ammonoids, bivalves. It is unknown why there are blooms of very different taxa in individual event beds. There are no described Devonian cold-water pelagic fossil associations but tentaculites, Chitinozoa and acritarchs extended into the boreal regions.

EQUATORIAL-PACIFIC CORAL MICRO ATOLLS AND VARIABILITY OF EL NINO OVER RECENT MILLENNIA M. BEECH1, C.D. WOODROFFE1 & M.K. GAGAN2 School of Geosciences, University of Wollongong, NSW 2522, Australia; 2Research School of Earth Sciences, The Australian National University, ACT 0200, Australia Variability in El Nino-Southern Oscillation (ENSO) events centred on the Pacific Ocean has far-reaching affects on tropical and extra-tropical climate. In order to discriminate between competing explanations of this variation, such as whether this reflects orbital parameters such as precessional forcing, it is crucial to obtain accurate estimates of sea-surface temperatures (SST) for the equatorial Pacific during the Holocene. Palaeoclimatology of living massive corals offers high-resolution multidecadal proxy data of SST back about 500 years. We demonstrate that this can be supplemented by extension to fossil corals where it is possible to find suitable material. Coral microatolls are discoid intertidal colonies of coral constrained in terms of upward growth by exposure at low water. Fossil microatolls offer considerable potential to decipher Holocene ENSO variability because when preserved they occur at or near reef or island surfaces. Modern reef-flat coral microatolls from Christmas (Kiritimati) Island in the equatorial Pacific preserve a proxy record of SST (and rainfall) in the oxygen isotope record within their skeleton (Woodroffe and Gagan, 2000). Analysis of fossil microatolls from former lagoonal areas of Christmas Island provides mid-late Holocene windows into the variability in frequency and intensity of ENSO-related SST. Average SST appears to have been less than at present despite relatively higher sea level. ENSO events occurred at similar frequency, but ENSO intensity was less pronounced during the mid-Holocene periods that were examined, and more pronounced during the late Holocene than seen at present. Although some of the variation could be related to precessional forcing, the variability is greater than can be explained by orbital parameters alone, and implies that other factors are involved at century or longer time scales. WOODROFFE, C.D. and GAGAN, M.K., 2000 Coral microatolls from the central Pacific record late Holocene El Nino. Geophysical Research Letters 27,1511-1514.

IPC2002 Oral Presentations UPWARDS AND DOWNWARDS - PLANTS INVADE THE SKY AND THE SOIL Christopher M. BERRY Department ofEarth Sciences, Cardiff University, PO Box 914, CARDIFF CF10 3 YE, Wales UK. [Berrycm @cardiff.ac. uk]. Early Devonian vascular land plants are in general characterised by predominantly dichotomous branching and by relatively small diameters of main supporting axes or stems (where present). The most morphologically and anatomically complex plants were able to exhibit limited development of regular branching patterns and differential development of stem, branch and appendage anatomies. Primary tissues, only, give support to the plants, and the stem and other tissues were incapable of significant lateral expansion after the initial burst of growth. The size and penetration of the roots, although significant in sedimentological terms, were not comparable with those of larger plants. In the Middle and earliest Late Devonian anatomical and morphological innovations preceding the latest Devonian appearance of seed plants led to an explosion of plant architectures, increases in height above ground and depth of root penetration, and to the potential for increasingly complex interactions both with other organisms and with the environment. These plants, although geographically widespread, were probably restricted to moister, lowland environments, and were unable to successfully colonise the harsher upland expanses, thereby limiting their impact in terms of atmospheric and global change. However their significance in terms of localised ecology, habitats and development of ecosystems must have been profound. This talk will present evidence of the development of stable associations of plants found in Middle Devonian deposits that suggest source areas of high plant diversity, and demonstrate some of the ways that these plants may have acted to create habitats suitable for the land animals of their day. GLOBAL ORDOVICIAN VERTEBRATE BIOGEOGRAPHY Alain R. M, BLIECK and Susan TURNER U.S.T.L.: Sciences de la Terre, Laboratoire de Paleontologie et Paleogeographie du Paleozoique (LP3), UPRESA 8014 du C.N.R.S., F-59655 Villeneuve d'Ascq cedex, France [Alain.Blieck@univ-lillelfr]; Queensland Museum, PO Box 3300, South Brisbane, Queensland 4101, and Department of Geosciences, Monash University, Clayton, Victoria 3172, Australia [SueT@qm.qld.gov.au]. Cambrian-Ordovician vertebrate and supposed vertebrate occurrences have been repeatedly claimed during recent decades, with confirmed taxa bearing mineralized tissues with a vertebrate histomorphology still relatively rare. The only biogeographic province that we can presently recognize is the Gondwana Endemic Assemblage (GEA) with possible Late Cambrian fragmentary remains from Australia but more definite Early Ordovician (Arenig) to early Late Ordovician (Caradoc) arandaspids (i.e., Sacabambaspis, Arandaspis) and other taxa known from South America and Australia (Turner et al., in press a-b). Chondrichthyans ("sharks", at first without teeth) might originate in East Gondwana province and then are found in the Late Ordovician and Early Silurian of Mongolia, Tarim and South China. The GEA fauna proper disappears by mid-Caradoc and vertebrates do not reappear in Gondwana until mid Late Silurian. Late Ordovician (-455 My or earlier) vertebrates are also known with certainty from Laurentia, viz., North America (pteraspidomorphs Astraspis, Eriptychius, and various gnathostome-like taxa including chondrichthyan-, placoderm- and acanthodian-like remains), and Siberia (astraspid-like microremains with an unusual histology, which might correspond to a new group of lower vertebrates) as well as scales from putative loganiid and thelodontidid thelodonts from North America and Russia (Timan-Pechora, the Severnaya Zemlya archipelago and Siberia). This is defined as the Laurentia-Baltica-Siberia Assemblage (LBSA) (Turner et al., in press a-b). We also mention one enigmatic reference to a Late Ordovician anaspid in South Africa. There is no clear association of taxa between the GEA and LBSA despite a small overlap in time. Various recent palaeogeographic models published for Ordovician are critically analyzed and considered within four groups: the archetypal palaeogeographic reconstructions, two alternative solutions, and a compact version. Habitats of vertebrates in mostly BA1 (marine intertidal) to BA3 (shallow subtidal) environments, and their dispersal capabilities are evaluated with regard to those models. The main feature of Ordovician vertebrate biogeography is endemism (Blieck and Turner, submitted). Furthermore, the present lack of complete descriptions of most taxa, which are often represented only by isolated microremains, and the need for a thorough phylogenetic analysis preclude any phylogenetic palaeobiogeographic study. In such a framework, we also evaluate possible links between external, physical factors and the Ordovician radiation of vertebrates. The Late Proterozoic outpouring of oceanic phosphate and the Early Cambrian increase in oxygen on Earth might have been the spur for vertebrate evolution before the phase when hard tissues appeared. The sharp decline of marine strontium isotope ratio during the Middle to Late Ordovician transition, interpreted as having been controlled 1

IPC2002 Oral Presentations primarily by continental collisional tectonics and its associated erosion and weathering, has been proposed as the consequence of a possible mantle superplume event which would have caused the prominent Caradoc transgressive phase (Barnes, in press). This might be a factor in the changeover from Gondwanan to Laurentian focus for vertebrates. IGCP 410 The Great Ordovician Biodiversification Event, the French IGCP National Committee (PICG France), and the French National Committee of Geology (CNFG) for financial support (AB). ST thanks the CNRS for a 3-month fellowship in late 2001. BARNES, C.R., in press. The Ordovician superplume event. In Webby, B.D., Droser, M.L., Paris, F. and Percival, I.G. (eds), The Great Ordovician Biodiversification Event. Columbia University Press. BLIECK, A.R.M. and TURNER, S., submitted. Global Ordovician vertebrate biogeography. In Servais, T., ALVARO, J.J. and BLIECK, A. (eds), Early Palaeozoic Palaeo(bio)geographies of Europe and North Africa. Palaeogeogr., Palaeoclimat., Palaeoecol. TURNER, S., BLIECK, A. and NOWLAN, G.S., in press a. Cambrian-Ordovician vertebrates. In Webby, B.D., DROSER, M.L., PARIS, F.

and PERCIVAL, I.G. (eds), The Great Ordovician Biodiversification Event. Columbia University Press. TURNER, S., BLIECK, A. and NOWLAN, G.S., in press b. Cambrian-Ordovician vertebrate database. Ann. Soc. Geol. Nord.

TETRAPOD DIVERSITY IN THE LATE DEVONIAN BASIN OF EAST GREENLAND Henning BLOM Department of Palaeontology, The Natural History Museum, Cromwell Road, London SW7 5BD, UK [H. Blom@nhm. ac. uk]. The discovery in recent years of many new Devonian tetrapods has demonstrated a greater diversity and disparity among these animals than was previously apparent from the fossil record. This increase in number of taxa and morphological variety among the earliest limbed vertebrates is apparent even from the fragmentary material, often comprising only isolated jaws or post-cranial elements, that comprises the majority of the new discoveries. Although these stem group tetrapods show a worldwide distribution already by the Famennian, only the Celsius Bjerg Group of East Greenland, the Ketleri Formation of Latvia and the Catskill Formation of Pennsylvania yield faunas containing more than one tetrapod taxon. The tetrapod fauna from the continental Devonian basin of East Greenland contains the famous genera Ichthyostega and Acanthostega, known from almost complete skeletons. The quality and magnitude of this collection makes the East Greenland fauna by far the best source for studies of population disparity, environmental adaptation and diversification potential of Devonian tetrapods. The largest amount of Ichthyostega and Acanthostega material has been collected at Gauss Halv0 from two formations within the Celsius Bjerg Group. The Britta Dal Formation, the uppermost and most productive formation, contains both Ichthyostega and Acanthostega, although the main fossiliferous horizon for the two taxa are stratigraphically distinctly separated. The main Acanthostega locality is close to the top of the formation, while most Ichthyostega specimens have been found at a horizon closer the base of the formation. The Aina Dal Formation, the lowermost and less productive of the tetrapod yielding formations, is clearly separated from the richer Britta Dal Formation by the unfossiliferous Wiman Bjerg Formation (about 100 m thick). The collection from this lower stratigraphical unit shows an Ichthyostega population distinctly different from the more robust population of the Britta Dal Formation, which has shorter and wider skulls. A few Acanthostega specimens have also been found in the Aina Dal Formation at Gauss Halvo, showing that this genus has a wide stratigraphic distribution and was contemporary with Ichthyostega. Several tetrapod specimens have also been collected from talus on the north and south sides of Celsius Bjerg, Ymer 0 . Although the successions at Celsius Bjerg have been recognised as equivalent to the Aina Dal, Wiman Bjerg and Britta Dal formations of Gauss Halv0, the sedimentological and stratigraphical context is still very problematic. Most specimens are, nevertheless, recognisable as Ichthyostega. This material contains in fact the first described specimens and type material of Ichthyostega. A comparison with the populations of Gauss Halvo shows that the stratigraphically unconstrained Ichthyostega skulls of Celsius Bjerg are morphologically distributed within and between both populations. Such disparity may simply reflect the recorded difference between the Aina Dal Formation and Britta Dal Formation populations at Gauss Halv0. Alternatively, some inconsistency in the morphological distribution may indicate the presence of microevolutionary lineages of intermediate age, equivalent to the unfossiliferous part of the succession on Gauss Halve. In addition to the Ichthyostega material, a single Acanthostega specimen and a partial skull (lower jaws plus fragments of palate) of a new tetrapod genus have been found on the south side of Celsius Bjerg. The large collection of tetrapods from East Greenland, with its disparity and high diversity, suggest that the apparent diversity of the other Famennian tetrapod faunas largely reflects sample size and preservation potential rather than true differences in diversity and migration patterns. Future work on known localities and discoveries of new faunas will hopefully verify this assumption and test the hypothesis that a significant

IPC2002 Oral Presentations tetrapod diversification occurred within the stem group, well before the post-Devonian radiation which was catalysed by the potential of the new and previously unexplored terrestrial habitat.

EOCENE TO OLIGOCENE PALAEOBOTANICAL-ECOLOGICAL CLIMATE STRATIGRAPHY: A USEFUL TOOL TO GENETICALLY UNDERSTAND COAL-BEARING CYCLES IN MIDDLE GERMANY Horst BLUMENSTENGEL & Wilfried KRUTZSCH Palaontologische Gesellschaft, Am Ganseberg 13, 07749 Jena, Germany. At the southern margin of the NW-European Tertiary Sea existed a nearly 170 km long and 50 wide estuarine system (Middle German Estuary). The coast line of this estuary migrated southward during the Palaeogene due to a rising sea level and backward during the Neogene towards the German Bay near Hamburg where it is situated today. The migration of the coast line was not linear but cyclic as indicated by the coal-bearing sedimentary cycles. The Mosaik of Tertiary depressions observed today is the result of later tectonic activity (tilding of blocks) combined with subrosion and subsurface dislocation of salt. According this complicated picture it is quite difficult to reconstruct the earlier sediment pathways (marine, estuarine, fluvial). Our present high level of knowledge after nearly 50 years of research on tertiary sediments (Krutzsch et al. 1992, Krutzsch 2000, Lotsch et al. 1969, 1981) allows us to recognize regional and global interactions between palaeogeography, sedimentology, tectonics, paleobiology (palynology), palaeoclimatic and sequence stratigraphy The tool for dating the palaeogene sediments is a pollen-grain-Zonation (Krutzsch 1966), created 35 years before and successful used in practice. 20 SPP-Zone (partly with subdivisions) are observed from drill cores (e. g. , from Egeln Depression, Blumenstengel & Unger 1993) and open castings, they reflect manifold climate changes so as beween evergreen broadleafed forests and mixed mesophytic (summergreen/evergreen) forests as indicating humidity from fullhumid to semiarid conditions in an extratropical area. A repeated change of humodil and dysodil floras is discernible and cyclic climate cooling occurred from Eocene to Oligocene. Such cycles can be charaterized by FAD- and LAD-Markers (spores, pollengrains, dinocystes, acritarches) and frequency relations of pollen-grain groups.Change of floras is the base of pollen-Zonation. Such a zonation is useful to distinguish parasequences of coal-cycles as lithological and lithostratigraphic units. This method is not biostratigraphy in a classical sense, it is palaeobotanical climatical stratigraphy. Palynomorphs are lithological markers in order to determine lithostratigraphic units (formations and members). In view of interfmgering of marine and terrestrial sediments we are able to integrate different biostratigraphies as by foraminifera, nannoplankton and dino-zystes as MP-Zonations after mammals (Geiseltalium). A very interesting result was to establish an evident temporal correspondence between paralic coal-cyclothemes (parasequnces) and sea level changes aft Haq et al. 1988, Hardenbol et al. 1998 (Blumenstengel et al. 1996). Thus we are able to determine paralic coalsediments of 3rd -order-cycles as formations (table 1: Chrono- and lithostratigraphic units of Eocene in southeastern part of Helmstedt/Egeln/Halle Bay). BLUMENSTENGEL, H., KRUTZSCH, W. & VOLLAND, L. (1996) Revidierte Stratigraphie Tertiarer Ablagerungen Im Siidlichen SachsenAnhalt, Teil 1: Raum Halle-Merseburg. Hallesches Jahrbuch Geowiss. Reihe B, Beiheft 1, 1-101. Halle. BLUMENSTENGEL, H. & UNGER, K-P. (1993) Zur Stratigraphie Und Fazies Des Flozftihrenden Tertiar Der Egelner Mulden (SachsenAnhalt). Geol. Jb. A 142 113-129. Hannover. HAQ, B.U., HARDENBOL, J. & VAIL, P.R. (1988) Mesozoic and Cenozoic chronostratigraphy and cycles of sea-level change. In C.K. Wilgus; S.B. Hastungs, Eds, Sea Level Research - An Integrated Approach. - Soc. Econ. Paleontol. Mineral. Spec. Publ. 42: 71108. HARDENBOL, J., THIERRY, J., FARLEY, M . B . , JACQUIN, Th., DE GRACIANSKY, P.-Ch. & VAIL, P . R . ( 1 9 9 8 ) M e s o z o i c a n d C e n o z o i c

Sequence Chronostratigraphic Framework of European Basins. In De Graciansky, P.-Ch., Hardenbol, J., Jacquin, Th. & Vail, P. R., Eds, Mesozoic and Cenozoic Sequence Stratigraphy of European Basins. - Sepm Special Publication 60. KRUTZSCH, W. (1966) Die Sporenstratigraphische Gliederung Des Alteren Tertiar Im Nordlichen Mitteleuropa (PalaozanMitteloligozan). -Abhandlungen Des Zentralen Geologischen Instituts Berlin 8, 112-149. Berlin. KRUTZSCH, W. (2000) Stratigraphische Tabelle Oberoligozan Und Neogen (Marin - Kontinental). Berliner Geowiss. Abh. E34, 153165. Berlin. KRUTZSCH, W . UNTER MITARBEIT VON, H. BLUMENSTENGEL, Y . KIESEL & L. RUFFLE ( 1 9 9 2 ) P a l a o b o t a n i s c h e K l i m a g l i e d e r u n g D e s

Alttertiars (Mitteleozan Bis Oberoligozan). In Mitteldeutschland Und Das Problem Der Verkniipfung Mariner Und Kontinentaler Gliederungen (Klassische Biostratigraphien - Palaobotanisch-Okologische Klimastratigraphie -Evolutionsstratigraphie Der Vertebraten. - N . Jb. Geol.-Palaont. 186 (1-2): 137-253; Stuttgart. LOTSCH, D., UNTER MITARBEIT VON, KRUTZSCH, W , MAI, D., KIESEL, Y . & LAZAR, E. ( 1 9 6 9 ) Stratigraphisches K o r r e l a t i o n s s c h e m a

Fur Das Tertiar Der Deutschen Demokratischen Republik. Abh. Zentr. Geol. Inst. 12: 1-438. Berlin. LOTSCH, D. (1981) Fachbereichsstandard Tertiar. Korrelationstabelle Der Lithostratigraphischen Stratigraphische Skala der DDR, Tertiar, TGL 25234/08, Berlin.

Einheiten

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IPC2002 Oral Presentations

CYATHOPHYCUS AND THE ORIGIN OF DEMOSPONGES Joseph P. ROTTING Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3BU, UK; [josephOO@esc. cam. ac. uk]. The relationships between the poriferan classes are currently obscure. Molecular phylogenies appear to be reaching a consensus that the siliceous sponges are closely related, despite previous attempts to separate the Hexactinellida from other sponges on cytological grounds. However, the details of the transition are unknown. The best-known palaeontological reconstruction of sponge evolution is that of Rigby (1986), where the protosponges are derived from an early demosponge lineage such as the Leptomitidae. The comparison of protosponges with leptomitids was based largely on a thin, reticulated wall of simple spicules (monaxons in Leptomitus, stauracts in Protospongia). A close relationship is, however, unlikely, since the protospongiids possessed a precise geometric arrangement of multiple spicule size orders that is lacking in demosponges. However, a close morphological similarity does exist between the skeletons of transitional protospongedictyosponge reticulosids such as Cyathophycus, and the early hazeliid demosponges. The inner spicule layer of primitive dictyosponges comprises a cross-hatched array of fine monaxons, precisely as seen in the wall of some early hazeliids. Although most described species of Hazelia were morphologically complex and often branched, a simple globose species is described from the Caradoc of Wales. Growth patterns have also been examined, and shown to compare closely with those of a co-occurring primitive dictyosponge. The evolutionary link between the classes is suggested to lie within these lineages. Although the direction of evolution cannot be certainly fixed, it is conceptually much easier to derive the demosponges from the hexactinellids, rather than vice versa. RIGBY, J.K., 1986. Sponges of the Burgess Shale (Middle Cambrian) British Columbia. Palaeontographica Canadiana Monograph, 2, 105 pp.

INVASION EARTH!: ICHNOLOGICAL EVIDENCE FOR THE CONQUEST OF LAND Simon J. BRADDY Department of Earth Sciences, University of Bristol, Wills Memorial Building, Queen's Road, Bristol, BS8 1RJ, UK. [S.J.Braddy@bris.ac.uk]. The invasion of land by arthropods was a major milestone in the evolution of life. The body fossil record is severely limited, based on only a handful of fragmentary remains from a few now famous localities. Palaeozoic terrestrial trace fossils (particularly arthropod trackways and trails), however, provide valuable data on the landfall, and subsequent diversification of early arthropods on land. This ichnological evidence indicates that the invasion of land predates the earliest body fossils (i.e. arachnids and myriapods from the Upper Silurian of Shropshire, UK) by c. 90 million years. Trackways reliably record the distribution of early terrestrial arthropods (as they are preserved in-situ), and extend the stratigraphic range of key taxa (e.g. myriapods and euthycarcinoids). More importantly, trackways can provide direct evidence for the walking techniques of early arthropods as they moved onto land, elucidating their biomechanics as they crossed a functional threshold from in-phase (aquatic) to more stable out-of-phase (terrestrial) gaits. Ichnological evidence indicates that the colonisation of non-marine settings began in the Cambrian, with periodic migrations of marine arthropods into marginal aquatic habitats in response to environmental perturbations. The earliest landfall of arthropods occurred in the ?Upper Cambrian; arthropod trackways preserved in sub-aerial deposits (i.e. an aeolian dune field in a marginal-marine setting), from Ontario (Canada), record the activities of large, amphibious arthropods, probably euthycarcinoids (MacNaughton et al., in press). Terrestrial arthropod trace fossils are rare in the Ordovician. Eurypterids trackways from New York State (USA) indicate that eurypterids were capable of amphibious excursions (via marine routes) from the mid-Ordovician, although this group never became fully terrestrial. Narrow myriapod trails from Cumbria (UK), and ?myriapod burrows from Pennsylvania (USA), indicate that myriapods colonized early bryophyte soils (via a freshwater route) in the Upper Ordovician, probably feeding on the early plants (as detritivores). Trace fossil diversity and distribution indicates that the major colonization of coastal marine and fluvial settings did not occur until the Upper Silurian; this coincides with the earliest body fossils. By the Early Devonian trackways occur in lake-shore settings within continental interiors. The widespread colonization of land progressed through the Devonian, until all non-marine habitats were colonized by the Carboniferous. Cluster analysis has revealed a similarity of Gondwanan, Scandinavian-Scottish and North

IPC2002 Oral Presentations American Siluro-Devonian terrestrial ichnofaunas, suggesting that palaeobiogeography was a controlling factor in the distribution of early terrestrial ecosystems (Draganits et al., 2001). But why did the arthropods invade the land? Explanations are traditionally linked to the exploitation of empty or under-utilized ecospace. The evolution of land plants in the Ordovician represents a major ecological shift, and is probably the most important factor associated with the terrestrialization of the myriapods. Other groups, however, may have responded to different selection pressures, probably associated with their life-cycle (e.g. spawning in marginal lagoons to protect their larvae from marine predators). A 'mass-moult-mate' hypothesis (Braddy, 2001) for eurypterid reproductory behaviour is supported by abundant accumulations of their exuviae in marginal settings, the functional morphology of their reproduction and respiration, ichnological data, and modern analogues (e.g. Limulus). BRADDY, S.J. 2001. Eurypterid palaeoecology: palaeobiological, ichnological and comparative evidence for a 'mass-moult-mate' hypothesis. Palaeogeography, Palaeoclimatology, Palaeoecology 172, 115-132. DRAGANITS, E., BRADDY, S.J., and BRIGGS, D.E.G. 2001. A Gondwanan coastal arthropod ichnofauna from the Muth Formation (Lower Devonian, northern India): paleoenvironment and tracemaker behavior. Palaios 16, 126-147. MACNAUGHTON, R.B., COLE, J.M., DALRYMPLE, R . W . , BRADDY, S.J., BRIGGS, D . E . G , a n d LUKIE, T . D . in press. First steps o n land:

Arthropod trackways in Cambrian-Ordovician eolian sandstones, southeastern Ontario, Canada. Geology.

QUESTIONING THE EVIDENCE FOR EARTH'S OLDEST FOSSILS Martin D. BRASIER1. O.R. GREEN2, A.P. JEPHCOAT3, A.K. KLEPPE4, M.J. VAN KRANENDONK2, J.F. LINDSAY3, A. STEELE5, & N.V. GRASSINEAU6 1 Earth Sciences Department, University of Oxford, Parks Road, Oxford OX1 3PR, UK; 2Geological Survey of Western Australia, 100 Plain Street, East Perth, Western Australia, 6004, Australia;3Research School of Earth Sciences, Australian National University, Canberra ACT 0200, Australia; 4School of Earth, Environmental and Physical Sciences, University of Portsmouth, Burnaby Road, Portsmouth POl 3QL, U.K.; 5School of Earth, Environmental and Physical Sciences, University of Portsmouth, Burnaby Road, Portsmouth POl 3QL, UK; 6Department of Geology, Royal Holloway University of London, Egham Hill, Surrey TW20 0EX, UK Structures resembling remarkably preserved bacterial and cyano-bacterial microfossils from -3,465 millionyear-old Apex cherts of the Warrawoona Group in Western Australia currently provide the oldest morphological evidence for life on Earth and have been taken to support an early beginning for oxygenproducing photsynthesis. Eleven species of filamentous prokaryotes, distinguished by shape and geometry, have been put forward as meeting the criteria required of authentic Archaean microfossils, and contrast with other microfossils dismissed as either unreliable or unreproducible. These structures are nearly a billion years older than putative cyanobacterial biomarkers, genomic arguments for cyanobacteria, an oxygenic atmosphere and any comparably diverse suite of microfossils. Here we will report on new research on the type and re-collected material, involving mapping, optical and electron microscopy, digital image analysis, micro-Raman spectroscopy and other geochemical techniques. We reinterpret the purported microfossil-like structure as secondary artefacts formed from amorphous graphite within multiple generations of metalliferous hydrothermal vein chert and volcanic glass. Although there is no support for primary biological morphology, a Fischer-Tropsch-type synthesis of carbon compounds and carbon isotopic fractionation cannot yet be rejected for one of the oldest known hydrothermal systems on Earth. BRASIER et al., 2002, Questioning the evidence for earth's oldest fossils. Nature, v. 416: 76-81 (March 7, 2002).

MASS EXTINCTIONS AND THE PROTEROZOIC - CAMBRIAN TRANSITION Martin D. BRASIER Earth Sciences Department, University of Oxford, Parks Road, Oxford OX1 3PR, U.K. The evidence for major biological turnover will be examined for two adjacent time intervals: 1, within the Terminal Neoproterozoic; and 2, across the Proterozoic - Cambrian boundary. The first of these bioevents in conjectured from the history of the Doushantuo-Pertatataka microflora, an assemblage of giant (ca. 300 jim) acritarchs that flourished immediately after the Marinoan glaciations but that died out before the appearance of frondose Ediacaran biotas. Their demise correlates with major sequence boundaries across Asia and Arabia, and perhaps with glacial deposits in Arabia, Baltica, Africa and Australia.

IPC2002 Oral Presentations Major biological turnover across the Proterozoic-Cambrian boundary is strongly indicated by a study of global facies and biotas, calibrated against the emerging chemostratigraphic-geochronologic times scale, including new data from Oman and elsewhere. In the latest Proterozoic, extensive, thick "reefal" carbonate biotas flourished in Namibia, Oman, India and the Americas. They contain the putative early skeletal fossils Cloudina and Namacalathus, which are here argued to have been secondarily calcified like the associated calcimicrobes. Data from an environmental transect across Asia to Oman suggest that these "oligotrophic" carbonate platform biotas and tophonomic facies were diachronously displaced by the spread of more "eutrophic" siliceous and phosphoric/phosphotized biotas. The latter appeared first in outer platform settings (Mongolia) and last or not all in interior basins (Oman). The diachronous decimation of "Ediacaran" taphonomic facies and biotas and spread out of "Cambrian" taphonomic facies and biotas coincided with a major re-organization of plate boundaries, involving the Damara and Arabian orogens (ca. 544 Ma onward) and the amalgamation of Gondwanaland.

STASIS AND BIOTIC TURNOVER EVENTS IN THE MIDDLE-UPPER DEVONIAN APPALACHIAN BASIN Carlton E. BRETT1. Gordon C. BAIRD2, Bradley B. SAGEMAN3, Adam E. MURPHY3, & , Charles A. VER STRAETEN4 department of Geology, University of Cincinnati, Cincinnati, OH 45221; 2Department of Geosciences, SUNY College at Fredonia, Fredonia, N.Y 14063; 3Department of Geological Sciences, Northwestern University, Evanston, IL 60208; 4 Center for Stratigraphy and Paleontology, New York State Museum, The State Education Dept., Albany, NY 12230 Middle and Late Devonian faunas in the Appalachian Basin display a pattern of long-term relative stability (ecological-evolutionary or EE subunits) punctuated by short intervals of abrupt change including: major extinction-emigration of long-standing lineages, rapid speciation, and immigration of new forms from outside of the basin. Many aspects of this pattern, which we have termed coordinated stasis, are as yet largely unexplained: to what degree are the biotic turnovers related to global, as opposed to regional physical events? Detailed correlations, using a combination of biostratigraphy, and cycle/event stratigraphy have established that these turnovers are nearly as abrupt in the thickest, conformable sections as in condensed successions, ruling out stratigraphic artifacts of condensation. Sedimentological and geochemical profiles have been determined through at least two key EE subunit boundaries in the Middle Devonian, and three faunal turnover pulses in the Frasnian, including the FrasnianFamennian boundary. A major feature common to each is abundant evidence for widespread perturbations in basinal redox conditions based on complementary palaeontological and geochemical proxies (e.g., bioturbation, TOC, DOP, Mo, V). The most severe faunal overturns are associated with evidence for fluctuating dysoxic-anoxic conditions, enhanced nutrient recycling efficiency, and elevated productivity (eutrophication) during sea-level highstands. These intervals are accompanied by a severe drop in faunal diversity. In contrast, intervals with low organic matter concentration, suggesting widespread, shallow oxic conditions seem to reflect oligotrophic periods during which benthic diversity levels, especially of corals, reached their highest values. Conversely, certain intervals showing evidence for prolonged stable stratification and euxinic conditions (e.g., Oatka Creek black shale) occur within stable blocks of EE subunits and do not correspond to major overturns. Hence, coupled changes in nutrient cycling, productivity, and redox conditions appear to be more important drivers of faunal turnover than extended anoxia. At least some of the Devonian bioevents recognized in the Appalachian basin are present over even broader global scales. In particular, both the beginning and end of the Hamilton fauna correspond to the Kacak-otamari and Taghanic (Pharciceras) global bioevents, respectively. These are recognizable in Baltica, Avalonia, and Gondwanaland, as well as eastern Laurentia. These and other extinction events in the Appalachian basin appear to be related to widespread black shales that record global events, comparable to Cretaceous oceanic anoxic events (OAEs). These apparently reflect responses to major sea-level and climatic changes. These results suggest that close integration of high-resolution data on faunal patterns and sedimentologygeochemistry may provide critical insights into the causes of ecological-evolutionary changes that have shaped the history of the marine biosphere.

IPC2002 Oral Presentations PALAEOENVIRONMENT OF LOWER DEVONIAN SILICICLASTIC SUCCESSIONS IN THE RHENISH SLATE MOUNTAINS (GERMANY) Rainer BROCKE , Guenther HERTWECK , Ulrich JANSEN , Peter KONIGSHOF , Gerhard PLODOWSKI , Eberhard SCHINDLER , Stephan SCHULTKA , Achim WEHRMANN and Volker WILDE 1

Forschungsinstitut Senckenberg, Senckenberganlage 25, D-60325 Frankfurt, Germany; Forschungsinstitut Senckenberg, Abt. Meeresforschung, Schleusenstr. 39a, D-26382 Wilhelmshaven, Germany; Museum fur Naturkunde HU Berlin, Institutfur Palaontologie, Invalidenstr. 43, D-10115 Berlin, Germany 2

The Lower Devonian of the Rhenish Slate Mountains (Rheinisches Schiefergebirge) is built up of up to 6000 m thick siliciclastic deposits. A variety of facies are present which reflect different environments from terrestrial to fully marine. Several well exposed Emsian sequences in the Mosel area have been studied with regard to facies, sedimentology and palaeoecology. The Aiken Quarry near Koblenz is an outstanding example. It is a known fossil site in the uppermost Lower Emsian (Nellenkoepfchen Formation, upper Vallendar Group). The exposed sequence has a thickness of 87 m and is predominantly built up of sandstones, in which two conspicuous units, predominantly siltstones, with considerable amounts of plant material are intercalated. These two fossiliferous units called "Lower Aiken fossiliferous Unit" (LAFU) and "Upper Aiken Fossiliferous Unit" (UAFU) measure 6 m and 4 m, respectively, and yield a mixed association of marine (brachiopods, tentaculitids, pteriomorph bivalves), probably brackish (eurypterids, fish) and terrestrial (land plants, arachnids) fossils. Brachiopods and bivalves are represented by oligospecific assemblages reflecting restricted marine conditions. Besides of the body fossils, bioturbation is frequent. Flaser bedding, horizontal bedding and ripple cross bedding are the predominant sedimentary structures in the fossiliferous units. The biotic and sedimentary features of these units point to a tidal lagoon reflecting a depositional environment with low hydrodynamic energy and probably changing salinity. This habitate was populated by eurypterids, fishes, brachiopods and pteriomorph bivalves. In the adjacent hinterland, terrestrial plant material was mobilized during distinct meteorological events and rapidly accumulated in the lagoon. Because of the unfragmented preservation of the flora and fauna a long transport distance is improbable. Besides the two conspicuous fossiliferous units the prevailing part of the Aiken sedimentary sequence is composed of sandstones predominantly showing longitudinal cross-bedding, channel-fill structures, scourand-fill structures, horizontal bedding and ripple cross-bedding. Desiccation cracks, wind-induced striations and water-level marks indicate subaerial exposure. From the combination of sedimentological features it is concluded that these beds were deposited in a high-energy intertidal environment characterized by meandering channels. This interpretation is supported by own observations in various modern tidal environments, where similar inventories of sedimentary structures are present. Concerning palaeogeography, an Early Emsian Hunsrueck Island or Archipelago to the South is supported by our data. Most probably it was a flat and only slightly emerged area with wetlands covered by densely growing terrestrial plants. The northern margin of this landscape was bordered by extended tidal flats and, in places, tidal lagoons. The Nellenkoepfchen Formation is conformably followed by the Upper Emsian Emsquarzit Formation (Lahnstein Group) which shows similar sedimentary structures reflecting tidal-influenced shallow water conditions. However, the Emsquarzit Formation contains a folly marine fauna with several species of brachiopods and bivalves. The Emsquarzit Formation is overlain by the Hohenrhein Formation which is sedimentologically characterized by the predominance of horizontal and ripple cross bedding. The Hohenrhein Formation contains a marine faunal association which may be related to the open shelf, e.g., brachiopods, bivalves, trilobites, crinoids, tentaculitids, bryozoans, and rostroconchs. The examples described show the variation of environments represented in the sedimentary column around the classical boundary between Lower and Upper Emsian in the central part of the Rhenish Slate Mountains. The succession from the Nellenkoepfchen Formation to the Emsquarzit Formation and to the Hohenrhein Formation clearly reflects a transgressive trend which may correspond to the global Daleje Event. HILLICHNUS LOBOSENSISIGEN. ET ISP. NOV., A COMPLEX TRACE FOSSIL PRODUCED BY TELLINACEAN BIVALVES, MONTEREY, CALIFORNIA, U.S.A. R.G. BROMLEY , R.G., A. UCHMAN , M.R. GREGORY & A.J. MARTIN 1

Geological Institute, University of Copenhagen, Denmark; Institute of Geological Sciences, Jagiellonian Universit, Krakow, Poland; Department of Geology, University ofAuckland, New Zealand; Department of Environmental Studies, Emory University, Atlanta, U.S.A. 2

IPC2002 Oral Presentations

A large, spectacular and highly complex trace fossil has been well exposed and long known at Lobos Point, south of Monterey, central California but has defied interpretation. This trace bears a remarkable resemblance to a feathered serpent or one of our grandmothers' "boa" stoles. It is found in rippled Paleocene sandstones that accumulated in the inner fan environments of a deep-sea canyon setting. Improvement of our knowledge of deposit-feeding bivalves has allowed a reasonable interpretation of the trace fossil as reflecting the activities of a tellinacean bivalve. The trace fossil has been designated Hillichnus lobosensis igen. et isp. nov. Excursions of the animal's inhalant siphon have created feather-like and spreite-like structures to either side of a basal axial tube complex. Siphonal excursions to the seafloor surface above have left an array of upwards-curving tubes following a straight or somewhat zigzag course, comprising the uppermost level of the structure. The length of these tubes indicates that feeding was taking place well below oxygenated sediments. This in turn suggest that, in addition to deposit feeding , chemosymbiosis with sulfide-oxidizing bacteria may have been practised. On the other hand, the continuous forward movement of the animal rather conflicts with this interpretation. Some individuals show a clustered grouping of the upward-curving tubes, which suggest short term feeding at the seafloor This complex trace was once been considered the fossilised impression of a seaweed. Later there was recognition that several ichnotaxa, including Nereites, Grossopodia, Myrianites, Arthrophycus, Phycodes, Radionereites and Baroccoichnites, were bedding plane and vertical section views of discrete elements that otherwise made up the trace here designated H. lobosensis .

ICHNOLOGY OF THE PUNCOVISCANA FORMATION IN NORTHWEST ARGENTINA: ANACTUALISTIC ECOSYSTEMS AND THE PRECAMBRIAN-CAMBRIAN TRANSITION Luis A. BUATOIS & M. Gabriela MANGANO Conicet-Insugeo, Casilla de correo (CC), 4000 San Miguel de Tucuman, Argentina [ichnolog@infovia. com. ar] The Puncoviscana Formation consists of a thick and folded succession of sandstones, mudstones, conglomerates, and slates of Vendian to Tommotian age, representing the metasedimentary basement of northwest Argentina. The Puncoviscana ichnofauna was documented originally during the seventies and additional descriptions were published subsequently. Recent research allows to re-evaluate its palaeoecological and evolutionary significance in the light of new ideas regarding the anactualistic nature of Precambrian-Cambrian ecosystems and the role of microbial communities in ecologic structure. Current depositional models for the Puncoviscana Formation envisage accumulation from turbidity currents in submarine fans. However, preliminary sedimentologic studies suggest a more complex palaeoenvironmental evolution, including not only deep-marine, flysch-type deposits, but also shallow-water settings affected by wave action, as indicated by the presence of interference ripples and probable wave ripple lamination in some localities. The ichnofauna includes a wide variety of ichnotaxa, such as Cochlichnus, Glockerichnus, Helminthopsis, Helminthorhaphe, Helminthoidichnites, Monomorphichnus, Nereites, Oldhamia and Treptichnus, as well as several types of arthropod trackways. The ichnogenus Oldhamia is represented by three ichnospecies: O. antiqua, O. flabellata and O. radiata. Though currently referred to the archetypal Nereites ichnofacies, the Puncoviscana ichnofauna includes a number of elements from the Cruziana ichnofacies. Feeding and grazing trace fossils of vermiform animals and crawling traces produced by arthropods are represented. Structures considered in previous studies as graphoglyptids (Agrichnia), such as Protopalaeodictyon and Squamodictyon, are reinterpreted here as wrinkle marks. Vertical dwelling structures (Domichnia) are absent. Accordingly, the ethologic groups represented in the Puncoviscana ichnofauna are Fodinichnia, Pascichnia and Repichnia. Arthropod locomotion traces are mostly undertracks. Nearly all the ichnofossils in the assemblage are oriented parallel to the bedding plane, displaying restriction to two-dimensional biotopes, and therefore they do not disturb the primary sedimentary fabric. Bedding plane trace fossils mostly reflect very shallow infaunal grazing by mobile, bilaterian metazoans. The only exception is Treptichnus, which represents a shallow infaunal, three-dimensional burrow system that records a feeding strategy of underground mining. The presence of Treptichnus in Vendian to Tommotian rocks reveals an early attempt of colonization of the infaunal ecospace. Integrated ichnologic and sedimentologic analysis suggests that the Puncoviscana ichnofauna reflects, at least in part, lifestyles related to microbial mats that protected the sediment from erosion. The presence of wrinkled surfaces and palimpsest ripples suggests that stabilization by microbial binding was a major factor in Vendian-Tommotian ecosystems. Some of the ichnofossils are directly associated with suspect-microbial structures. Close association of the ichnogenus Oldhamia with wrinkled surfaces and palimpsest ripples supports Seilacher's hypothesis that this icnotaxa records a feeding strategy of undermat mining. Microripple

IPC2002 Oral Presentations sets associated with Oldhamia are oriented perpendicular to each other, forming palimpsest ripples. These surfaces give evidence of microbial mats that provided the substrate with a thin veneer that was resistant to erosion. The ichnogenus Oldhamia is a common component of Tommotian ichnofaunas, although forms similar to O. flabellata were recorded from the Vendian. Diversification of behavioral patterns represented by several Oldhamia ichnospecies in relatively deep Tommotian strata reflects that feeding strategies associated with microbial mats persisted in certain environments after the agronomic revolution. This fact suggests a gradual closure of a taphonomic window during the Proterozoic-Cambrian transition and is consistent with the recognition of Ediacara-type body fossils in Cambrian strata of different continents.

EVOLUTION AND RELATIONSHIPS OF ACANTHODIANS WITH DENTIGEROUS JAW BONES Carole J BURROW Department of Zoology & Entomology, University of Queensland, QLD 4072 Ischnacanthid acanthodians are characterized by having dentigerous jaw bones of dermal origin forming occlusal surfaces on the lower, Meckel's cartilage and upper, palatoquadrate cartilage of the jaws. Most taxa in this group are based on isolated jaw bones rather than articulated fish; the oldest of these elements were collected from the ?late Wenlock/early Ludlow of Canada (Hanke et al 2001), and show the features typical of one of the two common morphotypes in Silurian to early Middle Devonian deposits worldwide. This first morphotype has a main lateral row of teeth comprising large conical cusps, usually with vertical ridges, which have smaller anterior and posterior cusps attached to them; some taxa (e.g. Plectrodus, Xylacanthus kenstewarti, Taemasacanthus spp.) also have a medial zone/row of denticles and/or teeth, while other taxa (e.g. Ischnacanthus gracilis, /. kingi, Gomphonchus, Xylacanthus grandis and a new taxon from western U.S.A.) lack the latter. The second morphotype has a similar arrangement, but the main lateral tooth cusps are triangular in parabasal section, as exemplified by the poracanthodids - in particular, the articulated specimens of Zemlyacanthus (Poracanthodes) menneri from Severnaya Zemlya - and also Xylacanthus minutis. Other Early Devonian taxa have also been assigned, perhaps erroneously, to ischnacanthid acanthodians: Hanke et al. (2001) suggested that the supposed dentigerous jaw bones with single-cusped teeth on specimens of the British species Uraniacanthus spinosus might have been misidentifled, and Helenacanthus incurvus, a taxon erected for isolated jaw bones from the western U.S.A., is probably an actinolepid placoderm rather than an ischnacanthid acanthodian. Except for one articulated specimen which was described by lessen (1973), all known ischnacanthid taxa from the late Middle to Late Devonian are based on isolated jaw bones. The first taxon described was Atopacanthus dentatus, based on a short, poorly preserved jaw bone fragment from New York state. Nearly all these elements are variations of the Atopacanthus-type with compressed cone-shaped teeth forming the main lateral tooth row, with or without a medial tooth row; taxa include Atopacanthus spp., Persacanthus spp. and a new taxon from the Hunter Formation in New South Wales. The North American Apateacanthus, a supposed ischnacanthid taxon which departs from the norm in having backward sloping monocuspid 'teeth', is undoubtedly a fragment of a fin spine rather than a dentigerous jaw bone. Two Carboniferous genera of acanthodians, Marsdenius and Acanthodopsis, have also been assigned to the Ischnacanthida by some workers in recent decades, although they had previously been assigned to the Acanthodidae. Acanthodopsis is represented by isolated upper and lower jaws on which ossification is continuous over the occlusal surface and cartilage, down to the mandibular splint on the lower jaw. Unfortunately, the type of Marsdenius was a complete fish which was never illustrated and is now lost (Denison 1979); its jaws were apparently similar to those of Acanthodopsis. Long (1986) reverted to assigning the latter genus to the Acanthodida rather than the Ischnacanthida because it had a double jaw articulation comparable to that of Acanthodes, rather than the simple single articulation of ischnacanthids. Earlier, Miles (1966) had commented on the differences between the teeth of Acanthodopsis and 'other' ischnacanthids. Comparison of jaws and dentition from the two groups shows that the dentigerous area on the jaws of Acanthodopsis and ischnacanthids are not homologous: whereas the dentigerous jaw bones of the latter are discrete dermal elements, the 'teeth' of Acanthodopsis possibly were formed as part of the perichondral ossification of the jaw cartilages. DENISON, R., 1979. Acanthodii. In Schultze, H.-P., ed., Handbook of Paleoichthyology, Part 5; Gustav Fischer Verlag, Stuttgart, 62p. HANKE, G.F., WILSON, M.V.H. & LINDOE, L.A., 2001. New species of Silurian acanthodians from the Mackenzie Mountains, Canada. Canadian Journal of Earth Sciences 38, 1517-1529. JESSEN, H., 1973. Weitere Fischreste aus dem oberen Plattenkalk der Bergisch-Gladbach-Paffrather Mulde (Oberdevon, Rheinisches Schiefergebirge). Palaeontographica 143A, 159-187. LONG, J. A., 1986. New ischnacanthid acanthodians from the Early Devonian of Australia, with a discussion of acanthodian interrelationships. Journal of the Linnean Society (Zoology) 87, 321-339.

IPC2002 Oral Presentations MILES, R.S., 1966. Articulated acanthodian fishes from the Old Red Sandstone of England, with a review of the structure and evolution of the acanthodian shoulder-girdle. Bulletin of the British Museum (Natural History), Geology 24, 113-213.

PATTERNS OF BRACHIOPOD FAUNAL CHANGE AT THE ONSET OF THE YANGHSINGIAN TRANSGRESSION (PERMIAN) IN SOUTH CHINA Monica CAMPI & G. R. SHI School of Ecology and Environment, Deakin University, Burwood 3125, Victoria, Australia [campi@deakin. edu. au]. The Yanghsingian supersequence is the middle of three supersequences that punctuated marine deposition across South China during the Permian (Chen et al., 1998). This supersequence incorporated the Liangshan, Chihsia and Maokou Formations of South China; it is bounded by regional unconformities separating it from the Late Carboniferous/Early Permian Mapingian supersequence below and the Late Permian/earliest Triassic Lopingian supersequence above. At the Chuanmu section in the Huaying Mountains of E Sichuan, the base of the Yanghsingian supersequence is marked by an unconformity between the Upper Carboniferous Huanglong Formation and the late Artinskian or possibly earliest Kungurian Liangshan Formation. The Liangshan Formation is a relatively short sequence (-15 m) that represents the initial transgressive sequence of the Yanghsingian supersequence, and is lithologically dominated by finely laminated mudstone and shale (both calcareous and carbonaceous) with some local development of thin coal seams. At the Chuanmu section it appears that the Liangshan Formation was deposited in a relatively quiet environment, probably representing a restricted, nearshore environment, as there are abundant plant remains in addition to marine invertebrates. Plant- and marine invertebrate-bearing horizons alternate, with some horizons bearing both. Some beds display burrow-mottling of their surface, but burrowing activity was not vertically extensive and had relatively little effect on the fine mudstone and shale laminations. The marine invertebrate community appears to be dominated by brachiopods, although bryozoans are also common. Rare trilobites and gastropods also occur. The brachiopod fauna is dominated by the rugosochonetid Linshuichonetes elfinis Campi & Shi (2002) comprising up to 94 % of specimens in some beds (Campi & Shi, 2002). It appears to have had interesting ecological adaptations; it exhibits several characters indicative of an opportunistic taxon (Levington, 1970) such as random orientation and lack of sizesorting of individuals, limited areal distribution, cluster aggregates of specimens, presence in thin isochronous horizons, abundance in several faunal assemblages, and overwhelming numerical dominance. It is also typically very small, with thin, flattened valves, and appears to have a high juvenile growth rate and conservative calcite secretion, exemplified by lack of capillation in juveniles and overall conservative ornamentation of adults. The small, flattened and thin shells give an overall low biomass to surface area ratio, possibly advantageous in an environment with oxygen and/or nutrient restrictions. The fauna of the Liangshan Formation at the Chuanmu section suggests it was probably a pioneer community able to colonise areas newly flooded by the transgression at the beginning of the Yanghsingian supersequence. Species able to reproduce quickly and in large numbers would have been primed to invade areas flooded during the frequent small-scale transgression-regression cycles of the transgressive systems tract. The Linshuichonetes elfinis opportunistic community was dominant during the Liangshan Formation at the Chuanmu section, but as the transgression progressed and the environment became less restrictive and more stable a more diverse suite of brachiopods appeared concurrent with disappearance of Linshuichonetes. At the base of the Chihsia Formation the lithology changed from predominantly argillaceous facies typical of the Liangshan Formation to micrite and argillaceous micrite intercalated with carbonaceous shales. The brachiopod faunas of the Chihsia Formation at the Chuanmu section are not very abundant, but diversity increased compared with the Liangshan Formation. CAMPI, M. J. & SHI, G. R. 2002. Linshuichonetes gen. nov., a new rugosochonetid (Brachiopoda) genus from the Liangshan Formation (Early Permian) in Sichuan, China, and its ecology. Acta Palaeontologica Sinica, 41(1): 105-118. CHEN, Z. Q., JIN, Y. G. & SHI, G. R. 1998. Permian transgression-regression sequences and sea-level changes of South China. Proceedings of the Royal Society of Victoria, 110: 345-367. LEVINGTON, J. S. 1970. The paleoecological significance of opportunistic species. Lethaia, 3:69-78.

IPC2002 Oral Presentations RESPONSE OF FLORISTIC DIVERSITY TO ENVIRONMENTAL CHANGE DURING THE TERTIARY: AN EXAMPLE FROM SEYMOUR ISLAND, ANTARCTICA D .J. CANTRILL1 J.E. FRANCIS2 & A-M.P. TOSOLINI2 British Antarctic Survey, Natural Environment Research Council, Madingley Road, High Cross, Cambridge, CB1 3BZ, United Kingdom; 2Department of Earth Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom The early Tertiary period, particularly the Eocene, has been a major focus for global change research because it represents the most recent phase of greenhouse climates, with mean global surface temperatures 2-6°C warmer than present. From this peak of warmth the Earth progressively cooled as the Antarctic landmass was isolated at the pole by plate tectonic processes. Despite such extensive interest in Tertiary climates, our understanding has been hampered by lack of data from southern high latitudes, particularly terrestrial environs. The Antarctic Peninsula region contains the main area of outcrop of Paleogene sediments in Antarctica. Seymour Island sits within a Mesozoic-Cenozoic back arc succession on the eastern side of the Antarctic Peninsula. The sediments of the Palaeocene Sobral and Cross Valley formations and the Eocene La Meseta Formation are sequences of fine-grained sandstones, siltstones and mudstones, representing shallow shelf and estuarine conditions. Plant fossils have been described from Paleocene (Dusen 1908, Case 1988) and Eocene (Doktor et al. 1996) strata on Seymour Island. Yet these records understate the abundance and temporal distribution of the floras. Well-preserved fossil plant assemblages occur at a number of stratigraphic levels and contain a detailed record of forest biodiversity, and how biodiversity changed as the climate deteriorated from a greenhouse to icehouse world. Paleocene floras are considerable more diverse than previously reported, at least 22 angiosperm leaf types along with pteridophytes (3 species) and conifers (podocarp and araucarians) are found in the ?late Paleocene. This is also supported by the pollen (Askin 1997) and wood flora (Nothofagaceae, Myrtaceae, Illiciaceae, Atherospermataceae, Cunoniaceae). The physiogonmy of the leaves suggests a mean annual temperature (MAT) of 13.8 ± 2.7 °C, and Growing Season Precipitation (GSP) of approximately 250 mm using CLAMP analysis. By the late Early Eocene subtle changes were taking place in the vegetation. Diversity decreased with around 12 angiosperm leaf taxa recognised, along with a few fern (2) and conifer (3) species. Within the leaf floras Nothofagus becomes more abundant and deciduous forms are increasingly encountered. The palynoflora is dominated by Nothofagus pollen with minor amounts of Proteaceae, podocarp and araucarian conifers. The wood flora is also rich in Nothofagoxylon but podocarp and araucarian conifers are more abundant. Unfortunately the decreasing leaf diversity precludes the use of CLAMP analysis, but the trend suggests climatic cooling and increasing seasonality. Overall diversity decreases through the Eocene and by late Eocene times the flora plicate Nothofagus is most abundant supporting a continued cooling trend. ASKIN, R.A., 1997. Eocene - ? earliest Oligocene terrestrial palynology of Seymour Island, Antarctica. In The Antarctic Region Geological Evolution and Processes, Ricci A.C., ed., Terra Antarctica, Siena, 993-996. CASE, J. A., 1988. Paleogene floras from Seymour Island, Antarctica. Geological Society of America Memoir 169, 523-530. DOKTOR, M., GAZDZICKI, A., JERMANSKA, A., POREBSKI, S.J. & ZASTAWINIAK, E., 1996. A p l a n t - a n d - f i s h a s s e m b l a g e f r o m the E o c e n e

La Meseta Formation of Seymour Island (Antarctic Peninsula) and its environmental implications. Palaeontologia Polonica 55, 127-146.

DUSEN, P., 1908. Die Tertiare flora der Seymour-Insel. Wissenschaftliche Ergebnisse Der Schwedischen Siidpolar-Expedition 19011903 3(3), 1-27.

HISTORY OF COAL SWAMP FORMATION IN HIGH SOUTHERN LATITUDES: EVIDENCE FROM THE LATE PERMIAN OF ANTARCTICA D.J. CANTRILL1., J.A. WEBB2, and A.N. DRINNAN3, British Antarctic Survey, Natural Environment Research Council, Madingley Road, High Cross, Cambridge, CB1 3BZ, United Kingdom; department of Earth Sciences, La Trobe University, Bundoora, Victoria, 3086, Australia; 3School of Botany, University of Melbourne, Melbourne, Victoria 3010. Australia Collapse of the great Late Palaeozoic Southern Hemisphere ice-sheet led to rapid forestation in mid- and high-latitude regions of Gondwana. Forests, dominated by Glossopteris communities, extended as far as 80° South (Taylor et al. 1992), and were one of the major coal-forming associations in Permian times, yet relatively little is known about the palaeoecology of this group. The Late Permian Bainmedart Coal Measures (Fielding and Webb 1996, McLoughlin and Drinnan 1997) of the Prince Charles Mountains (Antarctica) provide a unique insight into the development and processes of coal-forming environments during this period in Earth history. The upper 50cm of the stratigraphically highest coal horizon in the Toploje Member is

IPC2002 Oral Presentations silicified and preserves an exceptional record of plant community development, with beautifully preserved glossopterid roots (Neish et al. 1993), leaves (Mcloughlin & Drinnan 1996) and other plant material. Silicification occurred very rapidly immediately following deposition, so the peat was preserved before it could be affected by compaction, heat or other diagenetic processes. The silicification may be related to formation of the lake which deposited the overlying Dragons Teeth Member (Fielding and Webb 1996). The mire community was dominated by Glossopteris, with minor Noeggerathiopsis, small heterosporus lycopods and ferns. Detailed sampling profiles collected at several localities along the length of the silicified peat provide a chronology of environmental and vegetational change. Peat formation was dominated by leaf fall accumulations subject to mechanical and chemical breakdown, and recycling by colonizing vegetation (root layers). In general the lack of decomposers (e.g. fungi), except in certain horizons, shows that for much of the year the swamp was low in oxygen. As well as the leaf-rich layers, other plant fragments (megaspores, pollen sacs) are concentrated in particular stratigraphic horizons, suggesting discrete environmental events. Ecosystem disturbance was common within this community. Short-term depositional hiatuses can be identified; these often have features associated with slow current velocities, indicating fluctuating water levels within the mire. Periodic dessication is represented by layers of compacted, more oxidized and sometimes cracked organic material, often with topographic relief. Silt particles may infill the cracks. Dry conditions within the mire are also shown by the presence of charcoal, which is not believed to be transported because in this case it is accompanied by an increase in wood clast size, suggesting disruption of the ecosystem. This may indicate a seasonality in rainfall, a feature that is substantially more pronounced in the overlying Triassic strata. FIELDING, C. & WEBB, J.A., 1996. Facies and cyclicity of the Late Permian Bainmedart Coal Measures in the Northern Prince Charles Mountains, Macrobertson Land, East Antarctica. Sedimentolgoy 43, 295-322. NEISH, P., DRINNAN, A.N. & CANTRILL, D.J., 1993. Structure and ontogeny of Vertebraia from silicified Permian sediments in East Antarctica. Review of Palaeobotany and Palynology 79, 221-244. MCLOUGHLIN, S. & DRINNAN, A.N., 1996. Anatomically preserved Permian Noeggerathiopsis leaves from East Antarctica. Review of Palaeobotany and Palynology 92, 207-227 MCLOUGHLIN, S. & DRINNAN, A.N., 1997. Revised stratigraphy of the Permian Bainmedart Coal Measures, northern Prince Charles Mountains, East Antarctica. Geological Magazine 134, 335-353. TAYLOR, E.L., TAYLOR, T.N. & CUNEO, N.R., 1992. The present is not the key to the past: a polar forest from the Permian of Antarctica. Science 257, 1675-1677.

THE TRACE FOSSIL RECORD OF THE DECAPOD CRUSTACEAN RADIATIONS Noelia B. CARMONA, Luis A. BUATOIS & M. Gabriela MANGANO Conicet-Insugeo, Casilla de correo (CC), 4000 San Miguel de Tucuman, Argentina. [ichnolog@infovia. com. ar] The concept of evolutionary faunas represents a useful theoretical framework for describing and analyzing major changes in the composition of Earth's biotas through time. Although trace fossils provide valuable palaeoecologic and ethologic evidence, they have been relatively underutilized in evolutionary palaeoecology. Based on the analysis of an extensive database constructed from the literature and from our own field studies, we evaluate the ichnologic record through the Phanerozoic of one member of the Modern Fauna, the malacostracan crustaceans. Although crustaceans originated early in the Palaeozoic, decapods reach a maximum diversity in the Mesozoic and Cenozoic. More than 150 records of decapod-like burrow systems (mazes and boxworks) from all continents were included in the database; almost all of them belong to the ichnogenera Thalassinoides and Ophiomorpha. These data were plotted in a graphic that shows the abundance of these burrow systems through the Phanerozoic. Aspects considered in the database include burrow morphology, trophic type, burrowing depth, tiering position and potential tracemaker, among other features. Our analysis is restricted to softground shallow-marine ichnofaunas and therefore, examples of decapod burrows in deep-marine turbidite systems or in omission surfaces were not considered. Analysis of the database allows us to examine the fossil record of two- and three-dimensional burrow systems similar to recent decapod crustacean galleries, attempting to establish a link between the trace fossil record and the decapod radiations documented by body fossils. The number of early Palaeozoic records is low and all the examples correspond to the ichnogenus Thalassinoides, generally preserved in carbonate deposits. The Middle to Late Ordovician advent of extensive three-dimensional burrow systems reveals the successful colonization of a moderately deep infaunal ecospace. However, identification of the potential tracemaker is uncertain. Despite the overall similarity in arquitectural morphology, unquestioned malacostracan fingerprints have not been identified. The oldest decapods come from Upper Devonian strata and the first thalassinidean body fossils are known from the Jurassic. Similarities between early Palaeozoic burrow systems and modern examples point to behavioral convergence. Carboniferous-Permian records include both Ophiomorpha and Thalassinoides in

IPC2002 Oral Presentations clastic and carbonate shallow-marine successions, most likely reflecting the late Palaeozoic radiation of malacostracan crustaceans evidenced from the body fossil record. However, decapod burrows commonly are accessory components of Carboniferous-Permian shallow-marine ichnofaunas, typically are small and generally display poorly developed pelletoidal walls. The low number of late Palaeozoic decapod-like burrows is consistent with a macroevolutionary lag between the first appearance of decapods in the Late Devonian and their major radiation in the Jurassic, as suggested from the body fossil record. The Palaeozoic picture changed in the Mesozoic, when there is a continuous increase in the number of records, reaching a pronounced peak in the Cretaceous. This pattern undoubtedly reflects the late Mesozoic decapod radiation. Crustacean burrows commonly are dominant in shallow-marine ichnofaunas and are morphologically similar to their recent counterparts. The biological affinities of these burrow systems with decapod crustaceans is unquestioned, based not only on burrow architecture and fine morphology, but also on the presence of crustacean claws within the structures. The post-Cretaceous records show a sharp decline in the number of reported specimens during the Palaeogene. This sharp drop in abundance may be related to the CretaceousTertiary mass extinction or may simply reflect a sampling bias. A maximum peak of abundance of decapod burrow systems is recorded during the Neogene, probably reflecting the decapod radiation that took place during the Eocene. Crustacean burrows are among the dominant elements of Neogene shallow-marine ichnofaunas, displaying an increase in burrowing depth and ecologic complexity, as revealed by multipletiered structure. Environmental conditions in shallow-marine settings were conducive to the development of evolutionary innovations. Infaunalization was one of the major innovations that favored the great diversification of the decapod crustaceans. Infaunalization allowed exploitation of an underutilized environment, the deep endobenthic realm, which provided new food resources, shelter during moulting and protection against predators. Our preliminary analysis suggests a tendency towards an increase in tiering complexity and burrowing depth through geologic time, although this general trend may have been disrupted by mass extinctions. The ichnologic record reflects decapod radiations documented from body fossil data and may be useful to refine available models. PHYLOGENETIC SYSTEMATICS AND THE ARTHRODIRES (PLACODERMI): WHY HAVEN'T WE REACHED A CONSENSUS? Robert K. CARR Dept. Biological Sciences, Irvine Hall, Ohio University, Athens, OH 45701, U.S.A. Recent discoveries of eubrachythoracid arthrodiran fossils (Placodermi) add greatly to our understanding of their anatomy. Localities such as the Gogo Formation, Western Australia, have provided a wealth of new fossils (Gardiner & Miles 1990). These fossils and other information provide the basis for renewed analyses of phylogenetic relationships (e.g., Long 1995 and Carr 1991). Despite advances, such as phylogenetic systematics and our improved knowledge of eubrachythoracid arthrodires, the relationships of several basal taxa remain obscure. Different analyses have disagreed concerning the placement of these taxa. Three hypotheses explain the instability among these analyses. (1) Sampling biases (missing taxa or characters) result in an incomplete picture. Character based analyses clearly are affected by missing data. (2) Characters derived from pre-cladistic analyses may lack a critical review and potentially bias current analyses. In this case, a character is defined based on a preconceived phenetic group and then is used to confirm the validity of that group, a tautological approach. (3) Differences in the evolutionary patterns (tempo and the nature of morphological change) between sister taxa affect the assignment of basal members. Sampling theory suggests that rapidly changing groups or increased cladogenic events within a group are subject to increased sampling biases. Differences in the pattern of morphological change can also affect the outcome of phylogenetic analyses, for example, the unequal loss of plesiomorphic characters between sister taxa. Each of these hypotheses has explanatory value to account for the discrepancies among alternative hypotheses of relationships. The affects of evolutionary pattern are underestimated as an influencing factor. Among eubrachythoracid arthrodires, differences in evolutionary pattern leads to an asymmetrical instability for the position of basal taxa. In this study, an unequal loss of plesiomorphic characters is modeled, which supports an asymmetrical instability of basal taxa between sister groups. In this case, basal members of the clade losing plesiomorphic characters are combined in a paraphyletic stem group when using parsimony or distance methodologies. These patterns are not limited to a single taxonomic group, but form a common practical problem faced by palaeontologists in general. Recognition of the sources for differences among alternative hypotheses of phylogenetic relationships can lead to a unified solution. Continued fieldwork addresses discrepancies based on sampling biases. Among placoderms, it is clear that we are far from 100% sampling of critical taxa. Open discussion among colleagues and publication of character analyses leads to elimination of potential historical biases. Finally,

IPC2002 Oral Presentations recognition of other sources (e.g., evolutionary pattern) leading to different hypotheses of relationships enable researchers to determine and potentially correct for potential biases. A total evidence approach (Kluge and Wolf 1993) along with a numerical increase of fossil data should address the above biases. Recognition of these precautions portents a fruitful future for our understanding of phylogenetic relationships among arthrodires and other craniate taxa. CARR, R.K., 1991. Reanalysis of Heintzichthys gouldii (Newberry), an aspinothoracid arthrodire (Placodermi) from the Famennian of northern Ohio, with a review of brachythoracid systematics. Zoological Journal of the Linnean Society 103, 349-390. GARDINER, B.G. & MILES, R.S., 1990. A new genus of eubrachythoracid arthrodire from Gogo, Western Australia. Zoological Journal of the Linnean Society 99, 159-204. KLUGE, A.G. & WOLF, A.J., 1993. Cladistics: What's in a word? Cladistics 9, 183-199. LONG, J.A., 1995. A new plourdosteid arthrodire from the Upper Devonian Gogo Formation of Western Australia. Palaeontology 38, 3962.

ORIGIN AND EARLY EVOLUTION OF THE ENDOLITHIC AND TUBE DWELLING SUPERFAMILY GASTROCHAENOIDEA (MOLLUSCA, BIVALVIA, AUTOLAMELLIBRANCHIATA) Joseph G. CARTER1 and George D. STANLEY, JR.2 department of Geological Sciences, University of North Carolina at Chapel Hill, NC 27599-3315 [Clams@email.unc.edu]; 2Department of Geology, The University of Montana, Missoula 59812 [Fossil@selway. umt. edu]. The superfamily Gastrochaenoidea probably evolved from permophorids (superfamily Permophoroidea, ?Order Veneroida) similar to Middle Triassic Curionia gastrochaena (Dunker, 1849) and ICurionia goldfussi (Dunker, 1849). The latter two species resemble several Jurassic gastrochaenids in their prosopon, lateral profile, and in some instances also strong lateral compression. The oldest known gastrochaenid boring is Late Triassic in age. The oldest known gastrochaenid shell is Early Jurassic "Gastrochaena" infraliasina Terquem, 1855, a strongly laterally compressed species with a relatively narrow, anteriorly restricted pedal gape, i.e., features to be expected in a transition from a non-boring permophorid ancestor. Most Cenozoic gastrochaenids have relatively larger pedal gapes which allow wider application of their chemically boring mantle epithelium to the substratum. Gastrochaenopsis and Rocellaria may have first appeared during the Middle Jurassic, followed by Carterochaena and possibly also Spengleria during the Late Jurassic. At least some Late Jurassic gastrochaenids could outpace coral growth by greatly elongating their siphons, as in most modern gastrochaenids but unlike most lithophaginids. The evolution of the pedal probing organ, which can be transformed into a very long (several millimeters)digitate, boring apparatus, also gave gastrochaenids a navigational advantage over lithophaginds in smaller and thinner shell and coral substrates.

A TRIBOSPHENIC LOWER MOLAR FROM THE MAASTRICHTIAN OF MADAGASCAR: PHYLECTIC AFFINITIES, BIOGEOGRAPHY AND A NEW DISPERSAL MODEL Judd A. CASE1 and David W. KRAUSE2 ! Dept. of Biology, Saint Mary's College, Moraga, CA USA 94575; [jcase@stmarys-ca.edu]; Dept. of Anatomical Sciences, Stony Brook University, Stony Brook, NY USA 11794-8081. A left lower molar recovered from the Maastrichtian-aged, Anembalemba Member of the Maevarano Formation, Madagascar was reported by one of us (DWK) as belonging to a marsupial. Here we refine this analysis by reexamining the morphology of the specimen, UA 8699, and make comparisons to all tribosphenic taxa from the Mesozoic of Gondwana, as well as marsupials from Australia and the Americas. The salient features of UA 8699 are: the talonid is as wide and as long as the trigonid; trigonid angle at the protoconid is not anteroposteriorly compressed, so the angle between the pre- and postprotocristids is open, but still acute; the metaconid is posterior to the protoconid; an anterior cingulid declines labially at -45°; the cristid obliqua is anterolingually oriented and terminates at the carnassial notch of the trigonid; the hypoconid is anterior to the anterolabial corner of the tooth; the posthypocristid is posterolingually directed and ends at the anteroposterior midline; a short and labially displaced, posterior cingulid is present posterior to the hypoconid; the hypoconulid is complexed with the entoconid in anterolingual orientation; the entoconid is transverse to the hypoconid; the deepest part of the talonid basin is towards the metaconid and entoconid. In comparison to mid-Jurassic australosphenidans (biogeographic sense only), Ambondro mahabo from Madagascar and Asfaltomylos patagonicus from Patagonia, UA 8699 is derived in much greater development

IPC2002 Oral Presentations of the talonid in both size and cusp development, cristid obliqua strength and orientation, and location of the hypoconulid. The early Cretaceous australosphenidans from Australia, Ausktribosphenos nyktos and Bishops whitmorei, are more plesiomorphic in their lower molar morphology than UA 8699, in that the pre- and postprotocristids of the Australian taxa do not form strong shear walls for embrasure shear as in UA 8699. The two Australian taxa also lack a fully basined talonid, but instead possess a V-shaped trough. Thus, UA 8699 can not be assigned to any of the known australosphenidans. In comparison to Cretaceous boreosphenidans, UA 8699 is neither a placental mammal, nor a deltatheroidan, as the specimen has the derived character states of a low trigonid relative to the talonid, a talonid is equal in size to the trigonid, the hypoconulid is placed lingually, and presence of the postcingulid posterior to the hypoconid. All Australian marsupials have an upper molar morphology which is based on one with a V-shaped centrocrista. The corresponding lower molar structures include the following derived states of a postprotocristid that is transversely oriented between the protoconid and the metaconid, the posthypocristid is also transveresly oriented and extends to the posterolingual corner of the tooth and the hypoconulid is directly posterior to, and much smaller than, the entoconid. Compared to UA 8699, South American marsupials (i.e. microbiotheres, sparassodontans, didelphimorphians, polydolopimorphians and paucituberculatans), are dentally derived relative to this Maastrichtian specimen from Madagascar. Relative to Late Cretaceous North American marsupials, UA 8699 lacks the derived lower molar traits of stagodontids or pediomyids and thus exhibits the greatest affinties with the peradectids, which retain the most plesiomorphic dental traits relative to other marsupials. The specimen most closely resembles that of the alphadontine peradectids, which exhibit the more plesiomorphic dental morphology within the family, and within that taxon, UA 8699 shares the greatest number of features with the Judithian species, Alphadon praesagus. The recovery of what appears to be an alphadontine marsupial from Maastrichtian deposits in Madagascar, presents a very new view on marsupial biogeography, although the timing of such an event has been predicted. If alphadontine marsupials migrated into South America, then into Antarctica and finally into Madagascar, then this would be highly suggestive that the ancestor and origin for the Australian marsupials was deep in Gondwana during the Maastrichtian. This scenario is consistent with other elements of the Late Cretaceous North America fauna occurring in Gondwana in the latest Cretaceous. Hadrosaurs have been recorded in southern Patagonia in the Campanian and in Antarctica in the late Maastrictian. Thus UA 8699 is the first evidence leading to a hypothesis that the origin of the Australidelphia is deep in Gondwana during the latest Cretaceous and that the origin is from an immigrant peradectid marsupial. We present a new biogeographic model for dispersal of Late Cretaceous vertebrates into Madagascar as Indo-Madagascar was still connected to Antarctica until 82 Ma through the Gunnerus Ridge - Kainan Maru complex.

PATTERNS AND PROCESSES OF LATEST ORDOVICIAN GRAPTOLITE EXTINCTION AND RECOVERY BASED ON DATA FROM SOUTH CHINA CHEN Xu1, Charles E. MITCHELL2, Michael J. MELCHIN3,and FAN Jun-xuan1 1 Nanjing Institute of Geology and Paleontology, Academia Sinica, Nanjing, China, [xuchen@jlonline.com]; 2 The State University of New York at Buffalo, Buffalo, .14260-3050, [cem@geology.buffalo.edu]; 3 Geology Department, St. FrancisXavier University, P.O. Box 5000, Antigonish, Nova Scotia B2G 2W5, Canada [mmelchin@stfx. ca]. Based on four continuous Ashgillan to earliest Llandovery sections (at Honghuayuan, Ludiping, Wangjiawan and Fenxiang) from shallow water to deeper water belts in the Yangtze platform region, together with more than 30 other recollected or published sections, latest Ordovician mass extinction has been recognized and determined depending on the graptolite composite standard sequence and diversity changes. The mass extinction is stepwise and begins from a major extinction event from the top of Tangyagraptus typicus Subzone to middle Normalograptus extraordinarius-N. ojsuensis Zone, which swept across the Yangtze basin from the shallow-water belt to the central Yangtze deeper water belt. The following minor extinction within the mass extinction event happened late in the Normalograptus persculptus Zone. Fifty six percent of genera and 77.4 percent of species of Ashgillian graptolites expired through the major extinction event. The last five surviving species of the DDO fauna and some normalograptid species expired during the succeeding minor extinction. Graptolite faunal replacement was completed prior to the end of the Ordovician. Determination of the duration and magnitude of the major and minor extinction events among graptolites provides a framework for other fossil groups. The graptolite major extinction was preceded by a substantial evolutionary radiation. A survival-recovery interregnum includes continued extinction and the roots of recovery in the interval between the major and minor extinction events. Speciation among graptolites occurred not only during the Ashgillian radiation, but also in the mass extinction interval, including the

IPC2002 Oral Presentations survival-recovery interregnum. However, they were much less in the extinction intervals and survivalrecovery interregnum compared with the prior Ashgillain radiation period. All the new species occurring in the survival-recovery interregnum and minor extinction duration belong to ecologically generalized species. Graptolite Lazarus taxa may be absent from the extinction events and succeeding survival and recovery events. Discernible biologic factors associated with the risk of succumbing during graptolite extinction were mainly population size, specialized colony structure and probably a factor related to the astogenic pattern of the proximal end of the rhabdosome.

PALAEOBIOGEOGRAPHIC AFFINITIES OF THE ARGENTINE PRECORDILLERA ACCORDING TO ITS LATE PALAEOZOIC BRACHIOPOD FAUNAS Gabriela A. CISTERN A1, Tristan SIMANAUSKAS2 and Neil W. ARCHBOLD3 ] Facultad de Ciencias Naturales e Institute) Miguel Lillo (UNT), San Miguel de Tucuman, 4000, Argentina. cisternagabriela@hotmail.com; Museo de La Plata, Paseo del Bosque s/n, 1900, La Plata;3School of Ecology and Environment, Melbourne Campus, Deakin University, Burwood 3125, Victoria, Australia. Distinctive Late Palaeozoic brachiopod faunas of the Precordillera are found in marine sequences of the Rio Blanco and Calingasta-Uspallata basins and in marine horizons from the W part of the Paganzo Basin. Fusulinid foraminifers and conodonts are absent from these marine precordilleran faunas, hence reliance for zonation and correlation is primarily on brachiopods with support from palynological data. Genera used for palaeobiogeographic analysis are from four time intervals: 1) Early Carboniferous (Tournaisian) with very low brachiopod diversity: Protocanites scalabrinii-Azurduya chavelensis Zone (A. chavelensis, A. sp. nov., Chilenochonetes sp., and Pseudosyringothyrisl sp.); 2) Late Carboniferous (Namurian-Westphalian) with a typical "Levipustula fauna" (L. lev is, Kitakamithyris booralensis, K. immensa, Torynifer tigrensis, Spiriferellina octoplicata, Septosyringothyris keideli) appearing typically in association with glacial sequences; 3) Latest Carboniferous-earliest Permian with Micraphelia indianae, Tuberculatella peregrina, Aseptella aff. patriciae, Rhipidomellal sp. and Orbiculoidea sp; 4) Early Permian (Late Asselian) with brachiopods of the Tivertonia jachalensis-Streptorhynchus inaequiornatus Biozone (Tjachalensis, S. inaequiornatus, Coronalosia argentinensis, Tupelosia paganzoensis, Trigonotreta pericoensis, Septosyringothyris aff. jaguelensis and species of Orbiculoidea, Kochiproductus, Costatumulus and Crurithyrisl). Comparison is made by cluster analysis with Late Palaeozoic biogeographic units suggested by other authors for three intervals: Late Carboniferous, latest Carboniferous-earliest Permian and Early Permian. For the Late Carboniferous, the Precordillera has high affinity with the Austral Realm due to taxa of the Levipustula fauna in the Tepuel-Genoa Basin and eastern Australia. In other Southern Hemisphere Carboniferous localities, brachiopod diversity decreased from Early Carboniferous to Namurian, but Precordilleran Namurian brachiopod faunas are diverse compared with those from Tournaisian sequences; very low diversity of the latter may reflect a local high-stress environment. During the latest Carboniferousearliest Permian, the Precordillera lost affinity with the Austral Realm. This interval is characterized by a fauna with Tethyan and Boreal genera such as Micraphelia, Tuberculatella and Aseptella together with endemic forms. By Early Permian, probably latest Asselian, the Precordillera has highest affinity with the Austral Realm due to presence of the Gondwanan genera Tivertonia, Coronalosia, Trigonotreta and Costatumulus, characteristic of sequences in Australia and India, but the extra-Gondwanan genera Kochiproductus, Rhynchopora and Crurythyris link the Precordillera to the Tethyan and Boreal realms. The Precordillera underwent climatic amelioration after the Late Carboniferous glacial episode. Early Permian Precordilleran brachiopod assemblages have widely distributed cold-water Gondwanan genera together with subordinate genera such as Kochiproductus, Rhynchopora and Neochonetes suggesting a warmer influence. Viewed globally, diversity declined slightly from Early Carboniferous to Early Permian, but the Precordillera displays an increase in brachiopod diversity from Carboniferous to Permian, presumably connected with climatic changes associated with the glacial episodes and with palaeogeographic evolution of the SW Gondwana margin.

IPC2002 Oral Presentations THE BRAINCASE AND EAR REGION OF ICHTHYOSTEGA: A UNIQUELY SPECIALISED EAR IN AN EXCEPTIONALLY PRIMITIVE TETRAPOD BRAINCASE Jennifer A. CLACK1, Per Erik AHLBERG2, Richard A. KETCHAM3 & Patricio Dominguez ALONSO2 University Museum of Zoology, Downing St., Cambridge CB2 3EJ UK; 2Dept. of Palaeontology, Natural History Museum, Cromwell Road, London, SW7 5BD, UK; department of Geological Sciences, CI 110, University of Texas, Austin, TX 78712-1101, USA. The braincase and ear region of Ichthyostega have long defied anatomical interpretation. With the aid of new material, fresh surface preparation and CT scanning, it has been possible to produce a reconstruction of what is now seen to be a highly autapomorphic otic structure suggesting specialisation as an underwater hearing organ. Nevertheless the braincase shows some features more primitive than those seen in any other known stem tetrapod. The otoccipital region of Ichthyostega is unusually long for a stem-group tetrapod, but rather than resembling tetrapodomorph fish, it has a highly unusual configuration. The inner ears, represented in the CT scans by clearly visible sacculus chambers, are remarkably small and anterior in position, occupying approximately the anterior third of the otoccipital region. The posterior part of the braincase housing the hindbrain is unusually elongated, and the metotic fissure curves obliquely backwards and then downwards. Early tetrapods generally have smaller inner ears than similarly sized sarcopterygian fishes, but the combination of a tiny ear and long hindbrain in Ichthyostega is unique. The otoccipital is also unusual in being very narrow in the centre, with large posterior flanges suturing to the skull roof. Ichthyostega also differs from other early tetrapods in having a vestibular fontanelle that is not confluent with the fenestra vestibuli; this may be a primitive trait, as sarcopterygian fishes have a vestibular fontanelle that is separated from the hyomandibular articulations on the braincase wall. Semicircular canal grooves have not been certainly identified in Ichthyostega, due to the limited resolution of the CT scans and the poor internal ossification of the otic capsules. On either side of the otoccipital braincase block a large chamber is developed, defined by the transverse prootic flange anteriorly, the epipterygoid laterally, the skull roof dorsally, and by the transverse opisthotic flange and downwardly projecting tabular flange posteriorly. Mesially, the chamber extends above the otic capsules almost to the midline. This chamber, with its reinforced walls, is unique to Ichthyostega, and radically different from the narrow, undifferentiated margin of the skull table that forms the corresponding region in other early tetrapods. The position of the 'otic' (or spiracular) notch is also different, being posterolateral in Ichthyostega but dorsal in other Devonian tetrapods. The stapes appears to be double headed (the two heads just meet but do not appear to form a true footplate), with a large stapedial foramen separating them. The ventral 'head' contacts the basioccipital at a small facet, while the dorsal 'head' inserts into a hole in the braincase wall close to the saccular chamber, by definition a fenestra vestibuli, though it is unlike that of any other tetrapod. The stapes itself is unlike any other known tetrapod stapes or any fish hyomandibula. Its 'shaft' is a very thin, almost circular, anterodorsally curved lamina of bone, projecting dorsolaterally into the aforementioned chamber alongside the braincase. The anterior margin of the stapes approaches very close to the transverse prootic flange. Because of its position and relationship to the stapes and 'otic' notch, we interpret the chamber as housing a dorsal diverticulum of the spiracular tract (or 'middle ear'). If filled with air and sealed (or sealable) from the surroundings, it could have acted as a transducer for water-borne sound pressure waves by transmitting them to the stapes if the latter were incorporated into a ventral, soft tissue wall to the chamber. This would be functionally comparable to the way the middle ear functions in underwater sound reception in Xenopus and to the swimbladder-plus-Weberian-ossicles transducer of ostariophysian teleosts. The specialised nature of the ear of Ichthyostega, apparently adapted for aquatic hearing, may provide clues to the origin of the tetrapod auditory system and help us to understand the functional morphology of other stem tetrapod ears. We can no longer assume that the transformation of the fish spiracular region into the tetrapod ear involved a direct transition to aerial hearing.

EDIACARAN EPIFAUNAL TIERING Matthew E. CLAPHAM and Guv M. NARBONNE Department of Geological Sciences and Geological Engineering, Queen's University, Kingston, Ontario K7L 3N6, Canada [narbonne@geol.queensu.ca] Epifaunal tiering, the subdivision of vertical space within a community, is a fundamental attribute of Phanerozoic suspension-feeding communities. This paper documents tiering, including the presence of meter-tall organisms, in Neoproterozoic Ediacaran communities.

IPC2002 Oral Presentations Ediacaran tiering was studied from three exceptionally preserved deep-water communities at Mistaken Point, Newfoundland, which contain in situ census populations of hundreds to thousands of organisms. Tiering consists of overlapping populations of dominant organisms and is characterized by gradational, rather than abrupt, tier boundaries. At least three tiers are apparent: a lower level 0-8 cm above the seafloor, an intermediate level between 8-22 cm above the seafloor, and an upper level which extends as high as 120 cm. Tier boundaries are relatively consistent between communities, but the constituent organisms in each level are variable. Tiering structure appears to have been controlled by both constructional differences between taxa and chance factors such as age structure and order of colonization. Despite the common occurrence of tall organisms, all communities share a similar population structure in which biomass is concentrated in the basal 10 cm above the seafloor. Comparison with shallow-water Ediacaran assemblages suggests that this tiering structure is typical of Ediacaran communities. The affinities of the Ediacara biota are uncertain, but it is worth noting that the tiering structure in Ediacaran communities is strikingly similar to that of Phanerozoic suspension-feeding animal communities. Ediacaran tierers also show the fundamental subdivision of Phanerozoic tierers between organisms/colonies that fed along their entire length and those that developed a specialized feeding apparatus. Although there are no taxa in common between Mistaken Point communities and Phanerozoic skeletal assemblages, the presence of many key properties of tiered Phanerozoic epifaunal ecosystems — such as approximate tier boundaries, maximum organism height, and dominance of low-level organisms — in these Ediacaran communities implies that the features of Phanerozoic tiered skeletal ecosystems were first initiated in soft-bodied communities in the late Neoproterozoic. PALYNOLOGICAL EVIDENCE CONCERNING THE RELATIVE POSITIONS OF NORTHERN GONDWANA AND SOUTHERN LAURUSSIA IN THE MISSISSIPPIAN Geoff CLAYTON Department of Geology, Trinity College, Dublin 2, Ireland; [gclayton@tcd. ie]. The cosmopolitan nature of latest Devonian and earliest Mississippian (Lower Carboniferous) miospore assemblages accounts for their considerable value for inter-continental correlation but also severely limits their potential for large scale palaeogeographic studies. However, later in Mississippian time (late Tournaisian and Visean), at least four distinct floral provinces evolved, each characterised by distinctive miospore associations. The northern Gondwanan 'Aratrisporites saharaensis Microflora can be readily recognised from Brazil, through most of North Africa to the Arabian Peninsula, whereas the southern Laurussian 'Grandispora Microflora' is equally well documented from the Midwest USA, eastern Canada and western Europe. Basic statistical analysis of miospore records from selected areas has substantiated past, more intuitive interpretations, and has also led to the identification of a small association of taxa typical of the northern Gondwanan margin in North Africa and the Middle East. Mississippian miospore assemblages have recently been described from northern Morocco, the southeast USA and southwest Portugal, all of which have been problematic in terms of their palaeogeographic setting. In all three cases, the composition of their assemblages strongly suggests Laurussian affinities. 1

A NEW SPECIES OF POWICHTHYS (DIPNOMORPHA, SARCOPTERYGII) FROM THE LOWER DEVONIAN OF SPITSBERGEN Gael CLEMENT Laboratoire de Paleontologie, Museum national d'Histoire naturelle, 8 Rue Bujfon, 75005 Paris The Powichthyidae (Dipnomorpha, Sarcopterygii) were hitherto known by only one species, Powichthys thorsteinssoni, from the Lochkovian-Pragian of Arctic Canada (Jessen, 1975, 1980). According to Cloutier and Ahlberg (1996), Powichthys is considered as the sister-group of all others Dipnoiformes: {Powichthys (Youngolepis (Diabolepis (Dipnoans)). New material from the Pragian of Spitsbergen provides new data on the anatomy of the skull, the dermal elements of the buccal roof, the postorbital, and scales of this taxon. The structure of the skull is congruent with Jessen's description, although the junction between the supraorbital and infraorbital sensory canals is lacking. A strong, dorsally concave, internal process of the lacrimal, running from the posterior part of the posterior nostril towards the anterior margin of the orbit, is strikingly reminiscent of the naso-lacrimal canal of the tetrapods. The exceptional preservation of the dermal elements of the buccal roof shows that the supposed choana is in fact absent in the Powichthyidae [as in the Porolepiformes (Clement, 2001)] and that large palatine dental plates covering the buccal roof are likely to

IPC2002 Oral Presentations correlate with a strong crushing palatal bite, as in lungfishes. The postorbital, previously unknown, presents a unusual shape for a Dipnomorpha. The scales of this new specimen show a very strong, anteroventral process, that is unknown in any others osteichthyans. Although five of the seven oldest known sarcopterygians (Late Silurian and Lochkovian-Pragian) come from South China (Achoania, Psarolepis, Diabolepis, Youngolepis) and North Vietnam (Youngolepis, Langdenia), the occurrence of Powichthys in Arctic Canada and Spitsbergen challenges the hypothesis that the South China Block may be the centre of origin of the Sarcopterygii (Zhu et al., 2001). CLEMENT, G. 2001. Evidence for lack of choanae in the Porolepiformes. Journal of Vertebrate Paleontology, 21(4): 795-802. CLOUTIER, R. and AHLBERG, P. E. 1996. Morphology, characters, and the interrelationships of the basal sarcopterygians. In: M. L. J. Stiassny, L. Parenti et G. D. Johnson (eds), Interrelationships of Fishes II, Academic Press, New York, pp. 445-479. JESSEN, H. L. 1975. A new choanate fish, Powichthys thorsteinssoni n.g., n.sp., from the Early Lower Devonian of the Canadian Arctic Archipelago. In: J.-P. Lehman (ed.), Problemes actuels de Paleontologie: evolution des Vertebres. Colloques Internationaux du Centre National de la Recherche Scientifique, Paris, 218: 213-222. JESSEN, H. L. 1980. Lower Devonian Porolepiformes from the Canadian Arctic with special reference to Powichthys thorsteinssoni Jessen. Palaeontographica, 167: 180-214. ZHU, M., YU, X., and AHLBERG, P. E. 2001. A primitive sarcopterygian fish with an eyestalk. Nature, 410: 81-84.

NEW DATA AND NEW TREES: EARLY TETRAPOD RELATIONSHIPS REVISITED Michael I. COATES and Marcello RUTA The Department of Organismal Biology and Anatomy, The University of Chicago, 1027 East 57th Street, Chicago, Illinois 60637-1508, USA [mcoates@midway.uchicago.edu; mruta@midway.uchicago.edu]. In an attempt to investigate differences between the most widely discussed hypotheses of early tetrapod relationships, we assembled a data-base incorporating character sets from several recently published analyses. However, this has not been a purely literature-based exercise. We have incorporated original observations of numerous taxa spread throughout the major clades, as well as data from our own descriptions of Acanthostega, Tulerpeton and Caerorhachis. The complete data set includes 90 taxa coded for 319 cranial and postcranial characters. The analysis of these yielded a set of 64 equally parsimonious trees. Major differences between these trees concern the internal relationships of embolomeres and ai'stopods; and the branching pattern of the most derived of the diplocaulid nectrideans. The data set was subjected to a series of alternative treatments, including removal of lower jaw data, removal of postcranial data, and character reweighting. To test the coherence of fossil species or genera known from dissociated remains, we investigated the effect of coding fragments attributed to single taxa as separate operational taxonomic units. The overwhelming signal from the entire data set is of a deep split within early tetrapod phylogeny, dividing amniote and lissamphibian lineages. Nevertheless, a series of limbed (rather than finned) early tetrapods remain attached to the tetrapod stem. These include colosteids, Crassigyrinus, Whatcheeria and baphetids (listed in order of proximity to the crowngroup). The crowngroup base is bracketed by a pair of Scottish taxa known for their debated affinities and mixture of features otherwise regarded as unique to separate clades. Eucritta is the most basal stem-lissamphibian, and Caerorhachis is the most basal stem-amniote. In summary, important features of the branching sequence are as follows. (Crown-lissamphibians + albanerpetontids) is sister-group to a clade including amphibamids, micromelerpetontids and branchiosaurids. (Westlothiana + Lepospondyli) is sister-group to (diadectomorphs + crown-amniotes). Seymouriamorphs, Solenodonsaurus, gephyrostegids and embolomeres are progressively more basal stem-amniotes. Tuditanomorph and microbrachomorph microsaurs are successively closer to a clade including lysorophids, adelospondyls, nectrideans and ai'stopods. Lepospondyls are monophyletic, but the support for this node is weak. The placement of microsaurs on the amniote stem persists even when postcranial data are omitted from analysis. However, the relationships of remaining lepospondyls change significantly under these conditions: they are relocated as stem-group tetrapods, as sister-group to colosteids. This arrangement is not a significantly worse fit for the data than the tree topology obtained from the analysis of the entire data set. Elsewhere on the tree, it is noteworthy that the pattern of sister-group relationships in the crownward part of the temnospondyl branch re-emphasizes the importance of dissorophoids in the debate about lissamphibian origin. The evolutionary implications of these new results have yet to be explored in depth. Initially recognised patterns include the morphological conservatism of stem-lissamphibians relative to the diversity of stemamniotes, and an apparently coherent series of internested character-state changes related to the acquisition of terrestrial habits in several Permo-Carboniferous forms. The origin of crown-tetrapods is placed minimally within the Holkerian (-345 Ma), and falls somewhat short of the age postulated by certain recent molecular studies (360 ± 14.7 Ma). However, minimum divergence estimates for crown-amniotes and crownlissamphibians are in broad agreement with those predicted by molecular analyses. Given the patchy record of Palaeozoic tetrapods, morphology-based estimates of the chronology of major cladogenetic events will

IPC2002 Oral Presentations always remain heavily influenced by taxon samples from few, crucial fossil sites (e.g. East Kirkton). We suggest that this effect is also likely to deliver spurious patterns of biogeographical origin. Although our tree points to the midland valley of Scotland as the cradle of modern tetrapod evolution, we argue that this tells us more about the historical impact of characters such as Thomas Stock and Stan Wood.

THE SEARCH FOR A QUANTITATIVE BIOGEOGRAPHIC ANALYTICAL TECHNIQUE: A PROGRESS REPORT Peter COCKLE Centre for Ecostratigraphy & Paleobiology, Dept.ofEarth and Planetary Sciences, Macquarie University, Sydney, N.S.W. 2109 Australia [pcockle@laurel.ocs.mq.edu.au] An exhaustive brachiopod faunal database (Talent et al., 2001) is now available for modelling the changing similarity-dissimilarity patterns between crustal blocks for the mid Palaeozoic. The pattern of these blocks is now fairly well established for this time period Proposed methods for the analysis of the data were first applied to recent faunal distributions of brachiopods, echinoderms and crinoids where the relationships between their localities is known (localities were based on molluscan provinces of Valentine, 1973). The data set for this analysis was taken from Talent (1985). This data was used to test the reliability of different similarity indices. These included the method of Raup and Crick (1979) plus a range of similarity indices; Jaccard, Simpson, Dice and Legendre and Legendre's (1998) asymmetrical binary coefficient S9. To determine the effectiveness of these indices in predicting relationships between faunas the similarity indices were plotted against the separation distances of the various provinces. The index which gave the best fit to the modern data, i.e. the Jaccard Index, was used to analyse a sample Emsian brachiopod data set (Valentine, 2000) and the resulting separation distances compared to those given by a reconstruction by Scotese (Eldridge et. al., 1996) for the same period. The FOREL/KRAB software package was evaluated using the recent brachiopod data set and agreed closely with the actual relationships between the faunal provinces used for the constuction of the data set. The software also provided the ability to construct new faunal provinces based on the brachiopod distribution data. The Emsian data of Valentine (2000) was also analysed and the results compared favourably with those obtained Jaccard Similarity Index/Separtion Distance technique. Work is continuing using this FOREL/KRAB method to analyse the Palaeozoic brachiopod data and to compared the derived relationships with exiting reconstructions for the various time periods involved. ELDRIDGE, J., WALSH, C. and SCOTESE, C. 1996. Plate tracker for Windows, Version 1.0. LEGENDRE, P. and LEGENDRE, L. 1998. Numerical ecology: second English edition. Elsevier. Amsterdam. 853pp. RAUP, D.M. and CRICK, R.E. 1979. Measurement of faunal similarity in paleontology. Journal of Paleontology 53: 1212-1227. TALENT, J.A. 1985. Provintsialism i raskhozhgenie kontinental'nykh blokov v proshlom (Provinciality as a means for qualified resolution of separation of continental blocks in the past: Preliminary exemplification from western Pacific borderlands. In K.V. Simakov (ed.) Ekostratigrafiya, paleobiogeografiya i stratigraficheskie granitsy [Symposium papers XIV Pacific Sci. Cong., 1979]. Akademia Nauk, Magadan: 54-90 TALENT, J.A., GRATSIANOVA, R.T. and YOLKIN, E.A. 2002. Latest Silurian (Pridoli) to Middle Devonian (Givetian) of the AsioAustralia Hemisphere: Rationalization of brachiopod taxa and faunal lists; stratigraphic correlation chart. Courier Forschungsinstitut Senckenberg, 236. 1-221.

VALENTINE, J. 2000. Taxonomy and biogeographical relationships of silicified Emsian brachiopods from the Murrindal Limestone, Buchan, Victoria. Unpublished Honours Thesis. Macquarie University, Sydney. VALENTINE, J. W. 1973. Evolutionary paleoecology of the marine biosphere. Prentice-Hall, New Jersey. 472pp. YOLKIN, E . A . , YOLKINA, V . N . , TALENT , J.A., GRATSIANOVA, R.T., KIPRIYANOVA, T.P. & KIPRIYANOVA, Jr., A . A . , 2 0 0 0 . B r a c h i o p o d

biogeography of the Asia-Australia hemisphere during Pragian (Early Devonian) times. Records of the Western Australian Museum 58.

THE SUCCESSION OF ANIMAL COMMUNITIES PRESERVED IN THE GREATER PHYLLOPOD BED, MIDDLE CAMBRIAN BURGESS SHALE, BRITISH COLUMBIA, CANADA Desmond COLLINS Department of Paleobiology, Royal Ontario Museum, Toronto, Ontario, Canada M5S 2C6 Some 50 rock layers bearing significant numbers of soft-bodied fossils were excavated through 5 metres of shale below Walcott's Phyllopod Bed quarry on Fossil Ridge, British Columbia, between 1994 and 2000. The fossil assemblages collected are believed to accurately reflect the succession of animal communities

IPC2002 Oral Presentations living on the seafloor, seaward of the edge of the continental platform of Laurentia, some 505 million years ago. The fossil assemblages present a picture of one animal community, dominated by arthropods, especially Marrella, Burgessia, Waptia and Yohoia, appearing again and again through the 7 metre thick Greater Phyllopod Bed (= Walcott's 2 metre thick Phyllopod Bed added to the 5 metres excavated). In the basal 2.5 metres, this assemblage is intermittently replaced by assemblages dominated by polychaetes, Odontogriphus of unknown affinity, Canadaspis/Wiwaxia, the sea-cucumber Eldonia, and Odontogriphus again, respectively. The top 4 metres are dominated almost wholly by the typical Marrella, Burgessia, Waptia, Yohoia assemblage, with minor incursions of Eldonia. It is evident that animal communities on the seafloor half a billion years ago were just as dynamic and ephemeral as those on the seafloor today. OPTIMISED BIOSTRATIGRAPHY AND ITS APPLICATIONS IN BASIN ANALYSIS, TIMESCALE DEVELOPMENT AND MACROEVOLUTION R.A. COOPER & P.M. SADLER Inst. of Geological and Nuclear Sciences, PO Box 30368 Lower Hutt, NZ. [r. cooper@gns. cri. nz]; Dept of Earth Sciences, University of California Riverside, Riverside, CA92521 USA [sadler@mail.ucr.edu] 1

The stratigraphic range of species in measured sections provides the basic data for biostratigraphy. Biostratigraphic data sets thus contain much information, particularly the first and last appearance events (FA, LA) for all species, that potentially can be used for correlation and subdivision of stratigraphic successions. Yet, because of the contradictory nature of most data sets, the range of possible solutions to a correlation exercise is astronomically large. We refer to this as the 'correlation problem . Biostratigraphers generally get around this problem by relying on 'zonal indicator' species or 'key' species to control their correlation schemes, which are structured within a zonal (or stage) framework. They thus ignore a large proportion of the information that potentially can be used. Computer-assisted optimising procedures are increasingly being employed to capture this unused information. Because of the size of the task, an exhaustive search for the best solution to the 'correlation problem' is generally not practical. For example, there are more than 7 million ways of arranging the FA and LA events of just six species in two sections. For 40 species, the number exceeds 10 °. Instead, a searching algorithm can be used to find a very good solution. The constrained optimisation (CONOP) method proceeds in two stages. In the first, the number of possible solutions is constrained to those which honour the observed co-existence of species in single sections. In the second stage, a best-fit rank order of events is derived by trial and error by extending the stratigraphic ranges of individual species in individual sections as necessary to achieve a common order of events among the full set of sections. The best solution is that with the smallest net extension of species' ranges. If the extensions \ are measured by number of event levels rather than J number of metres, the influence of variable f T [GRAPTOLITE SPECIES STANDING DIVERSITY depositional rate is avoided. The CONOP method so has useful applications in basin analysis, timescale development and macroevolution. A CONOP-derived correlation of 8 well sections in the Taranaki Basin, New Zealand, I f j JJJ f yielded an order of magnitude improvement in ! i Hr /l| P I precision in correlation, comparable with that of \mn ff r y j seismic correlation. The CONOP composite A f' f vj jfl sequence of events, when calibrated against the 10 . I,' / A TIME ^SERIES OF2272 DIVERSITY V> v^ ..W • I J TR •I I I • timescale, provides a finely divided, basin-wide pi ESTIMATES BASED ON ISE STRATIGRAPHY IFLFYLI timescale that enables the depositional rate of well — 1,ffl sections to be charted with a precision not OBDQWCMfitZ—1—WUffiMILZ— achievable by any other method. Several widespread unconformities or condensed intervals were detected that were not previously apparent in seismic and biostratigraphic analyses. The time-calibrated CONOP composite of 200 deep-water Ordovician and Silurian graptolitic shale sections, containing 1100 species, provides a relative timescale with 2272 event levels that are spaced proportionally to their spacing in time. Radiometric zircon dates are automatically interpolated according to their associated graptolites or conodonts and provide firstly, a test of the linearity of the scale and secondly, a calibration for the scale. The result is a scale that combines the precision obtainable from high resolution biostratigraphy with the accuracy obtained from isotopic dating. 1

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IPC2002 Oral Presentations Measures of species diversity change through time generally scale time in discrete biozones or stages and are therefore open to 'time interval bias'. The CONOP graptolite analysis above provides a running diversity curve fixed at 2272 levels, a close approach to an interval-free, standing diversity curve through time (see figure).

A PLASTIC BOOMERANG: "REVERSE EVOLUTION" AND PROLONGED PHENOTYPIC PLASTICITY IN LATE ALBIAN A CTINOCERAMUS (EARLY CRETACEOUS BIVALVIA, INOCERAMIDAE) James S. CRAMPTON1 & Andy S. GALE2 institute of Geological & Nuclear Sciences, P.O. Box 30368, Lower Hutt, New Zealand [j.crampton@gns.cri.nz]; 2 School of Earth Sciences, University of Greenwich, Medway Towns Campus, Pembroke, Chatham Maritime, Kent ME4 4AW, UK [asg@nhm.ac.uk]. The cosmopolitan, Early Cretaceous inoceramid bivalve lineage that includes Actinoceramus sulcatus represents a remarkable example of apparent "microevolution". During the Albian, the lineage reveals a conspicuous, short-term excursion through morphospace, followed by a near-return to the ancestral form. Collections at all levels display a surprising level of morphological variability. The A. sulcatus lineage arose by cladogenesis from A. concentricus at about the middle/late Albian boundary (c. 102 Ma). Ancestral A. concentricus is weakly sculptured, bearing only low-amplitude, irregular commarginal folds. Actinoceramus sulcatus, in contrast, is affected by between 1 and c. 12 large, upstanding, high-amplitude radial or oblique folds ("radial elements"). Radial elements first appeared in the lineage over a short interval of time; this interval is marked by a high proportion of "subsulcate" forms intermediate between A. concentricus and A. sulcatus. Intermediates have one or more radial elements restricted to the juvenile, or adult, and/or posterior, or anterior parts of the shell. Subsequently, strongly sculptured forms, with about 6 to 8 radial elements on the adult shell, dominated assemblages for less than 1.6 Ma. During this interval, there was a progressive increase in the number of radial elements but subsulcate forms, with relatively few elements, persisted in low abundance. In the middle late Albian, strongly sulcate forms were replaced by shells with a single, weakly developed radial element. During this transition, assemblages were dominated briefly by subsulcate individuals with radial elements restricted to the anterior part of the adult shell, although other subsulcate forms were present also. Ancestral A. concentricus and descendant, weakly sculptured A. sulcatus are virtually identical, although they can be distinguished statistically on the basis of differences in outline shape. We infer that the initial, rapid evolution of radial elements at a cladogenetic event may have been linked to late Early Cretaceous oceanographic changes manifested in Oceanic Anoxic Subevent lc. The evolutionary development of radial elements apparently exploited pre-existing morphogenetic machinery and conferred some poorly understood selective advantage on post-larval individuals. Apparently sustained selection resulted in the progressive, gradual increase in the mean number of radial elements through the early late Albian. Subsequent evolutionary loss of numerous radial elements was not an exact mirror of their evolutionary acquisition and was relatively rapid, though far from "instantaneous". We argue that the initial acquisition, gradual increase in number, and subsequent loss of radial elements within the lineage are the phenotypic expressions of genetic evolution at varying rates. In contrast, the remarkable morphological variability within A. sulcatus populations, at all stratigraphic levels, is inferred to have resulted from environmentally induced phenotypic plasticity. This is evidenced by the changing relative proportions of different subsulcate morphotypes and shifts in the mean morphology within an otherwise unchanging total morphospace distribution. In other words, the potential to produce radial elements was an evolutionary innovation, the expression of those elements in any individual was determined by environmental cues. Phenotypic plasticity was itself probably an evolutionary response favoured by the presence of long-lived and widely dispersed planktotrophic larvae: plastic responses to environmental cues maximised phenotypic adaptability in the population whilst minimising physiological costs to the individual.

MACROFOSSIL ASSOCIATIONS FROM THE LOWER-MIDDLE PLEISTOCENE OF THE LUCANIA BASIN (SOUTHERN ITALY) AS A RESPONSE TO SEA-LEVEL FLUCTUATIONS Assunta D'ALESSANDRO, Rafael LA PERNA & Neri CIARANFI Dipartimento di Geologia e Geofisica, Universita di Bari, Via Orabona 4, 70125 Italy [tina@geo.uniba.it].

IPC2002 Oral Presentations The Lucania Basin is part of the Southern Italy Foredeep whose internal border during the Lower Pleistocene underwent almost continuous subsidence allowing accumulation of over 500 m of muddy deposits. From Middle Pleistocene an overall shallowing took place starting from more internal sectors of the basin. The marine succession cropping out in the badland area of Montalbano Jonico (Lucania, southern Italy) displays a general regressive trend from upper slope to inner shelf deposition, documented by fossil assemblages, which also clearly point to cyclic environmental changes. The studied succession is referred to the Lower Pleistocene "small" Gephyrocapsa Biozone and the Middle Pleistocene Pseudoemiliania lacunosa Biozone, providing a reference for selection of the Lower/Middle Pleistocene boundary stratotype (Ciaranfi et al., 1997; Maiorano et al., in press). An outcrop gap of variable thickness divides the succession into two intervals, the lower (interval A) represented by about 180 m of muddy bathyal deposits, the upper (interval B) of muddy to sandy shelf deposits with a minimum depth of 10-20 m near the top. The ecostratigraphic approach based on uniformitarian palaeoecologic analysis of the invertebrate macrofauna was particularly powerful in reconstructing environmental evolution. Palaeoecologic analyses combined with ichnologic and taphonomic observations, enabled inference of biotic responses to sea-level fluctuations. Associations from the bathyal sediments consisting mainly of molluscan communities, (recording depths of c. 500-200 m) dispersed with low to very low disarticulation degree. Many obrution episodes are indicated by well preserved complete crabs and echinoid tests with still articulated spines. Pyrite is frequent as steinkerns in small fossils and as shell cavity linings, indicating presence of organic matter inside skeletons at the time of burial. Palaeoecologic, taphonomic and ichnologic features all point to a background environment with low-to-moderate sedimentation rate, low energy and low oxygen content in the interstitial waters, affected by frequent mass deposition events. Associations from interval B range from bathyal-circalittoral transition to infralittoral, e.g. broadly from shelf break to inner shelf. Macrofaunas are mainly dispersed, but several shell concentrations—biologic, sedimentologic and mixed origin—occur. Disarticulation and fragmentation ratios are generally low; obrution episodes are not rare. Palaeoecologic and taphonomic features all point to a background environment with low-to-moderate energy and sedimentation rate, good oxygen content, and frequent massdeposition events. Five sixth-order cyclothems (41 k.y. duration) were recognised in interval A in a major cycle of which only the regressive system tract crops out. The wide bathymetric range (about 200 m) inferred for the lowest three cyclothems suggests tectonic control enhancing the effects of climatic fluctuations. In contrast, the upper two cyclothems, covering a depth range of about 100 m, seem to have been controlled mostly by climate. Interval B includes at least six sixth- and fifth-order cyclothems. One of these exceeds 150 m; it is believed to have been partly technically controlled. Overall there is a good match between cyclothems inferred from benthic associations and the available oxygen isotope ice-volume curve, extending from stages 25 to 19. CIARANFI, N., D'ALESSANDRO, A. and MARINO, M., 1997. A candidate section for the Lower-Middle Pleistocene Boundary (Appennine Foredeep, South Italy), pp. 201-211. In Naiwen, W. and Remane, J. (eds), Proceeding 30*11 International. Geological Congress, 11. MAIORANO, P., MARINO, M., DI STEFANO, E. and CIARANFI, N., in press. Calcareous nannofossil events and calibration with oxygen isotope and sapropel stratigraphy in the Lower-Middle Pleistocene transition at Montalbano Jonico section (Southern Italy) and ODP Site 964 (Ionian Sea). Quaternary International.

NEW FOSSIL FOREST WALLABIES AND A TREE KANGAROO (MARSUPIALIA: MACROPODINAE) FROM THE EARLY PLIOCENE OF EASTERN AUSTRALIA: THEIR PHYLOGENETIC AND PALAEOECOLOGICAL SIGNIFICANCE. Lvndall DAWSON School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney 2052. This paper reports new plesiomorphic forest wallabies (described in a new genus, Silvaroo: Macropodinae) from the early/middle Pliocene deposits of Chinchilla, Queensland, which have affinity with poorly understood taxa from the Pliocene of Wellington Caves in New South Wales and Hamilton in Victoria. They also resemble taxa from the late Pliocene Awe fauna from New Guinea and the modern forest wallabies (.Dorcopsis and Dorcopsulus) of New Guinea. The fossil evidence accords with most recent DNAhybridization studies of modern macropodines, which suggest that the Dorcopsis wallabies represent relict 'stem' macropodines. The species of Silvaroo have their closest phenetic affinity with the only Miocene macropodine, Dorcopsoides fossilis. The Chinchilla material on which Silvaroo is based is more intact than most of the comparable fossils from the Pliocene, some of which have been previously described as species of the genus Protemnodon. These comparisons have led to a revision of the concept of Protemnodon, and

IPC2002 Oral Presentations enabled a clearer picture of its generic boundaries. They also illustrate retention of plesiomorphic macropodines well into the Pliocene of mainland Australia, along with extraordinarily rapid diversification in the family from the late Miocene or earliest Pliocene A new 'giant' tree kangaroo from Chinchilla is suggested to belong in the genus Bohra, which was originally erected for a giant tree kangaroo from the Pleistocene Wellington Caves deposits. Species of Dendrolagus (the genus of modern tree kangaroos) have also been recorded from the early Pliocene of southeastern Australia, so this new tree kangaroo also illustrates the rapid diversification of macropodines following the extinction of their Miocene predecessors. Modern forest wallabies and tree kangaroos are now confined to tropical areas of Papua New Guinea, with the exception of two species of tree kangaroo which occur only in the Cape York Peninsula region of north Queensland. This distribution no doubt reflects the relict status of rainforest in Australia. However, the presence of forest wallabies and tree kangaroos in the mid-Pliocene Cinchilla Local Fauna and other regions of southeastern Australia does not necessarily indicate rainforest conditions. Rather, it is consistent with previous suggestions that a mosiac vegetation and seasonal climate prevailed in eastern Australia at that time.

EARLY TO MIDDLE JURASSIC MIOSPORE ZONATION, NEW ZEALAND Noel J. DE JERSEY1 & J. Ian RAINE2 7 77 Michelle Drive, Cedar Grove, Queensland\ Australia [dejersey@overflow.net.au]; 2Institute of Geological & Nuclear Sciences, P.O. Box 30368 Lower Hutt, New Zealand [i.raine@gns.cri.nz]. Fossiliferous shallow marine sediments of the Murihiku Supergroup, correlated at a number of levels by ammonites and other marine fauna, provide an opportunity to correlate global subdivisions of the Triassic and Jurassic Systems with austral terrestrial miospore bioevents. A zonation of the Early and Middle Jurassic, based on miospore assemblages from the Auckland and Southland regional synclines, extends our previous Triassic zonation (de Jersey & Raine 1990). Broad similarities in the palynofloral successions of NZ and Queensland (eastern Australia) enable more precise dating of the latter than was previously possible. The Triassic-Jurassic boundary is marked by considerable floral turnover, corresponding to the transition between Assemblages II and III of Zhang & Grant-Mackie (2001). The most continuous boundary succession known is in Taylors Stream, Southland, where strata with early Hettangian ammonites (Stevens 1999) overlie Rhaetian beds. Features include a decline in abundance of Densoisporites psilatus\ first appearance of Retitriletes austroclavatidites, R. semimuris, and Zebrasporites inters crip tus', and (a little higher) the first common occurrence of Corollina cf. chateaunovi. Earliest Jurassic assemblages differ from those of Australia in being dominated by fern and bryophyte spores, rather than Corollina. At higher levels the palynofloras are more similar, with abundant conifer pollen (Araucariaceae etc.) - an important datum is the first appearance of Callialasporites dampieri in the early Ururoan Stage (Late Pliensbachian). GLOBAL OXFORDIAN

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IPC2002 Oral Presentations

DE JERSEY, N.J. & RAINE, J.I., 1990. Triassic and earliest Jurassic miospores from the Murihiku Supergroup, New Zealand. New Zealand Geological Survey paleontological bulletin 62. 164 p. STEVENS, G.R., 1999. The Aratauran (Lower Jurassic) ammonite succession in New Zealand. Geological Society of New Zealand miscellaneous publication 107A, 151. ZHANG, W. & GRANT-MACKIE, J. A., 2001. Late Triassic-Early Jurassic palynofloral assemblages from Murihiku strata of New Zealand, and comparisons with China. Journal of the Royal Society of New Zealand 31, 575-683.

SEQUENCE OF THE LATE CENOZOIC MAMMALIAN FAUNAS FROM THE LINXIA BASIN IN GANSU, CHINA DENG Tao, QIU Zhanxiang, WANG Banyue, NI Xijun and WANG Xiaoming Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, China The Linxia Basin is located in northeastern margin of the Tibetan Plateau. In this basin, the Late Cenozoic deposits are well developed, and many mammalian localities with very rich fossils from the Late Oligocene to the Early Pleistocene have been discovered. The Late Oligocene: Tsaganomys sp., Allacerops sp., Indricotherium sp., Schizotherium sp., Paraentelodon sp. from one locality. The Early Miocene: Gomphotherium sp., Dzungariotherium orgosense, Rhinocerotidae gen. et sp. indet., Paraentelodon macrognathus from one locality. The early Middle Miocene: Carnivora, Choerolophodon sp., Gomphotherium sp., Acerorhinus sp., Kubanochoerus sp. from one locality. The late Middle Miocene: Amphicyon sp., Hemicyon sp., Zygolophodon sp., Platybelodon sp., Gomphotherium sp., Anchitherium sp., Alicornops sp., Hispanotherium matritense, Kubanochoerus sp., Listriodon sp., Paleotragus sp. from three localities. The early Late Miocene: Dinocrocuta sp., Machairodus palanderi, Tetralophodon sp., Hipparion dongxiangense, Parelasmotherium linxiaense, P. simplum, Ninxiatherium sp. nov., Shaanxispira sp. from three localities. The middle-late Late Miocene: Prosiphneus sp., Pararhizomys sp., Hystrix sp. nov., Simocyon sp., Pleisiogula sp., Parataxidea sp., Melodon sp., Meles sp., Promephitis sp., Ictitherium sp., Hyaenictitherium sp., Thalassictis sp., Dinocrocuta sp., Adcrocuta sp., Machairodus palanderi, Metailurus major, M. minor, Felis sp., Tetralophodon sp., Zygolophodon sp., Acerorhinus hezhengensis, Chilotherium wimani, Dicerorhinus sp., Iranotherium sp. nov., Hipparion dermatorhinum, H. chiai, H. weihoense, H. coelophyes, Chleuastochoerus sp., Microstonyx sp., Dicoryphochoerus medius, Muntiacus sp., Metacervulus sp., Cervavitus sp., Palaeotragus sp., Samotherium sp., Honanotherium sp., Protoryx sp., Sinotragus sp., Miotragocerus sp., Gazella sp., Shaanxispira sp., Hezhengia bohlini, Bovidae gen. et sp. nov. from thirty two localities. The Early Pliocene: Promephitis sp., Thalassictis sp., Chasmaporthetes sp., Proboscidea, Hipparion sp. nov., Cervavitus sp., Giraffidae gen. et sp. indet., Sinotragus sp. from one locality. The Early Pleistocene: Macaca sp., Procynocephalus sp., Sciuridae gen. et sp. nov., Vulpes sp., Canis cf. chihliensis, Sinicuon sp., Pannonictis cf. pachygnathus, Meles sp., Megantereon cf. nihowanense, Homotherium cf. nestianum, Lynx sp., Felis cf. paleosinensis, Sivapanthera sp., Pachycrocuta licenti, Chasmaporthetes sp., Nestoritherium sp., Coelodonta nihowanensis, Equus wangi, E. sp. nov., Pseudodama sp., Gazella sp., Leptobos sp. from two localities.

WHAT IS NEW IN THE MARINE PERMIAN OF EASTERN AUSTRALIA - IMPLICATIONS FOR AGE, EVENTS AND STRUCTURAL CHANGE IN THE PERMIAN ? J.M. DICKINS Innovative Geology, 14 Bent St., Turner, A.C.T., 2612, Australia. Description now nearing completion of gastropods and pelecypods (bivalves) from the oldest part of the Permian sequence in the Cranky Corner Basin of New South Wales shows major structural change, hiatus and unconformity between the Carboniferous and Permian in Eastern Australia. This is equivalent to the Hercynian Gap in other parts of the world and the end of the Hercynian (or Variscan) "Orogenic" Folding Phase.

IPC2002 Oral Presentations The fauna is regarded as most likely of Asselian age and is overlain by a Lower Sakmarian (Tastubian) fauna. Comparison and correlation of these faunas in Western and Eastern Australia and overlying faunas suggests that Upper Sakmarian (Sterlitamakian) marine faunas so prominent in Western Australia and in southern Asia, the southern Arabian Peninsula and South America may be largely or entirely missing in Eastern Australia. Beds of this age may be represented by a hiatus and in Tasmania by non-marine strata. This has significance not only for the marine beds but also for palynological correlations. Although overlooked in recent work, common elements from Eastern and Western Australia in the Lower Permian (twofold subdivision of the Permian) of the Queensland faunas allow correlation between the two areas and thus through Western Australia especially with other parts of the world. For the Upper Permian (twofold subdivision of the Permian) direct correlation of the Queensland faunas (and indirectly the faunas of New South Wales and Tasmania) is possible with other parts of the world. Because of differences in terrestrial climate in different parts of Australia during the Permian it is unlikely that that correlation based on plants will be as reliable as the marine faunas and so far radiometric dating leaves much to be desired. The correlations allow recognition of significant structural, tectonic and magmatic events especially at the end of Sakmarian and at the mid-Permian (base of Roadian, Kubergandian and "Upper" Ufimian Sheshminsk). The mid-Permian as recognized here corresponds to the beginning of the Hunter-Bo wen Orogeny in Australia and similar events in other parts of the world.

PALYNOLOGICAL ANALYSIS OF THE CODO FORMATION—LOWER CRETACEOUS OF THE PARNAIBA BASIN, NE BRAZIL. Rodolfo PINO1 & Luzia Antonioli2 ! Petrobras, Cenpes - BP A, Cid. Univ. Ilha do Fundao, 21949-900 Rio de Janeiro-Brazil and UERJ- Univ. do Estado do Rio de Janeiro 20550-013 Rio de Janeiro, Brazil; Petrobras, Cenpes - BP A, Cid. Univ. Ilha do Fundao, 21949-900 Rio de Janeiro-Brazil. One of the most important lithostratigraphic units of the Mesozoic rift sequence of the Parnaiba Basin, a vast sedimentary area of W-NE Brazil, is the Lower Cretaceous Codo Formation. The present study, based on palynostratigraphic and geochemical analyses of more than 200 samples from outcrop and eight cored wells, focuses on biostratigraphy and chronocorrelation of this unit. Total organic carbon (TOC) and total sulfur (TS) analyses delineate four chemostratigraphic intervals representing distinct palaeoenvironmental conditions, and also enable identification of the Aptian-Albian boundary global anoxic event. Systematic study of the palynoflora—dinoflagellate cysts, pollen grains, spores, fresh water algae, and fungi—and quantitative analysis of it demonstrates dominance of conifers of the Cheirolepidaceae and members of the Gnetaceae, with subordinate pteridophytes, primitive angiosperms, and dinoflagellate cysts. Qualitative results enable establishment of five informal palynozones, designated I to V in ascending order, correlated with palynozones in other North Gondwana late Aptian-early Albian sections The Aptian-Albian boundary in the Parnaiba Basin coincides with the extinction level of Sergipea variverrucata at the upper limit of palynozone IV. This accords with geochemical data indicating contemporaneity with the Early Cretaceous (transitional Aptian-Albian) global anoxic event.The bulk of palynozones I, II, III, and IV are dated as late Aptian; only the uppermost part of the formation (palynozone V) is regarded as early Albian. Palynological, sedimentological, geochemical, and tectonic evidence indicates fluvial-lacustrine environments for the lowest part of the formation, followed by increasing marine influence. The middle and upper parts of the formation indicate a restricted marine coastal setting with some fully marine incursions. The palaeoclimate is inferred to have been warm to hot, arid to semi-arid, with deposition in a relatively stable tectonic regime. Comparisons with approximately coeval palynofloras from elsewhere in northern Gondwana (particularly North Africa, Gabon, and Egypt) confirm alliance of the Codo palynofloral suite with the West AfricanSouth American (WASA) Province.

MOLLUSCAN AND FORAMINIFERAL ASSEMBLAGES: PALAEOECOLOGY AND QUANTITATIVE TAPHONOMY IN THE EARLY PLEISTOCENE SEDIMENTARY CYCLES OF WESTERN EMILIA, ITALY Stefano DOMINICI1, Simona STEFANELLI2 & Fabio MOLINARI3

IPC2002 Oral Presentations 1

Dipartimento di Scienze della Terra, via La Pira 4, Universita di Firenze, 50121 Firenze, ITALY; Dipartimento di Geologia e Geofisica, via Orabona 4, Universita di Bari, 70125 Bari, ITALY; sRegione Emilia-Romagna, Servizio Geologico, Sismico e Suoli, Viale Silvani 4/3, 40100 Bologna, ITALY 2

The lower Pleistocene shallow marine succession of western Emilia consists of meter to tens-of-meters thick sedimentary cycles. The deposition of the lower part, characterised by laminated fine sandstones, is thought to be controlled by the interplay of tectonic uplift and cold climates, resulting in increased sediment disposal, followed by episodic heavy rainfall or ice melt, resulting in the delivery of sands in the shallow shelf via flood-triggered hyperpycnal flows. The upper part of each cycle, characterised by bioturbated mudstones, was deposited during times of widespread forest cover of the nearby mountain fronts, under meteorological conditions similar to the present ones. This hypothesis is confirmed by the palaeoecological analysis of molluscan and foraminiferal assemblages present along the succession. Molluscs preserved in life position within the sandstone intervals and assemblages from the mudstone intervals indicate similar depth ranges (20-40m). Nearly-monospecific assemblages dominated by Arctica islandica from the sandstone interval are interpreted as diagnostic of dysaerobic conditions, while assemblages from the mudstone interval, with a more diverse fauna dominated by Venus multilamella, show normal aerobic conditions at the sediment-water interface. Palaeoecological data are better explained if a strong climatic imprinting on sedimentation is accepted, thereby suggesting that sealevel variation is not the main controlling factor of cyclicity (Dominici, 2001). Foraminiferal assemblages, showing overall similar compositions, similarly record slight, if any, depth change along each cycle. Those collected in the sandstone interval are characterised by higher proportions of miliolids, while assemblages from the mudstones bear Textularia and Valvulineria in higher abundance. Differences suggest that normal aerobic conditions prevailed during deposition of the sandstone interval, with the ecception of some anarobic events, while mudstone assemblages record occasional dysaerobic conditions, at least right below the sediment surface. The situation reminds cyclic oxygen level changes recorded in deeper settings of the palaeo-Adriatic, although levels fluctuated there in a more consistent way (Stefanelli, 2000). Taphonomy of the shell beds reveal that nearshore assemblages from the sandstone interval suffered some transport before final burial, many individuals while still alive, but no significant damage; anyway, they are often mixed with highly damaged bivalves eroded from preceding cycles and with black-stained bivalves from contemporaneous dysaerobic bottoms. No transport, nor reorientation or mixing is shown by bivalves from the mudstone interval, which were buried mostly in life position and preserved in a pristine state. A similar pattern is shown by foraminiferal taphonomic data, showing that assemblages from sandstone intervals are characterised by higher proportions of fresh tests and lower levels of dissolution. We hypothesize that evidences from both types of fossils can be explained through a change from episodic to continuous sedimentation passing from the lower to the upper part of each cycle. Differences of taphonomic signatures, which also occur and make it possible to differentiate patterns of hardpart preservation between the two groups, are a possible effect of taphonomic tiering (see Walker and Goldstein, 1999). Foraminiferal pyrite replacement is usually more consistent in assemblages from mudstone intervals with respect to those from the sandstone interval, while some pyrite coatings in mollsuks were detected in sandstone assemblages. Also breakage shows opposite patterns. Pyrite replacement in foraminifera depends on the initial shell structure and the access of iron and sulfate ions into shell, while only living mollsuks that get quickly buried under thick sandy beds are not allowed to the complete degradation of the organic matter under aerobic conditions, so that small pyrite coatings form on the internal surfaces. Foraminifera show higher alterations in mudstones possibly due to longer residence time in the TAZ, while high damage to bivalves is due to exposure on the seafloor before final burial. DOMINICI, S., 2001. Taphonomy and paleoecology of shallow marine macrofossil assemblages in a collisional setting (late Plioceneearly Pleistocene, western Emilia, Italy). Palaios 16, 336-353. STEFANELLI, S., 2000. Benthic foraminiferal assemblages in the paleoenvironmental reconstruction of the lower-middle Pleistocene Montalbano Jonico section. Unpublished Doctoral Thesis, Universita di Bari, Bari, 62. WALKER, S.E., and GOLDSTEIN, S.T., 1999. Taphonomic tiering: experimental field taphonomy of molluscs and foraminifera above and below the sediment-water interface. Palaeogeography, Palaeoclimatology, Palaeoecology 149, 227-244.

THE PHYLOGENETIC RELATIONSHIPS BETWEEN ACTINOLEPIDS ( PLACODERMI ARTHRODIRA) AND OTHER ARTHRODIRES (PHLYCTAENIIDS AND BRACHYTHORACIDS) Vincent DUPRET Laboratoire de Paleontologie, Museum National d'Histoirre Naturelle - UMR 8569 Museum -CNRS, 8 Rue Buffon, 75005 PARIS, France [dupret@mnhn.fr].

IPC2002 Oral Presentations In connection with the study (in progress) of some podolian and spitzbergen material, to investigate the interrelationships between Arthrodires (i.e. Actinolepids, Phlyctaeniids and Brachythoracids) and their neighbouring groups (e.g. Phyllolepids, Petalichthyids), a phylogeny of the Actinolepids is proposed. The most important taxon present in this analysis is the genus Kujdanowiaspis. This genus includes three main species: K. buczacziensis, K. podolica, and K. zychi, the last one probably erroneously attributed to this genus. The phylogeny of the best known Actinolepids and some Phlyctaeniids and Brachythoraci is exposed as a cladogram. Therefore, the problem of monophyly (Denison, 1978) vs. paraphyly (Denison, 1984) of the Actinolepids is investigated. Thus, the most closely relatives of Kujdanowiaspis are defined. A comparison with Johnson's et al. (2000) results is proposed. The main differences are due to discrepancies in used data: chosen outgroup , as well as the taxa sampling, are different. Moreover, the characters spectrum is enlarged. The relationships between Kujdanowiaspis, Heightingtonaspis and Eskimaspis is central to the analysis, because of both their phylogenetic neighbourhood and basal position. DENISON, R., 1978, Handbook of Paleoichthyology - Placodermi. Stuttgart, New York, 128 p. JOHNSON, H., ELLIOTT, D.K. and WLTTKE J.H., 2000, A new Actinolepid arthrodire (Class Placodermi) from the Lower Devonian Sevy Dolomite, East-Central Nevada, Zoological Journal of the Linean Society, 129, pp. 241-266.

UPPER DEVONIAN FORAMINIFERA AND CHAROPHYTA OF THE CANNING BASIN, NORTHWESTERN AUSTRALIA H. Stewart EDGELL Consultant, Canberra, A.C.T.2603, Australia. Distinctive Foraminifera occur in the Upper Devonian sequence of the northern Canning Basin. Those belonging to the Superfamily Endothyracea are useful stratigraphic indicators. The foraminiferal species mentioned here occur mainly in the Famennian Pillara Limestone and Piker Hills, Bugle Gap and Napier formations and the overlying Famennian -Tournaisian Fairfield Group. They have also been identified in the Meda No.l, Meda No.2, Hawkestone No. 1, and Langoora No.l wells. This study is based on the previously unrecorded results of the writer's 1963-64 examination of surface samples and cores when with the Geological Survey of Western Australia. Five microfossil assemblages recognized are: 1. Quasiendothyra Assemblage with primitive endothyroids, such as Quasiendothyra communis Rauser and Q. kobeitusana Rauser, both species being found in the Upper Famennian. Q. communis Rauser occurs in the upper Pillara Limestone, upper Bugle Gap Limestone and in the Piker Hills Formation. Q. kobeitusana Rauser is found at the base of the Piker Hills Formation equated with the uppermost goniatite zone of Wocklumeria to VI. Associated with this assemblage are frequent tournayellids, especially Septaglomospiranella primaeva (Rauser) and Septaglomospiranella primaeva graciosa Reitlinger, as well as Parathurammina spp. and Nodosinella cf. tatarstanica Antropov. 2. Septaglomispiranella Assemblage dominated by the species Septaglomospiranella primaeva (Rauser), (=Granulifera granulosa Zeller) and including Septaglomospiranella cf .crassa Reitlinger, Septabrunsiina sp. aff. krainica (Lipina), Septatournayella cf rauserae Lipina, Tournayella sp., Haplophragmella sp. and Rectaseptaglomospiranella sp., as well as occasional Umbella spp. This assemblage is undoubtedly high in the Upper Devonian occurring in Meda No. 2, Core 7 (6620-6629.5 ft.), which also contains the highest conodont zone of the Upper Devonian. In outcrops, it is found mainly in shallow water, fore-reef carbonates of the Napier Limestone, Bugle Gap Limestone, and Piker Hills Formation and rarely in the platform reef Pillara Limestone. 3. Spiroplectammina Assemblage characterized by Spiroplectammina cf tcheryshinensis Lipina in association with frequent Parathurammina spp., plus rare Chernyshinella cf. tumulosa Lipina and Tournayella sp. This assemblage occurs in fore-reef carbonates of the Piker Hills Formation, Napier Hills Limestone and Bugle Gap Limestone. Chernyshinella is typically Tounaisian in Russia but here ranges down into the Famennian. A.Nodosinella Assemblage predominantly with species of Nodosinella, particularly Nodosinella cf. tataristanica Antropov and occurring in fore-reef beds of the Napier Limestone, as well as in Hawkestone No. 1, Core 4 (1554-1557 ft.). Frequent Septaglomospiranella primaeva (Rauser) and Septabrunsiina sp. a f f . krainica (Lipina) are also found in this assemblage. 4. Umbella Assemblage. The genus Umbella, a charophyte previously referred to as the Foraminifera Umbellina, is strikingly abundant in certain Upper Devonian strata of the northern Canning Basin. Together with other Charophyta, such as Chovanella sp., Sycidium cf.foveatum Peck, Sycidium spp., and Trocholiscus spp., it frequently forms a distinctive microfossil assemblage in the platform reef facies of the Pillara

IPC2002 Oral Presentations Limestone. The main species of the Umbellaceae found are Umbella bella Maslov, Umbella saccaminiformis (E.Bykova), and more commonly Quasiumbella rotundata (E. Bykova). This assemblage indicates shallow water, brackish environment. Although Umbella bella Maslov extends from Middle-Upper Devonian, the more common Quasiumbella rotundata (E.Bykova) is typically Upper Devonian, as is also Umbella saccaminiformis (E.Bykova). These assemblages also comprise five descending microfossil zones with the Quasiendothyra Zone being the highest. Q. kobeitusana Rauser is generally considered Tournaisian in Russia and Kazakhstan, but occurs rarely in the uppermost Famennian. It is found in the Canning Basin together with Quasiendothyra communis Rauser , a species found elsewhere only in the uppermost part of Famennian strata. In addition, goniatite and conodont identifications from beds containing Q. communis Rauser prove a Late Famennian age (Upper Devonian to iv). Assemblages 2, 3, and 4 contain the species Septaglomospiranella primaeva (Rauser) known in the U.S.A. as Granulifera granulosa Zeller. This synonymous species is restricted to the Lower Kinderhookian or lowermost Mississippian, once considered Lower Tournaisian but now known to be uppermost Devonian. Septaglomospiranella primaeva (Rauser) occurs in the uppermost Famennian and rarely in the lowest Tournaisian. Nodosinella cf. tatarstanica Antropov is ftequent in samples correlated with the Cheiloceras to Platyclymenia zones of the Upper Devonian to II - to IV). The foraminiferal species, especially endthyroids, provide interregional correlation of the Canning Basin Upper Devonian.

TERRESTRIALIZATION IN THE SILURO-DEVONIAN - A TESTING TIME FOR BRYOPHYTES Dianne EDWARDS Dept. of Earth Sciences, Cardiff University, PO Box 914, Cardiff CF103YE, Wales For those interested in the colonization of the land by plants, Jane Gray's lasting legacy will be her pioneering work on Ordovician and Silurian obligate tetrads and her firm conviction that they derived from bryophyte-like plants which were thus the first embryophytes to grow on land. The latter has gained support from cladistical analyses based on both morphological and molecular data that show that bryophytes are the sister group to vascular plants. In this talk I propose to review the megafossil evidence for early bryophytes. I will concentrate on small fossils (mesofossils) from Silurian and Devonian rocks which contain obligate tetrads and dyads, and others which possess a diversity of conducting cells that cannot be attributed to tracheophytes. However, despite this progress in demonstrating some bryophyte characters in these early land plants, they cannot unequivocally be assigned to any extant group. This suggests that concepts of the nature of primitive bryophytes should be reappraised.

EXPERIMENTAL APPROACHES TO DETECTING THE EARLIEST WILD-FIRE Dianne EDWARDS Dept. of Earth Sciences, Cardiff University, PO Box 914, Cardiff, CF103YE, Wales The phenomenal cellular preservation in plant mesofossils from the basal Devonian has allowed the assessment of affinities of plants with extreme external simplicity plus interpretations of their reproductive biology and functioning of tissues. Homogenisation of cell walls suggests that the plants might have been burnt before burial, but reflectance values are inconclusive. Charring experiments of bryophytes and lower vascular plants have produced similar cellular features, and similar reflectance data on non-lignified tissues. Many of the mesofossils contain abundant pyrite, but the textures present and their distribution within cells are not typical of most ± coeval axial pyritised permineralisations. Experiments on the pyritisation of living plants, combined with investigations of textures in fossils and new insights into the chemistry of pyrite production have allowed the development of a model of plant pyritisation. The latter receives support from pyrite textures in Eocene and most Devonian plants but exceptionally not from the Lower Devonian mesofossils. This raises the possibility that pyritisation occurred after charcoalification - a hypothesis which is currently being tested by attempts to pyritise modern charcoal in the laboratory. Should the Lower Devonian mesofossils be charcoalified, this would be the earliest record of wild-fire.

IPC2002 Oral Presentations STRUCTURE OF CORAL COMMUNITIES BEFORE, DURING, AND AFTER THE LATEST ORDOVICIAN CRISIS IN LAURENTIA Robert J. ELIAS1 and Graham A. YOUNG1'2 department of Geological Sciences, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada; 2 Manitoba Museum of Man and Nature, 190 Rupert Avenue, Winnipeg, Manitoba R3B 0N2, Canada. The main Palaeozoic coral groups, Tabulata and Rugosa, diversified significantly during the Ordovician evolutionary radiation. The latest Ordovician mass extinction, however, resulted in a substantial reduction in diversity. This was followed by the Silurian recovery, when diversity rose above the pre-extinction level. Thus, events in the Late Ordovician and Early Silurian had a significant effect on the diversity and taxonomic composition of coral communities. Here, we examine changes in the structure of communities in Laurentia (North America) during this critical time interval. Typical Late Ordovician (Cincinnatian) coral faunas disappeared during an extinction event that coincided with the major end-Richmondian regression. Pre-extinction faunas belonged to the Red RiverStony Mountain and Richmond provinces. The Red River-Stony Mountain Province became established early in the Cincinnatian. It occupied a vast region of the epicontinental sea and stable continental shelf. Complex communities throughout the province involved tabulates as well as solitary and colonial rugosans, in cratonic and continental margin settings. There were specialized species, distinct species-associations, and fluctuations in the dominance of species. This type of community structure, with multiple associations of specialized taxa, accommodated and promoted high overall provincial diversity. The Richmond Province originated in Richmondian time, shortly before the major extinction event. This province coincided with a narrow platform along a margin of the epicontinental sea. Runoff from adjacent terrestrial areas probably elevated nutrient levels somewhat higher than in the Red River-Stony Mountain Province. As in the latter province, there were distinct species-associations and fluctuations in species dominance. Species were specialized to varying degrees. Unlike the Red River-Stony Mountain Province, however, two widespread solitary rugosan species spanned the spectrum of environments inhabited by corals. Both were highly variable morphologically. Their inherent plasticity apparently enabled them to occupy a wide range of conditions. This may have inhibited the introduction of more specialized taxa, thereby limiting diversification and contributing to low overall provincial diversity. The post-extinction Edgewood Province originated during the latest Ordovician (Gamachian), when global sea level was low during the glacial age. This province was situated in a small epicontinental sea. Fluctuating as well as elevated levels of nutrients and runoff from adjacent terrestrial areas likely contributed to overall environmental instability. The community structure was simple. Although corals inhabited a broad spectrum of environments and some species were specialized, there was just a single species-association. One extraordinarily variable solitary rugosan species was dominant throughout the range of environments, followed by two highly variable tabulates. Their dominance may have inhibited the appearance of a greater number of specialized taxa, thereby keeping diversity low. The lack of multiple species-associations would also have limited the potential for higher provincial diversity. In contrast to this simple community structure in the cratonic interior, various associations of specialized species are known from contemporary deposits on Anticosti Island, representing a stable continental-shelf setting along the open ocean. Within the cratonic interior, the Edgewood Province was succeeded by typical Early Silurian recovery faunas in the late Rhuddanian (early Llandovery). This occurred as the transgression associated with deglaciation increased the size of the epicontinental sea, which would have decreased the effects of nutrient input and runoff. Complex community structures involving tabulates as well as colonial and solitary rugosans reappeared. In the late Rhuddanian of Manitoulin Island, for example, there were distinct associations of specialized corals. Communities at the continental margin were also complex. During the middle to late Llandovery, several distinct coral associations coexisted within a shallow-shelf setting in New Brunswick and Gaspe Peninsula. Our examination of Late Ordovician to Early Silurian coral faunas reveals an anomalous community structure within the Laurentian cratonic interior during the latest Ordovician crisis. The simplicity of this community structure, and predominance of eurytopic opportunists, apparently limited overall diversity and hindered diversification. This may have been related to nutrient enrichment and associated environmental destabilization within the small epicontinental sea during the global sea-level lowstand.

CHARACTERIZATION OF SHALLOW MARINE COMMUNITIES FROM THE EARLY/MIDDLE CAMBRIAN TRANSITIONAL INTERVAL OF W-GONDWANA'S EUROPEAN SHELF Oiaf ELICKI Freiberg University, Geological Institute, D-09596 Freiberg, Germany, [elicki@geo.tu-freiberg.de].

IPC2002 Oral Presentations

The best known Early and Middle Cambrian Gondwana related deposits in Europe are known from the Iberian Peninsula, from France, Sardinia (Italy) and Germany. These deposits are well comparable in facies and evolution. Whereas in the higher Early Cambrian mainly carbonate and mixed carbonate-siliciclastic successions (ramps and platforms) were deposited, the Middle Cambrian is characterized by large and rather uniform siliciclastic shelfs. Investigations on middle and higher Early Cambrian (Germany) and on highest Early to early Middle Cambrian (Sardinia) profiles were focused on the characteristics of the palaeocommunities of these shallow marine habitats and their palaeoecology. Middle Early Cambrian (Ovetian) of E-Germany (Zwethau Fm., Doberlug Syncline). Three stages of sedimentation are known from this area: (1) deep subtidal carbonate ramp; fauna: open-marine, meso- to eutrophic, mobile and sessil benthic (trilobites, brachiopods, filamentous calcimicrobes [CM]); (2) shallow subtidal carbonate ramp; fauna: open-marine, rather oligotrophic, mainly sessil benthic, skeletal fossils, CMbiostromes (mainly Epiphyton, but also Kordephyton, Botomaella, Renalcis, Subtifloria, Girvanella) and CM-archaeocyathan bioconstructions (Epiphyton, 3 species but numerous specimens of irregular archaeocyaths, regular archaeocyaths only at the periphery); (3) shallow subtidal to intertidal mixed ramp (with oolite shoal complexes, lagoons and ?sabkhas); fauna: restrict-marine, mobile epi- and endobenthic, some redeposited skeletal remains. Higher Early Cambrian (Marianian/Bilbilian) of E-Germany (Charlottenhof Fm., Goerlitz Syncline). The succession is characterized by shallow subtidal open-marine and by restrict-lagoonal carbonates which are overlain by deeper-marine siliciclastics. The open-marine fauna of the carbonates is dominated by suspension feeders (hyolites, chancelloriids, echinoderms, trilobites) and filter feeders (poriferids, brachiopods, helcionellids). Deposit feeders (e.g. pelecypods as Pojetaia, Fordilla) and grazers (archaeogastropods) sometimes occur; predators (Rhombocorniculum, Halkieria) are rare. The most common mode of life is semiinfaunal, but also mobile and sessile epibenthic, endobenthic and (rare) nektonic modes were observed. Within the restrict-lagoonal, higher salinity areas only CM-mats occur. Highest Early to early Middle Cambrian (Bilbilian/Leonian) of Sardinia (Campo Pisano Fm.). The carbonate successions investigated represent the drowning stage of an isolated carbonate platform. The openmarine fauna starts with a predominance of subtidal sessil benthic filter feeders (poriferids) followed by mobile benthic sediment- and suspension feeders (trilobites) and then by more diverse benthos (echinoderms, brachiopods, hyoliths, chancelloriids). There are no indications for nectonic and for endobenthic organisms or for grazers, predators or scavengers. After that the succession changes into siliciclastic. The assumed trophic chains of these Cambrian faunas were rather short. Primary producers were represented by microbes. Primary consumers were mostly suspension and filter feeders. Predators were rather not important. The optimum depth for a high biodiversity was shallow subtidal. The German middle Early Cambrian habitats were oligotrophic, low agitated and favoured by archaeocyaths and calcimicrobes. Little increase of salinity or water energy led to distinct diminishing of the biocoenoses. The fauna was epibenthic. Predators were not observed. The German late Early Cambrian habitats were eutrophic and showed a wider biodiversity (lot of shelly fossil groups). CM-mounds and archaeocyaths were absent. Food strategies (suspension-, filter-, deposit feeders, grazers, predators), but also the kinds of habitats (infaunal, semi-infaunal, epibenthic, nectonic) were more numerous. Changes in the ecological conditions led no more to the diminishing of the ecosystem but to a reorganisation of its internal structure. In the Sardinian early Middle Cambrian sessil- and mobile benthic sediment- and suspension feeders were much more important. Especially trilobites and echinoderms were the dominant groups. In contrast to the Early Cambrian predators and bioerosion seem to be more widespread. Generally, the role of abiotic environmental conditions seem to be more important in the Early than in the Middle Cambrian. The outlined tendency can be observed in the Early/Middle Cambrian boundary interval over large areas of the European shelf of W-Gondwana.

HYDROTHERMAL VENT BIOTA IN BASAL CAMBRIAN BLACK SHALES OF THE YANGTZE PLATFORM IN CHINA AND THEIR BEARING ON THE EARLIEST CAMBRIAN BIORADIATION OF METAZOA Bernd-D. ERDTMANN & Michael STEINER Technical University Berlin, D-10587 Berlin, GERMANY Among the examples of transitional sedimentary sections across the Neoproterozoic III (Sinian or Vendian) to Cambrian boundary the Yangtze Platform in south-central China is unique due to its representation in both shallow shelf (incl. estuarine) to deep-water (restricted basin) black shale facies. Several of the SW-NE striking facies belts are crossed by a narrow fault-bounded zone (striking ca. 1.600 km ESE-WNW) which exhibits rich layers (lenticular bodies up to 40 cm thickness) of syngenetic sulfide ore debris containing

IPC2002 Oral Presentations abnormally high contents of Fe, Ni, Mo, As, and PGE, which are geochemically indicative of syngenetic submarine-hydrothermal exhalations. These up to several dm-thick lenticular ore bodies occur generally near to the base of the organic-rich Niutitang black shales which are considered of upper Tommotian (lowermost Cambrian) age. Within shallower lithotopes these black shales (with or without the ore bodies) delineate a sharp contact downsection with upper Sinian lime- and dolostones replete with various types of "Small Shelly Fossils", which are correlated with the Nemakit-Daldyn of the Lena-Aldan region of Siberia. Within a few tens of meters upsection of the Nuititang Formation Chengjiang-type biota occur at one recently discovered locality in Guizhou. The hydrothermal ore zone itself contains a low-diversity fauna consisting of hexactinellid sponge tufts, sponge bodies and scattered spicules together with organic-bivalved crustaceans which are provisionally referred to Perspicaris. More rarely, f.e. at a locality near Zunyi in northern Guizhou a new bivalve arthropod and in higher Niutitang beds, Scenella and Naraoia spinosa and, just below the Chengjiang-type biota, also very small carapaces of the eodiscid trilobite Tsunyidiscus appear. However, within the ore-related basal black shales only mass occurrences of hexactinellid sponges and Perspicaris are observed. This association is here considered to represent at least the fossilised part of the earliest known hydrothermal vent community. This ancient vent association differs strongly from recorded Palaeozoic to Recent vent faunas because, so far, no vestimentiferan tubes have been recognized nor early mollusc or brachiopod elements are seen in this assemblage. It is surmised that this sponge-Perspicaris assemblage, which is directly associated with the Fe-Ni-Mo sufide ore, represents (as far as fossilized) a bacteriophagous primitive metazoan "pioneer community" which may already translate a "relic" or "antiquity" fauna having been established in pre-Phanerozoic times and been preserved only in connection with sub-volcanic seafloor activities, which are usually not preservable resulting from their consumption at subduction margins. On the Yangtze Platform hydrothermal SEDEXtype ores appear to be related to a pre-Sinian arc system which was active farther south and expired during the Tommotian as fault-related back-arc exhalations. These hydrothermal activities are also made responsible for the early silicification of massive (pre-diagenetically) slumped upper Sinian Liuchapo Cherts within the Hunan and Guizhou Basins of the Yangtze Platform. The richly diverse late Atdabanian Chengjiang fauna of Yunnan is preceded by a less diverse poriferan and "early" organic-shelled arthropod fauna^ Due to high anoxia the Niutitang environment provides a "transitional preservational window" for the macro-bacterial and microbial ecosystem (Vendotaenia, microbial sheaths)predominating in Late Proterozoic basinal settings and which survived into the Cambrian together with the rise of organic-shelled metazoan biota in bathymetrically stacked oxyclinal biotopes.

NEOPROTEROZOIC SNOWBALL EARTH? INSIGHTS FROM BIOLOGY Douglas H. ERWIN Dept. of Paleobiology, MRC-121, National Museum of Natural History, Washington, D.C., 20056, USA [erwin. doug@,nmnh.si. edu /. The recent proposal of multiple global glacial events through the Neoproterozoic raises two substantive issues for evolutionary biologists and palaeontologists: First, is the evolutionary history of microbial, algal, and metazoan life permissive of such events, and what constraints does it place upon their course? Second, if global glaciations did occur, are they likely to have been linked to the pervasive evolutionary innovations of that interval? A snowball earth necessarily imposes a series of strong environmental filters on the Neoproterozoic biota of numerous single-celled lineages, metaphytes and possibly early metazoans. Such environmental filters would include: (1) a gradual decline in atmospheric carbon dioxide and biotic productivity prior to the onset of global glaciation, possibly associated with a rise in atmospheric methane levels; (2) sharply limited solar illumination in the oceans and a drop in oceanic pH during the glaciation; (3) non-linear increase in temperature during the glaciation, limiting the duration of the most inclement interval; and finally (4) as the release of volcanic C0 2 caused sufficient global warming and a rapid collapse of glacial conditions, marine waters shifted rapidly from acidic to highly alkaline conditions, with the development of a transient freshwater surface layer, followed by a gradual return to normal marine conditions. Significant biodiversity crises are likely during both the onset of the glaciation and during the deglaciation, but the glacial onset is believed to be of sufficient duration that adaptation will be possible; the deglaciation phase may be so rapid that only microbial populations may have been able to fully adapt. Simple simulations suggest that with a standing crop of at least several hundred open-water refuges, persistence of most lineages was likely. The critical issue would have been sufficient photosynthetic habitat for macroscopic algae and for metazoans. It seems difficult to construct an argument that the evolutionary record prohibits snowball earth events, although it does place constraints on the nature of such events.

IPC2002 Oral Presentations Could the attendant biodiversity crisis have fueled subsequent diversification? The absence of a rich fossil record spanning any of these events makes it impossible to characterize the magnitude of any changes in diversity, although they must have been substantial. Of the five major Phanerozoic mass extinctions, only the end-Permian event triggered a pervasive shift in the evolutionary trajectory of the marine biota, and even here the associated evolutionary innovations were dwarfed by those of the Cambrian metazoan radiation. Evolutionary innovation is not simply a response to open ecospace created by mass extinctions, but, particularly during the late Neoproterozoic-Cambrian, involves the interaction of developmental possibility with ecological potential in niche construction. Developmental and ecological innovations were a critical component of the Cambrian radiation but neither can be explained as a simple result of post-mass extinction biotic response. TESTING ALTERNATIVE SCENARIOS FOR THE END-PERMIAN MASS EXTINCTION Douglas H. ERWIN Dept. ofPaleobiology, MRC-121, National Museum ofNatural History, Washington, D.C., 20056, USA ferwin. doug&nmnh.si. edu]. Two severe mass extinctions brought the Palaeozoic to a close: one at the end of the Guadalupian, or Middle Permian (ca. 260 Ma) and a second at the close of the Changhsingian Stage (251.6 Ma). These were the most severe extinctions of the Phanerozoic and triggered an extensive reorganization of marine ecosystems and less pervasive changes in terrestrial ecosystems. The marine extinctions were selective, with epifaunal, suspension feeders more heavily effected than other clades, although significant variations occurred even within these clades. Relatively little is known about the first extinction pulse: the marine extinction was severe although some estimates appear to have been exaggerated by sampling effects, and the extinction appears to correspond with a major marine regression. Whether a mass extinction occurred at the same time among terrestrial organisms remains unclear, in part due to difficulties in correlating between marine and terrestrial sections. At this point relatively few possible causes can be excluded from consideration, although causes associated with the regression and release of methane hydrates are particularly worth further study.. In south China the Changhsingian marine extinction is nearly catastrophic, occurring in less than 500 ky. U/Pb single crystal zircon dating of at least two sections other than Meishan with tight biostratigraphic correlation confirm the U/Pb dates for the Meishan section. On land, vertebrates, plants and insects all experienced major extinctions. The Changhsingian event coincides with a drop of 8 C from about +2 to -2 per mil in both marine and terrestrial sections (although with some evidence of a latitudinal gradient in the isotopic shift); shifts in sulfur and strontium isotopes; with the eruption of the massive Siberian continental flood basalts; and with evidence of deep and shallow-water marine anoxia. There is growing evidence from Russia, Australia and possibly South Africa for rapid global warming at the boundary and into the earliest Triassic. The increase in fungal spores, interpreted as evidence of disruption of terrestrial ecosystems, and onset of deep-water anoxia both begin before any evidence of disruption of shallow marine ecosystems. The causes of the great end-Permian mass extinction must be consistent with this evidence. Although the cause of the extinction events remain unclear, significant advances have been made in the past decade, and a series of firm constraints on speculation have been established. Leading contenders for the cause are the climatic effects, including acid rain and global warming from the eruption of the Siberian flood basalts; marine anoxia or carbon dioxide poisoning; or an extra-terrestrial impact. The standing of each of these hypotheses can be evaluated in terms of evidence that is consistent, equivocal and inconsistent. Despite the absence of conclusive evidence for extra-terrestrial impact, much of the available data is consistent with such a mechanism. The principle pieces of evidence that are not consistent with an impact mechanism are: the early onset of deep water anoxia, the early onset of the fungal spike (at least 500 ky. before the marine extinction in S. China) and possibly the duration of the vertebrate extinctions in the Karoo of South Africa. For the Siberian flood basalts, the overlap in geochronologic dates has spurred interest in these as a cause of the extinction, however the causal connection between them remains unclear. There has been extensive speculation that the Siberian flood basalts may have been impact-induced, but Melosh has pointed out that there is no evidence of impact-induced volcanism here or elsewhere in the solar system. Further, the Siberian flood basalts include four identified centers spread over at least 1000 km. Any impactor sufficient to trigger massive flood basalts would have necessarily produced impact evidence far more extensive than that seen at the KT boundary. The most intriguing possibility is that the greatest mass extinction of the Phanerozoic left signals very similar to the end-Cretaceous mass extinction but was produced by entirely earth-bound processes. If true, this would tell us much more about the nature of ecosystems and how they fail than would identification of another impact event. 13

IPC2002 Oral Presentations PRESERVATION OF BALEEN WHALES IN TUFFACEOUS AND DIATOMACEOUS DEPOSITS OF THE PISCO FM, SOUTHERN PERU Raul ESPERANTE & Leonard BRAND Geoscience Research Institute. 11060 Campus St, Loma Linda, California 92350. USA [resperante@univ.llu.edu]; Natural Sciences Department, Loma Linda University, Loma Linda, California 92350, USA [lbrand@ns.llu.edu]. 1

Fossil baleen whales (Order Mysticeti) are abundant in the tuffaceous and diatomaceous rocks of the Miocene/Pliocene Pisco Formation, Peru. We have recorded n=484 specimens in four study areas. The whale skeletons did not experience extensive disarticulation prior to burial. Skulls are, in the majority of cases, articulated with lower jaws and vertebrae. Most whale skeletons are well articulated and almost complete, or partially disarticulated but still associated. However, some whales were disarticulated and had missing parts before burial. In all cases, the preserved bones show no evidence of pre-burial deterioration. Bones are very well preserved, showing no evidence of abrasion due to winnowing waters and/or dissolution due to long exposures to the sea water, and no evidences of colonization by invertebrates, which suggest that the whales were buried almost intact shortly after death. Disarticulation could have happened when the carcasses were floating and especially during the sinking process. Shark teeth are found associated with many of the specimens and shark teeth tips embedded in bones provide evidence for shark scavenging on some whale carcasses. However, no shark tooth bites were found on the bones. The relative integrity of many of the fossil whales, as well as the lack of shark tooth marks, indicate that either scavenging by sharks was minor, or that it did not affect articulation of the whales, though it could account for some missing parts such as limbs, lower jaws, and tail in certain specimens. The thick diatomaceous sequences record conditions of strong upwelling in the ocean; supported by the abundant occurrence of the diatom species Thalassionema nitzschioides, Delphineis sp., and Chaetoceros resting spores, which also indicate the occurrence of recurrent diatom blooms. This oceanic process along with frequent ash falls from continental volcanic activity enriched the waters on the shelf of the Miocene/Pliocene eastern Equatorial Pacific Ocean to achieve high levels of primary productivity, which resulted in diatom blooms and the formation of diatom aggregates and mats. Both aggregates and mats precipitated to the ocean bottom carrying significant amounts of fragmented and unbroken diatom frustules, abundant clay, and unweathered volcanic ash. Neither fragmented nor unbroken diatom frustules show evidence of dissolution or deterioration associated with long residence in the water column or on the sea bottom. Therefore, the degree of preservation of the diatoms and the occurrence of unweathered volcanic ash indicate that sedimentation rates must have been very high and that the diatoms and the volcanic particles reached the seafloor very rapidly. Several lines of evidence indicate that sediments and whales were deposited in a shallow continental shelf environment (an embayment), and not in a beach environment. The whales did not strand, but sank to the seafloor after death. Mortality of the marine mammals may have been caused by harmful algal blooms (HABs) that poisoned the food web. The occurrence of HABs is suggested by the presence of abundance of diatoms in species that indicate blooms, andseveral levels of fish remains (scales and bones) associated with the whale skeletons, which may indicate mass mortalities of fish. Since zooplankton and small fish are the primary food of baleen whales, the link between HABs and mortality of whales is reasonable. The sediments lack evidence of bioturbation by invertebrates, which might be due to the high rates of sedimentation and/or the occurrence of diatom mats that prevented invertebrates from burrowing into the diatomaceous sediments. The absence of bioturbation favored the high degree of preservation of the bones because the absence of invertebrates prevented boring and scavenging of the bones. However, bioturbation did occur in lower stratigraphic units containing more sandy and tuffaceous sediments, but few whales. The large number of whale specimens found, their excellent preservation, and their high degree of articulation make the Pisco Formation fossil whales probably the best occurrence of fossil Mysticetes known so far. The large number of fossil whales encountered in the diatomaceous beds, their excellent preservation, including evidence that soft tissue (baleen) was still present at burial, and the degree of articulation point to frequent mortalities of whales and other cetaceans followed by rapid sedimentation that prevented disarticulation of most of the skeletons, their colonization by invertebrates, and the deterioration of the bones. Sedimentation rates would be higher than rates inferred from some other modern and ancient settings where whale skeletons have been found. The preservation of fine details of the bones, baleen plates, and absence of bioturbating fauna suggest that burial of the whale skeletons occurred in an interval of time ranging from weeks to months, a few years at most, for any given whale

IPC2002 Oral Presentations OLIGO-MIOCENE MOLLUSC FAUNA FROM NEAR OTRANTO (SOUTHERN APULIA, SOUTHERN ITALY): A NON-MARINE TO MARINE TRANSITION Daniela ESU & Odoardo GIROTTI Dipartimento di Scienze della Terra, Universita "la Sapienza", P.le A.Moro, 5, 00185 Roma, Italy [daniela. esu@uniromal.it]. Southernmost Apulia (Salento), belonging to the Apenninic foreland, is characterized by stratigraphic successions laid down in a carbonate platform domain. The various formations, ranging from Cretaceous to Quaternary are discontinuous and separated by hiatuses of differing scales (Bosellini et al., 1999). The present communication deals with the mollusc fauna from two stratigraphic sections near Otranto, lying on a thick bauxitic cover and passing from continental to brackish and marine facies, in which rather rich (in specimens) assemblages of gastropods and bivalves of different environments have been discriminated. Palaeoecologic analysis of the mollusc faunas shows that lagoonal-continental environments prevailed for almost the whole succession, as testified to by oligotypic assemblages of prosobranchs, such as Neritidae, Hydrobiidae, Stenothyridae, Thiaridae, Potamididae and bivalves (Cyrenidae), alternately dominated by the Theodoxus, Hydrobia, Melanoides, Potamides, Granulolabium, Tympanotonus (or Mesohalina), Terebralia and Polymesoda. Littoral marine elements, such as Tectarius, Turritella, Cerithium, Anadara and Chama, are scattered along the succession but prevail towards the top, where corals and echinoids also occur. From the lithologic as well as palaeontological point of view, the Otranto sections are correlated with the Galatone Formation cropping out in the southern Salento area (Esu et al., 1994)—formalized by Bossio et al. (1998). Both biostratigraphy and lithostratigraphy suggest locating these transgressive deposits at the Oligo-Miocene transition. In fact, the stratigraphic range of the fauna is late Oligocene-early Miocene and the particular facies identified (bauxitic palaeosols and coal seams at the base, associated with non-marine molluscs, followed by brackish sediments and ending with truly marine beds) are in good agreement with the lowstandhighstand transition at the base of TB 1.4 of Supercycle TBI of the eustatic curve of Haq et al. (1987), where Steininger et al. (1997) proposed to locate the GSSP of the Paleogene-Neogene boundary. The fauna is of palaeobiogeographic significance, having strong affinities with those of the OligoMiocene basins of Aquitaine, Vienna and Turkey. Some new taxa have also been discriminated. BOSELLINI, A., BOSELLINI, F.R., COLALONGO, M.L., PARENTE, M., Russo, A. & VESCOGNI, A., 1999. Stratigraphic architecture of the

Salento coast from Capo d'Otranto to S. Maria di Leuca (Apulia, Southern Italy). Rivista Italiana di Paleontologia e Stratigrafia 105,

397-416. BOSSIO, A., Esu, D., FORESI, L.M., GLROTTI, O., IANNONE, A., LUPERTO, E., MARGIOTTA, S., MAZZEI, R., MONTEFORTI, B.,

RICCHETTI, G. & SALVATORINI, G., 1998. Formazione di Galatone, nuovo nome per un'unita litostratigrafica del Salento (Puglia, Italia meridionale). Atti della Societa Toscana di Scienze Naturali, Memorie, Serie A 105, 151-156.

Esu, D., GIROTTI, O., IANNONE, A., PIGNATTI, J.S. & RICCHETTI, G., 1994. Lagoonal-continental Oligocene of southern Apulia (Italy).

Bollettino della Societa Paleontologica Italiana 33, 183-195. HAQ, B.U., HARDENBOL, J. & VAIL, P., 1987. Chronology of fluctuating sea levels since the Triassic. Science 235,1156-1167.

STEININGER, F.F., AUBRY, M.P., BIOLZI, M., BORSETTI, A.M., CATI, F., CORFIELD, R., GELATI, R., IACCARINO, S., NAPOLEONE, C., ROGL, F., ROTZEL, R., SPEZZAFERRI, S., TATEO, F., VILLA, G. & ZEVENBOOM, D., 1997. Proposal for the global stratotype section

and point (GSSP) for the base of the Neogene (the Paleogene/Neogene Boundary), pp. 125-147. In Montanari, A., Odin, G.S. & Coccioni, R. (eds), Miocene Stratigraphy. An Integrated Approach; Elsevier, Amsterdam.

AN APPARENTLY UNIQUE MODE OF INCREASE IN SILURIAN RUGOSA: STAURIA FAVOSA Yoichi EZAKI & Yumi YASUHARA Department of Geosciences, Osaka City University, Osaka, Japan Stauria favosa is a Silurian rugose coral that exhibits a typical pattern of axial, parricidal division, and massive or fasciculate growth forms as well as composites of them. A unique mode of increase, apparently different from the usual axial division, is observed in a massive corallum collected from the Wenlock of Gotland, Sweden. What is this, and what is its cause? Is this against the rules characteristic of Stauria favosal Several daughter corallites, including cases of two, three, or four such, are observed to be axially contiguous with each other within individual parent calices, as seen on the weathered periphery of a corallum. These daughter corallites look like budding offsets in the axial region of parent corallites ("axial budding"). Both transverse and longitudinal sections at a level of increase also reveal the presence in part of distinct double walls consisting of an original parent wall and an inner wall as well as intercorallite matrix infilling, temporarily forming a fasciculate, instead of cerioid corallum growth form. Vertical changes in transverse morphology of corallites were examined in detail by use of acetate peels. Parent corallites give rise to daughter corallites by means of axial division, not budding, at four protosepta sites. The four protosepta

IPC2002 Oral Presentations first appear in offset corallites with a polarity identical to those of the parent, whereas metasepta are inserted serially, following Kunth's rule. Protosepta then axially connect with each other to form a cross-shaped structure. These modes of increase and septal insertion are essential to the axial division typical of Stauria favosa. The double wall structure and temporarily fasciculate form were caused by the contraction of polyps (rejuvenescence). The apparently unique mode of increase noted herein is interpreted as having been caused by a simultaneously accidental phenomenon that happened during an ordinary, possibly seasonal, period of budding. It is difficult to specify the immediate factors that hindered the growth of corallites. However, they are inferred to have been related to rather abrupt, deteriorating habitat conditions that were not seasonal. Corallites at the periphery of a corallum were especially susceptible to these environmental changes. Thus, those corallites, some of which were also undergoing axial division, were killed by the conditions that caused rejuvenescence. The unique mode of increase is only apparent, the result of axial division immediately followed by rejuvenescence. This study confirms the regularity in both modes of asexual reproduction and septal insertion in the case of Stauria favosa. Although Stauria favosa usually exhibits quadripartite increase, both tripartite and bipartite increases are also observed in these particular colonies. It remains an open question whether or not this might have been an adaptation for coping with deteriorating habitat conditions, as indicated by the rejuvenescence. Nonetheless, this particular massive cerioid rugosan provides valuable information as to: 1) regularity and variability in asexual reproduction, 2) the palaeoecological significance of rejuvenescence and its causes, as well as 3) the relationship between mode of increase and growth form of coralla.

THE CRETACEOUS-TERTIARY BOUNDARY: A PALAEONTOLOGICAL VIEWPOINT David E. FASTOVSKY1 and Peter M. SHEEHAN2 1 Department of Geosciences, URI, Kingston, RI02881 USA [defastov@uri.edu]; Department of Geology, Milwaukee Public Museum, Milwaukee, WI53233 USA [sheehan@uwm.edu]. It would be nice to know what happened to the biota at the K/T boundary, but the fact that reasonable scientists can't agree after 20+ years of intensive study may more reflect the way that these issues have been addressed than their intractability. Perhaps the most significant thing that we can learn from the K/T boundary is more effective ways to study extinction boundaries in general, and - even at this late date - this one in particular. The initial proposal (that an asteroid struck Earth and caused the extinction) justifiably engendered skepticism; the database was slim, apparently deus ex machina, and the patterns of extinctions were poorly understood. But at least this hypothesis had predictable consequences for the biota: it had to go extinct abruptly. Unfortunately, estimates of the rate and timing of any extinction event are meaningless without a quantitative understanding of exactly what is meant by "gradual" and "sudden." Consider dinosaurs, the poster children for the K/T extinction: only one vertebrate-rich K/T boundary region in the world, the upper Great Plains (GP) of the western interior of North America, has ever been extensively studied. Until 1991, there was no geologically meaningful stratigraphy within the key units; indeed, many palaeontologists (ironically, with the exception of an amateur) continue to collect stratigraphically unconstrained vertebrate fossils there. In GP, quantitative published data show that dinosaurs went extinct within as little as 200 Kyr. Even so, many palaeontologists, possibly misled by the high diversity of Campanian dinosaurs in GP, remain convinced that a multi-million year diminution in dinosaur diversity took place prior to the K/T boundary. Our understanding of the patterns of extinction of non-dinosaurs is in similar shape. Plants are now known to have undergone an 88% extinction in North America within several hundred thousand years, but suffered little to no extinction in New Zealand. Ammonites - the embodiment of Cretaceous biostratigraphy - underwent an initial 11% decline followed by total extinction. A war of attrition continues over the fate of planktonic foraminifera; the issue, for all the acrimony, devolves down to whether "Cretaceous" planktonic foraminifera in Paleocene parts of DSDP and ODP cores are reworked (the extinction was catastrophic) or in situ (the extinction was gradual). It has been observed that the normal -4-5 °/oo difference in 813C between benthic and planktonic foraminifera effectively disappeared after the K/T boundary, leaving what was termed a "Strangelove" (dead) ocean. It was subsequently noted that the isotope record could be equally explained by a reduction in the export of surface-originated organic carbon to the bottom. Regardless, both cases suggest a profound perturbation of the world's oceans, a situation that renders the dinosaur extinction virtually irrelevant. Nannoplankton are known to have gone extinct abruptly while the record of bivalves is not well-constrained stratigraphically, leaving interpretations of catastrophic or gradual extinction to the predisposition of the reader. Amphibians in the upper GP region appear to have been unaffected. Mammals evidently survived, but where the boundary is preserved (GP), they underwent a 96% extinction.

IPC2002 Oral Presentations The issue of recovery may give as much insight into the nature of extinction events as the actual event itself. The Cenozoic was evidently a brave new world, characterized by an opportunistic biota and high rates of speciation. The oceans took approximately 3 million years to recover, while the recovery of a mammalian fauna with ecological specializations took as much as 4 million years. These are surely indications that the K/T boundary was not, evolutionarily speaking, business as usual. The ultimate key to understanding this extinction (and all extinctions) is careful stratigraphy. Answers will not be found in the generation of facile causal hypotheses, nor in the naive expectation of bone beds, nor in the falsification of straw men erected on the basis of the supposed effects of impacts (or other environmental disasters), nor in the rampant establishment of killing scenarios, nor in non-parsimonious hypotheses that only explain part of the data, nor in the promulgation of untestable hypotheses, nor - finally in the concatenation of penecontemporaneous global events so that each outcrop requires special pleading. Answers must be found via tightly developed, robust stratigraphies paired with hypotheses that parismoniously explain global events. Considered thus, the K/T boundary extinctions must have been abrupt, synchronous, and are best explained by the most dominant contemporaneous environmental perturbation known, an asteroid impact.

CRETACEOUS-TETIARY (K/T) BOUNDARY INTERVAL AT POTY QUARRY, NORTHEASTERN BRAZIL: AN INTERPRETATION USING OSTRACODES Gerson FAUTH1 & Eduardo A.M KOUTSOUKOS2 1

Departamento de Paleontologia e Estratigrafia, Universidade Federal do Rio Grande do Sul, Caixa Postal 15001, 91501-970, Porto Alegre-RS, Brazil, [fauthgerson@hotmail.com]; 2Petrobras-Cenpes/Divex/Sebipe, Cidade Universitaria, Ilha do Fundao, 21949-900 Rio de Janeiro-RJ, Brazil. [koutsoukos@cenpes.petrobras. com. br] The Poty Quarry is located near Recife in the Pernambuco-Paraiba basin, northeastern Brazil, and is presently the best known outcropping marine section of the Cretaceous-Tertiary (K-T) boundary in southern low latitudes. The detailed study of this section offers a significant opportunity towards reconstructing the sequence of palaeoenvironmental changes and the microfaunal succession across the boundary in the region. In the last few years the Poty section has been the target of intense discussions about the positioning of the boundary and the evidence of a possible extraterrestrial bolide impact in the earliest Danian. The exposed quarry section, about 30 m thick, is represented by two lithostratigraphic units: the Gramame Formation (upper Maastrichtian), characterized by calcareous sandstones (near to its base), calcarenites, marlstones and carbonate mudstones; and the Maria Farinha Formation (uppermost Maastrichtian-Danian), which is dominated by bioclastic limestones and marlstones. Both yield abundant micro and macrofauna. In this study 59 outcrop and 143 core samples were collected. Thirty ostracode species belonging to thirteen genera were recorded. In most of the samples ostracodes are quite frequent and often well-preserved. In the Poty section the K-T boundary can be defined by the first local occurrence of Soudanela lanciniosa Apostolescu, a typical Palaeocene species. In addition, two distinctive ostracode assemblages can be distinguished in the section, and a palaeoenvironmental assignment interpreted after the main composition and dominance distributional patterns. The Maastrichtian deposits yield assemblages dominated by the genera Brachicythere, Cytherella, Protobuntonia, and Cythereis, with subordinate occurrences of Bairdia, Bythocypris, Paracypris and Cytheropteron, suggesting a deep outer shelf to upper bathyal environment. The Danian strata yield assemblages dominated by the genera Soudanella, Costa, Cytherella, and Loxoconcha, with subordinate numbers Monoceratina, Henryhowella and Bythoceratina, suggesting a middle shelf environment. A major sea-level fall, from upper bathyal to middle shelf water depths, is thus inferred to have occurred across the K-T boundary, which supports the conclusions drawn from previous stratigraphic and micropalaeontological studies in the section.

DINOFLAGELLATE CYSTS, PALYNOFACIES AND SEQUENCE STRATIGRAPHY IN THE MIDDLE JURASSIC OF SOUTHWEST GERMANY Susanne FEIST-BURKHARDT1 & Annette E. GOTZ2 department of Palaeontology, The Natural History Museum, Cromwell Road, London, SW7 5BD, England, UK, [s.feist-burkhardt@nhm.ac.uk]; 2Institute of Applied Geosciences, Darmstadt University of Technology, Schnittspahnstrasse 9, D-64287 Darmstadt, Germany [agoetz@geo.tu-darmstadt.de].

IPC2002 Oral Presentations Dinoflagellate cysts as well as palynofacies have been studied in early Middle Jurassic sediments of outcrops and core sections from Germany, England, France and Poland. As one example, the data from a core in SW Germany are presented in detail and compared to the results from the other regions. The Hasental well comprises a continuously cored succession spanning the uppermost Aalenian, Bajocian, and lower Bathonian. Based on the well established lithostratigraphic and biostratigraphic framework in this area, the stratigraphic distribution of sedimentary organic matter and the dinoflagellate cyst assemblages have been analysed with respect to relative sea level changes. Palynofacies parameters used for palaeoenvironmental and sequence stratigraphic interpretations are (1) the ratio of continental to marine organic particles (CONT/MAR ratio), (2) the ratio of opaque to translucent phytoclasts (OP/TR ratio), and (3) the relative proportion and species diversity of dinoflagellate cysts. Ternary diagrams are used to decipher transgressive-regressive trends within the succession by significant proximality changes. Four 3rd order depositional sequences have been identified by sedimentological signatures and stratigraphic variations of sedimentary organic matter. Sequence boundaries are marked by a significant change in the ratio of continental to marine constituents. Transgressive deposits are characterised by increasing marine particles. Maximum flooding intervals show high values of the OP/TR ratio and maximum abundances of dinoflagellate cysts. High values of the OP/TR ratio and high amounts of the marine fraction are still occurring during the early highstand. Within the late highstand marine phytoplankton is decreasing, phytoclasts and sporomorphs are increasing again. The major eustatic signal observed in the lower Bathonian (zigzag Zone) is related to a peak transgression during the Middle Jurassic of Western Europe. Throughout the entire succession dinoflagellate cyst assemblages show a more or less steady increase in diversity. This increase in diversity is superimposed by a major microfloral change in the Bajocian, when gonyaulacacean cysts take over from phallocystacean and valvaeodiniacean cysts.

USE OF MICROGASTROPOD DIVERSITY AS INDICATORS OF THE LATE QUATERNARY PALAEOENVIRONMENT OF NANSHA ISLANDS, SOUTH CHINA SEA FENG Weimin Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008 P. R. China [fwm@jlonline. com]. Microgastropods, an important group of organisms in the South China Sea (SCS) are characterized by abundant individuals, diversity of species and wide distribution; they are useful in bore-core geology. Research on microgastropods of the surface sediment of the southern shelf of the SCS shows that microgastropod distribution is closely related to temperature, salinity, currents, water masses and topography, as well as substrates. Abundance and diversity of microgastropods have high values on the eastern and western parts of the shelf—the high value area in the eastern part occurs in a relatively deeper area with more pronounced topography than in the western part. Complex diversity, H(S), coincides with topography, but in the middle part of the shelf the value of H(S) = 2 can extend to the outer edge of the shelf where dominant representatives of the inner shelf, such as Turritella, appear in large numbers—most likely reflecting input of surface waters from the Java Sea driven northwards by monsoons. Shells of the inner shelf are generally larger than those of the outer shelf; the obvious change occurs at 80-100 m depth at the boundary between the surface waters and the subsurface waters. Biodetritus is the most common sediment in the shelf; it generally contains abundant shells of microgastropods. In other types of substrate, such as clay and sand, microgastropod diversity is low. Some dominant genera and species—Turritella, Argyropeza, Scaliola, Ringicula, etc—are significant indicators of environment. For example, Argyropeza is typical of the outer shelf, and Turritella is dominant in the inner shelf, becoming more abundant with shallowing of the sea and strengthening of currents. Some genera, for example Scaliola, which live in shallow water along the coast of Japan, are inclined to occur deeper in the SCS. Distribution of microgastropods helps elucidate environmental change in the SCS since the late Quaternary. For example, quantitative analysis of microgastropods of core NS931225, from the outer shelf edge, shows a general sea level rise followed by rise and renewed rise after a short period of fall post-14 ka. In the last deglaciation, microgastropods were commonly larger; Turritella filiola was obviously dominant, probably signifying an inner shelf environment. In the early Holocene with the 5 18 0 continuously getting lighter, the regular decrease in percentage of T. filiola and high diversification of microgastropods (pteropods especially becoming very plentiful, exceeding the percentage of benthic microgastropods) indicates sea level rise and occurrence of high sea level. As a consequence, channels between islands became open. In the middle Holocene T. filiola became abundant again, probably reflecting a brief fall in sea level. In the late Holocene, increase in Scaliola is inferred to indicate cooling of climate. Nanyong core 3, Yongshujiao reef, displays good correlation between microgastropod abundance and sedimention rates. Moderate sedimentation

IPC2002 Oral Presentations rate and stable sedimentary environment favoured development of lagoonal gastropods. Four periods of environmental change can be discriminated in the last 1680 years: 1459-1680 B.P. unstable with low gastropod abundance; 1081-1459 B.P. stable with high gastropod abundance; 559-1081 B.P sharp turbulence and low gastropod abundance; 1-559 very stable and very high gastropod abundance. The project was supported by NSFC (40176030).

UNRAVELLING THE KEY FACTORS IN THE EXTINCTION OF THE AUSTRALIAN MEGAFAUNA: PALAEONTOLOGY, ARCHAEOLOGY AND ENVIRONMENT Judith FIELD & Joe DORTCH Archaeology, University of Sydney, N.S.W., 2006 Investigating the extinction of the Australian megafauna has been hampered by the lack of evidence with which to test the two competing explanatory theories: climate change and human overkill (blitzkrieg). The way forward in this debate is to investigate new sites and to examine in detail the pre-human fossil record, including both fauna and environment. Excavations at the Pleistocene archaeological site of Cuddie Springs in southeastern Australia has provided evidence for the association of people with a range of extinct species, including Diprotodon, Genyornis, Protemnodon, Sthenurus and Megalania from around 35,000 years ago. The prehuman fossil record includes numerous species of crocodile, diprotodontoids (e.g. Ramsayia curvirostris), as well as Megalania. Future work will undertake systematic excavation through the pre-human levels in conjunction with dating and taphonomic studies. Research in the Riversleigh region will involve systematic survey and excavation of sites with the potential to provide associated faunal and archaeological sequences through the critical extinction period prior to the Last Glacial Maximum between 18-22,000 years BP.

CARBON ISOTOPIC COMPOSITION OF ORGANIC MATTER FROM NON-MARINE PERMIAN-TRIASSIC BOUNDARY SECTIONS AT DALONGKOU AND LUCAOGOU, XINJIANG NW CHINA. Clinton FOSTER1 and Ian METCALFE2 1 Geoscience Australia, GPO Box 378, Canberra Australia 2601; 2Asia Centre, University of New England, Armidale, Australia 2351 As part of a multidisciplinary study to characterise the Permian-Triassic boundary in non-marine sections and to correlate this with marine sections, carbon isotopic ratios (813C) were determined for 60 kerogen samples from three classic localities in NW China. Twenty seven (27) samples from the North Limb (NL) of Dalongkou Anticline (DA), 12 from South Limb DA and 21 from Lucaogou. Samples span the Early Triassic Jiucaiyuan Formation and underlying Guodikeng and Wutonggou formations. The section from the NL of 138m is most complete and associated palynofloras and vertebrates (Lystrosaurus and Dicynodon) suggest that the Permian-Triassic boundary is between 20m and 95m below the base of the Jiucaiyuan Formation. Within this internal (20m-95 m) there is a significant shift of 7%o in isotopic composition. However, this is only one of five significant excursions of 4%o to 10%o within the entire NL section. Within the upper lower Guodikeng (NL) over 40m there are three closely spaced excursions between -26%o and -34%o. The pattern of rapid isotopic excursions within the upper lower Guodikeng is also apparent in the South Limb and Lucaogou sections, and the palynofloras belong to the same zone. The isotopically light kerogen assemblages are dominated by algal remains including Reduviasporonites chalastus (= Tympanicysta stoschiana), Botryococcus sp; lycopod spores, often occurring in tetrads, and non-striate bisaccate pollen; woody tissue is less common. These excursions, from lacustrine sediments, reflect organic composition effected by the biota and its response to the environment. However these assemblages are not confined to NW China. The first appearance of the megaspore Otynisporites eotriassicus within these kerogens allows correlation with compositionally similar palynofloras in Russia and Poland (Lozovsky et al. 2001). Like the Russian assemblages from Nedubrovo, assemblages from the NL are characterised by the same abnormal morphotypes of the pollen Klausipollenites schaubergeri, indicating the same reaction of the parent plants (gymnosperms) to environmental stress. The common occurrence of lycopsid tetrads has also been used as an indicator of stress (Looy 2000). We suggest that the upper lower Guodikeng equates with the main mass extinction level seen globally, and it is worth noting that R. chalastus (as T. stoschiana) is also common in the marine global Changhsingian below the GSSP for the Permian-Triassic boundary at Meishan, South China. The cause of global change is open to speculation, but the carbon isotopic composition of R. chalastus

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( 32%o) remains the same in both Permian and Early Triassic assemblages in other parts of the world (Foster et al., in press). Negative isotopic excursions in the middle and upper Guodikeng and within the Early Triassic Jiucaiyuan Formation cannot be correlated with global events with the same degree of certainty. They may reflect local environmental changes, as indicated by the change in cyclic sedimentation, marked by the coarser sandstones of the basal Jiucaiyuan Formation. The isotopic composition of organic matter reflects its biologic origins; but the temporal significance of isotopic changes can only be assessed within a tightly constrained multidisciplinary study where independent time controls are available.

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GREENWOOD, P., in press. A revision of Reduviasporonites Wilson 1962: description, illustration, comparison and biological Wiitongpf?!) affinities. Palynology. LOOY, C.V., 2000. The Permian-Triassic biotic crisis: collapse and recovery of terrestrial ecosystems. LPP Contributions 13, 114pp. LOZOVSKY, V . R., KRASSILOV, V . A., AFONIN, S.A., BUROV, B.V., YAROSHENKO, O.P., 2001. Transitional Permian-Triassic deposits in European Russia, and non-marine correlations. "Natura Bresciana" Ann. Mus. Civ. Sc. Nat., Brescia, Monografia N.25, 301-310. WIWNGPFIT fj

END PERMIAN EXTINCTION AND THE 'FUNGAL SPIKE* C.B. FOSTER & M. H. STEPHENSON Geoscience Australia, GPO Box 378, Canberra, ACT 2601, Australia [Clinton.Foster@ga.gov.au]; British Geological Survey, Keyworth, Nottingham, NG12 5GG, UK. [m.stephenson@bgs.ac.uk]. The enigmatic fungus-like organism Reduviasporonites Wilson 1962 is reported to occur as a 'spike' of high abundance close to the Permian-Triassic boundary. Optical and electron microscopy of topotype material of the organism confirms that Reduviasporonites Wilson 1962 is the senior synonym of Chordecystia Foster 1979 and Tympanicysta Balme 1980, first described from the Permian-Triassic of Australia and Greenland respectively. Moreover the type species of the last two genera, assigned in 1999 to Reduviasporonites by Elsik as R. chalastus (Foster) and R. stochianus (Balme), are conspecific. The type species, R. catenulatus Wilson 1962, differs from R. chalastus in that its constituent cells are significantly smaller, more rounded, and have less well developed connecting areas (terminal rims) between cells. The stratigraphical occurrences of the species of Reduviasporonites suggest that R. catenulatus is most common in the Wordian (Kazanian) of Oklahoma, though specimens of the size range associated with R. catenulatus are present very rarely in the Early Triassic Mazzin Member of the Werfen Formation, Austria. R. chalastus is present in Changhsingian to Griesbachian rocks spanning several million years and is therefore present outside narrow sequences spanning the Permian-Triassic boundary. The size of the constituent cells present in R. chalastus appears to be related to palaeolatitude with large examples occurring in the palaeotemperate Permian of China, Russia, Sverdrup and Moura, Australia and smaller cells occurring in the palaeotropical and palaeoequatorial Permian of northern Australia, Saudi Arabia, UK and Austria. Pyrolysis GCMS analysis of R. chalastus from the Mazzin Member (Lower Triassic, Austria) suggests that it may be of algal rather than fungal origin. Radioisotopic study shows that the body wall is isotopically lighter than plant material from the environments it occupied hence it is unlikely to have consumed this material as food, as would be expected in a fungal saprophyte. This implies that R. chalastus is unlikely to be integral to the process of mass extinction occurring at or near the Permian-Triassic boundary, as suggested by Visscher and other workers, because it appears to range outside the postulated time of mass extinction, and because as a probable alga rather than a fungus, it cannot have acted as a saprophytic metaboliser of dead vegetation formed in the extinction event. 1

IPC2002 Oral Presentations PALAEOZOIC GASTROPOD PHYLOGENY: PROGRESS AND PROBLEMS Jiri FRYDA Czech Geological Survey, Klarov 3/131, 118 21 Praha 1, Czech Republic, [bellerophon@seznam.cz]. Gastropods have a very rich fossil record for the last 500 million years. This, coupled with their occurrence in almost all marine, fresh-water and terrestrial environments makes them a unique group for evolutionary, ecologic and biogeographic investigations. Great progress in evaluation of the phylogenetic relationships of modern gastropod groups has been made during the past 29 years due to new morphological, anatomical and molecular data. However, a typical feature of the new evolutionary models is absence of data concerning their fossil record. Continuing studies of protoconch morphology in Palaeozoic gastropods provide observations, which considerably modify or even conflict with the present models of gastropod evolution. The early evolution of the class Gastropoda was much more complex. New data provide evidence that the main groups of modern gastropods separated from one another by the Middle Palaeozoic. The pattern of protoconch development in the anisostrophically-coiled Archaeogastropoda has not changed for at least 400 Ma (Silurian to Recent). The oldest convolute protoconchs of the Neritimorpha are known from the Carboniferous. The oldest members of the Caenogastropoda and Heterobranchia with their characteristic larval shells (protoconch II) were recently discovered in Lower Devonian strata. Data on protoconch morphology also show that during the Palaeozoic there were several gastropod groups (Cyrtoneritimorpha, Perunelomorpha, Mimospirida, Euomphalomorpha, Macluritina, and Amphigastropoda), which cannot be easily placed in any of four extant gastropod megataxa (Archaeogastropoda, Neritimorpha, Caenogastropoda, and Heterobranchia). On the other hand, there is no undoubted evidence for Palaeozoic limpet-like Patellogastropoda (Eogastropoda) even though the latter group has been considered to represent the first gastropod offshoot. Palaeontological data support the opinion that the ancestors of the Patellogastropoda had anisostrophically-coiled shells. Thus, patellogastropod limpet-like shells were secondarily developed; and shell shape cannot be considered archetypal for the Gastropoda. Bellerophontiform molluscs, torsion, and interpretation of muscle scars. Data on protoconch morphology have suggested that Amphigastropoda (Bellerophon and related taxa) had planktotrophic development. The recent discovery of an independent origin of larval muscles in extant gastropods provides undoubted evidence that torsion of the soft body (a diagnostic feature of Gastropoda) cannot be recognized from muscle scars in the teleoconchs of fossil shells. Thus, all phylogenetic models for the bellerophontiform molluscs, based on muscle scars, should be rejected. Evolution of planktotrophy. Recent neontological models of gastropod evolution have suggested that larval planktotrophy probably evolved twice in the class Gastropoda: 1.) In the Neritimorpha and 2.) In the common ancestors of the Caenogastropoda and Heterobranchia. However, new data on early shell ontogeny in Paleaozoic gastropods has revealed that the number of gastropod groups developing a true larval shell (protoconch II) was much higher. Thus, evolution of planktotrophy in the class Gastropoda was much more complex than has been suggested by neontologists. Uncoiling as a plesiomorphic shell character of the higher gastropods? Uncoiled protoconchs were recently found in several, long-lived groups of Palaeozoic gastropods (Cyrtoneritimorpha, Perunelomorpha, and Euomphalomorpha). This shell feature may be very old. Its presence suggests that the higher gastropods (Caenogastropoda, Heterostropha, and Neritimorpha) as well as the extinct Euomphalomorpha may have evolved from a common ancestor with an uncoiled tubular shell, and thus not directly from Ordovician Archaeogastropoda and/or Amphigastropoda as has been often suggested. This work was supported by the Alexander von Humboldt-Stifitung and grant 205/01/0143 (Grant Agency of the Czech Republic). LATE PALAEOZOIC AMMONOIDS FROM THE HAT YAI AREA, SOUTHERN PENINSULAR THAILAND Masavuki FUJIKAWA , Katsumi UENO , Apsorn SARDSUD , Wirote SAENGSRICHAN , Yoshihito KAMATA , and Kenichiro HISADA Graduate School ofScience and Technology, Niigata University, Niigata 950-2181, Japan; Faculty of Science, Fukuoka University, Fukuoka 814-0180, Japan; Geological Survey Division, Department of Mineral Resources, Bangkok 10400, Thailand; Faculty ofScience, Yamaguchi University, Yamaguchi 7538512, Japan; institute of Geoscience, University ofTsukuba, Ibaraki 305-8571, Japan 1

A considerable number of studies on palaeontology have been made in Southeast Asia in the last century, and a great number of papers have been published which deal with all kinds of fossils. Especially some of international projects, as "Geology and Palaeontology of Southeast Asia"(Kobayashi, Toriyama and

IPC2002 Oral Presentations Hashimoto (ed.), 1964-1984) organized by the Geological Survey of Thailand and the team of Japanese scientists, have greatly effected for the palaeontology of Southeast Asia. "Palaontologie von Timor" (Wanner (ed.), 1914-1929) is also one of the best publications published in Stuttgart. Thereafter, numerous fossils as fusulinids, corals, brachiopods, bryozoans, ammonoids, bivalves, plants, and even vertebrate fossils, have been found and examined up to the present. In Southeast Asia, the Palaeozoic ammonoid fossils have been quite restricted except a few regions as Timor Island, and so far the study of that has been superficial for a long time. Nevertheless, recently there have been some reports from Thailand, Peninsular Malaysia, Timor and Belitung Islands, and western Irian Jaya of Indonesia. Especially in the last decade, there has been considerable number of studies in Thailand. Nowadays fifteen genera of Carboniferous ammonoids and the same number of Permian ones have been reported in Thailand, though the occurrence reports of fossils have not been enough for quantitatively yet. The carbonate and limestone beds are extensively distributed around Hat Yai area, southern Peninsular Thailand. Some attempts have been made at these sedimentary rocks to clarify the geologic era but based on litho-faces. Just a little is known about the geology at Hat Yai area. There have been some palaeontological studies in this area. The first palaeontological evidence in Hat Yai should be the Carboniferous ammonoid from Kuan Lin Soh, published by Reed in 1920. Middle Triassic conodonts (Igo et al, 1988) and Triassic radioralians (Sashida and Igo, 1992) reported from Khao Chiak in this area. In a last decade some more palaeontological studies have been published. Triassic ichthyopterygian marine reptile (Mazin et al., 1991), Triassic foraminifers and corals (Fontaine et al., 1993), and Permian shallow marine faunas and floras (Fontaine et al., 1994). Recently Ueno et al. (1996) has described Permian foraminifers and corals in this area. In recent years, we have investigated the geology around there, and collected some ammonoid fossils from the three localities (HY13, HY16, and PH13). Six species referable to three genera of the Permian ammonoids occurred. Adrianites adamsi Miller and Furnish, Adrianites sp., Agathiceras suessi Gemmellaro, A. girtyi Bose, Agathiceras^?) sp., and Miklukhoceras sp. have been collected from the Locality HY13. From the two other localoties, HY16 and PHI3, the only Agathiceras(?) sp. has been distinguished. Three genera of ammonoids, Adrianites spp., Agathiceras spp., and Miklukhoceras sp., indicate HY13 as Bolorian to Kubergandian (Middle Permian). Agathiceras(l) sp., which has been reported from the other two localities HY16 and PHI3, indicates Late Palaeozoic era. This is the first occurrence of genus Adrianites in Thailand. Moreover, Adrianites adamsi and Agathiceras girtyi have been reported for the first time in Southeast Asia. These genera and its assemblages are so close to those from West Malaysia, and the rare genus Miklukhoceras sp. indicates the relationship with the ammonoid from the central Thailand. These facts support the previous opinions that the Hat Yai area situated around Sibumasu terrane. However, we have only limited information on the occurrences of Palaeozoic ammonoid yet, it cannnot be discussed palaeogeography in detail.

HOW THE GEOCHEMISRTY OF BLACK SHALE LAGERSTATTEN AFFECTS EXCEPTIONAL PRESERVATION Sarah GABBOTT Department of Geology University of Leicester, Leicester, LEI 7RH, UK. In ancient marine communities taxa with robust, easily fossilizable hard parts accounted for only a small proportion of the original biota. Consequently, deposits which contain the preserved remains of soft bodied organisms, termed conservation-lagerstatten, are invaluable to palaeontologists in the investigation of the biology, ecology and evolution of ancient life. Conservation lagerstatten provide us with the most convincing scenes from past life but the preservation of soft tissues does not necessarily indicate that the full gamut of the biota is represented, with preservational biases influential from a molecular to a whole organism perspective. These biases introduce two main problems when interpreting ancient life: 1) the special environmental conditions which serve to promote soft-tissue preservation may not be conducive for the establishment of a normal marine community and may create a palaeoecological bias; and 2) the chemical conditions that control soft-tissue preservation are still poorly understood and may influence which organisms and/or tissue types are preserved, producing a preservational bias. Research on the Soom Shale, an Ordovician lagerstatten from South Africa (Theron et al. 1990; Aldridge et al. 1994) demonstrated that preservational processes controlled the tissue types preserved and therefore the faunal profile (Gabbott 1998). This research threw light on the chemical interplay of sea floor sediments and Ordovician seawater in the conversion of carcasses to fossils, and demonstrated that the sediment should no longer be thought of as an inert packing medium to carcasses, but as a chemically active participant in the preservation of soft-tissues. Geochemical analyses have constrained interpretation of the conditions in the sediment and bottom waters of the Soom Shale basin during deposition and early diagenesis. Anoxic-euxinic

IPC2002 Oral Presentations conditions prevailed with low carbonate and iron concentrations in the sediment; hence there was no mechanism to buffer or fix H2S produced by organic matter decomposition. Under low pH conditions and in the presence of cations, organic substrates would have had an affinity for colloidal clay minerals and may have acted as templates, controlling the absorption of clay minerals which eventually completely replaced them. An initial phase of mineralization involving phosphate, followed by its replacement by clay minerals, is unlikely because the low pH conditions in the sediment would have been inimical to phosphate concentration, and the high fidelity of some soft tissue replication militates against two phases of replacement (Gabbott 1998). In the Soom Shale the clay minerals responsible for preservation have an illitic composition. Comparison of the compositions of the authigenic illites that replace the soft tissues and of the detrital illites in the host sediment show that the former have higher magnesium numbers and enhanced potassium contents. These compositional differences are better explained if illite directly replaced the soft tissues (Gabbott et al. 2001/ The Middle Cambrian Burgess Shale, perhaps the world's most famous fossil deposit, preserves the soft tissues of many animals which would otherwise be unknown. The fossils of the Burgess Shale feature prominently in many hotly debated palaeontological problems, including the rapid appearance of diverse multicellular life and animal disparity through time. However, we still do not fully understand the sedimentary geochemistry and preservational biases that operated in the Burgess. New geochemical analyses reveal details of how the fossils were preserved and the conditions in the bottom and pore waters. ALDRIDGE, R.J., GABBOTT, S.E. & THERON, J.N. 1994. The Soom Shale: a unique Ordovician fossil horizon in South Africa. Geology Today, 10,218-221. GABBOTT, S.E. 1998. Taphonomy of the Upper Ordovician Soom Shale lagerstatte: a unique example of soft tissue preservation in clay minerals. Palaeontology, 41, 631-667. GABBOTT, S.E., NORRY, M.J., ALDRIDGE, RJ. & THERON, J.N. 2001. Preservation of fossils in clay minerals: a unique example from the Upper Ordovician Soom Shale, South Africa. Proceedings of the Yorkshire Geological Society, 53, 237-244. THERON, J.N., RICKARDS, R.B. and ALDRIDGE, R.J. 1990. Bedding plane assemblages of Promissum pulchrum, a new giant Ashgill conodont from the Table Mountain Group, South Africa. Palaeontology, 33, 577-594.

TAPHONOMIC AND PALAEOECOLOGIC SIGNIFICANCE OF THE "LE GRAND BEDS," A CRINOID-RICH OBRUTION DEPOSIT FROM THE LOWER CARBONIFEROUS (TOURNAISIAN) OF IOWA, USA Forest J. GAHN & Tomasz K. Baumiller Museum of Paleontology, University of Michigan, Ann Arbor, MI 48109-1079, [fgahn@umich.edu]; Event beds, such as obrution deposits, are responsible for the preservation of fossil Lagerstatten and provide invaluable windows into taphonomy and palaeoecology. The "Le Grand Beds" refer to a horizon from the Lower Carboniferous (Tournaisian) Maynes Creek Formation of Marshall County, Iowa, USA, renown for the exceptional preservation of fossil crinoids. Thousands of crinoids have been recovered from this interval in densities of as high as 600 individuals/m2. Their preservation is typically pristine with stalk, calyx, and arms intact. Even differences in the color of individual specimens can be observed and used as a basis for distinguishing between species. Despite the large number of specimens and the high quality of preservation, no comprehensive taphonomic or palaeoecologic analysis of this fauna has been conducted. Herein, we present data pertinent to the interpretation of the depositional environment and burial history of the Le Grand Beds, to preservational attributes of different taxa including disarticulation, compression, and orientation, to taxonomic differences in survival response, to faunal composition and distribution, to resource partitioning, and to crinoid predation. The crinoids Le Grand examined in this study were collected from atop a lensoidal deposit approximately 5m in diameter, consisting mostly of intraclastic crinoid grainstone. Multiple generations of intraclasts are present within the lens, and the intraclasts themselves are often imbricated, bored, and encrusted by edrioasteriods and crinoid holdfasts. Although the lens is highly fossiliferous, it grades laterally into sparsely fossiliferous, laminated dolomitic mudstone. The intraclasts are identical in composition to the laminated mudstone of the adjacent facies. We interpret the Le Grand crinoids to have lived and died in an inner shelf surge channel that transected an otherwise restricted marine mudflat; the crinoids preserved at Le Grand were buried by a storm-generated channel-fill event, coincident with the exhaustion of accommodation space in the channel. We examined 87 slabs from the Le Grand Beds with nearly 2,300 individual crinoids assigned to 26 species. The crinoid fauna is dominated by diplobathrid (49%) and monobathrid (45%) camerates; cladids (6%) and flexibles (1%) are present, but relatively rare. The dominant taxon is the diplobathrid camerate, Rhodocrinites kirbyi, which makes up approximately 40% of the crinoid fauna. A careful examination of all arms indicates a high frequency of arm regeneration (25%) and based on an analysis of complete stalk

IPC2002 Oral Presentations lengths, it occupied the highest tier above the seafloor (35cm). Arm regeneration has been used as a measure of predation intensity on extant crinoids, and our observations of the Le Grand crinoids have bearing on predation intensities in the Lower Carboniferous. Taphonomic analyses revealed that distinct crinoid morphotypes differ in the degree of disarticulation. These disarticulation patterns could be explained by morphological differences, but variable survival responses of different taxa may have also played a significant role. Also, patterns of calyx compression revealed distinctive responses of each morphotype to sediment compaction.

OLIGOCENE COLONIAL CORALS FROM GABAL HAFIT, (AL AIN AREA, UAE) Mohammed GAMEIL United Arab Emirates University, Faculty of Science, Geology Dept., PO 17551, Al Ain, UAE; [mgameil@uaeu. ac. ae] A highly fossiliferous Lower Oligocene (Rupelian) section is well exposed on the flanks of Gabal Hafit anticline near Al Ain City, United Arab Emirates. The section contains different kinds of macro- and microfossils. Corals are the most abundant faunal element in that area and are represented by colonial and solitary forms where colonial forms dominate. Colonial corals are the main target of the present work and are studied here for the first time. The present work focuses on the taxonomic and stratigraphic aspect of these colonial corals. The study includes the identification and description of 21 species of which two species are believed to be new. These are Tarbellastraea hafitensis and Siderastraea osmani. The outcrops of the Oligocene strata of Jebel Hafit afford the opportunity to document the response of ancient reef coral communities to a broad range of habitats and substrates in a variety of depositional settings and in different stages of ecological successions. The reef corals, herein, are associated with the different benthic fauna such as algae, bryozoa, foraminifera, ostracods and pectinid pelecypods. These communities grow under conditions of relatively pure carbonate sedimentation, which provide valuable comparative models of carbonate sedimentary facies and diagenetic sequence. Five microfacies associations are recognized: coralline framestone, algal coralline packstone/grainstone, algal bindstone, algal bryozoan wackestone and nummulitic wakestone/packstone. Studies from sedimentological and palaeontological standpoints indicate a platform carbonate sequence of Oligocene age.

BIOSTRATIGRAPHIC CORRELATION OF THE TERMINAL PROTEROZOIC IN CHINA GAP Linzhi and YIN Chongyu Institute of Geology, the Chinese Academy of Geological Sciences, Beijing 100037 P. R. China Neoproterozoic is an important period from Cryptozoic eon to Phanerozoic eon in geological history, the period of the tectonic movement in globe and higher activity of life evolution. There are some important geological events in globe, which the breakup of Rodinia super-continent (1000 Ma) caused an important life evolution and variation in mesophyta. After "snowball" events (730 Ma), two important evolution radiations appear, the Miaohe biotas are developed in the Doushantuo stage (650 Ma) and the Xilingxia (Ediacara) fauna are developed in the Dingying stage (600-570). Late, the Cambrian small shelly fossils occurs, which is represent the end of Neoproterozoic. The biota evolution of the terminal Proterozoic is mainly developed in both blocks of Yangtze and North China. A large member of fossils of masophyta and metazoa and a lot of acritarchs, found in the succession of the mix facies of carbonate and clastic rocks in the margin of North China Block, shows the evidence for the Neoproterozoic strata correlation. In the Yangtze Block, after the Nantuo glacial period (700 Ma), a large number of various fossils developed and preserved in siliceous rocks in deep water environment. Because of different latitude, the early glacial was never developed in the whole North China Block at the same time. The different biota developed in the Sino-Korean continent and the Yangtze continent which was drifted separately and belongs to different biozones. According to the biostratigraphic study in recent years (Yin et Gao, 1996, 1990, 2000), we consider that the characteristic fauna can be correlated in both blocks. Even the whole biota has each character in two blocks, yet the total forms can be correlated. For example, the Sinian biota can be subdivided into two assemblages in the Yangtze block. One is "Miaohe biota" named by Chen Meng'e (1994) and Ding Lianfang (1996) in the Doushantuo period. Anther is "Xilingxia biota" in the Dengying period. The two biota also appear in the eastern margin of North China (Qiao et Gao, 2001). There are five fossil assemblages in the Miaohe Biota, which are microplants, magefossil algae, metazoa, sponge and trace fossils and even appears and preserved embryo fossils (Yin, 2001). There are four classes in the Xilingxia biota, e.g. microplants,

IPC2002 Oral Presentations magefossil algae, metazoa and trace fossils. The metazoa is consisted of coelenterate and annelid. The fossil of Paracharnia deng-yingensis (Ding et Chen, 1981) emend Sun, 1986, is much similar to the sample of Rangea, which is belong to the Ediacara fauna found in England, Canada and Australia. The fauna developing in different regions in the eastern margin of North China block, which can be subdivided into two types, that is the Liaonan type and Huainan type with worms of Sabellidites and Paleolina. Some medusa shows cast trace forms, which are Cyclomedusa, Paracyclomedusa and Discifera, in the Sinian Xingmincun Formation. In Yangtze Platform (block), worms are found in Doushantuo and Dengying formations separately. The worms developing in the Doushantuo Formation belongs to annelid with inner seta, intestine structures, expand head, bristle and gemma. In the Dengying Formation, the worms show as irregular tube and gear wall, hollow and segment in a pyrite body. The fauna also consists of medusa, Clodina, Paracharnia and Vendotaenides. However, according to our study, the aspect of Doushantuo fauna (650-600 Ma) is not known in globe, but the fauna in the Dengying period is same as those in Terminal Proterozoic in other continents

LATE PLEISTOCENE CHAROPHYTES (CHARALES, ALGAE) FROM THE GULF OF CARPENTARIA, AUSTRALIA: PALAEO-SALINITY HISTORY DURING THE "LAKE" PHASE. Adriana GARCIA, Allan R. CHIVAS, Sabina HOLT & Jessica REEVES School of Geosciences. University of Wollongong. NSW2522 [E-mail:adriana@uow.edu.au]. The charophytes are non-marine Algae living in a range from fresh to hypersaline water. Some species are restricted to fresh water (0-3 %o), others can tolerate a small increase in salinity (3-15 %o) while others can survive under hypersaline conditions, up to 70 %o. The gyrogonite is the structure of the charophyte that commonly fossilises and represents the calcified cover of the oospores. The study of modern charophytes, and their collection in Australia, allows their use as modern analogues for palaeo-ecological reconstruction. The finding of these taxa in the Quaternary allows also to identify routes of colonisation, i.e. Lychnothamnus barbatus from SE Asia. The Gulf of Carpentaria, located in the northern part of Australia is an epicontinental sea with maximum water depth of 70 m. Australia's separation from Papua New Guinea by the Torres Strait at the East is only 12 m deep, and the Arafura Sill connecting with the Indian Ocean to the West is 53 m deep. During glacial times when the sea level dropped about 130 m, connection with the ocean was severed and a palaeo-lake called "Lake Carpentaria" developed in the basin. Six sediment cores ranging from 6 to 15 m long where obtained, spanning the last 125 ka (Last Interglacial), and two non-marine/marine transitions have been identified. A multi-proxy approach based on foraminifers, ostracods, nannofossils, pollen and charophytes, and geochemistry is under development, to produce an accurate palaeoenvironmental reconstruction and to understand the pivotal role of this tropical area during the global climatic changes which occurred during the Quaternary. The palaeo-lake Carpentaria existed mostly recently, from ~ 40 ka to 9.6 ka (radiocarbon years), between the onset of the Last Glaciation and the last marine transgression. During its development it changed from a saline waterbody still connected with the ocean, to a saline lake disconnected from the ocean to a freshwater lake. These changes are evident in the palaeo-biota. Euryhaline taxa such as Ammonia sp., Leptocythere sp., Cyprideis sp. and Pistocythereis sp., were replaced by an association of Ammonia sp., Cyprideis sp , and Ilyocypris sp., indicating that salinity diminished. Charophytes are absent in these levels showing that an open connection with the sea is still present. The disconnection of the lake from the ocean, increased the freshwater input, and the biota changed to an assemblage of taxa of fresher-water affiliation represented by Ammonia tepida, Ilyocypris sp., Cyprinotus sp., Cypretta, Darwinula sp., together with charophytes. The species of charophytes present are Chara vulgaris, C. zeylanica and Lychnothamnus barbatus. The main points explored in relation with these species are: The role of charophytes in the environment: interaction with other organisms. Charophytes interact with the environment giving habitat, food and protection to invertebrates. They sustain the clear water state versus turbid water state, keeping the health of the water-body. Salinity as a main factor for modern species distribution: palaeo-ecological approach. C. vulgaris and C. zeylanica are indicative of a water-body with fresh to mesosaline conditions (less than 15 %o). L. barbatus is restricted to freshwater, and related in Australia to flood-drought events. It is present in the uppermost levels of the lacustrine facies indicating the period of fresher water conditions. Geographical distribution: patterns of colonisation in Australia. C.vulgaris and C. zeylanica are both cosmopolitan species but the later is restricted to the tropical belt. The finding of fossil Lychnothamnus allows the confirmation of the SE Asian route for colonisation by this species with a Euro-Asiatic distribution, instead of anthropogenic introduction during the past 200 years, as has been postulated.

IPC2002 Oral Presentations

TAPHONOMY OF A TOURNAISIAN FOSSIL FISH LOCALITY NEAR MANSFIELD, VICTORIA Jillian GARVEY1. Anne WARREN1 and Susan TURNER2 1 Dept of Zoology, La Trobe University, Melbourne, Victoria, Australia, 3086, [J.Garvey@zoo.latrobe.edu.au]; 2 Queensland Museum, P.O. Box 3300, Brisbane, Queensland 4101. The earliest tetrapods are known from the Late Devonian with articulated specimens from the Famennian of East Greenland (e.g. Coates 1996) and more fragmentary remains from the Frasnian of Scotland (Ahlberg 1995). Devonian tetrapods were also present in Gondwana as indicated by trackways in the Genoa River Beds of northern Victoria (Warren & Wakefield 1972), and a jaw from NSW (Campbell & Bell 1977). Besides several isolated fragments from Nova Scotia and an undescribed specimen from Scotland, no tetrapods are known from the first 30 million years (referred to as Romer's Gap) of the Early Carboniferous. This gap, until recently, was even larger in Australia, spanning 100 million years until the latest Permian. In 1995 a fossil fauna of fish and tetrapods was located, towards the end of Romer's Gap, in the Early Carboniferous Ducabrook Formation of the Drummond Basin, Queensland (Thulborn et al. 1996). These first Carboniferous tetrapods from Gondwana have re-ignited interest in a Tournaisian site near Mansfield, Victoria, originally excavated by Sweet during the late 1800s, with the fauna being described by Woodward (1906). Sweet made excavations principally at Tannery Paddock but fossils are also known from sediments exposed in the bed of the Broken River, Since this discovery some Mansfield taxa have been redescribed (Long 1988, 1989) including the only known articulated remains of Gyracanthides (Warren et al. 2000). Although the fish assemblage is similar to that of Early Carboniferous tetrapod bearing faunas of Euramerica and Queensland, no tetrapods have yet been found at Mansfield. The fossil fish locality at Mansfield provides an excellent opportunity to find the earliest Carboniferous tetrapods or, alternatively, to establish palaeoecological reasons for their absence. This study involves a systematic taphonomic analysis of the fossiliferous strata at Mansfield, including re-opening Sweet's original quarries in Tannery Paddock, searching the Broken River and examining the region examined for new localities. In considering the structure of the palaeoenvironment and palaeocommunities, both the macrovertebrate and microvertebrate faunas are being considered. AHLBERG, P.E., 1995. Elginerpetonpancheni and the earliest tetrapod clade. Nature 373, 420-425. CAMPBELL, K.S.W. & BELL, M.W.A., 1977. A primitive amphibian from the Late Devonian of New South Wales. Alcheringa 1, 369381. COATES, M.I., 1996, The Devonian tetrapod Acanthostega gunnari Jarvik: postcranial anatomy, basal tetrapod interrelationships and patterns of skeletal evolution. Transactions of the Royal Society of Edinburgh: Earth Sciences 87, 363-421. LONG, J.A., 1988. New palaeoniscoid fishes from the Late Devonian and Early Carboniferous of Victoria. Memoirs of the Association of Australasian Palaeontologists 7, 1 -64. LONG, J.A., 1989. A new rhizodontiform fish from the Early Carboniferous of Victoria, Australia, with remarks on the phylogenetic position of the group. Journal of Vertebrate Palaeontology 9, 1-17. SWEET, G., 1889. On the discovery of fossil fish in the Old Red Sandstone rocks of the Mansfield district. Proceedings of the Royal Society of Victoria 2, 1-14. THULBORN, T., WARREN, A., TURNER, S. & HAMLEY, T., 1996. Early Carboniferous tetrapods from Australia. Nature 387, 77-780. WARREN, J.W. & WAKEFIELD, N.A., 1972. Trackways of tetrapod vertebrates from the upper Devonian of Victoria, Australia. Nature 238, 469-470. WARREN A., CURRIE, B.P., BURROW, C. & TURNER, S., 2002. A redescription and reinterpretation Gyracanthides murrayi Woodward 1906 (Acanthodii, Gyracanthidae) from the Lower Carboniferous of the Mansfield Basin, Victoria, Australia. Journal of Vertebrate Paleontology 20, 225-242. WOODWARD, A.S., 1906. On the Carboniferous fish fauna from the Mansfield district, Victoria. Memoirs of the National Museum, Melbourne 1, 1-32.

ZONATION OF THE TERMINAL PROTEROZOIC (EDIACARIAN) James G. GEHLING1 and Guy M. NARBONNE2 1 South Australian Museum, Division of Natural Science, North Terrace, Adelaide, South Australia 5000; 2 Queen's University, Department of Geological Sciences, Kingston, ON, Canada K7L 3N6. Biostratigraphic subdivision of the terminal Proterozoic (Ediacarian) will involve biozones based on organicwalled microfossils, Ediacaran body fossils and trace fossils. Existing problems with taxonomic assignment of both microfossils and megafossils from this interval will require careful assessment of taphonomic differences between assemblages around the globe and calibration of successions using such methods as U/Pb dates from zircons in ash beds, and carbon isotope patterns from carbonates and organic rich sediment.

IPC2002 Oral Presentations While palaeo-environmental factors must have influenced the composition of local assemblages, the recognition of the some taxa in widely separate environments suggests their use as index fossils. Two preliminary epochs are proposed for the Ediacarian interval based on organic walled microfossil biozonation of the lower part and Ediacaran macrofossil biozonation of the upper part. In stratigraphic order upwards, the distinctive Ediacaran associations of the Avalon (ca. 575-560 Ma), White Sea (ca. 560-550 Ma) and Nama (ca. 550-543 Ma) may be used to define stage boundaries below the Cambrian. The first diverse Ediacaran megafossils (large fronds and discs) appear 5-15 million years after the Marinoan glacial stage. Bilaterian animals and trace fossils first occur at around 560 Ma. Ediacaran body fossil diversity increases up to about 550 Ma where after there is an apparent decrease in diversity up to the base of the Cambrian. PALAEOBIOLOGY OF EDIACARAN TRACE FOSSILS James G. GEHLING , Bruce RUNNEGAR , Soren JENSEN3, and Mary DROSER South Australian Museum, Division ofNatural Science, North Terrace, Adelaide, South Australia 5000; University of California, Los Angeles, Institute of Geophysics and Planetary Physics, Los Angeles, CA 90095-1567, USA; University of California, Riverside, Department of Earth Sciences, Riverside, CA, 92521, USA. It is unlikely that sediment-moving animals evolved twice. Isolated megascopic traces from early Proterozoic rocks are best explained as either shrinkage cracks or some other inorganic structures. The robust record of animal trace fossils is apparently confined to the latest Neoproterozoic. Trace fossils have not been recognised amongst the earliest dated Ediacaran fossils of the Mistaken Point assemblage (circa. 575-565 Ma) in SE Newfoundland and the correlative Sheepbed assemblage from NW Canada. Serial impressions such as Palaeopascichnus are some of the earliest, most widely distributed and longest ranging Ediacaran forms, but they are not trace fossils. The first reliable record of coherent trace fossils comes from the classic South Australian and the correlative White Sea assemblages, dated from circa 558 to 555 Ma. The simultaneous appearance of plentiful surface trace fossils with the first bilaterian grade body fossils is unlikely to be a chance coincidence. Bilateral forms such as Spriggina, Kimberella, Praecambridium and Parvancorina are of similar dimensions to the organisms responsible for the arrays of furrows trails, radular marks, back-fill and radial traces. The consistency of many of the ichnotaxa excludes an origin as cnidarian locomotion marks or flatworm mucus trails. Traces associated with key Ediacaran taxa, such as Kimberella and Dickinsonia, suggest particular feeding strategies involving microbial mats. Just before the beginning of the Cambrian, there is evidence of a decline in diversity of Ediacaran body fossils, and an increase in diversity of trace fossils, coinciding with the first skeletal fossils. 1

MICROPLANKTON CHANGES ACROSS A MASS EXTINCTION: THE EARLY SILURIAN IREVIKEN EVENT David GELSTHORPE Department of Geology, University ofLeicester, Leicester, LEI 7RH, UK [dngl@le.ac.uk] The Ireviken extinction Event in the early Silurian (Landovery/Wenlock, 428 Ma) has been related to a major change in global climate. Within the Event at least 8 extinction horizons in the conodonts (early vertebrates) have been reported. It has been established that changes in the phytoplankton (acritarchs and prasinophyte algae) at this time were severe (Le Herisse 1989), but until now these have not been analysed in detail. The Ireviken Event was first recorded in the Visby Beds on the island of Gotland (Sweden). It has been interpreted as an example of the change between P to S climate state (Jeppsson 1993), reflecting severe changes in the ocean atmosphere system. The data shows a significant turnover in the phytoplankton at the Ireviken Event, with most of the extinctions at the end of the event, when many of the conodont extinctions have taken place. Most of the species that become extinct belong to the genus Oppilatala. The originations occur very gradually across the whole event, apart from around the Upper Visby Beds/ Lower Visby Beds boundary where they mostly cease. If the P and S model is correct, these data indicate a higher diversity of phytoplankton occurred in the S state, perhaps reflecting a greater specialisation in a low-nutrient environment.

IPC2002 Oral Presentations

SOME HYPOTHESES ABOUT THE LIFE CYCLE OF THE FIRST EUTRACHEOPHYTES Philippe GERRIENNE Paleobotanique, Paleopalynologie et Micropaleontologie, Universite de Liege, Allee du 6 Aout, Sart Tilman (B18), B-4000 LIEGE 1, Belgium [Gerrienne@ulg.ac.be]. The kingdom Plantae (Embryophytes) includes all multicellular autotroph organisms, algal protists excepted. Plants have multicellular sporangia and gametangia; their zygote develops into an embryo; they show alternation of generations (i.e. diplobiontic life cycle). The kingdom Plantae includes Bryophytes s.l. and Tracheophytes. Bryophytes s.l. are devoid of tracheids; their gametophyte is dominant. Tracheophytes differentiate tracheids; their gametophyte is reduced. Little is know about the alternation of generations in fossil plants. Recently, Remy et al. (1993) have demonstrated the presence of axial gametophytes in the Rhynie Cherts (Lower Devonian). Interrelationship between those gametophytes and previously know vascular sporophytes has been suggested. On this basis, it has been concluded that isomorphic alternation of generations is the plesiomorphic condition amongst the Tracheophytes (Kenrick, 1994). Subsequent evolutionary processes have led to drastic reduction of the gametophyte. It should be noted however that all the plants for which a gametophyte/sporophyte correspondence was established, are either devoid of conducting tissue, or possess a peculiar type of water-conducting cells, called S-type tracheids. Plants with S-type tracheids (Rhyniaceae sensu Kenrick & Crane, 1991) became extinct during the Devonian. All the other vascular plants (Eutracheophytes sensu Kenrick & Crane, 1991) have water-conducting cells with a completely different structure. The oldest fertile axial fossil of embryophytes is reported from the late Wenlock (mid-Silurian) (Edwards and Feehan, 1980). This plant bears terminal Cooksonia-type sporangia. Cooksonia Lang is the emblematic figure of early land plants. Its mid-Lochkovian (Lower Devonian; Edwards et al1992) representatives are the oldest demonstrated Eutracheophytes (Kenrick & Crane, 1997). To date, the gametophyte of Cooksonia is unknown. A new species of this genus, Cooksonia paranensis Gerrienne et al. (2001) from the Lower Devonian of Brazil, might well shed some light on the life cycle of this early Eutracheophyte. More than 1000 specimens have been collected, amongst them an exceptional one consisting of a much branched axial system with each distal segment bearing a cup-shaped structure interpreted as a sporangium. The proximal part of the specimen is a small poorly preserved structure on which at least four axes are borne. This small basal structure might be the remains of the gametophyte generation of the plant. This could mean that Cooksonia, and hence perhaps all the other early Eutracheophytes, had a heteromorphic alternation of generations. This could also signify that the gametophytic phase has always been reduced amongst the Eutracheophytes sensu Kenrick & Crane (1991). This could further imply that plants with S-type tracheids arose independently from all the other vascular plants or that the axial gametophyte of the former is a derived character. EDWARDS, D. & FEEHAN, J., 1980. Records of Cooksonia-type sporangia from late Wenlock strata in Ireland. Nature 287, 41-42. EDWARDS, D., DAVIES, K.L. & AXE, L., 1992. A vascular conducting strand in the early land plant Cooksonia. Nature 357, 683-685. GERRIENNE, P., BERGAMASCHI, S., PEREIRA, E. RODRIGUES, M.A.C. & STEEMANS, P., 2001. An Early Devonian flora, including

Cooksonia, from the Parana Basin (Brazil). Review of Palaeobotany and Palynology 116, 19-38. KENRICK, P., 1994. Alternation of generation in land plants: new phylogenetic and palaeobotanical evidence. Biological Review 69, 293-330. KENRICK, P. & CRANE, P.R., 1991. Water-conducting cells in early fossil land plants: implications for the early evolution of tracheophytes. Botanical Gazette 152, 335-356. KENRICK, P. & CRANE, P.R., 1997. The origin and early diversification of land plants. A cladistic study. Smithsonian Institution Press, Washington, 441 pp. REMY, W., GENSEL, P.G. & HASS, H., 1993. The gametophyte generation of some Early Devonian land plants. International Journal of Plant Science 154, 35-58.

TRACE FOSSILS ARE THE MOST USEFUL INDICATOR OF PALAEOGEOGRAPHIC LOCATION IN ANCIENT BAYS AND ESTUARIES Murray K. GINGRAS1 and Stephen HUBBARD2, and S. George PEMBERTON3 department of Geology, PO Box 4400, University of New Brunswick, Fredericton, NB E3B 5A3, Canada; 2 Department of Geological and Env. Sciences, Stanford University, Stanford, CA 94305-2115, U.S.A.; department of Earth and Atmospheric Sciences, 1-26 Earth Sciences Building, University of Alberta, Edmonton, AB T6G 2E3, Canada

IPC2002 Oral Presentations Ichnology has been widely used to characterize physico-chemical stresses in ancient strata. Several notable core and outcrop studies underscore the utility of ichnology as a tool in palaeoecological research. Those studies have demonstrated that palaeo-turbidity, -salinity, and -oxygenation influence trace fossil assemblages. Although palaeo-stresses cannot be quantified, the ability to assess the relative importance of physico-chemical stresses is invaluable to sedimentologists. Studies of modern organisms and their burrows (neoichnology) focus on expanding our knowledge of how environmental stresses shape ichnofacies. Through detailed mapping of depositional subenvironments at Willapa Bay and the Bay of Fundy, it is seen that animal traces systematically decrease in size and diversity from: (1) the outer- to the inner-estuary; (2) from outer- to inner-intertidal zones, and; (3) between high- and low-energy deposits. Also, characteristic traces dominate particular sedimentary environments: Arenicolites in low-stress intertidal deposits; minute Diplocraterion in moderately stressed intertidal deposits, and; Trichichnus (or small Skolithos) in stressed environments. These observations are bolstered by salinity, substrate caliber, and oxygenation assessments. Several taphonomic considerations confound these generalizations: most notably sediment texture and the degree of sediment reworking due to differing tidal ranges (energy). Identification of those taphonomic parameters enhances resultant depositional models. The aforementioned characterizations are successfully applied to estuarine deposits of the Cretaceous Bluesky Formation (Cadotte Region, Alberta). In this deposit, proxy salinity gradients are successfully mapped facilitating the generation of a detailed palaeogeography. A similar application to the intractable McMurray Formation in northeastern Alberta shows promise for identifying individual estuarine systems in the complex stratigraphy.

MICROBIAL BORING ORGANISMS AS PALAEOECOLOGICAL (ESPECIALLY PALAEOBATHYMETRIC) INDICATORS Ingrid GLAUB. Marcos GEKTIDIS & Klaus VOGEL Geologisch-Palaeontologisches Institut, Johann Wolfgang Goethe-Universitat Frankfurt, Senckenberganlage 32-34, D-60325 Frankfurt, Germany [I.Glaub@em.uni-franlrfurt.de] Borings produced by microbial organisms are globally distributed in calcareous substrates (e.g. molluscan shells) from supratidal to deep sea. Studies on modern and ancient tropical and sub-tropical environments resulted in development of a new method to reconstruct palaeodepths (Glaub 1994, Gektidis 1997, Glaub 1999, Vogel et al. 1999, Vogel et al. 2000). Based on traces of microendoliths a scheme was developed representing a vertical succession of index ichnocoenoses (typical microboring assemblages) related to a photic zonation (euphotic zone with subzones, dysphotic zone, aphotic zone). Photoautotrophic microendoliths (Cyanobacteria, Chlorophyta, and Rhodophyta) are of major importance. Further studies demonstrated that this scheme is applicable to sedimentary basins from the Silurian onwards (e.g. Vogel et al. 1999). The composition of assemblages as well as their vertical sequence show astonishing constancy through Earth history. We are studying fossil (Alaska, Tertiary, 53°N) and modern (Mauritania, 19°N; Scotland, 56°N; and Norway, 70°N) non-tropical sites from different latitudes. Data to date indicate that essential characteristics of the bathymetric scheme, mentioned above, are also present in non-tropical sites under investigation. Generally, the lower boundary of the euphotic zone shallows towards higher latitudes, except for the upwelling area off Mauritania. Altough situated at low latitude, its biogenous-matter content and high suspension load are responsible for a small extension of the euphotic layer (Glaub et al., in press). Some microborings known from tropical areas are missing or less frequent in non-tropical study areas. Whether there are direct indicators for lower temperatures is under investigation. GEKTIDIS, M., 1997. Vorkommen, Okologie und Taxonomie von Mikrobohrorganismen in ausgewahlten Riffbereichen um die Inseln Lee Stocking Island (Bahamas) und One Tree Island (Australien). PhD thesis, Johann Wolfgang Goethe-Universitat Frankfurt am Main, 276 pp. GLAUB, I., 1994. Mikrobohrspuren in ausgewahlten Ablagerungsraumen des europaischen Jura und der Unterkreide (Klassifikation und Palokologie). Courier Forsch.-Inst. Senckenberg 174, 324 pp. GLAUB, I., 1999. Microborings and bathymetrical reconstructions. Bulletin of the Geological Society of Denmark 45, 143-146. GLAUB, I., GEKTIDIS, M. and VOGEL, K. (in press): Microborings from different North Atlantic shelf areas - Variability of the euphotic zone extension and implications for paleodepth reconstructions. Courier Forsch.-Inst. Senckenberg. VOGEL, K., BALOG, S.-J., BUNDSCHUH, M . , GEKTIDIS, M . , GLAUB, I., KRUTSCHINNA, J. a n d RADTKE, G., 1999. B a t h y m e t r i c a l studies

in fossil reefs with microendoliths as paleoecological indicators. Profil 16, 181-191. VOGEL, K . , GEKTIDIS, M . , GOLUBIC, S., KIENE, W . E . a n d RADTKE, G., 2 0 0 0 . S t u d i e s o n m i c r o b i a l b i o e r o s i o n at L e e S t o c k i n g I s l a n d

(Bahamas) and One Tree Island (Great Barrier Reef, Australia) and their meaning for paleobathymetric reconstructions. Lethaia 33 190-204.

IPC2002 Oral Presentations

EARLIEST PALEOCENE MARSUPIALS FROM PATAGONIA Francisco J. GOIN1, Analia M. FORASIEPI2, Adriana M. CANDELA1, Edgardo ORTIZ JAUREGUIZAR3, Rosendo PASCUAL1, Michael ARCHER4,5. Henk GODTHELP5, Jeanette MUIRHEAD5, Michael AUGEE5, Suzanne HAND5 and Stephen WROE6'4 1 Departamento Paleontologia Vertebrados, Museo de La Plata, Paseo del Bosque s/n, 1900 La Plata, Argentina. 2Section Paleontologia de Vertebrados, Museo Argentino de Ciencias Naturales 'Bernardino Rivadavia', Angel Gallardo 470, 1405 Buenos Aires, Argentina. 3Departamento de Paleontologia Vertebrados, Museo Paleontologico "Egidio Feruglio", Fontana 140, 9100 Trelew, Argentina. 4Australian Museum, 6 College Street, Sydney, New South Wales 1010. 5 Vertebrate Palaeontology Laboratory, School of Biological Science, University of New South Wales, Sydney, New South Wales, Australia 2052. 6School of Biological Science, University of New South Wales, Sydney, New South Wales, Australia 2052. The Paleocene fauna from Punta Peligro (Hansen Member, Salamanca Formation; Chubut Province, Argentina) is the oldest Cainozoic vertebrate association known from Patagonia. It includes a variety of vertebrates: several fish, pipid and leptodactilyd frogs, chelid turtles, crocodiles, and a unique combination of Gondwanan and Laurasian mammalian lineages: monotremes, gondwanatherians, dryolestoids, marsupials and placentals (Bonaparte et al., 1993; Gelfo & Pascual 2001). Field work carried out during the last decade in this area led to the recovery of the earliest Patagonian Cainozoic marsupials, as well as one of the oldest marsupial faunas from South America. Punta Peligro marsupials. The Punta Peligro marsupials include the following. 1) A new species of the "opossum-like" marsupial Derorhynchus differs from the other species of the genus in its very small size and in that the lower molars have more mesially placed paraconids and shortened entocristids. 2) A new species of Didelphopsis differs from the type species of the genus in having upper molars with very large, prismaticshaped stylar cusp C, deep trigon basin, and high, eccentric protocone. 3) A small, toothless dentary fragment, whose size does not match that of other marsupials from Punta Peligro, indicates that at least one more species of "opossum-like" marsupial was present in this fauna. 4) An isolated astragalus belonging to a fox-sized borhyaenoid constitutes the largest marsupial known from this fauna. 5) A new polydolopimorphian species is characterized by its large-basined lower molars, small but distinct paraconids and sligthly inflated anterobasal cingulids. 6) Finally, a second polydolopimorphian, representing a new genus and species of bonapartheriid, is presently being described elsewhere. The composition of this marsupial fauna indicates that, already by Peligran times, adaptive trends towards insectivory, carnivory, frugivory, and omnivory were established. Also, Peligran marsupials suggest that the origin and radiation of several South American lineages (especially, the polydolopimorphians) seem to have pre-dated the Cainozoic. Comments on the age of Punta Peligro mammals. Three hypotheses have been postulated about the age of Punta Peligro Local Fauna (LF), particularly with respect to the Tiupampa LF of Bolivia: (1) both are contemporary (Danian; Pascual and Ortiz Jaureguizar, 1991); (2) the Tiupampa LF is older (although both Danian; Bonaparte et al., 1993); (3) the Punta Peligro LF is younger (earliest Selandian in age; Marshall et al, 1997). When marsupials of both faunas are compared, Tiupampan taxa are clearly more plesiomorphic than those of Punta Peligro. The Punta Peligro marsupial assemblage shares at least two genera (Derorhynchus and Didelphopsis) with younger (Itaboraian Age) marsupials from Itaborai (Brazil) and Las Flores (Argentina). Despite this, similarity analyses among late Cretaceous/Paleocene South American mammal faunas suggest affinities between Punta Peligran mammals and those from older (Alamitian) assemblages, hence the absolute age of the Punta Peligro LF is unclear. If the ages of the Tiupampa and Punta Peligro LFs are similar, and this is not yet established, taxic differences between them would suggest some degree of isolation between Patagonia and the rest of the South American continent at that time, with relatively plesiomorphic taxa having been isolated in the more southern region of the continent. Palaeogeographic evidence supports the hypothesis that there could have been biogeographic barriers at least in the Paleocene enabling even contemporaneous assemblages to develop regional distinctions. Field work at Punta Peligro was supported by the Australian Geographic Society, the University of New South Wales, and CONICET (Argentina). BONAPARTE J. F., VAN VALEN, L.M. & KRAMARZ, A., 1993. La fauna local de Punta Peligro, Paleoceno Inferior, de la provincia del Chhubut, Patagonia, Argentina. Evolutionary Monographs 14: 1-61. GELFO J. N. & PASCUAL, R., 2001. Peligrotherium tropicalis (Mammalia, Dryolestida) from the early Paleocene of Patagonia, a survival from a Mesozoic Gondwanan radiation. Geodiversitas 23: 369-379. MARSHALL, L. G., SEMPERE, T. & BUTLER, R. F. 1997 Chronostratigraphy of the mammal-bearing Paleocene of South America. Journal of South American Earth Sciences 10:49-70. PASCUAL, R. & ORTIZ JAUREGUIZAR, E., 1991. El ciclo faunistico Cochabambiano (Paleoceno Temprano): su incidencia en la historia biogeografica de los mamiferos sudamericanos. Pp. 559-574 in: R. Suarez Soruco (Ed.), Fosiles y facies de Bolivia. Revista Tecnica de YPFB 12 (3-4).

IPC2002 Oral Presentations

NEW INSIGHTS ON THE PHYLOGENY OF PLACODERM FISHES Daniel GOUJET Laboratoire de Paleontologie, Museum National d'Histoire Naturelle - UMR 8569 Museum-CNRS, 8 Rue Buffon, 75005 PARIS, France; [goujet@mnhn.fr]. Placoderm fishes are now considered as the sister-group of all other gnathostomata (Chondrichthyes + Osteichthyes) (Young 1986). Their phylogeny has been investigated and a cladogram of all the major groups has been proposed (Goujet&Young, 1995). Given their basal position in the gnathostome phylogenetic scheme, a number of supposed diagnostic characters had to be reevaluated. Some where unique to the Placoderms as a whole , for example, the unique presence of an optic fissure . In view of the new scheme, this feature which could initially be interpreted as an apomorphy can as well represent a "primitive" gnathostome feature. A similar suggestion has been proposed to interpret the monobasal articulation of the pectoral fin in early Placoderms (Goujet 2000). Taking into account a series of endocranial features and new observations on the body armour of early placoderms, a reevaluation of some "classic" characters has been performed and a revised scheme of character distribution on the cladogramme will be proposed. GOUJET D. 2000 Placoderms and basal gnathostome apomorphies . In Ahlberg, P. E. (ed), Major Events in Early Vertebrate Evolution : Palaeontology, Phylogeny and Development: Systematics Association / Taylor & Francis, London. Pp: 209-222. GOUJET D. & G.C. YOUNG, 1995 Interrelationships of Placoderms revisited ; in H.Lelievre et al.(eds) Premiers Vertebres et Vertebres Inferieurs . Geobios , M.S.19: 89-95. YOUNG G.C., 1986 The relationships of placoderm fishes. Zoological Journal of the Linnean Society 88:1-57

PLANT COMMUNITIES AND CLIMATE CHANGE IN SOUTH EASTERN AUSTRALIA DURING THE PALEOGENE TO EARLY NEOGENE David R. GREENWOOD1, Andrew I. ROWETT2, Patrick T. MOSS3, and Rachael L. KEEFE1 1 School of Life Sciences & Technology (S008), Victoria University of Technology, PO Box 14428, Melbourne City MC, VIC 8001, Australia [david.greenwood@vu.edu.au]; 2Mineral Resources Group, Minerals and Energy Resources, PIRSA, GPO Box 1671, Adelaide, SA 5001, Australia.; department of Geography, University of Iowa, Iowa City, IA 52242, USA Data from fossil leaf and spore-pollen floras in south eastern Australia are used to reconstruct vegetation and climates for the Paleogene to early Neogene. Discrepancies between the spore-pollen (microfloral) and leaf (macrofloral) records presented here, are relatively minor - pollen of Nothofagus in Middle Eocene microfloras is abundant (primarily subgenus Brassospora) and Lauraceae are absent, whereas Nothofagus is rare or absent as macrofossils and Lauraceae are abundant and of high diversity in Middle Eocene leaf floras. This bias between the 2 records is largely due to taphonomic effects and can be mitigated by considering the combined microfloral and macrofloral records. Foliar physiognomic analyses and bioclimatic analyses of palaeoclimate, based on the fossil floras, reveal regional cycles of warming and cooling superimposed on the global Cenozoic cooling trend. Quantitative analyses of floristic richness and diversity, employing rarefaction analysis, show that plant diversity rose and fell in parallel to the regional climatic cycles. Our data show that for much of the Late Paleocene to Middle Eocene, complex, multistratal species-rich forests were predominant in south eastern Australia, under mesothermal humid climates (MAT 16-18°C, CMMT >3°C, MAP >200 cm/yr). These mesothermal-megathermal mesic forests were dominated by taxa characteristic of present-day humid tropical Australian rainforests; e.g. Cunoniaceae, Elaeocarpaceae, Gymnostoma (Casuarinaceae), Lauraceae (e.g. Beilschmiedia, Cryptocarya & Endiandra), and Proteaceae (e.g. Musgraveinae, Embothrieae). The relictual araucarian conifer, Wollemia, and other Araucariaceae were present through the Late Paleocene to Early Eocene, with both Agathis and Araucaria present throughout the mid-Paleogene to early Neogene. The megathermal mangrove palm, Nypa, was present in coastal sites in the Early Eocene. Megathermal climates may have been present in lowlands in the latest Early Eocene, during the Cenozoic Global Climatic Optimum, and again in the late Early Miocene climatic optimum. Taxa characteristic of modern-day microthermal to mesothermal forests (e.g. Nothofagus (Nothofagaceae), Eucryphia (Eucryphiaceae), Libocedrus (Cupressaceae) and Podocarpaceae (Acmopyle & Dacrycarpus)) were present throughout much of the Paleogene, but were most prominent during cool phases. Cooler and possibly more seasonally dry climates (MAT 10-14°C, MAP -140 cm/yr, TDM <200 mm/qtr) in the

IPC2002 Oral Presentations Oligocene to Early Miocene are reflected in lower diversity forests that included sclerophyllous taxa such as Eucalyptus and microthermal-mesothermal taxa such as Nothofagus subgenus Lophozonia. Significant floristic turnover is expected after major climatic change, such as at the rapid warming of the Paleocene-Eocene Thermal Maximum (PETM) and the Late Eocene cooling event. However, our data show the most profound shifts in floristic composition and relative dominance by key taxa such as Lauraceae and Nothofagus, occurred at other times. Lauraceae dominated floras thoughout most of the early Paleogene, however palynological data indicate a significant increase in the importance of Nothofagus after the EarlyMiddle Eocene boundary, coinciding with the shift from megathermal-mesothermal climates to mesothermal climates. Lauraceae decline in importance after the Early-Middle Eocene boundary, but Nothofagus macrofossils remain insignificant contributors to macrofloras until the Late Oligocene. Late Early Miocene floras show many of the same floristic characteristics as the megathermal-mesothermal floras of the Earlyearly Middle Eocene (i.e. high Lauraceae and other wet-warm taxa, low Nothofagus). We interpret these patterns as suggesting that mesothermal-megathermal plant taxa, and the plant communities that they formed, retreated north during cool phases and reinvaded south-eastern Australia during warm phases. Mesothermalmicrothermal taxa retreated south (to Tasmania) and to highlands during warm phases. This ebb and flow would have resulted in some regional extinction of taxa, as well as origination of taxa, and reorganisation of plant communities. The patterns of first and last appearance of key taxa, and changes of dominance / diversity support this model. This research was supported by the Australian Research Council. ROOTING STRUCTURES, DISJUNCT ICHNOFABRIC AND OMISSION SURFACES IN QUATERNARY COASTAL DUNE SETTINGS FROM NORTHERN NEW ZEALAND M.R. GREGORY and K.A. CAMPBELL Department of Geology, University ofAuckland, New Zealand. 3

During Quaternary times extensive siliciclastic aeolian dune field and coastal sand accumulation led to the development of two large tombolo-like features in northern New Zealand. These have permanently linked an archipelago of small and once-upstanding, erosionally resistant islands to the mainland. Terraces cut into, and palaeosols developed across dunes or in swales between them are common in these deposits. Their development is related to sea level changes. The dunes were once extensively forested. Today large expanses are bare of any vegetation, with areas of both active deflation and erosion, and others of advancing dunes and deposition. Case-hardened, ferricrete (limonitic and humic cemented) crusts, subconcordant to erosional surfaces and/or related to water-table movement and later exumation are common. Trace fossils produced through the rooting activities of plants are a conspicuous feature of these deposits. In vertical profile this may be a vague-to-strong, pervasively mottled texture. On bedding surface exposures, patterns suggestive of degraded "Thalassinoides" and/or irregular Planolites are often evident. A strong vertical fabric, sometime reaching depths of >40cm, is commonly associated with brownish organic-rich sands and palaeosols. Where enhanced by limonite precipitation, structures suggestive of Skolithos (and pipe rock) are often prominent. One spectacular large trace (the Phoebichnus look-alike), exhibiting the rooting architecture of the endemic New Zealand nikau palm, bears remarkable resemblance to the outer- shelf, deeptier trace fossil, Phoebichnus trochoides. Skolithos traces are often truncated at case-hardened or otherwise cemented crusts, where a characteristic omission suite of firmground clavate burrows and borings may also be developed. Limonitic crusts also form around voids left by the decay of fallen tree trunks, large branches and roots, as well as cracks, cavities and open fissures in these dunal sediments. These subsurface features are also often bored or burrowed in firmground fashion. Unconsolidated fill, passively fallen from openings to the suface, may be colonised by invertebrates seeking a damp or humid safe haven. The backfill in some (? wasp) traces left in this softground are faintly meniscate. Trace fossil orientation is generally either orthogonal or parallel to depositional surfaces. Around these cavities, traces and tiering fabrics may cross one another in an irregular fashion, or develop oblique to primary bedding surfaces. In some instance they can even be inverted. In older sedimentary sequences, such disjunct relationships could further complicate or mislead ichnologic and palaeontologic interpretations, already fraught through mistaking terrestrial rooting structures for marine ichnotaxa.

IPC2002 Oral Presentations TOWARDS NEOPROTEROZOIC BIOZONATION IN AUSTRALIA Kathleen GREY Geological Survey of Western Australia, 100 Plain Street, East Perth, WA 6004, Australia Despite numerous reports of fossils including prokaryotic microfossils, eukaryotic phytoplankton, metazoan body and trace fossils, metaphytes, and stromatolites, progress towards Proterozoic biostratigraphy remains limited. The lack of zonal schemes (standard for the Phanerozoic) has been attributed to such factors as low species diversity, taxonomic uncertainty, morphological simplicity, sporadic distribution, and conservative evolution rates. Instead, Australian Neoproterozoic acritarch studies suggest that the lack of zonation reflects a non-systematic approach and a failure to apply standard biostratigraphic techniques, such as plotting range charts. In the race to describe new taxa, relative stratigraphic positions have not commonly been recorded, so it is impossible to determine time distributions or produce meaningful correlations. However, the search for hydrocarbons and minerals in the Centralian Superbasin and Adelaide Rift Complex (ARC) has prompted the development of biostratigraphic correlations using range charts. The Australian Neoproterozoic palynological record is based on studies of nearly 2000 samples from about 30 drillholes in the ARC and Officer, Amadeus and Georgina Basins (Zang and Walter, 1992; Zang, 1995; Gravestock et al., 1997; Grey, 1998, in press, Hill et al, 2000; and references therein). Acritarchs are organic-walled, acid-insoluble, mostly phytoplanktonic, polyphyletic microfossils. They are ideal for biostratigraphy because of their complex morphology, abundance, short stratigraphic ranges, and wide geographic and lithofacies distributions. Palynomorphs from c.850 to 700 Ma are well represented in Western Australian drillholes and differ little from those recorded globally back to c.1200 Ma. They comprise benthic microbial mats (cyanobacterially dominated) and a shelfal plankton of leiospheres (single-celled green algae) and rare, complexly ornamented taxa (e.g. Cerebrosphaera), which are important marker fossils. Assemblages from c.700 Ma to c.580 Ma (i.e. ranging through the Sturtian and Marinoan glaciations) are found in South and central Australia. They are similar to pre-glacial ones, but species are fewer. Samples immediately above Marinoan glacial sediments are barren, but benthic mats and leiospheres quickly re-established and proliferated as sea level rose. However, the same species are present after the glaciation as before it; the only difference is a further depletion of an already impoverished biota. There is no evidence for recolonisation by rapidly diversifying species from different ecological niches, nor for evolution from extremophiles that might have survived glaciation in hot-spring refugia, so Australian assemblages do not match Snowball Earth predictions. There is a later marked change in phytoplankton assemblages, when >50 species of large, acanthomorph (spiny) acritarchs first appear. They resemble resting cysts of modern dinoflagellates and differ considerably from previous taxa. Acanthomorph diversification was rapid, but terminated at about the time of the main radiation of the Ediacara fauna, c.565 Ma. Four biostratigraphic assemblage zones can be identified. Acanthomorph radiation did not occur until the second post-glacial marine excursion and appears unrelated to sedimentology or sequence stratigraphy (Arouri et al., 2000). However, there is a remarkable coincidence between the first appearance of the acanthomorph palynoflora, a S C organic carbon excursion (Calver and Lindsay, 1998), and the Acraman impact ejecta layer. It is still not clear whether the Acraman impact played a role in the acanthomorph explosion. Global extension of the zonation scheme is not yet possible because ranges of key species have not been determined outside Australia. Nevertheless, there are, species in common with Svalbard, Norway, Siberia, and China, indicating a potential for global correlation. 13

AROURI, K., CONAGHAN, P.J., WALTER, M.R, BISCHOFF, G.C.O. and GREY, K., 2000. Reconnaissance sedimentology and hydrocarbon

biomarkers of Ediacarian microbial mats and acritarchs, lower Ungoolya Group, Officer Basin. Precambrian Research 100, 235281.

GRAVESTOCK, D.I., MORTON, J.G.G. and ZANG, W-L., 1997. Biostratigraphy and correlation, pp.87-97. In Morton, J.G.G. and Drexel,

J.F. (eds), Petroleum Geology of South Australia, Volume 3: Officer Basin; South Australia, Department of Mines and Energy Resources, Report Book 97/19. GREY, K., 1998. Ediacarian acritarchs of Australia. PhD thesis, Macquarie University, 669 p. (unpublished). GREY, K., in press. Ediacarian palynology of Australia. Association of Australasian Palaeontologists Memoir. HILL, A.C., COTTER, K.L. and GREY, K., 2000. Mid-Neoproterozoic biostratigraphy and isotope stratigraphy in Australia. Precambrian Research 100,283-300. ZANG, W-L., 1995. Early Neoproterozoic sequence stratigraphy and acritarch biostratigraphy, eastern Officer Basin, South Australia. Precambrian Research 74, 119-175. ZANG, W-L. and WALTER, M.R., 1992. Late Proterozoic and Early Cambrian microfossils and biostratigraphy, Amadeus Basin, central Australia. Association of Australasian Palaeontologists, Memoir 12, 1-132.

IPC2002 Oral Presentations TEMPORAL AND SPATIAL RELATIONSHIPS BETWEEN NEW ZEALAND AND VICTORIAN CORALS (SCLERACTINIA) Montague GROVER Deakin University, Melbourne Campus, 221 BurwoodHighway, Burwood, Vic., 3125, Australia It is now understood that one of the fundamental aspects of coral biogeography is that widely separated localities with similar physical environments have a greater affinity than those having adjacent locations, even though ocean currents drive dispersion. For example, in the modern context, corals of the north-west shelf of Australia have a greater similarity to those of the Great Barrier Reef than they have with adjacent mainland coasts (Veron, 1995). The same can be seen between the Cenozoic corals of southeastern Australia and New Zealand. One possible mechanism to allow this similarity in fauna is the reversal of the Leeuwin Current. There has been some discussion on this reversal during the Pliocene (see McGowran et al, 2000; Leach & Wallace, 2001) but was this reversal longer lasting, or did it occur more than once? There appears to be evidence that certain coral genera and species evolved in New Zealand and were then transported to southeastern Australia. For example, both Stephanocyathus (Acinocyathus) springer Cairns & Parker, 1992 and Flabellum (Pavonium) distinctum Milne Edwards and Haime, 1848, first appeared in the Bortonian (Middle Eocene) in New Zealand (Squires, 1958) and then appeared in the Janjukian (Oligo-Miocene) of southeastern Australia. On a generic scale, Oculina again appears first in the lower Miocene of New Zealand (Park, 1917) and then doesn't appear until the Cheltenhamian (Pliocene) of southeastern Australia (Dennant, 1904). Trochocyathus appears in the Bortonian (mid-Eocene) (Squires, 1958) before being present in southeastern Australia during the Oligo-Miocene and Notocyathus first appears in the Duntroonian (Lower Oligocene) (Squires, 1962) of New Zealand before showing up in the Janjukian of southeastern Australia. The reversal of the current flow between Australia and New Zealand would explain this inconsistency. DENNANT, J., 1904. Descriptions of new species of corals from the Australian Tertiaries. Part VII. Transactions of the Royal Society of South Australia 28, 52-76. LEACH, A.S. and WALLACE, M.W., 2001. Cenozoic Submarine Canyon Systems in Cool Water Carbonates from the Otway Basin, Victoria, Australia, pp. 465-473. In PESA Eastern Australasian Basin Symposium, Melbourne, Vic, 25-28 November 2001. MCGOWRAN, B., ARCHER, M . , BOCK, P., DARRAGH, T.A., GODTHELP, H., HAGEMAN, S., HAND, S.J., HILL, R., LI, Q., MAXWELL, P.A., MCNAMARA, K.J., MACPHAIL, M . , MILDENHALL, D., PARTRIDGE, A . D . , RICHARDSON, J., SHAFIK, S., TRUSWELL, E . M . a n d

WARNE, M., 2000. Australasian palaeobiogeography: the Palaeogene and Neogene record. Memoir of the Association of Australasian Palaeontologists 23, 405-470. PARK, J., 1917. On a new species of coral from the Lower Oamaruian Tuffs near Deborah, Oamaru. Transactions and Proceedings of the New Zealand Institute for the year 1916, 49, 396, plate 27. SQUIRES, D.F., 1958. The Cretaceous and Tertiary corals of New Zealand. New Zealand Geological Survey Paleontological Bulletin 29, 1-107, 16 plates. SQUIRES, D.F., 1962. Additional Cretaceous and Tertiary Corals from New Zealand. Transactions of the Royal Society of New Zealand Geology, 1, 134-150, plates 1-4. VERON, J.E.N., 1995.Corals in space and time: biogeography and evolution of the Scleractinia, UNSW Press, Sydney.

THE ROLE OF ABIOTIC FACTORS IN THE EVOLUTION OF THALASSOID PULMONATE GASTROPODS ON THE EXAMPLE OF LAKE PANNON PLANORBIDAE Sandor GULYAS University of Szeged Department of Geology and Paleontology, H-6722 Szeged, Egyetem u. 2-6 fgubanc@yahoo. com]. The nature of the relationship between environmental change and evolutionary change while always believed important is very poorly understood. Studying an "ancient" lacustrine system offering both very spectacular endemic evolutionary diversification and a very detailed environmental history might help us in elucidating something from the nature of this relationship and furthermore to shed light onto some very interesting aspects of intralacustrine speciation, i.e how genetic isolation is formed in case of communities living in such close proximity. More than 80 species of the family Planorbidae colonize today's major ancient lakes, 45% of them being endemic forms. The majority of them inhabit shallow water, littoral environments and display a large variance in size and shape at the same time. Most of the endemic Gyraulus taxa from both today's ancient lakes (Lake Ohrid, Lake Biwa, Lake Titicaca, Lake Preszpa) and those previously described from known "fossil ancient" lakes ( miocene Lake Steinheim) bear so called "thallassoid" shells as opposed to the traditional flat discus-like shells of shallow lacustrine, marshy and fluvial ubiquist species. The major characteristics of these shells are strong carination on both the umbilical and spiral side of the shell, high

IPC2002 Oral Presentations ornamentation (striation, transverse and spiral) and the deflection of the ultimate whorl and the aperture. In some cases even the development of trochospiral shells could be observed as well. The Late Miocene fossil ancient Lake Pannon of Central-Eastern Europe harbored an exceptionally diverse endemic fauna with about 40 described endemic species of Planorbids. This lakes system offers an exceptional opportunity for understanding something about the development of thalasoid shells not only because of its age (7 My.) but it also offers a highly detailed chronostratigraphic background and information of palaeoenvironmental conditions as well. Most of the endemic Planorbids occupied shallow water littoral regions of the lake, developing highly globose, thalassoid shells bearing strong keels and variable ornamentation as well as deflected ultimate whorls from the original flat, discus-like species invading the new niches of this lacustrine system from the neighboring marshes and fluvial systems following the birth of the lake. (Gyraulus varians varians (FUCHS), Gyraulus lorenthey (BRUS), Gyraulus constans (BRUS), Gyraulus varians radmanesti (FUCHS), Gyraulus striatus (BRUS)). As it has been emphasized in case of the thalassoid gastropods of Lake Tanganyika by Hubendick (1952) time is one of the major factors responsible for the development of these shell forms. Other assumptions of predator-prey coevolution could not have been justified on the basis of information collected from recent ancient lakes. Sedimentological and palaeoecological investigations of the lacustrine deposits of Lake Pannon, bearing the thallassoid fossils of Planorbidae as well as the SEM ultrastructural analysis of the shells refer to a strong correlation between the shell ornamentation and form and the energy conditions of the habitat reflected in the composition of the embedding sediments. According to our findings one of the major factors influencing the formation of thalassoid Planorbid shells in Lake Pannon was that of the adaptational pressure to higher energy littoral conditions in a more open lacustrine system. As the forms with higher thalassoidicity have come to light from higher energy littoral sands and indicated some sort of strengthening mechanism in their ultrastructures as well (development of double cross layers e.g). Our work is supported by OTKA Grant T029342 and NSF Grant EAR9706230.

GONDWANATHERE MAMMAL JAW REMAINS FROM ARGENTINA: A PRELIMINARY ASSESSMENT Yamila GUROVICH Section Paleontologia de Vertebrados. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia". Av. Angel Gallardo 470 (1450) Buenos Aires, Argentina [ygurovich@alpa.com] Gondwanatheres (Suborder Gondwanatheria) are an extinct clade of derived multituberculate or multituberculate-like mammals exclusively found in the Late Cretaceous of Argentina, India and Madagascar and Early Paleocene of Argentina. The family Ferugliotheriidae recorded only in the Late Cretaceous of Argentina includes the distinctive multituberculate Ferugliotherium windhauseni, whereas the Family Sudamericidae consists of the highly specialized hypsodont genera Gondwanatherium patagonicum from the Late Cretaceous and Sudamerica ameghinoi from the early Paleocene of Argentina. Sudamericidae have also been recorded from Madagascar and India indicating their Gondwana distribution Most gondwanathere material has been discovered in Argentina; it consists of isolated teeth and three fragmented dentaries—one edentulous, another bearing a single tooth, and the third a more complete jaw with two molariforms cheek-teeth. Recently, Pascual et al. (1999), who described a lower dentary of Sudamerica ameghinoi, a gondwanathere mammal from the Early Paleocene of Argentina, regarded the gondwanathere families Ferugliotheriidae and Sudamericiidae as Mammalia incertae sedis, whereas KielanJaworowska & Hurum (2001) consider some specimens of Ferugliotherium windhauseni of the Family Ferugliotheriidae to have multituberculate affinities and thus to be considered as Gondwana multituberculates. In this study, fragmentary jaw remains of Ferugliotherium windhauseni, Gondwanatherium patagonicum and Sudamerica ameghinoi are compared with general characteristics of the multituberculate jaw; similarities are the strong and massive lower jaw, elongate and pronounced diastema, procumbent gnawing lower incisors, elongate and blade-like lower first molariform or premolar, molariforms with more than one longitudinal row of multiple cusps and molar occlusal pattern indicating palinal jaw movement. Differences include hypsondont molariforms covered with a thick cementum layer, and a lower dental formula consisting of four? molariforms considered here as derived characters of the hypsodont family Sudamericidae. It is suggested that the development of hypsodonty was not an isolated phenomenon affecting only the molars. It probably also affected the premolars and some aspects of the morphology of the lower jaw including musculature involved in mastication. KJELAN-JAWOROWSKA, Z. & HURUM, J. H. 2001. Phytogeny and systematics of multituberculate mammals. Paleontology 44. 389-429.

IPC2002 Oral Presentations PASCUAL, R., GOIN, F. J., KRAUSE, D. W., Ortiz-Jaureguizar, E. & Carlini, A. A. 1999. The first gnathic remains of Sudamerica: implications for gondwanathere relationships. Journal of Vertebrate Paleontology 19, 373-382.

MID-LATE CRETACEOUS OSTRACODES AND THE CENOMANIAN/TURONIAN BOUNDARY EVENT IN THE EAST INDIAN OCEAN Michelle GUZEL 17 View St., Pascoe Vale, Victoria 3044 A study of the mid-Late Cretaceous (Albian-Maastrichtian) ostracodes, derived from the cores of four petroleum exploration wells on the Exmouth Plateau and the southern end of the North West Shelf (northwest Australian margin), revealed a dramatic faunal dichotomy at the Cenomanian/Turonian boundary. This mass extinction was due to 'an intensified and probably expanded oxygen minimum zone' (Thurow, Brumsack, et al., 1992). In this region the east Indian Ocean, which had opened in the Albian when India separated from Australia-Antarctica, was a small arm of Tethys, which lay to the north. Consequently, this post-rift passive continental margin bordered an open ocean and because of this oxic conditions prevailed at greater water depths during the Cenomanian/Turonian Boundary Event (Thurow, Brumsack, et al., 1992). Within the Albian-Cenomanian ostracode fauna, which existed prior to the Cenomanian/Turonian Boundary Event, 16 genera were identified. The genera Arculicythere, Robsoniella, Cytherella and Bairdia predominated. The presence of Arculicythere tumida, Collisarboris? Stanleyensis, Isocythereis sealensis and Pirileberis indicates this fauna has strong affinities with South African, Falkland Plateau and Madagascar faunas, and hence, Dingle's (1988) distinctive South Gondwana Fauna B. This study also revealed a minor incursion of a more endemic Australian component in the Late Cenomanian, just prior to the Cenomanian/Turonian Boundary Event, which reappears during the Santonian recolonization and species radiation. It is represented by three genera: Semicytherura, Paramunseyella and Premunseyella. Recovery from this mass extinction was slow, as demonstrated by the impoverished ostracode fauna of the Turonian-Coniacian, which yielded only two cosmopolitan genera. It was not until the Santonian that a new strongly endemic fauna, combined with a cosmopolitan element, successfully recolonized the region and rapidly speciated to such an extent that diversity was much greater than in the previous Albian-Cenomanian fauna. It is composed of 34 genera with the dominant genera being Apateloschizocythere, Paramunseyella, Karsteneis, Scepticocythereis, Bairdia, Cytherella, Cytherelloidea and Bythocypris. The presence of Apateloschizocythere, Cythereis, Curfsina and Unicapellinae indicates affinity with South African and Tanzanian faunas; the presence of Anebocythereis provides a link to Argentinian faunas. Consequently, there is some similarity with Dingle's (1988) Pan Gondwana Fauna. However, this ostracode fauna is still distinctly Australian, which is a result of Australia's increasing isolation. Within these two ostracode faunal assemblages, lying on either side of the Cenomanian/Turonian Boundary Event, there are also subtle differences in composition related to environmental changes in the east Indian Ocean. DINGLE, R., 1988. Marine ostracod distribution during the early breakup of Southern Gondwanaland, pp. 841-854. In Hanai, T., Ikeya, N. & Ishizaki, K. (eds), Evolutionary Biology of Ostracoda - Its Fundamentals and Applications; Developments in Palaeontology and Stratigraphy No. 11, Elsevier and Kodansha. THUROW, J., BRUMSACK, H-J., RULLKOTTER, J., LLTTKE, R. & MEYERS, P., 1992. The Cenomanian/Turonian Boundary Event in the

Indian Ocean - a key to understand the global picture, pp. 253-273. In Duncan, R. A., REA, D.K., KIDD, R.B., VON RAD, U. & WEISSEL, J.K. (eds), Synthesis of Results from Scientific Drilling in the Indian Ocean; Geophysical Monograph 70, American Geophysical Union.

CONSERVATISM AND INNOVATION AMONG FORAMINIFERA FROM AUSTRALIA'S ANCIENT INTERIOR SEAS David W. HAIG School of Earth and Geographical Sciences, The University of Western Australia; [dhaig@geol.uwa.edu.au]. The vast shallow seas that flooded across interior Australia during the Cisuralian (Early Permian) and Early Cretaceous, contain analogous foraminiferal microfaunas. During these periods, Australia lay at mid to high palaeolatitudes in cool, apparently humid, climatic belts. The interior seas were probably microtidal with constricted openings to the open ocean. They seem to have been characterised by low-energy shorelines and a shallow wave base, and were the depositional sites of generally thin shore-face sands and laterally extensive organic-rich offshore muds. The present-day Gulf of Carpentaria may be analogous in terms of water depths and gateways to the open ocean. It has shallow water depths, less than 60 m deep, and silled

IPC2002 Oral Presentations passageways (<12 m deep) to the ocean. However, unlike the Permian and Cretaceous seas, the Gulf of Carpentaria lies in a tropical climatic belt periodically affected by cyclones. Foraminiferal assemblages from the cool-water interior seas of the Early Permian and Early Cretaceous are characterised by an abundance of organic-cemented siliceous agglutinated foraminifera. These faunas represent the conservative Ammobaculites Association with many of the same genera and even similar species represented in both periods. At intervals where more open-marine conditions were present in the interior seas and bottom waters were more oxygenated, the siliceous agglutinated species were accompanied by calcareous benthic foraminifera including lagenids and miliolids during both the Permian and Cretaceous, and spirillinids, robertinids, buliminids, and rotaliids during the Cretaceous. Among the organic-cemented siliceous agglutinated foraminifera, which are usually preserved as deformed deflated tests, most of the genera known from the Permian are represented by similar morphotypes in the Cretaceous. The composition of the agglutinated assemblages changes with water depth with at least some similarities in morphotype distribution between the Permian and Cretaceous. There is little evidence of agglutinated-species evolution during the time intervals represented by the marine incursions. However, during both the Permian and the Cretaceous, unusual agglutinated genera not known elsewhere and without a known ancestry, abruptly appear in the interior-sea successions (e.g. Giralliarella in the Permian, Andamookia in the Cretaceous). Other agglutinated species migrated into the interior seas at various times after the initial marine transgressions and their first appearances provide datum levels for biostratigraphic zonation. The benthic foraminifera that precipitate calcareous tests first appear in the interior-sea successions following the initial siliceous agglutinated assemblages of the basal marine units. Lagenids belonging to Howchinella and Nodosaria are the most widespread Permian calcareous species within the interior seas. Calcareous porcellaneous foraminifera (for example, the attached Calcitornella and Trepeilopsis) are abundant at certain intervals within the Permian succession and seem to have been confined to areas of high biogenic carbonate-sand production, possibly in macroalgal meadows. Similar facies were apparently absent from the Cretaceous interior seas. Elements of the calcareous microfauna evolved rapidly within the interior seas; for example, certain lagenids in the Permian, and some of the buliminids and rotaliids (gavelinellids) in the Cretaceous. In the Cretaceous, the interior-sea microfauna is distinct from that on the open continental margin (which is more diverse and includes agglutinated foraminifera with calcareous cement - the Marssonella Association). The boundary between areas occupied by the Ammobaculites and Marssonella Associations seems to be sharp and probably represents a narrow salinocline separating slightly brackish from normalmarine waters. Open continental-margin faunas of the Permian are not clearly distinguished from Australia or in equivalent palaeolatitudes elsewhere. The foraminiferal assemblages from the Permian and Cretaceous interior seas resemble, in terms of broad composition and diversity, microfaunas from present-day cool-temperate estuaries and marshes located in humid climates. These present-day shallow-water brackish environments are characterised by seasonal variation in temperature, salinity, and sea-floor dissolved-oxygen conditions, and by low diversity foraminiferal assemblages composed mainly of cosmopolitan species. The Permian and Cretaceous foraminifera that flourished in the vast interior seas may have evolved and survived, particularly during low stands of sea level, in estuarine and marsh communities that, through time, formed a tenuous but continuous marginal marine biota. THE EARLIEST LEAVES Shou-Gang HAO . Charles B. BECK & De-Ming WANG School ofEarth and Space Sciences, Peking University, Beijing 100871, P. R. China, and Museum of Paleontology, The University of Michigan, Ann Arbor, Michigan, 48109 USA [sghao@pku.edu.cn]. 1

New fossils of the Early Devonian (Pragian age, Posongchong Formation) plant, Eophyllophyton bellum from the Wenshan district of southeastern Yunnan of China, provide morphological and anatomical information that contributes to understanding of the origin and early evolution of the megaphyll. These earliest leaves are characterized by leaf divisions, apparently arranged in several planes, with branching venation and a mesophyll of longitudinally elongate cells. The mesophyll is polygonal or hexagonal in transverse view, structurally similar to that of a modern isobilateral leaf without differentiation into layers of palisade and spongy parenchyma, but differs in lacking a conspicuous system of intercellular air channels. These features support the hypothesis that the megaphyll was derived from an axial branching system. The small size and deeply incised margin of these leaves suggest adaptation to an environment of heat stress and high concentration of atmospheric C0 . Whereas the available evidence suggests that the megaphyll evolved during the Early Devonian, a period of harsh environmental conditions, the evolution and radiation of larger 2

IPC2002 Oral Presentations megaphylls were apparently correlated with a massive drop in atmospheric C0 2 during the Late Devonian and Early Carboniferous. It is probable that the presence of megaphylls such as those of Eophyllophyton contributed to increase of 0 2 and the decrease of C0 2 in the Early Devonian atmosphere. This study was supported by NSFC (grant no. 49972009) and MBRP (G2000077700). BERNER, R.A., 1994. GEOCARB II: A revised model of atmospheric C0 2 over Phanerozoic time. American J. Sci. 297, 56-91. BERNER, R.A., 2001. Modeling atmospheric 0 2 over Phanerozoic time. Geochimica et Cosmochimica Acta 65, 685-694. BEERLING, D.J., OSBORNE, C.P. and CHALONER, W.G., 2001. Evolution of leaf-form in land plants linked to atmospheric C0 2 decline in the Late Palaeozoic era. Nature 410, 352-354. KENRICK, P., 2001. Turning leaves. Nature 410, 309-310. HAO, S-G and BECK, C.B., 1993. Further observations on Eophyllophyton bellum from the Lower Devonian (Siegenian) of Yunnan, China. Palaeontographica B 230, 27-41. HAO, S-G and GENSEL, P.G., 1998. Some new plant finds from the Posongchong Formation of Yunnan, and consideration of a phytogeographic similarity between South China and Australia during the Early Devonian. Science China (SD) 41, 1-13. HAO, S-G and GENSEL, P.G., 2001. The Posongchong floral assemblages of southeastern Yunnan, China - diversity and disparity in eErly Devonian plant assemblages, pp. 103-119. In Gensel, P. G. and Edwards, D. (eds), Plants invade the land. Columbia University Press, New York.

EARLY PLIOCENE MOLLUCAN FAUNA FROM MARINE PLAIN, ANTARCTICA Lucy HARDING1. Stephen GALLAGHER1, Tom DARRAGH2 and Pat QUILTY3 1 University of Melbourne; 2Museum of Victoria;3 University of Tasmania Marine Plain (68° 37.7'S, 78° 07.8'E) covers an area of approximately 10km2, and is located 10km southeast of Davis Station. The sediments at Marine Plain are considerably older than others found around the Vestfold Hills and unconformably overlie Precambrian gneiss. To date Marine Plain has yielded the best preserved, most diverse and available Pliocene fossils in Antarctica. A change in the marine invertebrate benthic assemblages occurs from 4 million years to present in the Vestfold area. Today's shelly marine communities in the vicinity of Davis station consist essentially of one species of Laternula, echinoids and pectins, with ice rafted diatoms. The analysis of the Pliocene invertebrate fauna at Marine Plain is providing a rare insight into both; the evolution of modern Antarctic marine communities and the Pliocene global warming debate. However, limited areal exposure, poor preservation and often-bad distortion due to compaction hamper the utility of the analysis of macrofossils at Marine Plain. The assemblages at Marine Plain can be separated into two distinct bands. The only common species present in both bands is the bivalve Chlamys tuftensis Turner. The Early Pliocene age of the sediments at Marine Plain is based on the presence Chlamys tuftensis in the sediments. The highly lithified upper unit is the Graveyard Sandstone Member, and is 30-50 centimetres thick. The fauna in the Graveyard Sandstone Member is better preserved than that in the lower diamictite unit, with greater shell preservation and higher occurrence of articulated valves. Bivalves, from five genera, make-up the total macrofossils present in the unit. The lower unit is diatomaceous sandstone, 1.4 meters thick. This unit has a high diversity of macrofossils, including archiogastropods (and burrowing trails), echinoids, serpulid worms, algae and bryozoa (both sheet and stick). This is the only unit with both bivalves and gastropods. To date the two bivalves Chlamys tuftensis and Neilo sp. have been identified along with the four gastropods Litorinid sp., Falsimargarita sp., Trophon c.f. disparoides and Chlanidota c.f. lamyi. All valves of Chlamys tuftensis are disarticulated and encrusted with Spiorbidae, both internally and externally. In contrast Neilo sp. has no encrustation on the external surface of the valves due to their burrowing nature and thus lack of exposure following death. There is however encrustation on the internal surfaces, although rare, which would have occurred post death when the shell would have fully opened and been exposed on the sea floor. The Neilo sp. was also interestingly never found preserved in life position, leading to the conclusion that the valves were partially transported. There was no shell material remaining of the Neilo due to the dissolving of the aragonite shell during low rates of accumulation.

DEVONIAN MIOSPORES OF THE ADAVALE BASIN, QUEENSLAND, AUSTRALIA Hossein H A S H E M I Department of Geology, Teacher Training University, Tehran 15614, Iran [hashemi338@yahoo.com].

IPC2002 Oral Presentations Diverse and reasonably well-preserved palynofloras occur in core samples of the marginal marine to continental sediments of the Adavale Basin. Miospores dominate the assemblages; acritarchs, prasinophyte phycomata, and scolecodonts also occur as minor components in all palyniferous rock units. Eighty-two species of miospores distributed among 38 genera are recorded herein, as are representative examples of microphytoplankton and scolecodonts; only miospores are treated systematically. Of these several species show features not matched with those found in the literature and may proved to be new species. From the vertical distribution of certain miospore species and inception of particular spore-morphological traits, three successive spore floras, informally termed "assemblages", are identified within the pre-Buckabie sedimentary sequence of the Adavale Basin. Of these, Assemblage I, occurring in the Eastwood beds, represents the oldest known Devonian spore assemblage yet reported from Australia. The three assemblages are compared with others recorded previously from the Adavale Basin and elsewhere in the Australian Devonian. In the absence of chronostratigraphically conclusive faunal evidence, this spore-based subdivision of the Adavale succession offers considerable scope for intra- and inter-basinal biostratigraphic correlation. The Adavale spore floras and the upper Lower Devonian to lower Upper Devonian Euramerican (Old Red Sandstone Continent) spore zones have 20 miospore species (including three cf. identifications) in common. Whereas the oldest Adavale spore flora (Assemblage I) is not comparable with any of the Euramerican spore zones, Assemblages II and III can be confidently correlated with the devonicus-naumovae and optivustriangulatus Assemblage Zones, respectively. This suggests a trend towards progressive palynological, hence floristic alliance between Gondwanic Australia and Euramerica through the Middle and Late Devonian; i.e., increasing floral cosmopolitanism. Based on miospore species and/or form features shared with Euramerican spore zones, the Adavale spore floras are collectively dated as possibly late Early Devonian (Emsian) to early Late Devonian (Frasnian). This dating slightly extends the time interval previously adduced, partly on faunal evidence. Sampling restrictions in the present study leave open the question of depositional breaks within the Adavale sequence, previously inferred from maturity and geophysical data. Information from elsewhere of spore-plant relationships implies that Zosterophyllopsida, Barinophytopsida, and Lycopsida were probably the main sources of sporae dispersae in Assemblages I and II. The dominant miospore species in Assemblage III - Geminospora lemurata - is known to have been produced by arborescent archaeopterids. Restricted sedimentological and palaeontological evidence in conjunction with palynological composition data indicate shallow marine to continental sedimentary environments for the Adavale sequence. LIVING ON THE EDGE: PALAEOECOLOGY OF A MID-CRETACEOUS BLACK SHALE FAUNA FROM THE TOOLEBUC FORMATION, EROMANGA BASIN, QUEENSLAND Robert A. HENDERSON School ofEarth Sciences, James Cook University, Townsville Q4811, Australia The Toolebuc Formation (Late Albian) is a thin (<40m), very widely distributed unit marking the maximum deepening of the Cretaceous epicontinental sea recorded by the infill of the Great Artesian Basin, eastern Australia. It consists of organic-rich shale, with TOC ranging to 35%, and limestone as laminae and thin beds comprised of Inoceramus sutherlandi McCoy, and less commonly Aucellina hughendenensis Etheridge. Finely interlayered organic-rich shale and coquina as typical of the Toolebuc Formation are a unique association for the entire early Cretaceous sedimentary sequence of eastern Australia, suggesting a genetic linkage. Inoceramus valves are commonly disturbed by breakage, reorientation and imbrication and in many cases have disintegrated into prism horizons. Sedimentary laminae show that the sea-floor was subject to some current activity but benthic scavengers missing from the fossil record are considered to have been active agents of shell disturbance. Although shelly substrate suitable for encrusting epibenthos or colonization by endoliths was available in abundance other benthic elements, inclusive of trace fossils, are very poorly represented. The formation contains diverse planktonic, pelagic and nektonic fossil remains, including a range of ammonites, belemnites and teuthids, fish and marine reptiles, attesting to deposition beneath a water column of normal salinity, supporting a complex food chain. It is associated with a negative excursion of 8 C, consistent with high productivity and suggestive of appreciable recycling of organic carbon from the sea-floor to the water column. In the context of the Toolebuc Formation, Inoceramus sutherlandi and Aucellina hughendenensis represent ecological specialists, with shell growth strategies designed to cope with soft substrates and physiologies that were tolerant of oxygen-poor bottom conditions. Their abundance in, and intimate association with, organic-rich shale suggests a trophic link with sea-floor bacterial productivity, supported 13

IPC2002 Oral Presentations from the organic-rich substrate, having sustained this unusual benthic community. The extensive stratiform character of the Toolebuc coquinas and the occurrence of both Inoceramus sutherlandi and Aucellina hughendensis in the overlying Allaru Formation, in association with a more diverse benthos, suggests they were filter feeders rather than dependent on chemotrophic symbionts. Fine scale interlayering of coquina and organic-rich shale attests to frequent alternation of sea-floor conditions conducive to colonization by bivalve communities and those which were not. This is attributed in part to an autocyclic mechanism, with sea-floor accumulation of shelly debris having progressively isolated bivalve communities from the food source causing their episodic demise.

PLANT (MACRO- AND MICROFOSSILS) OF THE SHEMSHAK FORMATION, SHAHRUD, IRAN Freshteh Saiiadi HEZAVEHI Department of Geology, University of Tehran, Tehran, P.O. Box 14155/6455, Iran Poorly preserved palynofloras and reasonably well preserved plant megafossils occur in lagonal sediments of the Shemshak Formation of the Tazareh area, W of Shahrud, in NE Iran. All plant macro- and microfossils are recorded and treated systematically. The studied interval contains a taxonomically diverse assemblage of plant macrofossils comprising 28 species (in 16 genera) indicating a Rhaetian-Middle Jurassic age. The plant microfossils consist of 44 species (in 32 genera) suggesting an Early-Middle Jurassic age for the upper part of the section studied. Inferred natural relationships of the dispersed spores and pollen of the Shemshak palynofloras imply derivation from a diverse parental flora (bryophytes, lycopods, pteridophytes, ginkgophytes and cycadophytes) growing under moist and warm climate during Early-Middle Jurassic. The presence of Phlebopteris muensteri, Clathropteris meniscoides and Cladophlebis sp. cf C. nebbensis indicates that basal layers of the Shemshak Formation are Rhaetian. A Middle Jurassic (Bajocian-Bathonian) age for the upper part of the formation has been inferred from the presence therein of Ptilophyllum sp., Coniopteris hymenophylloides, and Podozamites lanceolatus. Moreover, some species of the palynofloras such as Concavissimisporites verrucosus, Murospora florida, Perotriletes whitfordensis, Matonisporites crassiangulatus and Klukisporites variegatus in the upper part of the section suggest a Middle Jurassic age for this interval. Palynological composition data in conjuction with the relatively abundant macrofloral data suggest that the Shemshak Formation accumulated under marginal lagoon settings. Additionally, the presence of marine microphytoplankton (namely Cleistosphaeridium) suggests brief marginal marine incursions during accumulation of the Shemshak Formation in the study area.

INTRA-ANNUAL VARIABILITY IN SKELETAL GROWTH OF THE DEVONIAN TABULATE CORAL SCOLIOPORA Jindrich HLADIL Institute of Geology, Academy of Sciences CR, Rozvojova 135, 165 02 Prague, Czech Republic Information from intra-annual skeletal variation in Moravia, Czech Republic, involves promising but still unrefined tools for understanding puzzles of palaeogeography and palaeoclimates. Practically, fine banding in corals or sponges is optically best discernible in lagoons between lowstand and transgressive system tracts. Here, the embedding limestone mud has included organic matter, iron and sulphur, but the brown-coloured dense bands contain increased concentrations of Fe and A1 (terrestrial influx). The above conditions repeated several times during the Givetian-Frasnian, but the most convenient for study were from early Givetian and early Frasnian beds. Rapidly growing organisms (such as Caliapora 4.0-7.5 mm/yr or Actinostroma 3.0-8.0 mm/yr) recorded many disturbances; these high-metabolic and environmentally sensitive corals are not promising recorders. By contrast, Scoliopora skeletons accreted at a low rate of 0.4-0.6 mm/yr and are useful for fine-scale optical density studies. These corals are subordinate components in variety of facies from reefs to the middle of carbonate slopes; low metabolism and modest feeding are possible (ultra-fine organic suspensions?). Even simple observations on sectioned Scoliopora suggest that the early Givetian and early Frasnian intra-annual bandings are different. Detailed measurements were carried out on two colonies of Scoliopora: (1) Slavkov-2, 1257.9 m, Drilling Sector Middle, Scoliopora serpentina-denticulata, early Givetian, and (2) Ochoz V-la, 216.0 m, Moravian Karst, Scoliopora denticulata beta, the early Frasnian [8 year layers, each with 8 nodes, each with 8 sections - 512 optical sections, x2]. A typical early Givetian "marine year" in Moravia consisted of five major, regular and approximately equal oscillations (within the annual cycle). The high-frequency changes (and noise) are slight. An ideal early Frasnian "marine year" has

IPC2002 Oral Presentations three different low-frequency oscillations of fuzzy outline, with strong disturbances by high-frequency rhythms. These changes may have mirrored organic suspensions (and seawater composition/temperature). The possible engine for these low frequency but major changes is seen in geostrophic currents (50-day cycles, Indonesian Throughflow - Kashino et al1999; 70 days, N of Oahu Chiswell, 1996; or, 60 days, SW Atlantic - Johns et al, 1993). Sheltered basins are characterises, by contrast, by numerous small eddies (e.g., 10 days, Sea of Japan Palshin et al., 2000). In this view, the Moravian Block (MB) had to be, during the Givetian, in close contact with a wide and deep ocean wedge. During the Frasnian, the MB had to be placed within a system of reefbank-barred ocean basins.

AVERAGE FLUCTUATION DURING AN IDEAL EARLY GIVETIAN YEAR

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CHISWELL, S. M., 1996. Intra-annual oscillations at Station ALOHA, north of Oahu, Hawaii. Deep-Sea Research, 43, 305-319. JOHNS, W. E., FRATANTONI, D. M. & ZANTOPP, R. J., 1993. Deep

western boundary current variability off northeastern Brazil. Deep Sea Research, 40, 293-410. KASHINO, Y., WATANABE, H., HERUNADI, B., AOYAMA, M. & HARTOYO, D., 1999. Current variability at the Pacific entrance of the

Indonesian Throughflow. Journal of Geophysical Research, 104 (C5),

11,021-11,035. Project A3013209 "Weathering products ... and climates PALSHIN, N. A., VANYAN, L. L., MEDZHITOV, R. D., SHAPIRO, G. I., YEVDOSHENKO, M. A., UTADA, H., SHIMIZU, H. & TANAKA, Y., 2000. Studies of current variability in the Sea of Japan using longterm cable voltage measurements. Geophysical Research Abstracts 2 (EGS XXV), OA029.

ENVIRONMENTAL INFORMATION IN N AND C FROM BONE GELATIN OF EXTINCT NEW ZEALAND BIRDS 15

Richard N. HOLD AWAY , David J. HAWKE , John R. LEATHWICK , & Trevor H. WORTHY Palaecol Research, P.O. Box 16 569, Hornby, Christchurch, New Zealand; Christchurch Polytechnic Institute of Technology, P. O. Box 540, Christchurch, New Zealand; Landcare Research, Private Bag, Hamilton, New Zealand; Palaeofaunal Surveys, 2A Willow Park Drive, R.D. 11, Masterton, New Zealand 1

Levels of enrichment of N (5 N) and C (5 C) in bone gelatin samples from two species of extinct bird varied more than expected for single species. The samples were all of Holocene age from sites in both the North and South Islands of New Zealand. Within-species differences in 8 N from both an insectivorous bird and a primarily herbivorous species were equivalent to those expected for taxa from two trophic levels. Variation was unrelated to geographic distribution, but related to present climate. Regressions against climatic parameters predicted for individual sites indicated significant negative relationships between 8 N and total annual rainfall and driest month rainfall at each site. No correlations were found between 8 N and other climatic parameters, including humidity and insolation. Correlations for both taxa were most significant between 5 N and predicted rainfall in the driest month. These results agree broadly with those of Grocke et al. (1997) who found a relationship between 8 N from bone gelatin of macropods and annual rainfall in arid Australia. In New Zealand, there are few C4 plants and 8 N values for a range of C3 plant species from sites covering the climatic range of the fossil deposits were also negatively correlated with lowest month rainfall. The greater enrichment of N in bone gelatin from organisms living in low rainfall areas probably results from moisture stress on plants both promoting deeper root penetration to soil depths where N has been enriched by soil organisms and also from retention and recycling of proteins within the plant. The enhanced levels of N are then passed on to herbivorous birds and, via herbivorous insects, to insectivorous birds. The results on extinct birds in New Zealand extend the observations on mammals to birds and also the range of precipitation over which the effect can be expected. The near-total absence of C4 plants in New Zealand removes the potential for masking the palaeoprecipitation signal. Levels of enrichment of C in the bone gelatin of fossil birds in New Zealand were not associated directly with rainfall, but were apparently associated with feeding location of the species with respect to closed vegetation associations and changes in cover of dense forest over the Pleistocene-Holocene boundary. 15

GROCKE, D.R., BOCHERENS, H. and MARIOTTI, A., 1997. Annual rainfall and nitrogen-isotope correlation in macropod collagens: application as a palaeoprecipitation indicator. Earth and Planetary Science Letters 153, 279-285.

IPC2002 Oral Presentations

LATE QUATERNARY MICROFOSSILS, PALAEOENVIRONMENTS AND SEA LEVEL CHANGE IN THE GULF OF CARPENTARIA, AUSTRALIA Sabine HOLT, Allan R. CHIVAS, Adriana GARCIA School of Geosciences, University of Wollongong, Wollongong, 2522, NSW, Australia Situated on the Australian continental plate, between northern Australia and New Guinea, the Gulf of Carpentaria is a shallow epicontinental sea, with a maximum depth of 70m. It is bordered to the west by the Arafura Sill, 53m below present sea level, and to the east by the 12m deep Torres Strait. During the last glacial cycle at times when sea level was lower than the Arafura Sill, the Gulf of Carpentaria was separated from the Indian and Pacific Oceans, forming Lake Carpentaria. Six sediment cores were collected from the Gulf of Carpentaria, in water depths ranging from 59m to 68m, effectively spanning the maximum possible extent of the palaeolake. The foraminiferal and sedimentological study of all cores from around the Last Glacial Maximum (LGM) to the present will be presented here. Benthic foraminifer dominate all assemblages in the Lake and Gulf of Carpentaria. Ammonia spp., Elphidium spp., Asterorotalia spp., Pararotalia spp., Quinqueloculina spp., and Textularia spp., are common in the marine and transitional assemblages, while Helenina anderseni and Ammonia becarrii dominate the lacustrine phase. Rare planktic species are found in marine-influenced assemblages, mainly Tenuitella spp. and Gallite Ilia vivans. Foraminiferal assemblage and sedimentological data indicate that around the LGM, Lake Carpentaria fluctuated between the -65m contour (its minimum extent) and the -57m contour (maximum) - an approximately 200km lateral difference in its western shoreline. Around Ilka the presence of rare reworked marine species indicates partial breaching of the Arafura Sill and the onset of the transition to marine conditions. By 10.5ka marine waters had inundated the entire basin, and by lOka a marine assemblage was established near the Arafura Sill, with the remainder of the Gulf fauna characteristic of a brackish environment. True marine conditions prevailed around 5ka when sea level rose over the Torres Strait Sill.

ORIGINS OF SOUTH AMERICAN UNGULATES Ines HOROVITZ Mammalogy, Natural History Museum of Los Angeles County, 900 Exposition Blvd., Los Angeles, CA 90007, USA Several ungulate lineages inhabited South America during the Cenozoic Era. Their phylogenetic affinities among other placental mammals are obscure and it is not clear whether they share a common ancestor or not. The earliest known members of the South American ungulate groups are so well differentiated from each other that it is very difficult to establish their interrelationships. Fairly complete skeletons for many members of these groups have been described, including a few Paleocene species. The goal of this study was to investigate the affinities of two South American ungulate lineages for which postcranial remains are available: notoungulates and litopterns. Notoungulata includes the grater number of forms, mostly from but not restricted to South America, none of which attained an unguligrade position. The most basal species are only known from teeth, however two early Eocene genera that display a relatively primitive morphology are also known from postcranial skeletons: Pleurostylodon Ameghino 1897 and Thomashuxleya Ameghino 1901. The best known skeletons are from the Casamayoran of Canadon Vaca, Chubut Province, Argentina (Simpson, 1967). Litopterns are exclusively Southamerican, and although the group was not as speciose as the notoungulates, some types became more orthodoxly ungulate in morphology. Two groups differentiated early in the history of this group, and amongst their best known members are Diadaphorus Ameghino 1887 and Theosodon Ameghino 1887 from the Santacrucion Miocene, Santa Cruz Province, Argentina. Both are known from almost complete skeletons (Gregory, 1951 and 1957). A preliminary data set of postcranial osteological characters was compiled for most major groups of living placental mammals, notoungulates, litopterns, and early members of North American, European, and African ungulate lineages. Included were skeletons of the notoungulates Thomashuxleya and Pleurostylodon, the litopterns Diadiaphorus and Theosodon, as well as the North American/European condylarths Arctocyon, Hyopsodus, Meniscotherium, Phenacodus, Chriacus, Ectoconus and Periptychus, and the African proboscidean Numidotherium. A maximum parsimony analysis of this data set suggested that notoungulates and litopterns originated from different stocks of ungulates.

IPC2002 Oral Presentations

GREGORY, W.K. 1951 and 1957. Evolution Emerging. Macmillan, New York. SIMPSON, G.G. 1967. The beginning of the age of Mammals in South America. Part 2. Systematics: Notoungulata, concluded (Typotheria, Hegetotheria, Toxodonta, Notoungulata incertae sedis); Astrapotheria; Trigonostylopoidea; Pyrotheria; Xenungulata; Mammalia incertae sedis. Bulletin of the American Museum of Natural History 137, 1-259.

EARLY CARBONIFEROUS FLORAS FROM CENTRAL-NORTHERN SOUTH AMERICA: BRAZILIAN AND BOLIVIAN RECORDS Roberto IANNUZZI1, Hermann W. PFEFFERKORN2, Vera ALLEMAN3 1 Departamento de Paleontologia e Estratigrafia, Instituto de Geociencias, Universidade Federal do Rio Grande do Sul, Cx. P. 15.001, Porto Alegre, RS, 91.501-970, BRAZIL; 2Department of Earth and Environmental Science, University of Pennsylvania, Philadelphia, PA 19104-6316, U.S.A.; sFacultad de Ciencias Biologicas, Universidad Ricardo Palma, Av. Armendariz 349, Lima 18, Peru. In northeastern Brazil, fossil plants were found in the middle-upper part of the Poti Formation from the Parnaiba Basin. The Poti Formation has been dated through palynology as late Visean. Deltaic system have been identified in this formation. The very fragmentary fossil plants come from small floodplain, large tidal flat and interdistributary bay deposits. The reevaluation of fossil plants found the following taxa: "Lepidodendropsis" sp., Archaeocalamites sp., Paulophyton sommeri, P. sp. nov., Nothorhacopteris cf. N. kellaybelenensis, "Triphyllopteris" [Fedekurtzia] alvaro-albertoi, ?Sphenopteridium sp., IFryopsis sp., Kegelidium lamegoi, Aneimites sp., Diplothmema gothanica, D. cf. D. bodenbenderi, ?Calymmatotheca sp. Pteridosperm foliage (Diplothmema, Aneimites, "Triphyllopteris", Nothorhacopteris, in order of abundance) dominates the assemblages. Paulophyton, an enigmatic plant with psilophytic habit, and pteridosperm reproductive structures (Kegelidium, Calymmatotheca) are not uncommon while lycopsids and sphenopsids occur only rarely. The Bolivian fossil plants have been found in the Siripaca Formation from the Copacabana Peninsula in the Altiplano of Bolivia, northwestern Bolivia. The Siripaca Formation is considered to be latest Early Carboniferous (late Visean-early Serpukhovian interval) in age based on megafloristic and lithostratigraphic correlations with the Kaka Formation and the regional stratigraphic context. Deltaic and fluvial environments occur in the Siripaca Formation and fossil plants were collected in flood plain deposits. The latest studies indicate the presence of the following taxa: Tomiodendron sp., "Lepidodendropsis" sp., Pseudobumbudendron sp., Porostrobus sp., Archaeocalamites radiatus, Paulophyton sommeri, Nothorhacopteris kellaybelenensis, "Triphyllopteris" boliviana, ? Sphenopteridium intermedium, Diplothmema bodenbenderi. Pteridosperm foliage (Nothorhacopteris, "Triphyllopteris", Sphenopteridium, Diplothmema, in order of abundance) dominates these assemblages, lycopsids and sphenopsids are common, and Paulophyton is rare. The Brazilian and Bolivian floras represent the same stratigraphic level and are comparable to the flora from the Paracas Peninsula in Peru. The flora from Paracas grew in a warm temperate climate, and is the base for the definition of a distinct floral unit called the "Paraca Floral Realm". Thus, the floras analyzed represent an extension to the south and the east of this realm, and help to define an area and time interval of similar climate.

LOWER DEVONIAN SPIRIFERIDS (BRACHIOPODA) FROM GERMANY AND MOROCCO AND THEIR PALAEOBIOGEOGRAPHIC IMPLICATIONS Ulrich JANSEN Forschungsinstitut Senckenberg, Senckenberg-Anlage 25, D-60325 Frankfurt am Main, Germany. [ujansen@sngkw. uni-frankfurt. de]. Spiriferids of the superfamily Delthyridoidea are very common fossils in the Lower Devonian of the Rhenish Slate Mountains (Rheinisches Schiefergebirge). A detailed biostratigraphy mainly based on spiriferids has been established there (e.g. Mittmeyer, 1982), which has been transferred to regions in Western Europe (Armorican Massif, Cantabrian Mountains, Celtiberian Chains) and North Africa (e.g. Anti-Atlas Mountains). Accordingly, very close relationships between marine faunas of the Rheno-Ardennan region (southern margin of Laurussia) and the Mauro-Ibero-Armorican region (North Gondwana) have been postulated in many papers.

IPC2002 Oral Presentations New studies on spiriferid brachiopods (Jansen, 2001) confirm strong similarities between the contemporaneous faunas of the regions mentioned, but reveal important differences, too. The latter are either due to palaeobiogeographical circumstances or due to different facies developments in the different regions. The genus Arduspirifer, for example, including many stratigraphic index taxa (Solle, 1953), shows a separate development in W Europe and Morocco, and a higher diversity than in the Rheno-Ardennan Mountains. The subspecies A. arduennensis arduennensis, hitherto used for the lower limitation of the Upper Emsian in Germany, western France, Spain and North Africa, seems to be absent in the North Gondwanan regions. There are other forms which are very similar only at first sight but belong to different subspecies and species. These arduennensis-like forms already occur in the Lower Emsian. The very common Middle to Upper Siegenian genus Acrospirifer has been used stratigraphically in all regions under consideration as well. However, according to the new investigations, it seems to be absent in North Gondwanan regions, where the similar but not very closely related Siegenian to Lower Emsian genus Filispirifer Jansen, 2001 is present. The distribution of Acrospirifer is probably restricted to the RhenoArdennan region (questionable occurrences in England, Czechia, Roumania). On the other hand, certain representatives of Euryspirifer can be traced from the Rhenish Slate Mountains via the Armorican Massif and the Celtiberian Chains to the Anti-Atlas Mts. and allow stratigraphic alignments and correlations. The genus Dixonella is restricted to the Mauro-Ibero-Armorican region. The absence of the genus in the Rheno-Ardennan region may be not caused by palaeobiogeographic circumstances, but is due to unsuitable facies during its stratigraphic range. D. assaensis Jansen, 2001 from the Anti-Atlas Mts. is a probable ancestor of the genus Euryspirifer, which is not present either in the Rhenish sections for the same reason. The results from the spiriferids support the presence of a minor oceanic barrier restricting the faunal exchange between Laurussia and North Gondwana during the Early Devonian. On the other hand, many species occur both in the Ardenno-Rhenish region and in the Mauro-Ibero-Armorican region. Accordingly, it is concluded that there was not a very wide ocean as e.g. proposed by Tait et al. (1997) who argued with palaeomagnetic data. The new investigations support very close palaeobiogeographic relationships between Armorican Massif, Cantabrian Mountains, Celtiberian Chains and Anti-Atlas Mts., and confirm that these regions belonged to the shelf of North Gondwana. The relationships between the respective Mauro-IberoArmorican faunas are a little closer than the relationships of these to the Rheno-Ardennan faunas. JANSEN, U., 2001. Morphologie, Taxonomie und Phylogenie unter-devonischer Brachiopoden aus der Dra-Ebene (Marokko) und dem Rheinischen Schiefergebirge (Deutschland). Abhandlungen der senckenbergischen naturforschenden Gesellschaft 554: 1-389. MLTTMEYER, H.-G., 1982. Rhenish Lower Devonian biostratigraphy. Courier Forschungsinstitut Senckenberg 55: 257-269. SOLLE, G., 1953. Die Spiriferen der Gruppe arduennensis-intermedius im rheinischen Devon. Abhandlungen des hessischen Landesamtes fur Bodenforschung 5: 1-156. TAIT, J.A., BACHTADSE, V., FRANKE, W. and SOFFEL, H.C., 1997. Geodynamic evolution of the European Variscan fold belt: palaeomagnetic and geological constraints. Geologische Rundschau 86: 585-598.

ECOLOGY OF BENTHIC FORAMINIFERA OF TAMBARAPARNI RIVER ESTUARY, EAST COAST OF INDIA N. JAYARAJU Department of Geology, Sri Venkateswara University, Tirupati-517 502, India. The ecology of recent benthic foraminifera from the Tambaraparni estuary situated along the east coast of India in Tamil Nadu was studied. A collection of 30 samples of bottom sediments and waters each was done from 15 stations for two seasons viz., premonsoon (July-Sept. 1997) and postmonsoon (June-March, 1998) periods. A set of environmental variables such as pH, salinity, dissolved oxygen and organic matter were measured. Salinity recorded as low as 6 at st. no. 15 and high (31) at st.no. 8 and moderate at the channel (st.no.4, 6). The higher salinity values found in the central part of the estuary may be attributed to the lesser flow of fresh water due to intricate estuarine system coupled with sand tributaries. A total of 30 foraminiferal species were recognised. Rotaliids are predominant followed by Milioliids and Arenaceous fauna. Salinity and organic matter showed positive relation with faunal density and distribution. Dissolved oxygen has erratic relation with microbiota. Postmonsoon is more congenial for the faunal crop. Faunal total (Dead + Live) populations range between 10 and 1225 with living crop 6 to 865/50 gms of dry sediment with the maximum in postmonsoon. The higher organic flux that was brought down by fresh waters during the floods through river channel may be the reason for the potential populations during postmonsoon.

IPC2002 Oral Presentations BIOZONATION OF THE EDIACARAN IN AUSTRALIA Richard J. F. JENKINS Department of Geology and Geophysics, University ofAdelaide; [richard.jenkins@adelaide.edu.au]. Biozonation of the Ediacaran (c. 600-540 Ma) poses intrinsic difficulties because of the haphazard nature of the palaeoenvironmental and subsequent diagenetic/maturation characteristics attending the preservation of appropriate biotic elements. Interrelationships between known biotas and significant stratigraphic sequences including signatures for potential global events, such as the record of glaciations and so-called "secular" curves denoting progressive trends in isotopic records, are also commonly obscure, at least at fine scales. While the preferred stratigraphic marker for an "Ediacarian" System lies at the base of the post-glacial Nuccaleena Formation in the central Flinders Ranges, South Australia, sections in this area have experienced low grade (greenschist) metamorphism, removing the record of all but the most resilient spheroidal acritarchs. Moreover, the regional record of the immediately underlying "Elatina" glaciation is far from uniform. Tundra-like characteristics are evident on what was the emergent Stuart Shelf and ice-transported stones are usually uncommon within the western Adelaide Fold Belt; prevalent "glacio-marine" deposits occur within the Nackara Arc, where several dolomitic bands interbedded with homogeneous sandstones loosely equate with the Nuccaleena Formation. The author's opinion is that correlation of these phenomena with deposits in central and north-western Australia is problematic. In the central Flinders Ranges, several thousand metres of barren strata intervene between the Nuccaleena Formation and a regional disconformity at the top of the Wearing Dolomite and below the Wonoka Formation marking a base for the Ediacaran. Lower parts of the fine siltstones of the the immediately underlying Bunyeroo Formation include dropstones and isolated patches of granules or small pebbles evidently dispersed from sunken pieces of gritty ice. The still older ABC Range Quartzite exhibits cyclothem-like cycles. The homotaxial geology is readily traced into the Officer Basin, where till pellets recognised by V. A. Gostin (pers. comm. 2001) low in the Dey Dey Mudstone denote a distal glacial outfall. Similarities in 8 C isotopic curves and other aspects of Centralian geology suggest the direct correlative may be with the glacigenic Olympic Formation. Large and diverse acanthomorph acritarchs appear in the fossil record at the apparent time of waning of the above glaciation, perhaps in response to warming and changing nutrient levels. The distinction between Grey's (e.g. 1998*) acrtarch zones E\ and E corresponds to the basal Ediacaran boundary, offering potential for its wider resolution. Grey's two subsequent zones E and E apply to later parts of the Ediacaran. The time of the late Wonoka Formation is characterized both by the appearance of small fusiform pellets indicating the presence of animals with a gut, and controversial "thigmotactic" structures on bedding planes close in form to Palaeopascichnus. Surfaces also show tissue-grade organisms which sometimes form large fan-shapes and can become torn or somewhat fragmented. Discoidal forms may also be present. Fragmentary Palaeopascichnus, other simple traces and rare small discs occur in the Bonney Sandstone, which shows repeated sequence boundaries below cycles of red fossil soils and fluviatile- ?marginal-marine sands. In the far northeastern Flinders Ranges, the facies just described is replaced by basinal silstones including thin diamictites with till pellets. Clusters of pebbles and cobbles formerly ice-bound accompany dropstones exceeding a metre in diameter, and sometimes strange zig-zag deformation of bedding resulted when icebergs scraped the bottom. Probably as a result of climatic eustacy linked to this ice-age, sea levels continued to oscillate through into the time of the older Rawnsley Quartzite. Here, four levels of biota are evident: reticulate "algal" films in the beach and shorface Chace Member; Rangea, Hiemalora, Kullingia, and Ernietta-\ike forms with rare Dickinsonia costata present in a succeeding reddish channel facies(along with a stranded jellyfish); Charnia cf. masoni, Charniodiscus, Pteridinium nenoxa, and Inkrylovia lata occur in the top of the fill of the following deeply incised sandy channels; and above, the type Ediacara assemblage has abundant Dickinsonia, uncommon Spriggina and rare Glaessnerina characterizing the Ediacara Member. The upper Rawnsley Quartzite is largely barren of fossils, perhaps a reflection of mainly fluvial deposition. The recent finding of "Cambrian" traces in the defined Proterozoic of Newfoundland means that the srtict placement of the Cambrian lower boundary within the Uratanna Formation is uncertain. 13

GREY, K.,1998. Ediacarian acrtarch biozonation in Australia. Geol. Soc. Aust. Abstracts No.51,22-23.

A REVISED ESTIMATION OF THE GUADALUPIAN-LOPINGIAN BENTHIC CRISIS JIN Yugan and WANG Wei Nanjing Institute of Geology and Palaeontology, CAS, Nanjing 210008, China

IPC2002 Oral Presentations Substantial demise of dominant benthic groups near the Guadalupian-Lopingian boundary in South China has been documented in the last decade. However, understanding the pattern and causes of this event has long been handicapped by uncertainty of the synchrony of Guadalupian-Lopingian boundary sequences in major depositional regions. Based on studies of the stratotype section for the Guadalupian-Lopingian boundary at Laibin and a correlation of conodont successions of boundary intervals in South China and other areas of Tethys, a scenario of stepwise extinction of faunas can be proposed. The extinction began with rapid decline of reef communities, large-sized fusulinids, colonial rugosa and bryozoans before maximum regression. A disaster fauna dominated by small fusulinids, solitary corals and brachiopods occurred during the subsequent lowstand. Guadalupian ammonoids persisted upward into the lower Lopingian. The Cathaysia flora flourished as continent basins expanded, continuing on into the Lopingian. Carbon isotope profiles in South China, Iran and Salt Range each exhibit a significant depletion, which appears coincident with a major transgression surface above the sequence boundary of the latest Capitanian. A simultaneous drop of strontium isotope ratios in South China further indicates a significant oceanographic change. With the Lopingian Series as the global standard for the Upper Permian and a set of bio-, magneto-, and sequence stratigraphic tie points, a world correlation of the Guadalupian-Lopingian boundary sequences is tentatively suggested. This correlation reveals a general trend of regression beginning near the end of the Guadalupian and a marine sequence developed during the subsequent Lopingian transgression in northern Gondwana and Arctic regions. Apparently, the high diversity faunas of the Upper Wargal and Chhidru Formation in the Salt Range and coeval units in other peri-Pangea basins display no dramatic benthic crisis across the Guadalupian-Lopingian boundary, although reefs off the northern Gondwana margin were largely eliminated. In continental interior basins the lacustrine deposits in the Late Guadalupian were replaced in the Late Permian by fluvial deposits. No drastic declination of vertebrate faunas has been recorded in association with this sedimentary change. Eruption of the Omeishan Basalts, global sea level change and hypercapnia have been suggested as possible causes of the Guadalupian-Lopingian Benthic Crisis. As an event largely limited to the Tethyan areas, a global sea level change does not match well in scale. In addition to the Omeishan Basalt, Late Guadalupian basalts of comparable scale occurred in Kashmir, Tarim etc. They are in coincident essentially with the benthos crisis in time and space. Permian profile of carbon isotope ratio shows hypercapnia can not be excluded as a key cause.

NICHE PARTITIONING OF REEF-DWELLING BRACHIOPOD COMMUNITIES IN THE LOWER SILURIAN ATTAWAPISKAT FORMATION, HUDSON BAY BASIN, CANADA Jisuo JIN Department of Earth Sciences, University of Western Ontario, London, Ontario, Canada, N6A 5B7; [jjin@julian. uwo. ca]. The Attawapiskat Formation of the Hudson Bay Basin comprises one of the few large coral-stromatoporoid reef complexes that are known to occur in the Lower Silurian. These reefs represent the full recovery stage of marine shelly benthos after the Late Ordovician mass extinction event. Compared to other known Early Silurian reefs, the Attawapiskat reefs feature an unusually high-diversity shelly fauna dominated by pentamerid and smooth strypoid brachiopods. Although corals and stromatoporoids are the predominant frame builders, calcimicrobes, calcareous sponges, and bryozoans are also common components of the reef framework. Other common groups of shelly organisms include gastropods, nautiloids, bivalves, trilobites, and ostracodes. The reef-dwelling brachiopod fauna in the Attawapiskat Formation shows several characteristics: (1) The majority of brachiopod shells are preserved intact, regardless of shell size and location within a reef. In places, Pentameroides shells are densely clustered and hollow, with only isopachous calcite cement inside the shells. The large-shelled "inarticulate" bachiopod, Trimerella, is also common and unusually well preserved. Although the disarticulated valves are more common than conjoined shells, the initially aragonitic (now calcific) trimerellid shells typically have little damage, with physically intact shell material preserved. The excellent state of preservation of these large and delicate reef-dwelling shells suggests a minimum level of storm influence on the Attawapiskat reef tract where these pentamerid animals flourished during the early Silurian. (2) The brachiopod-dominated assemblages have a wide range of variation in species composition over short distances. Over metres or tens of metres within the Attawapiskat reef facies, a brachiopod association dominated by large, globular shells of Pentameroides and Trimerella may change to a medium-shelled Septatrypa-Gypidula-Clorinda dominated brachiopod association, or to a small-shelled Lissatrypa-Meifodia association. This points to a high degree of substrate heterogeneity and partition of ecological niches. In general, the Pentameroides-Trimerella association commonly occurs immediately adjacent to large colonies

IPC2002 Oral Presentations of colonial corals and stromatoropoids; the Septatrypa-Gypidula-Clorinda association in muddy, relatively flat areas between the large coral-stromatoporoid colonies; and the small-shelled Lissatrypa-Meifodia association in shelly grainstone facies filling small, deep depressions or large cavities within the reefs. (3) The brachiopods show both high species diversity and great abundance. Spot collections from areas of 3-5 square metres usually yields 300-1000 brachiopod shells belonging to 15-25 species. The Attawapiskat Formation contains 46 species brachiopods, which are considerably more diverse than the largely coeval brachiopod fauna of the Chicotte Formation of Anticosti Island. The high diversity and high density of the shelly organisms in the coral-stromatoporoid reef of Attawapiskat Formation suggest an open marine, rimmed carbonate shelf environment. In combination with the lack of storm influence on shell taphonomy, this suggests that the Attawapiskat reef tract was developed on the palaeoequatorial belt during the Early Silurian (latest Telychian). This is analogous to the "calm zone" within five degrees of the equator in modern tropical environment.

PLACODERM FISHES AND THE VERTEBRATE OROPHARYNGEAL DENTITION Zerina JOHANSON^ Moya Meredith SMITH2 1 Palaeontology, Australian Museum, 6 College Street, Sydney, NSW 2010, Australia; department of Craniofacial Development, Dental Institute, Kings College London, Guy's Campus, London SE1 9RT, UK The developmental correlation of teeth and jaws in vertebrate history has recently been challenged with an alternative to the view that teeth derive from skin denticles (Smith & Coates 2001). This alternative suggests that organised denticle whorls on the pharyngeal arches are precursors to tooth families developing from a dental lamina along the jaw. Denticle whorls occur within the pharyngeal cavity of jawless fishes such as the thelodont Loganellia, a shared character with sharks, and show several of the characteristics of tooth whorls found in acanthodians, sharks and bony fishes. These tooth-family precursors in Loganellia not only indicate that homologues of denticle whorls were present, but also illustrate that they possessed the relevant developmental controls, which could be co-opted for the dentition, prior to the evolution of jaws. In particular, epithelium derived from the foregut endoderm provides molecular signals responsible for the ordering and positioning of the pharyngeal denticles. This is in contrast to ectodermal epithelium producing external skin denticles. However, in the Placodermi, a phylogenetically basal group of jawed fishes, the state of pharyngeal denticles is relatively unknown. As well, the presence of teeth homologous to those in extant jawed fishes (Chondrichthyes + Osteichthyes) is controversial. Thus, placoderms would seem unable to provide evidence as to the arrangement, either of denticle whorls, or of tooth families, at the base of the clade of jawed fishes. Still, important information is available, particularly within groups occupying the basal nodes of the placoderm clade (Goujet & Young 1995). For example, the Rhenanida possess regularly spaced gill rakers along the gill arches (Stensio, 1969). Additionally, organised denticles occur at the rear of the placoderm gill chamber, but are associated with the postbranchial lamina of the anterior trunk shield and have been assumed to be part of the denticle cover associated with the external surfaces of the head and trunkshield. Nevertheless, the differing morphology and organisation of denticles on the postbranchial lamina relative to these external dermal tubercles suggest the influence of patterning controls comparable to those involved in patterning pharyngeal denticles in Loganellia and teeth in acanthodians and 'crown group' jawed fishes. The patterning and spacing of the gill rakers along the gill arches of the Rhenanida would also be influenced by endoderm. In the Rhenanida, the dentition comprises tesserae, morphologically similar to tesserae covering the external surface of the head and trunk, produced here and in the mouth by ectodermal, rather than endodermal epithelium. This is also true of another basal placoderm group, the Antiarchi in which the suborbital plate (otherwise forming the cheek in other placoderms) functions as the upper gnathal element. Gill arches are unknown in antiarchs, but in both antiarchs and rhenanids, the postbranchial lamina is covered in organised denticles. In other words, these early placoderms provide evidence for differently organised denticles in the posterior regions of the pharyngeal cavity under the influence of foregut endoderm, in conjunction with stomadeal ectoderm anteriorly in the mouth. Stomadeal ectoderm could not produce or pattern, or organise denticles in the posterior parts of the oropharyngeal cavity. GOUJET, D.F., & YOUNG, G.C., 1995. Interrelationships of placoderms revisited. Geobios Memoire Special 19, 89-96. SMITH, M. M., & COATES, M. I., 2000. Evolutionary origins of teeth and jaws: Developmental models and phylogenetic patterns. In Development, Function and Evolution of Teeth, M. F. Teaford, M. M. Smith & M. W. J. Ferguson, eds. Cambridge University Press, Cambridge, 133-151. STENSIO, E., 1969. Placodermata; Arthrodires. In J. Piveteau (ed.): Traite de Paleontologie, vol. 4,71-692. Masson et Cie: Paris.

IPC2002 Oral Presentations

LATEST DEVONIAN AND EARLY CARBONIFEROUS PARAPARCHITOID OSTRACODS FROM THE BONAPARTE BASIN, NW AUSTRALIA: THEIR BIOSTRATIGRAPHY AND PALAEOZOOGEOGRAPHIC LINKS P.J. JONES Department of Geology, The Australian National University, Canberra, ACT, 0200, Australia. [peter.jones@geology. anu. edu. au] Paraparchitoids are represented in the latest Famennian (Strunian) and Dinantian (Tournaisian, Visean) benthic ostracod fauna of the onshore Bonaparte Basin by nine species distributed among five genera as follows: Chamishaella (2), Shishaella (3), Shivaella (2), Parashivaella (1) and Armenites (1), tentatively referred to the superfamily. These genera are cosmopolitan, with the exception of Armenites and Parashivaella (respectively, the first records outside the Former Soviet Union and South China). The species are mostly conspecific with those previously described from Siberia, Kazakhstan, Russian Platform (Upper Petchora Depression, Moscow Basin), the Dnieper-Donetz depression, Belgium, Germany, North England/Scotland, and South China (Guangxi, Hunan). The Strunian (Fa2d, Tnla) paraparchitoid fauna of the Buttons Formation consists of Armenites sp. nov., Shishaella electa Tschigova 1977 and S. suborbiculata (Mtinster, 1830). After a regressive-transgressive phase, both Shishaella species pass into the Burt Range Formation, where they are joined by Chamishaella lysi Tschigova 1977, and Shishaella porrecta (Zanina 1956) in the early Tournaisian (Tnlb) part, and by Parashivaella cf. xinhuaensis Zhang 1985 in the early Tn2a part. Of these species, Shishaella electa and S. porrecta continue into the Septimus Limestone (Tn2bc), where they are associated with Chamishaella subinornata Buschmina 1986, Shivaella armstrongiana (Jones & Kirkby 1886) and S. quasiporrecta (Buschmina 1968). Shishaella porrecta, Shivaella armstrongiana and S. quasiporrecta range throughout most of the Visean, where they are present in both the shaly Milligans Formation (Tn3c-V3b) and the Utting Calcarenite (V2b/V3a) alike. Only S. armstrongiana appears to have survived into the latest Visean (V3c), where it is present in the oolitic limestone of the uppermost Tanmurra Formation. The presence of Armenites in the Strunian of the Russian Platform, Kazakhstan, Siberia and the Bonaparte Basin indicate palaeozoogeographic links between these areas. These links, together with others with Belgium, and to a lesser extent, Germany, were maintained in the Tournaisian, as evidenced by the presence of Chamishaella lysi, Shishaella electa, S. suborbiculata and S. porrecta. Links with South China (iShishaella electa, S. suborbiculata, S. porrecta and Shivaella armstrongiana) are supported by the presence of the provincial genus Parashivaella in the Bonaparte Basin. Siberian links are emphasised by the presence of Chamishaella subinornata and Shivaella quasiporrecta. It is reasonable to assume that benthic ostracod species of the Late Devonian and Early Carboniferous, like those living today, lacked a pelagic larval stage and could not cross deep oceanic barriers. However, the observed zoogeographic links suggest that they could have migrated during transgressive pulses along juxtaposed shallow shelves of the adjacent blocks of Siberia, Laurentia-Baltica and Kazakhstan. Moreover, these links indicate that that by the latest Devonian the shallow shelves of the western part of Gondwana and Laurentia-Baltica were close enough to permit exchange of genetic material. This exchange, facilitated by southern anticlockwise ocean currents, would have permitted the migration of species along the isolated terranes of the southern shelf margin of Palaeotethys as far as northwestern Australia. A similar connection probably existed between the South China Plate and northwestern Australia within the eastern end of the palaeotethyan equatorial belt during the Early Carboniferous.

THE EARLY PLEISTOCENE OF SOUTH-EASTERN AUSTRALIA Greg JORDAN1 and Kale SNIDERMAN2 1 School of Plant Science, University of Tasmania, P.O. Box 252-55, Hobart, Tasmania 7001, Australia; 2 Department of Geography and Environmental Studies, Monash University, Clayton, Vic 3800, Australia A few periods over the last 65 million years have been turning points in the evolution of the Australian biota. Some have received intense scientific scrutiny: for example the transition from glacial to post-glacial conditions 14,000-10,000 years ago and the advent of humans about 50,000 years ago. However the transition into the massive climate fluctuations of the Quaternary is arguably just as significant, but has received much less scientific attention. During early Quaternary, the extreme climate fluctuations of the glacial/interglacial cycles reached their full amplitude, bringing large, rapid and repeated changes in temperature, rainfall and atmospheric carbon dioxide. As a result many authors have conjectured that severe

IPC2002 Oral Presentations stresses imposed by these early climate changes would have caused extensive evolution, extinction and migration. In spite of the ecological importance of the early climate cycles, there is surprisingly little fossil data on the character of the Australian flora during the Latest Pliocene or Early Pleistocene. Some fossil pollen floras from this period provide data indicating regional changes in the distribution of families and genera of plants. However, the limited taxonomic resolution of pollen makes these data much less useful in identifying extinctions or evolution. Thus, any extinction of a species with surviving close relatives will be invisible in the fossil pollen record. This appears to be have been common. In contrast to fossil pollen floras, fossil leaves, flowers or fruit often can be identified much more precisely, and closely related species distinguished. Thus extinction and evolution of species is much more clearly shown by the macrofossil record. The diverse Early Pleistocene Regatta Point site shows this: many western Tasmanian plant species have become extinct in the last million years or so. Furthermore, many of these are closely related to species that still survive in the region, and pollen-based evidence shows no sign of these extinctions. Other species are of groups that no longer exist in the region, but survive in other areas. The macrofossils clearly show that these are extinct species rather than once widespread species. Unfortunately, the character of the site ensures that the dating and stratigraphy are both relatively. Thus although the site gives some clear insights into the processes of extinction and evolution during the Early Pleistocene, the scope of these inferences is limited both spatially and temporally. Some of the issues raised by this site include the persistence or extinction of species, and that of climatically anomalous assemblages (of which Regatta Point is an extreme example). A recently discovered site in the central highlands of Victoria (Stony Creek Basin) has considerable potential to resolve some of the problems raised by the Regatta Point site. This site contains a long pollen record spanning the Latest Pliocene to earliest Pleistocene, has a reasonably well resolved age, and contains a rich macrofossil assemblage, currently under investigation.

MUSEUM PERSONNEL: EDUCATING THE NEXT GENERATION Roger L. KAESLER Paleontological Institute, Department of Geology, and Natural History Museum, the University of Kansas, Lawrence, KS 66045-7613, USA; [kaesler@ku.edu] The relationship of museums to natural history is the same as that of libraries to culture in general. In at least two ways, however, museum are more than libraries, too. First, museum collections, as the repositories of specimens, are replete with information that even the greatest library cannot provide. With the development of new techniques in science—including new ways of looking at old fossils—we are repeatedly challenged to return to the specimens and to reexamine them for new kinds of information for which no one had thought previously of looking. Often the specimens we need are to be found nowhere but in museums. Yet there is a second paralibrarial aspect of museums. In these times of impending biodiversity crisis, museum curators have become increasingly aware of the fact that in many instances in this new century the data about museum specimens have become as valuable as the specimens themselves. Although perhaps less true of fossils than of other kinds of natural history collections, this statement nevertheless applies in part to palaeontological museums—enough so that we ought to watch what our biological colleagues are doing and take note of the attention they pay to the databases associated with their museums' collections. We must find ways of coping with the information explosion in natural history while not losing sight of our traditional roles of collection, preparation, preservation, and conservation. One key player in all this is the collection manager. There was a time in the past when museum curators curated museums. In today's research-oriented academic museums, however, and in large, free-standing museums as well, the role of curator has been largely redefined to encompass research at the expense of curation. Concomitantly, the position of collection manager has been added to the modern museum's panoply of professionals. Few things elicit less sympathy from me than to hear curators lament that a collection is a mess and then to learn that the collection manager, far from managing the collection, is off somewhere doing his own research. The collection manager is a professional whose business—and whose area of research—is to deal with the collections. The education of a collection manager should be aimed at broad aspects of collection management, and the position should not be used as a guise to allow an otherwise unemployed recent doctoral graduate to do palaeontological research and build a resume while waiting for a real job. The Museum Studies program at The University of Kansas has five degree tracks, each of which leads to a magisterial degree: American Studies, Anthropology, Geology (primarily Palaeontology), History, and Natural History. The degree program has been a part of the University curriculum since 1980, but the Geology (Palaeontology) track is only two years old. All the tracks require students to complete 42 semester hours of graduate-level coursework, and they all take two years to complete. The coursework comprises six

IPC2002 Oral Presentations core courses required of all students in the program, an internship typically lasting for a year, a series of courses required for the track, and various numbers of electives through which the students broaden their exposure to aspects of other collections specific to the other tracks. The core curriculum comprises the following courses: The Nature of Museums, Museum Management, Introduction to Museum Exhibits, Introduction to Museum Public Education, Principles and Practices of Museum Collection Management, and Conservation Principles and Practices. The number of palaeontology students in the program has been small and is likely to remain no higher than about two new students each year. So far our graduates have competed well for the increasing number of positions for collection managers. An added advantage for the Department of Geology is the greater general palaeontological hubbub that ensues from having more students of fossils around. These students bolster the enrollments in our graduate courses, but their education is not a drain on scarce resources that support field work and research in the laboratory. We are enthusiastic about this degree program and optimistic about its future.

ECOLOGICAL REVOLUTION WITHIN ORDOVICIAN MARINE ECOSYSTEMS: START OF COHERENT EVOLUTION OF THE BIOSPHERE Aleksander V. KANYGIN Institute of Petroleum Geology, Russian Academy of Sciences, Siberian Branch, Novosibirsk, Russia Four major pre-Ordovician events—biological innovations drastically changed functional properties, spatial parameters, biological diversity and the pace of ecosystem evolution have been registered in the geological record of the biosphere. Two main regularities can be noted: 1) Innovations: rapid rise of biological variations and expansion of new forms of life occurred at the time of drastic changes of physical and chemical properties of the environment, i.e. were related to global geological reconstructions; 2) At each new stage, innovations developed at higher bio-systems hierarchic levels (at biogeochemical, genetic, physiological, and organism-rank successively) resulting in enlarged spectra of morphologic and physiological varieties and their adaptive possibilities. The general trend in early evolution of the biosphere is well illustrated by the succession of global geological changes in environment and biological innovations. (1) Archean is marked by origin and distribution in marine anoxic environment of two-layered benthic prokaryotic ecosystems possessing a combination of autotrophic and heterotrophic types of metabolism and capacity to exist due to both solar (exogenic) and hydrothermal (endogenic) energies. (2) The Early Proterozoic was the time of origin of the protozoans (autotrophic eukaryotes) with diverse combination of gene centres in chromosomes and with sexual reproduction (innovations on the genetic level, acceleration of evolutionary rates, rise of biogenic generation of oxygen, occupation of pelagic zone by autotrophs). (3) Vendian (Late Proterozoic) is related to the origin of Metazoa lacking skeletons (first metazoan heterotrophs) in cold-water seas with increased concentration of oxygen (innovations at morphologic and physiological levels). (4) The Early Cambrian is characterized by appearance of the main types and rapid divergence of skeletal Metazoa possessing all basic marine animal anatomic elements: on the level of protoplasm, cells, texture, organs, and skeleton (innovations at the individual organism level; rapid colonization of shallow seas). The Early Cambrian taxonomic burst is commonly related to increase in oxygen in atmosphere and hydrosphere, though its concentration varies over a wide range (from 1% and higher compared to present day). The Ordovician is a pivotal interval in evolution of marine ecosystems: when the basic mechanisms of adaptation to physico-chemical conditions were generally formed at different hierarchic levels of biosystems (from biochemical to organismal). From that time, trophic adaptation to biotic components of ecosystems became the main evolutional strategy because of increased competition for nutrition. The Ordovician taxonomic burst of hydrobionts was accompanied by unprecedented pace and scale of innovations in digestive systems and accordingly by a sharp rise in number of trophic specializations. Over 50% of presently known ecologic-trophic groups of benthic hydrobionts originated at that time. New modifications appeared among previous morpho-physiological types (i.e., there were no drastic changes in structure), however interactions between components of the global ecosystem changed greatly. Thus, important changes took place at the ecosystem hierarchic level. New constructional groups first appeared in abundance in the Ordovician and reached their acme in the Middle Ordovician: articulate brachiopods and sessile colonial (tabulates, tetracorals, heliolitoids and stromatoporoids), aggregated (crinoids), and colonial-aggregated (bryozoans) filter-feeding organisms with carcase skeletons. This resulted in breakdown of the biotopes and complication of the heretogeneity of food webs. Ostracodes - the first small hydrobionts with the universal ecologic valence, simultaneously belonging to several trophic levels and capable of more profound transformation of organic matter dominated in the

IPC2002 Oral Presentations lowest trophic level, instead of the former detritophages (mainly trilobites). In Ordovician the pelagic zone become a constant (rather than intermittent as previously) habitat for zooplanktonic and nektonic organisms: graptolites, radiolarians, conodontophorids, nautiloids, meroplankton (mainly larvae of colonial organisms and brachiopods), pelagic trilobites, ostracodes and primitive fishes. Spatial rearrangement of the lowest trophic level took place during the Ordovician. This had a dramatic effect on the state and structure of trophic chains. Until the early Middle Ordovician, bottom cyanobacterial associations (or meadows), widespread in the Late Precambrian and Early Palaeozoic epicontinental seas, were the main photosynthesizing producers. At the Early-Middle Ordovician boundary, the areas of these meadows decreased, and phytoplankton became the main producer. This global ecological event was accompanied by the greatest (in the entire Phanerozoic) burst of diversity of Ordovician marine biota followed by rapid stabilization. This stability was maintained subsequently by a phylogenetic succession of ecologically equivalent taxa supplemented by replacement of some ecologic guilds at critical boundaries. The Ordovician global biotic events chronologically coincide with the large-scale geologic events (abrupt climatic changes, maximum range of transgressions and regressions of epicontinental seas, changes in Mg and Ca balance in marine sediments, increase in content of oxygen in the Earth's atmosphere and hydrosphere, appearance of an ozone screen). It is supposed that the appearance of the ozone screen during the Ordovician and increase of sea-water oxygen content had a primary impact on populating the pelagic zone by heterotrophs and formation of coherent (ecologically complete) benthic ecosystems. Dramatic fluctuations of biodiversity in bottom and pelagic associations were determined by profound changes in spatial parameters of sea shelves (the main habitat of life) caused by eustatic fluctuations of the World Ocean level during the initial metastable stage of the ozone screen development. The Late Ordovician extinction of marine biotas resulted from abrupt shrinkage of the shelf habitat due to lowering of the World Ocean level, which, in turn, resulted from fixation of great volumes of water in continental glaciers after the Ordovician transgression maximum. During the Ordovician, ecologically unsaturated (incoherent) ecosystems were transformed to ecologically saturated (coherent) ecosystems. This conclusion coincides with that of J.J. Sepkoski on radical differences between marine faunas of "Cambrian" and "Phanerozoic" types.

COMPETITION AS AN ORGANIZER OF PALAEOZOIC COMMUNITIES Peter KAPLAN University of Michigan Museum of Paleontology, Ann Arbor, MI, USA; [pefty@aya.yale.edu]. Biotic interactions, such as predation and competition, are the chief structurers of modern communities. A uniformitarian view would suggest the same for palaeocommunities, but palaeontologists have made little headway in demonstrating such a relationship through deep time. Although competition and predation have certainly been documented in the fossil record, these accounts have been largely anecdotal or qualitative. Studies that have succeeded in meaningfully quantifying palaeobiotic interaction strengths have failed to examine community-level consequences. The main difficulty in meaningfully quantifying palaeobiotic interactions is the measurement of ecological processes on truly ecological timescales. Competitive interactions leading to competitive exclusion of species, for example, can hardly be expected to appear in the fossil record, as such exclusions normally take place within a geologic "instant." A more profitable tack might be examination of competitive interactions that led to coexistence among species. In such a case, the particular equilibrium of coexistence might yield clues as to the ecological processes that gave rise to the observed community. Specifically, some ecological aspect of the coexisting species should adjust in each so as to minimize overall interspecific competition at equilibrium. If a number of species are competing, then each must minimize its competition with both of its nearest ecological neighbors. Such a scenario should lead to equal spacing of species along some ecological resource axis. Past work has suggested that the size of some part of the organism is the usual means for niche differentiation when other means are unavailable. Thus, in this scenario, the mean adult body sizes should differ by equal amounts among all community members — a pattern known as "limiting similarity." If such a scenario were recorded in fossil communities, we might still be unable to recognize it as such. Time-averaging and differential taphonomy of community members might disrupt the pattern. We might be unable to find a morphological measurement that accurately reflects the ecological resource being partitioned — or such a morphological measure may be unpreserved or not exist at all. We might pick the wrong species as the hypothesized competitors. Any of these pitfalls would produce a pattern of unequal spacing. Therefore, if a pattern of equal spacing is indeed found, it means not only that interspecific competition was structuring the community, but also that the community had had time to reach equilibrium, that a limit to interspecific similarity had been reached, that the morphological measure was accurately reflecting the ecological resource of interest, that the measure was appropriate for every taxon under consideration, that the hypothesized

IPC2002 Oral Presentations nearest niche neighbors really were neighbors and were competing as such, that the niches all lined up along one resource axis, and that time-averaging and differential taphonomy were of insufficient strength to disrupt the biotic signal. "Having had time enough" to reach equilibrium also suggests that biotic (predation) and abiotic (storms) disturbances were rare compared to competitive interactions. As an example, a brachiopod community from the Upper Ordovician Richmond Group of Indiana, USA, is subjected to tests of limiting similarity. Bootstrap analyses of body size suggest that the niche spacing among these species was surprisingly (p < 0.03) consistent, and that the total niche overlap was significantly (p < 0.03) minimized. All the above conclusions are reached; the "indirect" inferences above provide substantial information about ecological, physiological, and depositional processes. In addition, they suggest that biotic interactions, such as predation and competition, have been important in structuring communities throughout the Palaeozoic and on through today. NEW ZEALAND LATE CRETACEOUS AND PALEOCENE CLIMATES FROM LEAF MORPHOLOGY Elizabeth M. KENNEDY Institute of Geological & Nuclear Sciences Ltd, Lower Hutt, New Zealand. [E. Kennedy@gns.cri.nz] Leaf morphological methods of palaeoclimate analysis (Leaf Margin Analysis and CLAMP - Wolfe, 1993) have been applied to Late Cretaceous and Paleocene leaf assemblages from South Island coal measures, New Zealand. Assemblages were collected from the Rakopi and Farewell Formations in Northwest Nelson, the Paparoa Coal Measures on the West Coast and the Taratu Formation in North Otago. New Zealand was a relatively isolated landmass at this time at a palaeolatitude of 50-60°S, which is outside the polar circle and therefore vegetation was not limited by winter darkness. A Late Cretaceous leaf assemblage from Northwest Nelson produced mean annual temperature estimates of 12-16°C whereas another Late Cretaceous assemblage from North Otago produced estimates of 7-11°C. In contrast three assemblages from the Paleocene of Northwest Nelson and the West Coast all produced mean annual temperature estimates that fall within the range 6-12°C suggesting cool-temperate conditions. Rainfall estimates from multivariate analysis have high levels of statistical uncertainty but the estimates suggest that all five floras grew in conditions of moderate to abundant rainfall, and that the Late Cretaceous Northwest Nelson flora experienced drier conditions relative to the other floras. Palynological zonation of the Late Cretaceous and Paleocene is currently the only means of dating these assemblages (Raine, 1984). The two Late Cretaceous localities both fall into the last Cretaceous pollen zone which equates approximately to the late Campanian and Maastrichtian (77-65Ma). It is therefore possible that the differences in temperature estimates from the two localities reflect an age and climate difference between the floras that is undetectable with current biostratigraphy. Based on stratigraphic inferences, it is likely that the North Otago assemblage is younger than that from Northwest Nelson. The similarities in palaeoclimate estimates between North Otago and the Paleocene assemblages may also support this. It is also likely that the West Coast and Northwest Nelson Paleocene assemblages are Early Paleocene in age. However poor outcrop exposure and structural complexities make it difficult to establish this with certainty. Pollen records suggest that in the Late Cretaceous the vegetation was dominated by gymnosperms and ferns but the macrofloral record seen in these five assemblages is dominated by dicotyledonous angiosperm leaf forms. This is likely to reflect preservational differences between the micro- and macrofloral records. The Paleocene assemblages all contained less than 30 dicotyledonous leaf forms whereas both Late Cretaceous assemblages had higher dicotyledonous diversity. There is good agreement in temperature estimates between methods (univariate and multivariate leaf methods, local and regional studies, limited oxygen isotope data and palaeoclimate models) for the Late Cretaceous Northwest Nelson locality (Kennedy et al., in press). This provides more confidence in the palaeoclimate interpretation of a mild temperate climate. The Late Cretaceous assemblage from North Otago shows similarities to both the other Late Cretaceous assemblage and the Paleocene sites. It has higher diversity than the Paleocene assemblages, but has a similar leaf physiognomic signature. The Paleocene assemblages consistently suggest cooler temperatures and cluster together in multivariate analysis. From these data it appears that cooling from the Late Cretaceous into the Paleocene could have occurred very late in the late Cretaceous rather than on the Paleocene side of the Cretaceous/Tertiary boundary. However refinements to the dating of New Zealand Late Cretaceous and Paleocene assemblages and more data from new assemblages are needed to assess this interpretation. KENNEDY, E.M., SPICER, R.A., REES, P.M. in press. Quantitative paleoclimate estimates from Late Cretaceous and Paleocene leaf floras

in the northwest of the South Island, New Zealand. Palaeogeography, Palaeoclimatology, Palaeoecology.

RAINE, J.I., 1984. Outline of a palynological zonation of Cretaceous to Paleogene terrestrial sediments in West Coast region, South

Island, New Zealand. New Zealand Geological Survey Report 109.

IPC2002 Oral Presentations WOLFE, J. A., 1993. A method of obtaining climatic parameters from leaf assemblages. U.S. Geological Survey Bulletin 2040, 71p.

EXPERIENCE IN APPLICATION OF DATA ANALYSIS METHODS (FOREL AND KRAB) IN PALAEOBIOGEOGRAPHY T.P. KIPRIYANOVA1, A.A. Jr. KIPRIYANOV2, V.N. YOLKINA1 and E.A. YOLKIN1 institute of Petroleum Geology, Russian Academy of Sciences, Siberian Branch, 630090, Russia; Novosibirsk State University, 630090, Russia This presentation is the attempt to analyze experience in application of data analysis methods in palaeobiogeography. We have Pragian and Emsian brachiopod data from regions of the Asia-Australia hemisphere using a special package of programs (system: "Biogeography"). This system is part of a large system for processing different kinds of quantitative and qualitative information. The main menu of the system "Biogeography" is: 1 - Description of the initial data, 2 - Programs of taxonomy (classification), 3 Additional programs, 4 - Text editor. First of all it is necessary to describe the initial data (to determine the number of objects and the number of features). For different tasks these parameters (objects; features) can interchange their roles. For example, when we are concerned with regions, they are considered as objects, and in this case species are their features. The opposite situation occurs when we analyze species (points or objects) in features (regions) of multidimensional space. The next step is to choose a program for classification (taxonomy) for processing data. It may be FOREL - with taxa (groups) of a spherical shape, or KRAB - with taxa of an indeterminate shape. The general idea of both FOREL and KRAB algorithms is to combine, in the same way (as people usually do it), the considered objects into groups according to their highest similarities/dissimilarities. The KRAB program firstly builds a "tree" of regions (graph/minimum spanning tree) from Jaccard coefficients widely applied in biogeography as a measure of similarity. According to the Jaccard coefficients, the similarity for any two points (objects) is the ratio of shared occurrences of species to their complete number. In this respect a biogeographic province represents a "cloud" (group) of areas (regions) with similar fossil associations. At the first step, the KRAB program separates "absolute endemics" from the whole list of regions and then, on its successive steps, groups of regions ("provinces") according to their closest relations. The FOREL program is based on the compactness hypothesis and detects spherical "taxa" within initial set of objects (points). The objects (species) of one "taxon" are located inside a hypersphere with a certain radius R. Such a "taxon" includes objects, similar according to their properties to the "central" object of the "taxon". The measure of similarity is defined by the Hemming distance in the space of properties. The Hemming distance means a number of non-coincidences in codes (features) of compared points (objects). For each meaning of R the procedure stops when the hypersphere stabilizes in the area of a local maximum of density of point's in the property space. The section "Additional programs" has some other points: 1 - Building of a minimum spanning tree (MST), 2 - Evaluation of similarity, 3 - Occurrence of certain species in regions and regional lists of species, 4 - Initial data (common list of species). This information is very useful when you wish to understand the structure of your data. Using such possibilities of the "Biogeography" system you can see: (1) Graphical presentation of an MST, (2) The number of shared species in regions, (3) A matrix of Jaccard distances and similarity coefficients, (4) Distribution certain species through regions and (5) Regional lists of species. Applying this system (now with an English version) in biogeography gives positive results and confirms that data analysis using methods with Jaccard and Hemming measures of similarity are very prospective for generating a global geodynamic scenario. This work was supported by grant RFBR 02-05-64993.

UPPER PALAEOZOIC BIOSTRATIGRAPHY OF MARGINAL SEDIMENTARY BASINS AROUND THE ANGARIDA CONTINENT Aleksander G. KLETS Institute of Petroleum Geology, Russian Academy of Sciences, Siberian branch, Novosibirsk, 630090, Russia The Angarida Continent, becoming structurally complicated at the beginning of the Carboniferous, includes the ancient Siberian Craton together with associated microcontinents, island-arc systems seamounts accreted during the Middle Palaeozoic. In the late Palaeozoic Angarida was surrounded by marginal seas extending over continental shelves. Synchronization of geological processes occurred not only on the land but also

IPC2002 Oral Presentations within shelf sedimentary basins around its periphery. Ten such basins are recognized, among them the LenaAnabar, Verkhoyan'ye, Okhotsk, and Tugur-Chumikan basins along its eastern margin, the Mongolia-Amur and South Mongolia basins around its southern side, the East-Kazkhstan, Kuznetsk and West-Siberian basins around its western, and the Taimyr basin on its northern margin. Each basin has its own peculiarities of sedimentation. The best marine Carboniferous and Permian sections around Angarida occur in the Verkhoyan'yeOkhotsk area. Their biostratigraphy and stratigraphic correlations are based mainly on brachiopods and ammonoids. Twelve regional horizons and 27 biozones have been established for the Carboniferous and Permian of this area (Fig. 1). Alignments of Carboniferous and Permian stratigraphic charts of the different regions along the periphery of Angarida were made on the basis of: (1) A detailed biostratigraphic chart for the Verkhoyan'ye-Okhotsk area; (2) Established global-event boundaries within the studied region; (3) Reference correlative intervals. The latter correspond to maximum transgressions. Associations of brachiopods characterizing local stratigraphic units have been of the prime importance for interregional correlation. The names of the units used for the reference interregional correlative intervals include the Krapivino, Magarsky, Latekygyltass, Khorokyt, Early Echiy and Early Delenzha intervals. The main events influencing the history of continental development recorded in the sediments of the marginal seas occur at the base of the Bazovsky and Imtandzhin horizons, the Carboniferous-Permian boundary (lower boundary of the Setlanda Formation) and the base of the Tumara and Delenzha horizons. Five events were recognized: 1 - Scheglovo event, 2 - Tylakh event, 3 - Setlanda event, 4 - Tumara event and 5 - Delenzha event (Fig. 1). It should be noted that the subdivision and correlation of the sections were based on brachiopod studies, but location of the stage boundaries in the particular sections were defined mainly by ammonoids and conodonts. The Tournasian and Visean boundary is distinguished by change from the Pseudopolygnathus multistriatus conodont association to Cavusgnathus charactus association. Presence of the goniatites Neogliphioceras abramovi defines the Upper Visean age of strata. The Upper Bashkirian substage is characterized by the ammonoid association of Jakutoceras aldanicum, Diaboloceras ruzhencevi, Stenopronorites omolonicus, Glaphyrites operosus, Phanerosus lenaense and others. The BashkirianMoscovian stage boundary is recognized by change from Christioceras domochotovi to Eoshumardites artigensis. Appearrance of the Roadian ammonoid association of Sverdrupites harkeri, Daubichites goochi, Popanoceras subtumarense and Anuites kosynskyi defines the lower and upper series of the Permian System. This work was supported by grant RFBR 02-05-64993

TRIASSIC CONODONT DATUM LEVELS IN SIBERIA AS A POSSIBILITY OF BOREALTETHYAN CORRELATION Tatvana V. KLETS Novosibirsk State University, Novosibirsk, Russia For the past two decades Siberia has been an important testing ground for development of a Boreal standard for the Triassic—with appreciable success in study of major components of marine ecosystems and correlation, sequence to sequence. Biostratigraphic investigations in Siberia have provided data on various groups of microfauna, especially foraminifers and conodonts. Continued progress in Triassic correlation is related not only to precision in zonal scales but to application of various methodological approaches. One such method is determining datum levels for correlation; these are treated as stratigraphic intervals corresponding to levels of biota composition. Conodont assemblages found recently in northern Siberia at different stratigraphic levels and comparison of these with the Tethyan conodont standard will provide more reliable Boreal-Tethyan correlation. The Olenekian (time of maximum Triassic transgression) is the first datum stage. Early Olenekian deposits have endemics (Neogondolella buurensis, N. composita and others) as well as widely distributed cosmopolitan species dominated by Neospathodus waageni, Neogondolella mosheri, N. milleri and in late Olenekian by N.jubata. In late Anisian time the quantity and diversity of conodonts decreased greatly. Boreal basins were inhabited only by cosmopolitan Neogondolella cornuta and N. aff. longa, forms with precise stratigraphic confinement in European and Asian sections, allowing the host rocks to be compared with the Neogondolella cornuta Zone, the youngest Anisian conodont zone established in the Balkans. Neogondolella aff. haslachensis, N. aff. constricta and N. cf. balkanica penetrated the Siberian basin in the early Ladinian. The early Carnian cosmopolitan Paragondolella foliata was widespread in high latitudes, allowing host rocks to be compared with the diebeli-tethydis zones of the European conodont standard.

IPC2002 Oral Presentations Norian time was characterized by entry of Norigondolella navicula and N. steinbergensis from low latitudes. N. navicula is the index species of the lowest subzone of the Norian in the European conodont standard for Tethys; N. steinbergensis is known from the middle and late Norian of Austria and other regions. The study was supported financially by grant E00-9.0-8 from the Ministry for Education of the Russian Federation.

RAPID DIVERSIFICATION IN BIVALVE LIFESTYLE AND HABITAT BEGINNING FROM THE LATE CRETACEOUS: IMPLICATION FOR THE FORMATION OF MODERN EVOLUTIONARY FAUNA Yasuo KONDO Department of Natural Environmental Science, Kochi University, Kochi 780-8520 The evolutionary palaeoecology of post-Palaeozoic bivalves was studied in terms of lifestyle and habitat, based on sedimentologic, taphonomic and palaeoecologic analysis of fossiliferous siliciclastic sediments including ecological observation of living species around Japanese Island. Based on present study and available information, the bivalve lifestyles were classified under 16 categories by the combination of feeding type, and mode of locomotion and attachment following Kondo (2001). Ten nearshore habitats were selected for compilation, as inferred from the observation of sedimentary facies, mode of fossil occurrence, and functional shell morphology. Number of new lifestyle categories which appeared every 10 Ma, and the number of newly colonized habitat categories per 10 Ma, were defined as indices, and calculated for the time period from Triassic to Neogene. Lifestyle and habitat diversity pattern. The data show that number of new lifestyle categories per 10 Ma is maximum in the Late Cretaceous (0.62), as compared to the average value of 0.32 from the Triassic onwards, and reached the present level by the end of Late Cretaceous. Similarly, number of newly colonized habitat categories per 10 Ma is highest in the Late Cretaceous (0.92), as compared to the average value of 0.32 from the Triassic onwards. It is therefore concluded that the Late Cretaceous was a time of rapid diversification for the evolutionary history of bivalves in terms of both lifestyle and habitat. Taking into account of the number of taxa involved in the diversification event, the change is inferred to have continued later, at least to the Eocene.

IPC2002 Oral Presentations Habitat dispersion pattern. When individual taxa are examined, a pattern from offshore to onshore (shelf to nearshore) habitat shift emerges, in addition to the previously proposed onshore to offshore general trend across the shelf for marine invertebrates through the Phanerozoic (Jablonski, et al., 1983). In bivalves, this onshore pattern is typically seen among "secondary soft-bottom dwellers" defined by Seilacher (1984), such as Ostreidae, Isognomonidae, Spondylidae and Plicatulidae in the subclass Pteriomorphia. Most of these changes occurred during the Late Cretaceous and Paleogene. More importantly, most of the nearshore habitats were newly colonized by bivalves firstly for shelly benthos during the same time period. For example, trigoniids already invaded lower and upper shoreface during the Early Cretaceous, but they expanded the habitat into even physically unstable substrate influenced by tidal currents by the beginning of the Late Cretaceous. Donacids invaded intertidal zone of dissipative beaches in the Late Cretaceous, followed by the colonization of reflective beaches by mesodesmatids in the Paleogene. Also, vertical niche dispersion both to deeper, higher and more free positions from the sea floor occurred in the habitat already colonized by bivalves, such as inner shelf and bay. These various habitat changes can be understood as a dispersion from physically stable optimal environment to physically unstable, and formerly inhospitable environments.

ENDEMISM IN PLIO-PLEISTOCENE VERTEBRATE FAUNAS OF THE ITALIAN PENINSULA AND THEIR PALAEOBIOGEOGRAPHIC MEANING T. KOTSAKIS1, C. PETRONIO2, C. ANGELONE1, P. ARGENTI3, G. BARISONE1, C. BEDETTI2, L. CAPASSO BARBATO2, E. Di CANZIO3, F. MARCOLINI1 & R. SARDELLAR2, 1 Dipartimento di Scienze Geologiche, Universita di Roma Tre; 2Dipartimento di Scienze delta Terra, Universita di Roma "La Sapienza ";3Dipartimento di Scienze delta Terra, Universita di Perugia. Italian Neogene continental vertebrate faunas are characterized by strong endemism until latest Miocene. The unbalanced composition of the fossil assemblages, dwarfism of large mammals and gigantism of small ones, testify to the presence of insular conditions. At least three different palaeobiogeographic provinces emerged during the Late Miocene: the Tuscany-Sardinia (Oreopithecus-Maremmia fauna), the Apulia-Abruzzi (Hoplitomeryx-Microtia fauna), both with endemic insular characters, and the Calabria-Sicily with a "normal" African mammalian assemblage. During latest Miocene (Late Turolian, MN 13 Unit) the changing palaeogeographic conditions made possible the arrival of typical European elements in the Italian peninsula. The assemblages of this age (with the exception of the Apulian area where the endemic Hoplitomeryxicrotia fauna survives till the end of the Miocene or the beginning of the Pliocene) are characterized by the absence of peculiar characters. However some endemic species are present. Knowledge of Early Pliocene vertebrate faunas of Italy is very limited but from the Middle Pliocene the number of fossil assemblages increases. In the Villafranchian (Middle Pliocene-Early Pleistocene) faunas of the Peninsula the endemisms are rather limited, while insular conditions persist in both major Italian islands (Sicily and Sardinia). Among the large peninsular mammals some cervids of the genus Eucladoceros, the equid Equus stehlini and the elephantid Mammuthus (Archidiskodon) meridionalis vestinus are restricted in Italy as also a lineage of the cervid Axis, present in Italy with many species. Knowledge of fossil assemblages of this age from the Balkan peninsula (Greece excepted) is rather poor, and this restricts knowing if a species is endemic or not. Until now, very few micromammals of Villanyian or Early Biharian age (corresponding to Villafranchian) have been assigned to endemic species (perhaps the soricid Asoriculus castellarini and the arvicolid Microtus (Allophaiomys) ruffoi). But the populations of some arvicolids (Mimomys) and murids (Apodemus) of these periods are characterized by morphologies slightly different from those beyond the Alpine belt. Some members of the Villafranchian herpetofauna belong to taxa that had disappeared from other parts of the European continent: the last European soft-shelled turtle of the genus Trionyx (Trionychidae) and the last discoglossid frog Latonia (Discoglossidae) have been collected in Italy in sediments of Late Pliocene and Early Pleistocene age respectively. Because the Peninsula is elongate over many degrees of latitude, it acts as a refuge area: some relict populations of a species may survive after extinction of the taxon elsewhere in Europe. This role of the Peninsula is not so evident during the Villafranchian; it becomes very important with the beginning of the Middle Pleistocene climatic deterioration. The Galerian and Aurelian faunas of the Italian peninsula include a considerable number of endemic taxa (at specific or subspecific level). The cervids are prominent in this process of differentiation, with some populations of Megaceroides and many subspecies of Cervus elaphus and Dama dama typical of the Italian peninsula. Some other herbivore populations, such as the caprine Capra ibex, are slightly different from the other European populations. Two species, the bovid Bos galerianus and the equid Equus graziosii are reported only from Italy, but are rare elements known only from their type-localities. Very few carnivores are endemic at subspecific level (e.g. Ursus arctos marsicanus). Some large mammals, both carnivorous and herbivorous, survive as relict populations long after their extinction in other parts of Europe: the canid Canis

IPC2002 Oral Presentations ex. gr. C. arnensis-C. mosbachensis, and a trogontherioid proboscidean reported in the literature as Mammuthus chosaricus. Among small mammals the number of endemic species is higher and includes some very well known species such as the talpid Talpa romana, the soricids Sorex samniticus and Crocidura zorzii, the arvicolid Terricola savii and the leporids Oryctolagus burgi and Lepus corsicanus. Several species of amphibians and reptiles are also endemic (e.g. Vipera ursinii); some of them are Miocene relicts (iSalamandrina terdigitata). In Sardinia, insular conditions persist until now whereas in Sicily insular phases are interrupted by rather brief periods of peninsular conditions. It is evident, so far, that both palaeogeography and climate affect vertebrate distribution in the PlioPleistocene of the talian peninsula, even if the climatic factor becomes more and more important with approach to the present day.

GRAPTOLITE ASSEMBLAGES OF THE KLABAVA AND LOWER PART OF THE SARKA FORMATIONS AND THEIR SPATIAL DISTRIBUTION (ORDOVICIAN, PRAGUE BASIN, CZECH REPUBLIC) Petr KRAFT1 and Jaroslav KRAFT2 Charles University, Institute of Geology and Palaeontology, Albertov 6, 128 43 Praha 2, Czech Republic; [kraft@natur.cuni.cz]; 2 West Bohemian Museum, Kopeckeho sady 2, 301 36 Plzen, Czech Republic, Ijkraft@volny. cz] Distribution patterns of planktic graptolite species at localities in the Klabava and lower Sarka formations, (upper Arenigian to lower Llanvirnian) show the presence of two or three typical assemblages within each biozone. These assemblages occur in tracts approximately parallel to the NE margin of the Prague Basin. Individual zones represent biotopes that reflect bathymetric conditions. In general they correspond to distance from coast or to elevations within the basin. Biotope 1 represents environments with higher dynamics, usually close to the coast. Graptolites inhabiting such environments have small rhabdosomes as a rule. The only "planktic dendroid" known from this biotope has flexible, relatively robust stipes without interconnecting elements. Biotope 2 represents an environment with lower dynamics and probably with favourable trophic conditions that provided circumstances for developing high species diversity of planktic graptolites. The largest number of species is recorded in this biotope at every stratigraphic level. Multibranched forms with large rhabdosomes are also present. Biotope 3 is the most distant from the coast. It occupied the water column above the deepest parts of the basin; it has the lowest species diversity. Only restricted groups of taxa inhabiting concurrently biotopes 1 and 2 are also recorded from this biotope. The pecies composition of the assemblages typical of the biotopes may be differentiated into two groups of planktic graptolites: a) species occurring in all biotopes, and b) species restricted to one and/or two offshore biotopes, i.e. independent and dependent on depth facies, respectively. The Prague Basin is a good example illustrating whether planktic graptolites are differentiated bathymetrically across limited basinal areas.The index species of all biozones are independent of depth. This is a contribution to the project MSM 113100006 and IGCP 410. The research was completed with financial support from the Grant Agency of the Czech Republic, project 205/02/0934.

IPC2002 Oral Presentations

Formation Sarka

Klabava

Biozone Corymbograptus retroflexus

Azygograptus ellesi Tetragraptus reclinatus abbreviatus Holograptus tardibrachiatus

Biotope 1 Corymbograptus retroflexus, Undulograptus novaki, Didvmograptus spinulosus. Aulograptus cucullus, Undulograptus n. sp., "Dendrograptus " titanus

Biotope 2 Corymbograptus retroflexus. Undulograptus novaki. Didvmograptus spinulosus. Aulograptus cucullus, Didymograptus (s. 1.) stanislavi, D. (s. 1.) n. sp., D. (s. 1.) ferrugineus Tetragraptus reclinatus Tetragraptus reclinatus abbreviatus, Azvsosraptus abbreviatus. Azvsosraptus ellesi. "Dendrograptus" ellesi. ".Dictyonema " titanus rokycanense, Holograptus membranaceus, Acrograptus cf. infrequens, A. crassus Holograptus tardibrachiatus. Holograptus tardibrachiatus. Tetragraptus cf. Tetragraptus cf. quadribrachiatus. quadribrachiatus. Acrograptus Acrograptus nicholsoni. nicholsoni. Didvmograptus (s. 1.) Didvmograptus (s. 1.) goldschmidti, goldschmidti. Pseudoreticulograptus Pseudoreticulograptus inusitatus, Didymograptus inusitatus rokycanensis, D. chlupaci, Corymbograptus deflexus, Corvmbosraptus v-similis. C. holubi. Acrograptus nicholsoni. Didvmograptus (s. 1.) goldschmidti. Pseudoreticulograptus inusitatus, Corymbograptus deflexus

Biotope 3 Corymbograptus retroflexus, Undulograptus novaki, Didymograptus spinulosus

Tetragraptus reclinatus abbreviatus. ? Azygograptus ellesi

Holograptus tardibrachiatus, Tetragraptus cf. quadribrachiatus. Acrograptus nicholsoni, Didvmograptus (s. 1.) goldschmidti.

Corymbograptus v-similis, C. holubi, Acrograptus nicholsoni, Didvmograptus (s. 1.) goldschmidti Tab. 1. Species distributions in the biotopes of four studied biozones of the Klabava and lower part of the Sarka formations. Species independent of depth facies are underlined; species recorded from both offshore biotopes are shown bold; other species were restricted to only one biotope.

Corymbogra ptus v-similis

DETAILED DOWNHOLE EARLY MIDDLE CAMBRIAN AGNOSTID BIOSTRATIGRAPHY John R. LAURIE Geoscience Australia, Canberra, ACT The current Australian Middle Cambrian biostratigraphic scheme (from Floran to Boomerangian) was developed by Opik (1979) from surface outcrop in the Georgina Basin. Because outcrop is generally poor and measurable sections lacking, most information came from spot localities. The Swedish zonal scale of Westergard (1946) was used as a framework on which these spot localities were hung. Some minor amendments were made to the Swedish scheme, most notably replacing the H. parvifrons Zone with that of Euagnostus opimus and separation of the P. punctuosus and P. lundgreni-G. nathorsti Zones into three zones (P. punctuosus, D. notalibrae and G. nathorsti Zones). The Solenopleura brachymetopa and Lejopyge laevigata Zones were also subdivided into a tripartite Lejopyge laevigata Zone (i.e. L. laevigata I, II and III). The earlier Ordian and Templetonian was more difficult. Despite the presence in the Templetonian of the Triplagnostus gibbus Zone at the top and the Peronopsis longinqua Zone (Opik, 1979) below, agnostids were scarce. Consequently, Opik (1970, 1975) used species of Redlichia and Xystridura to subdivide these stages. A succession of five Redlichia assemblages were asserted to be in stratigraphic order and all were considered Ordian. Species of Xystridura, on the other hand, were known from both the Ordian and Templetonian. Thus Redlichia with or without Xystridura was considered Ordian, and Xystridura without Redlichia, Templetonian. This simplistic separation of Ordian and Templetonian could not be sustained and the sequence stratigraphic analysis of Southgate & Shergold (1991) showed that the R. chinensis biofacies was probably coeval with the X. templetonensis biofacies. This led them to unite the T. gibbus Zone with the Floran Stage (i.e. 'Late Templetonian/Floran') while the remainder was termed 'Ordian/Early Templetonian' and comprised only the nebulous Xystridura templetonensis-Redlichia chinensis assemblage. Opik's (1979) undefined Peronopsis longinqua Zone was considered to be coeval with, or in part to predate the T. gibbus Zone. Work by the author on the trilobite succession in the Ord Basin (NT) has cast further doubt on Opik's Ordian story. In this basin there is a succession of two Redlichia species; R. forresti below and R. amadeana above, the latter with Xystridura negrina. These two Redlichia species are in reverse order to that given by Opik (1970). When one considers that these were the only two of Opik's 'zones' in demonstrated superpositional order, doubt over the supposed order of the others becomes overwhelming. Material from 14 coreholes in the Georgina Basin further demonstrate the inadequacy of the current Australian Middle Cambrian biostratigraphic scheme. Agnostids abound in these cores, probably because

IPC2002 Oral Presentations their small size and opportunistic lifestyle overcomes many of the drawbacks of using marine macrofossils in downhole biostratigraphy. This material demonstrates that Xystridura survived in the Georgina Basin until at least the Late Floran, and that Redlichia survived until what Opik termed the Peronopsis longinqua Zone (middle Templetonian). Furthermore, the succession of agnostid faunas allows development of a more refined early Middle Cambrian agnostid zonation, based in large part on a succession of species of Pentagnostus. These include, from bottom to top, P. n. sp. 1, P. anabarensis, P. praecurrens and P. n. sp. 2. There is also a succession of species of Itagnostus (/. elkedraensis, I. n. sp. 1, /. n. sp. 2) and about a dozen other species. The few previously discovered species indicate correlations with the Early Amgan Oryctocara and Kounamkites Zones of Siberia, as well as the immediately succeeding T. gibbus Zone. OPIK, A.A., 1970. Redlichia of the Ordian (Cambrian) of Northern Australia and New South Wales. Bureau of Mineral Resources, Geology and Geophysics, Bulletin 114, 67p., 14pls. OPIK, A. A., 1975. Templetonian and Ordian xystridurid trilobites of Australia.. Bureau of Mineral Resources, Geology and Geophysics, Bulletin 121, 84p., 32pls. OPIK, A.A., 1979. Middle Cambrian agnostoids: systematics and biostratigraphy. Bureau of Mineral Resources, Geology and Geophysics, Bulletin 172, vol. 1, 188p., vol. 2, 67 pis. SOUTHGATE, P.N. & SHERGOLD, J.H., 1991. Application of sequence stratigraphic concepts to Middle Cambrian phosphogenesis, Georgina Basin, Australia. BMR Journal of Australian Geology and Geophysics 12, 119-144.

ENVIRONMENTAL CONTROL OF EVOLUTION IN NEOGENE ANTARCTIC RADIOLARIAN FAUNAS David B. LAZARUS Museum fur Naturkunde, Humboldt Universitat, Invalidenstrasse 43, 10115 Berlin, Germany [david. lazarus@rz. hu-berlin. de]. The primary factors driving evolution of faunas can be either extrinsic (change in the physical environment) or intrinsic (interactions between species). These alternative views of evolution have been formalised in the Stationary and Red Queen models of evolution. Although these hypotheses have been extensively studied and debated, the issue remains largely unresolved. Published Neogene radiolarian stratigraphic range chart data from several ODP Sites on the Kerguelen Plateau has been synthesised to examine rates of evolutionary change, and to compare evolutionary patterns to changes in the environment as recorded by isotope and sedimentological data from the same sediments. The radiolarian data set consists of 168 named taxa from 377 samples, drawn from the works of Caulet (1991), Lazarus (1992) and Abelmann (1992). Due to significant differences in species lists and taxonomic concepts, the three data sets are analysed independently, although they are compared to each other to check the consistency of calculated evolutionary patterns. Environmental data is mostly from Mackensen et al. (1992). All three radiolarian data sets show the same patterns, strongly suggesting that the patterns are not artifacts of taxonomic or other data collection bias, and thus reflect the actual history of radiolarian evolution in the region. A clear correlation between rates of evolutionary change and enviromental change is seen. Major changes in the radiolarian fauna, particularly increased rates of extinction, are associated with the mid Miocene (15-13 Ma) and Miocene-Pliocene boundary (7-4 Ma) glacial events recorded in stable isotopes and sediment carbonate-opal ratios. Overall diversity is most strongly correlated to estimated palaeo-productivity, with higher productivity, later Neogene faunas being less diverse than earlier Neogene ones. The data also record a shift towards Nassellarian dominated faunas in later time intervals, possibly reflecting a change from near-surface water, partially symbiont bearing oligotrophic assemblages to Nassellarian dominated, non symbiont bearing subsurface faunas that characterise the nutrient rich intermediate waters of the modern Southern Ocean. The average longevity of species also changes dramatically over the Neogene. Taxa originating prior to 13 Ma are nearly twice as long-lived (8.20 my, N=38) as those originating after 13 Ma (4.20 my, N=29). The acceleration of evolutionary change seen in this study is unusual when compared to the available published literature on change in other groups of (mostly warm water) marine microplankton, where average longevities appear to have changed little over the Cenozoic. Preliminary conclusions from this work are: 1) Plankton evolution has operated in distinctive ways in high latitude regions in the Neogene, particularly in the apparent acceleration of rates of change. 2) Change in the physical environment is the ultimate pacesetter of evolutionary change in these faunas, although biologically mediated processes such as productivity are more directly important than temperature. 3) The role of biotic interaction in creating the evolutionary history observed is however still unknown. It is possible that increased interpolar faunal exchange in the later Neogene, due to increased global low

IPC2002 Oral Presentations latitude upwelling, increased biotic interactions and evolutionary turnover in the faunas. Only global study of polar biotas will be able to fully answer this question. ABELMANN, A. 1992. Early to mid-Miocene radiolarian stratigraphy of the Kerguelen Plateau (ODP Leg 120), p. 757-784. In Wise, S. W. and Schlich, R., Proc. ODP, SR, 120. ODP, College Station, TX. CAULET, J. P. 1991. Radiolarians from the Kerguelen Plateau, ODP Leg 119, p. 513-546. In Barron, J. and LARSEN, B. (eds.) Proc. ODP, SR, 119. ODP, College Station, TX. LAZARUS, D. B. 1992. Antarctic Neogene radiolarians from the Kerguelen Plateau, ODP Legs 119 and 120, p. 785-810. In Wise, S. W. and Schlich, R. (eds.), Proc. ODP, SR, 120. ODP, College Station, TX. MACKENSEN, A., BARRERA, E. and HUBBERTEN, H.-W. 1992. Neogene circulation in the Southern Indian Ocean: evidence from benthic foraminifers, carbonate data, and stable isotope analyses, p. 867-880. In: Wise, S.W., Schlich, R. (eds.), Proc. ODP, SR, 120. ODP, College Station, TX.

LATEST ORDOVICIAN EXTINCTION EVENT, SOUTHERN GREAT BASIN, USA: THE RECORD OF CONODONT BIOSTRATIGRAPHY AND CARBON-ISOTOPE CHEMOSTRATIGRAPHY W. Britt LEATHAM1, John D. COOPER2 & Robert L. RIPPERDAN3 1 Dept. of Geological Sciences, CSU San Bernardino, San Bernardino, CA 92407; 2Dept. of Geological Sciences, CSU Fullerton, Fullerton, CA 92834;3 Dept. of Geology, University of Puerto Rico, Mayaguez, Puerto Rico 00681. In eastern California and southern Nevada, the upper Ely Springs Dolomite (ESD) includes peritidal to shallow subtidal, microbial-laminated dolobindstone, mottled dolomudstone and dolowackestone, and dolograinstone containing a diverse, and moderately abundant latest Richmondian (Gamachian?) conodont fauna. This fauna includes Aphelognathus spp., Plectodina tenuis, Gamachignathus sp., Drepanoistodus suberectus, Pristognathus rohneri, Pseudobelodina spp., and several other distinctly Upper Ordovician species. The overlying Tony Grove Lake Member (TGLM) of the lower Laketown Dolomite includes bioclastic (Verticellipora sp., brachiopods, tabulate and rugose corals, and pelmatozoans), high-energy dologranstone/rudstone interbedded with microbial laminites. Early Llandoverian (Silurian) conodonts occur in the bioclastic TGLM; the fauna is neither diverse nor abundant, but includes specimens of Distomodus sp., Ozarkodina hassi, and Oulodus fluegelil. This assemblage is older than the D. staurognathoides appearance datum and characteristic of the D. kentuckyensis biozone. The faunal change is preceded by an apparent drop in species diversity. This Late Ordovician-Early Silurian (O/S) carbonate succession documents a major, species-level extinction of important Ordovician stocks (e.g. Amorphognathus, Hamarodus, Drepanoistodus, etc.) and the abrupt appearance of several lineages of conodonts of Silurian aspect. Historically, this global extinction event has been attributed to sea-level draw down associated with Hirnantian glacioeustasy. The question arises: what is the lithostratigraphic expression in the ESD for physical evidence of a sea level drop, and what is its relationship to the stable isotope record near the biostratigraphic definition of the O/S boundary in our baseline Nopah Range, CA section? Preliminary carbon isotope results from the Nopah Range show an interesting relationship to the conodont data. There is expression of a significant negative C-13 excursion that ends at a karstified surface approximately 190 meters above the base of the ESD, and just below the first major influx of cold-water conodonts. Approximately 40 meters higher in the section, a small but significant C-13 excursion ends at a sharp contact that separates conodonts of Silurian aspect from truly Ordovician species. This contact is a major regional sequence boundary that can be traced eastward into craton-margin sections in the Spring Mountains of southern Nevada. These preliminary results, when guided by biostratigraphic data, permit speculation on some alluring interregional correlations to well-documented O/S intervals in central Nevada and Anticosti Island, Canada. For example, the negative excursion likely correlates with a large negative excursion in the upper Vinini Formation in Nevada and in the upper Vaureal Formation on Anticosti Island. The positive excursion correlates well with a large positive excursion in the upper Hansen Creek Formation in Nevada and in the upper Ellis Bay Formation on Anticosti Island. These chemostratigraphic correlations are constrained biostratigraphically and coincide with biotic events and correlations related to onset and maximum development of glaciation. The upper Ely Springs Dolomite in the southern Great Basin provides another North American perspective on the long-standing dilemma of reconciling conflicting notions about Hirnantian glaciation duration: the North African tillite record suggests a protracted glaciation; the relatively short stratigraphic range of the Hirnantian fauna, which is presumed to represent the influx of high-latitude faunas into tropical regions, suggests a short glaciation event. Hopefully also the ESD provides another perspective on mechanistic linkages between late Ordovician glaciation, sea-level changes, and resulting perturbations of the biosphere and carbon cycling.

IPC2002 Oral Presentations

SCYPHOCRINITES LOBOLITHS, THE UNUSUAL FLOATS OF A CRINOID, FROM THE UPPER SILURIAN SETUL LIMESTONE, OF MALAYSIA Chai Peng LEE Department of Geology, University of Malaya, 50603 Kuala Lumpur, Malaysia; [j4chaip@umcsd. um. edu. my] Scyphocrinites loboliths are the bulbous floats attached to the roots of an Upper Silurian to Lower Devonian inverted free-floating crinoid found in Europe, North America, North Africa and Asia. There are two types of Scyphocrinites loboliths according to Haude (1972). The first is the cirrus type with walls of dense three-layered latticework of numerous spicule-like skeletal elements called cirrals. The second is the plated type that differs from the first in its plated appearance, the occurrence of a short projecting collar around the stem base and presence of primary roots, associated with fewness of chambers (usually 4 to 7, apparently 11 at most) and the existence of an opening to each chamber in the axil of the primary roots (Ubaghs, 1978). Loboliths with features of the plated type have been found in the Upper Silurian Upper Setul Limestone from two localities in the northwestern part of Peninsular Malaysia (Lee, 2001). The first occurrence is in a band of nodular limestone exposed at Teluk Memplam, northwest Pulau Langgun,Langkawi Island, Kedah and the second is from limestone blocks in an earth quarry near Guar Jentik, Berseri, Perlis on the mainland. These loboliths are found as clusters of micrite or sparry calcite-filled inflated structures up to 16 cm in diameter, with external chamber walls up to 1.5mm thick and paper-thin internal partitions. Globular loboliths from the first locality are not squashed and embedded in micrite while those from the second locality are flattened and associated with crinoidal debris including stem ossicles of Scyphocrinites. HAUDE, R., 1972. Bau und Funktion der Scyphocrinites-Lobotithen. Lethaia 5, 95-125, text-fig. 1-21. LEE, C.P., 2001. Occurrences of Scyphocrinites loboliths in the Upper Silurian Upper Setul limestone of Pulau, Langgun, Langkawi, Kedah and Guar Sanai, Berseri, Perlis. Proc. Geol. Soc. Malaysia. Ann. Conf. 2001, 99-104. UBAGHS, G., 1978. Skeletal Morphology of Fossil Crinoids. Treatise on Invertebrate Paleontology, Part T, Echinodermata 2(1), T58T216.

GLOBAL SEA SURFACE TEMPERATURES FROM THE EARLY EOCENE TO LATE PLIOCENE: BIOTIC EVIDENCE FOR THE SPATIAL DISTRIBUTION OF TROPICAL AND SUBTROPICAL REGIONS Daphne E. LEE1, Brian R. ROSEN2 & Alan GRAHAM3 department of Geology, University of Otago, Box 56, Dunedin, New Zealand; 2Department of Palaeontology, The Natural History Museum, Cromwell Road, London, SW7 5BD, UK; 3Department of Biological Sciences, Kent State University, Kent, Ohio 44242, USA Major discrepancies between estimates of sea surface temperatures derived from biotic evidence and those calculated from isotopic studies have been highlighted for more than a decade (Adams et al., 1990). Oxygen isotope research over the past 20 years has tended to suggest surprisingly "cool" sea surface temperatures for tropical and subtropical regions through the Late Cretaceous and Cenozoic. Such low temperature estimates (15-23°C, compared to modern values of 20-28°C) are at variance with the consistently higher estimates derived from the distributions of temperature-sensitive (*tropothermal) plants and animals that indicate stable tropical sea surface temperatures close to present levels from at least the Early Eocene. Recently Pearson et al (2001) have raised doubts about the validity of many earlier oxygen isotope temperature estimates derived from planktonic foraminifera due to previously unrecognised, and widespread, diagenetic alteration and poor preservation of the foraminiferal tests. Their study suggests that tropical sea surface temperatures in the Late Cretaceous and Eocene, at least, may have been up to 4°C higher, rather than lower than those of the present. Global climate models for the Cenozoic are largely based on oxygen isotopic data, and although numerous references have been made to serious mismatches between models and biotic evidence for terrestrial and marine climates, little attempt has been made to resolve these problems. Adams et al. (1990) mapped the distributions and generic diversity of selected unrelated tropothermal organisms such as mangroves, larger foraminifera, and reef corals in modern oceans. They then plotted the occurrence and diversity of larger foraminifera in the Middle and Late Eocene, Early and Middle Oligocene, and Early/Middle Miocene which indicated constant tropical/subtropical sea surface temperatures close to

IPC2002 Oral Presentations those of the present, and demonstrated the expansion and contraction of the tropical/subtropical regions as climate fluctuated. Here we expand this approach and present new estimates of global sea surface temperatures, and the geographical extent of tropical and subtropical seas for selected time intervals (Early, Middle and Late Eocene, Early and Late Oligocene, Early, Middle and Late Miocene, Early, Middle and Late Pliocene) using existing and new data on generic diversity and richness of several unrelated groups of tropothermal organisms including large foraminifera, reef corals, bivalve and gastropod molluscs, brachiopods, mangroves and tropical lowland plants. Ongoing research will refine these preliminary estimates of the limits of the expanding and contracting tropical and subtropical regions through the Cenozoic. Detailed analyses of the maximum and minimum temperature limits for living organisms are needed, and more precise dating of shallow marine and terrestrial organisms is required, to allow better correlation with data obtained from deep-sea drilling programs. The development of reliable models of changing global climates must integrate palaeotemperature estimates derived from distribution and diversity of plants and animals (biotic evidence) and data obtained from isotopic studies. Using data from both sources should make it possible to provide accurate reconstructions of sea surface temperatures for at least the past 60 million years. *tropothermal = organisms which require tropical/subtropical temperatures to survive and reproduce new term. ADAMS, C.G., LEE, D.E., and ROSEN, B.R. 1990. Conflicting isotopic and biotic evidence for tropical sea-surface temperatures during the Tertiary, Palaeogeography, Palaeoclimatology, Palaeoecology 77, 289-313. PEARSON, P.N., DITCHFIELD, P . W . , SINGANO, J., HARCOURT-BROWN, K . G . , NICHOLAS, C.J., OLSSON, R . K . , SHACKLETON, N.J., a n d

HALL, M.A. Warm tropical sea surface temperatures in the Late Cretaceous and Eocene epochs. Nature 413, 481-487.

CAMBRIAN TO ORDOVICIAN ECHINODERMS OF GONDWANAN AFRICA AND PERIGONDWANAN EUROPE Bertrand LEFEBVRE1 and Oldrich FATKA2 } UMR CNRS Biogeosciences, Universite de Bourgogne, 6 bid. Gabriel, 21000 Dijon, France; 2Department of Geology and Palaeontology, Faculty of Science, Charles University, Albertov 6, Praha 2, CZ-128 43, Czech Republic, [fatka@natur.cuni.cz]. During Cambro-Ordovician times, echinoderms underwent a major radiation, with appearance of more than twenty classes. Palaeoecological aspects of this diversification have been considered until now only for low latitude, North American (Laurentian) echinoderm faunas. These faunas show two successive bursts : (1) in the Early to Middle Cambrian (e.g. 'eocrinoids', stylophorans), and (2) in the Early Ordovician (e.g. crinoids, edrioasteroids). The 'Ordovician radiation' took place on carbonate hardgrounds in the shallow, warm waters of Laurentian shores. This two-phase pattern closely matches Sepkoski's Evolutionary Faunas Model (1979): it has been extended to all echinoderms (Guensburg and Sprinkle, 2001). However, careful examination of Lower Palaeozoic echinoderm faunas from Gondwanan Africa and peri-Gondwanan Europe shows similarities with Laurentian faunas (especially Cambrian), but also important differences (mainly for the Ordovician). The resulting pattern is clearly different from that described for North America, with the persistence of Cambrian-like faunas into the Ordovician (e.g. 'cystoids', stylophorans) and quasi-absence of any obvious 'Ordovician radiation' (e.g. crinoids and edrioasteroids are rare). This different evolution observed on Gondwanan shores is partly due to gradual shift of the palaeocontinent from low palaeolatitudes (Early to Middle Cambrian) to much higher palaeolatitudes (Late Cambrian to Ordovician), and resulting shifts in available palaeoenvironments (e.g. absence of Ordovician carbonate hardgrounds). OF's research was supported by the Czech Ministry of Education grant MSM 113100006.

ALIENACANTHUS. NEW WAYS TO BUILD AND FEED A PLACODERM? Herve LELIEVRE1 & Eileen D. Grogan2 } UMR 8569 Museum-CNRS. 8, rue Buffon, 75231 Paris cedex 05, France; [lelievre@mnhn.fr]; 2St. Joseph's University, Biology Dept., 5600 City Ave, Philadelphia, Pennsylvania, U.S.A. 19131; [egrogan@sju.edu]. The Late Devonian fish Alienacanthus malkovskii, described by Kulczycki (1957 PL 13, fig. 1) from the Famennian of the Holy Cross Mountains is one of the acanthodian taxa considered to be Incertae sedis by Denison (1979). It was originally identified on the basis of fragmentary isolated unpaired spines. In the same paper, on material of similar nature, Kulczycki errected Sentacanthus zelchowskae. Paucity of information about these species resulted in them being virtually forgotten or ignored by Devonian fish workers.

IPC2002 Oral Presentations During a field trip in the Late Devonian of Morocco one of us (H.L.), collected unusual fish macroremains—a skull roof and thoracic plates belonging to a new pachyosteomorph—associated with Dunkleosteus sp. The material was partially prepared using dilute formic acid and conodonts were obtained. According to Prof. P. Bultynck (Belgium) the conodont fauna contains Palmatolepis helmsi indicating the interval from Early trachytera to Early postera zones, i.e, Fa2b-Fa2C. The strange macroremains included nearly complete Alienacanthus spines that careful observation revealed to be inferognathals of a new design. Those were associated with other fossil material of the same specimen, namely the anterior part of a skull roof connected with both anterior and posterior superognathals and a fragmentary parasphenoid. Other gnathal remains from the same Moroccan locality provide evidence of two additional (and smaller) specimens of Alienacanthus. The larger and most complete specimen also provides new information on the brachythoracid Meckelian and ceratohyal ossifications. The morphology of the Alienacanthus inferognathal is without precedent in these armored fishes. Its shape, the extent of the dental field, and its histological design are novel. The uniserial "teeth" were not borne on a dental crest, as in other placoderms, but on the lateral margin of the spear-shaped lower jawbone. It appears they developed at the posterior margin of the element and added on as growth proceeded. Histologically there is evidence of an outer layer of enameloid. Below this layer, the synapomorphic placoderm tissue, semidentine grades, from apex to base, into osteosemidentine and a coarse, lamellar bone. Osteonal contact bone is present along the tooth base. Trabecular tissue formed the core of the inferognathal and evidently permitted continuous growth of this element. The abundance of trabecular tissue in the cranial dermal plates is comparable to that noted for other advanced arthrodires and represents a derived placoderm condition. The new fossils have also provided the means by which to assess other enigmatic placoderm remains, including the genus Alienacanthus The Moroccan material, being a partially articulated specimen, has undeniably revealed the true nature of the elongated bones originally interpreted as spines. In comparing the information for Alienacanthus with that of other Upper Devonian placoderm material, we are lead to conclude that the diversity of the placoderm fishes has probably been underestimated. The cumulative data indicate that, immediately prior to their extinction, there was greater species richness among placoderms than previously recognized. DENISON, R., 1979. Acanthodii. In H.P. Schultze (ed) Handbook of Paleoichthyology, vol. 5. Gustav Fischer Verlag, Stuttgart, New York. KULCZYCKI, J., 1957. Upper Devonian Fishes from the Holy Cross Mountains (Poland). Acta Palaeontologica Polonica, 11, 285-380.

MOLECULAR DATING OF THE CUPRESSACEAE SUBGROUPS AND THE BREAKUP OF PANGEA LI Chunxiang and QUN Yang Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China Cupressaceae is a family of Coniferae widely distributed today in northern and southern hemispheres, including 20 genera. Traditional classification of the family (5.5.) into two subfamilies (Cupressoideae and Callitroideae) (Li, 1953) is roughly in accordance with geographic distribution: the Cupressoideae all occur in the Northern Hemisphere whereas all Callitroideae except for one genus (Tetraclinis) occur in the Southern Hemisphere. Molecular phylogenetic studies reveal similar relationships except for one genus, Tetraclinis, which has closer relationship to Cupressoideae than to Callitroideae—suggested by traditional systematics (Brunsfeld et al., 1994; Gadek et al., 2000). The subfamilial classification matches perfectly with their discontinuous distribution. This pattern has been explained to have resulted from separation of Laurasia and Gondwana during the Mesozoic. The current study was intended to test this hypothesis for origin of modern Cupressaceae s.s. distribution. We analysed all 20 genera of Subfamily Callitroideae (Pilgerodendron, Libocedrus, Fitzroya, Widdringtonia, Diselma, Neocallitropsis, Callitris, Austrocedrus, Actinostrobus and Papuacedrus, four of them for rbcL) and of Subfamily Cupressoideae (Juniperus, Cupressus, Microbiota, Playcladus, Chamaecupris, Fokienia, Calacedus, Thuja, Thujopsis, Tetraclinis) using rbcL (1428 bp) and matK ( • 1530 bp) genes as molecular markers. rbcL and matK. were used separately for constructing molecular trees by parsimony, neighbor-joining and maximum likelihood methods with Subfamily Taxodioideae as the outgroup. In order to establish a molecular clock, rate constancy over all lineages of Family Cupressaceae s.l. (including subfamilies Callitroideae, Cupressoideae, Taxodioideae and Sequoioideae, and genera Athrataxis, Taiwania, Cunninghamia) and Family Pinaceae (Pinus, Cathaya and Pseudotsuga) was assessed for genes by the relative rate test (Robinson et al., 1998) on the basis of established molecular trees. Due to saturations of synonymous substitutions existing in both rbcL and matK sequences among studied taxa, only nonsynonymous sites were included in molecular clock analysis. Our test results show that for rbcL, the two

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IPC2002 Oral Presentations subfamilies for this study experienced remarkably different nucleotide substitution rates, whereas the substitution rate of matK. are statistically uniform among all taxa used in the relative rate test. Thus, only matK sequences were used for assessing the divergence time of two subfamilies in Cupressaceae s.s. The matK clock was established among all tested taxa using Kimura-2 genetic distance and the earliest fossil record of the three Pinaceae genera (Pinus, Cathaya and Pseudotsuga) (Wang et al, 2000) as the age reference point. Based on this clock, we calculated the divergence time of Subfamily Callitroideae (Southern Hemispere) and Subfamily Cupressoideae (Northern Hemisphere) to be 123.67±23.20 Ma in the latest Jurassic to Early Cretaceous, whereas the extant genera of Callitroideae diverged around 90.26± 16.93 Ma and those of Cupressoideae around 96.95±18.19 Ma. Our study suggests that the extant subfamilies of Cupressaceae s.s. might have been totally separated from each other during the Early Cretaceous when the genetic exchanges between them were blocked out by a MAJOR geographic or other ecological barrier—considering that plants over a large region could conduct interbreeding through pollen and spore dispersal. Since the supercontinent Pangea started disintegration during Triassic and Jurassic times, the separation of the northern and southern subfamilies of Cupressaceae probably indicates that by latest Jurassic or Early Cretaceous time, the ocean separating the southern continent Gondawana and the northern continent Laurasia (namely, Tethys) was of large dimensions. Although we note that the current age-estimates by molecular clocks have considerable error margins, results of our preliminary study support the hypothesis of a tectonic origin for the current phytogeographic distribution pattern for the Cupressaceae. BRUNSFELD, S.J., SOLTIS, P.S., SOLTIS, D.E., GADEK, P.A., QUINN, C.J., STRENGE, D . D . and RANKER, T.A., 1994. P h y l o g e n e t i c

relationships among the genera of Taxodiaceae and Cupressaceae: evidence from rbcL sequences. Syst. Bot., 19: 253-262. GADEK, P.A., ALPERS, D.L., HESLEWOOD, M.M. and QUINN, C.J., 2000. Relationships within Cupressaceae sensu lato: a combined morphological and molecular approach. Amer. J. Bot., 87: 1044-1057. Li, H.L., 1953. Present distribution and habitats of the conifers and taxads. Evolution, 7: 245 - 261. ROBINSON, M., GOUY, M., GAUTIER, C. and MOUCHIROUD, D., 1998. Sensitivity of the relative-rate test to taxonomic sampling. Mol.

Biol.Evol., 15: 1 0 9 1 - 1 0 9 8 . WANG, X.-Q., TANK, D.C. and SANG, T., 2000. Phylogeny and divergence within the pine family: evidence from three genomes. Mol Biol. Evol., 17: 733-781.

DIFFERENTIATION OF ACRITARCH ASSEMBLAGES REFLECTING LITHOFACIES CHANGES IN THE EARLY-MIDDLE ORDOVICIAN OF THE YANGTZE PLATFORM, S-CHINA Jun LI & Kui YAN Nanjing Institute of Geology and Palaeontology, Academia Sinica, Nanjing 210008, China; [junli@nigpas ac.cn]. The Yangtze Platform of South China is an important area for the study of Ordovician acritarchs. More than 40 articles that focus essentially on the taxonomy, biostratigraphy and palaeobiogeography have already been published (Li et al., 2002a). The palaeogeography and the palaeoecology of the Yangtze Platform are today fairly well understood. From shallow-water environments in the west of the platform, the facies changes first into carbonate dominated rocks and then, to the south-southeast, into the graptolitic shale facies of the Jiangnan Belt (Chen Xu, 1995). Ongoing palynological investigations on several sections across the upper Yangtze Platform provide palaeoecological results that indicate a clear relationship between the composition of the acritarch assemblages and the lithofacies changes. Seven Ordovician sections located in different parts of the upper Yangtze Platform are investigated. The palynological study is concentrated on the Lower Ordovician (Yushanian) Didymograptus deflexus graptolite biozone and the Middle Ordovician (Dawanian) Azygograptus suecicus graptolite biozone. From west to east the geological sections show a lithofacies change that reflects different palaeoenvironmental conditions : near Kunming, in the western part of the upper Yangtze Platform, Lower Ordovician rocks are typical near-shore shallow water deposits of clastic rocks with ripple marks, cross-bedding and rich ichno-facies (Tangchi and Hongshiya formations); eastwards, near Tongzi and Guiyang, in the central part of the upper Yangtze Platform, the terrestrial deposits decrease and carbonates intercalate with arenaceous-argilaceous shales (Meitan Formation); further eastward in the Yichang area, in the eastern part of the upper Yangtze Platform, terrestrial deposits are less common and the carbonates intercalate only with argillaceous rocks (Dawan Formation). From west to east the acritarch assemblages show a remarkable increase in both abundance and diversity with the deepening of the water column. Poorly diversified in the eastern part of the platform (e.g., Fang, 1986 ; this study), the acritarchs are more abundant and diversified in the central (e.g., Li, 1987 ; Li et al., 2002b) and eastern part of the Platform (e.g., Lu Lichang, 1987 ; Tongiorgi et al1995 ; this study). The composition of the acritarch assemblages also varies. The genera Coryphidium and Striatotheca occur in all

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IPC2002 Oral Presentations sections, being most abundant in the central part of the upper Yangtze Platform, while the taxa Baltisphaeridium and Peteinosphaeridium are more common in the eastern part of the upper Yangtze Platform and rare in the western part. These differences thus probably reflect a facies-dependence and an inshore-offshore trend, and not only palaeogeographical changes, as previously suggested in the literature. CHEN XU, 1995. Regional stratigraphy and paleogeography. In Chen Xu and Bergstrom, S. (eds), The base of the austrodentatus zone as

a level for global subdivision of the Ordovician System, Paleoworld 5, 7-13.

FANG XIAOSI, 1986. Ordovician micropaleoflora in Kunming-Luquan region, Yunnan Province and its stratigraphical significance.

Professional Papers in Stratigraphy and Palaeontology 16 : 125-172. Li JUN, 1987. Ordovician acritarchs from the Meitan Formation of Guizhou Province, southwest China. Palaeontology 30, 613-634. LI JUN, SERVAIS, T, and BROCKE, R., 2002a. Chinese Paleozoic acritarch research: review and perspectives. Review of Palaeobotany and Palynology (in press). LI JUN, WANG YI, SERVAIS, T., and BROCKE, R. 2002b. Ordovician acritarchs from Meitan Formation of Huanghuachong, Guizhou, South China. Acta Palaeontologica Sinica 41, 96-104. Lu LICHANG, 1987. Acritarchs from the Dawan Formation (Arenigian) of Huanghuachang in Yichang, western Hubei. Acta Micropalaeontologica Sinica 4 : 87-102. TONGIORGI, M., YIN, L., DI MILIA, A., 1995. Arenigian acritarchs from the Daping section (Yangtze Gorges area, Hubei Province, Southern China). Review of Palaeobotany and Palynology 86, 13-48.

ACANTHODIAN FISH (GNATHOSTOMATA: ACANTHODII) BIOSTRATIGRAPHY OF THE LATEST PRAGIAN-EMSIAN MURRUMBIDGEE GROUP, SOUTHEASTERN AUSTRALIA I.D. LINDLEY Department of Geology, The Australian National University, Canberra. A.C.T. 0200. Australia; [lindley@geology. anu. edu. auJ. Diverse acanthodian fish faunas of the limestones of the Lower Devonian Murrumbidgee Group, spanning the 15 Ma Emsian Stage, have been described by Lindley (2000, 2001, in press). These studies documented well preserved jawbones, fin spines and ornamented body scales, the only fossilised elements of these small, largely unossified fishes, from three pre-selected levels in the sequence. Collection horizons included the lower Cavan Bluff Limestone, at the base of the Murrumbidgee Group, where faunas may cross the lower boundary of the dehiscens CZ, equivalent to a latest Pragian-earliest Emsian age. Faunas were also collected from the Currajong Limestone and lower Bloomfield Limestone Members of the lower Taemas Limestone {dehiscens CZ: early Emsian), a stratigraphic position approximately mid-level in the Murrumbidgee Group. At the top of the Murrumbidgee Group faunas were collected from the middle-upper Taemas Limestone (upper dehiscens CZ/lowerperbonus CZ to serotinus CZ: Emsian). Dentigerous jawbones. Amongst the acanthodians only those of the Order Ischnacanthida possessed dentigerous jawbones with teeth firmly ankylosed on both upper and lower jaws. Seven endemic ischnacanthid species, whose varied morphologies are considered indicative of rapid evolutionary change, are present in the Murrumbidgee Group. The locally abundant Cavan Bluff Limestone fauna consists of four species: Taemasacanthus erroli Long, 1986, Cavanacanthus warrooensis Lindley, 2000, Cambaracanthus goodhopensis Lindley, 2000 and Taemasacanthus porca Lindley, 2000. The equally locally abundant ischnacanthid faunas of the lower Taemas Limestone consist of three species. T. erroli persists from the Cavan Bluff Limestone, while Taemasacanthus narrengullenensis Lindley, 2001 and Taemasacanthus cooradigbeensis Lindley, 2001, both bearing mesial row teeth with distinctive lunate parabasal sections, are incoming species. Only meagre acanthodian remains are present in the upper Murrumbidgee Group, consisting of three ischnacanthid species. T. narrengullenensis and T. cooradigbeensis persist from the lower Taemas Limestone in addition to a new incoming indeterminate ischnacanthid. Fin spines. Four acanthodian fin spine morphotypes are present in the Murrumbidgee Group. The limited species numbers reflect generally conservative morphologies for this body element, especially with respect co-occurring dentigerous jawbones. From the lower Cavan Bluff Limestone fin spines were recovered juxtaposed to jawbones of C. goodhopensis and T. erroli suggesting that they were derived from the same carcass. These two spine morphotypes were not recognised from higher levels in the sequence. Fin spine Ischnacanthid indet. A is a third morphotype from the Cavan Bluff Limestone. Two spine morphotypes are present in the lower Taemas Limestone: Ischnacanthid indet. A persists from the lower Cavan Bluff Limestone and a new incoming spine morphotype Acanthodii gen. indet. The only fin spine noted from the upper Murrumbidgee Group is Acanthodii gen. indet., considered to have been derived from T. narrengullenensis. Body scales. Four acanthodian body scale morphotypes are recognised from the Murrumbidgee Group and, like fin spines, they reflect particularly conservative morphologies with respect those of co-occurring dentigerous jawbones. Scales of the cosmopolitan climatiid Cheiracanthoides Wells, 1944 and Ischnacanthid indet. C are present at all studied levels in the Murrumbidgee Group. Scale morphotype Ischnacanthid indet.

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IPC2002 Oral Presentations B is restricted to the lower Cavan Bluff Limestone and scales of the climatiid Nostolepoides sp., the upper Taemas Limestone (Basden et ah, 2000). BASDEN, A., BURROW, C., HOCKING, M., PARKES, R. & YOUNG, G.C., 2000. Siluro-Devonian microvertebrates from southeastern

Australia. In Palaeozoic Vertebrate Biochronology And Global Marine/Non-Marine Correlation - Final Report of IGCP 328 (19911996), A. Blieck & S. Turner, eds, Courier Forschungsinstitut Senckenberg 223, 201-222. LlNDLEY, I.D., 2000. Acanthodian fish remains from the Lower Devonian Cavan Bluff Limestone (Murrumbidgee Group), Taemas district, New South Wales. Alcheringa 24, 11-35. LLNDLEY, I.D., 2001. Lower Devonian ischnacanthid fish (Gnathostomata: Acanthodii) from the Taemas Limestone, Lake Burrinjuck, New South Wales. Alcheringa 25,269-291. LlNDLEY, I.D., In press. Acanthodian, onychodontid and osteolepidid fish remains from the middle-upper Taemas Limestone (Early Devonian), Lake Burrinjuck, New South Wales. Alcheringa.

REVIEW AND REVISION OF THE FAMILY DAMESELLIDAE, KOBAYASHI 1935, IN NORTH CHINA AND ITS BIOSTRATIGRAPHIC AND CHRONOSTRATIGRAPHIC SIGNIFICANCE LUO Kunli and A. R. PALMER institute of Geographical Sciences and Natural Resource, Chinese Academy ofSciences, Beijing, 100101, P. R. China, [luokl@igsnrr.ac.cn[; Institute for Cambrian study, Cedarbrook Rd. North Cedarbrook, Boulder, Colorada 80304 USA 1

Damesellidae are common and widespread in the Cambrian of North China. They characterize an interval that has historically incorporated the upper Changhian and Kushanian Stages. Some of the earliest trilobites described from China in the late 19 and early 20 centuries by Walcott (1913, p. 3-8) and Zhang and Jell (1987, p. 1,2). The Damesellidae were recognized as a family by Kobayahi (1935) and the family has been reviewed in whole or in part by Kobayashi (1942) and Zhang and Jell (1987). However, these studies were based primarily on material from small collections made by other geologists mostly before the Second World War when the necessity for precise stratigraphic controls was not fully appreciated. There has also been a proliferation of names for trilobites assigned to this family in various Chinese monographs during the last 40 years, also based on materials from small collections with poor stratigraphic control. The reason for this new review is that detailed larger collections with precise stratigraphic controls, made by the senior author, and more modern preparation techniques, have established accurate associations of exoskeletal parts of many damesellids, better understanding of critical aspects of cranidial and pygidial morphology, and more precisely controlled biostratigraphy that require re-evaluation of the taxonomic relationships and stratigraphic significance of these trilobites. This paper presents the results of that reevaluation. th

CORAL RECORDS AND GLOBAL CHANGE J.M. LOUGH and D.J. BARNES Australian Institute of Marine Science, PMB 3, Townsville MC, Australia; [j.lough@aims.gov.au; d. barnes@aims.gov. au]. Climate and environmental processes vary naturally on a range of time-scales. Understanding the full range of climate and environmental variability and their possible causes is not possible with the short instrumental record period. Such understanding is, however, crucial for separating natural from unnatural sources of variability and detecting global change. Annual density bands in the CaC0 skeletons of massive corals (analogous to tree rings) were first discovered almost 30 years ago. Such corals can live to be several hundred years old and are often well preserved after death - opening windows to the more distant past. The discovery of annual banding paved the way to deriving high-resolution proxy climate and environmental records for shallow-water, tropical ocean regions occupied by coral reefs. These regions are of special interest as they are influenced by the major source of short climate variability - El Nino-Southern Oscillation events. Understanding the past environmental histories of coral reefs and changes in coral growth rates is also important for assessing the natural range of variability of coral reefs and possible anthropogenic impacts on these increasingly threatened ecosystems. Massive corals lock away in their skeletons a wide range of parameters that can provide insights into past environmental and climatic conditions. These include coral growth rates, luminescent lines and various isotopic and geochemical tracers (eg O , C , Sr/Ca). There are, however, no perfect proxy climate and 3

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IPC2002 Oral Presentations environmental recorders and understanding coral growth processes has been a key to extracting reliable information from corals. We are only now starting to fully exploit the natural historical archive provided by massive corals. EXPLAINING EXTINCTIONS: EVIDENCE FOR LONG-TERM ECO-MACROEVOLUTIONARY COUPLING BETWEEN THE BIODIVERSIFICATION OF MARINE PLANKTON AND PHANEROZOIC EXTINCTION-RATE CONTROLS N. MACLEOD

Department of Palaeontology, The Natural History Museum, Cromwell Road\ London SW7 5BD, UK, [N. MacLeod@nhm. ac. uk]_ The Phanerozoic marine invertebrate extinction record shows two widely recognized trends: (1) a quasiperiodic spacing between temporally localized extinction-intensity maxima and (2) a prolonged and seemingly linear decline in overall extinction-intensity values from the Palaeozoic through to the Recent. This latter pattern has often been referred to as the 'background extinction gradient'. Any comprehensive explanation for the causes of an controls on this long-term record must account for both pattern classes. Raup and Sepkoski (1984, 1986) argued that Monte Carlo analyses of the Permo-Triassic-Recent portion of the extinction-intensity maxima signal exhibited a statistically significant 26-million year periodicity; a conclusion that strongly implicated an extraterrestrial forcing mechanism. This conclusion was subsequently disputed on a wide variety of analytical and data-source grounds. New Monte Carlo simulation studies of the entire Phanerozoic extinction-intensity maxima record detect no statistically significant periodicities. These results, coupled with the concerns raised by other authors over the original Raup and Sepkoski study, would seem to close off this line of argument in favor of the extra-terrestrial forcing of 'mass extinctions'. In terms of accounting for this extinction pattern, alternative Monte Carlo tests of the association between the Phanerozoic extinction-intensity maxima and the stratigraphical records of Phanerozoic bolide impact events, eustatic sea-level falls, anoxia events, and large igneous province eruptions indicate that only the latter association is both frequent and exclusive enough to reject the a null hypothesis of coincidental association at the p = 0.05 significance level. Despite the successful identification of terrestrial volcanism as the primary Phanerozoic casual agent responsible for temporally localized pattern of extinction-intensity maxima, the interaction between this source of environmental perturbation and alternative eco-macroevolutionary biosphere characteristics has remained largely unexamined. However, a closer look at the second prominent extinction pattern—the socalled background extinction-intensity gradient, yields surprising results. First, this gradient does not extend throughout the entire Phanerozoic, but is confined to the Late Palaeozoic o Recent interval. The Early Palaeozoic is characterized by a random pattern of extinction intensities. Second, the general pattern of directional change in Phanerozoic extinction-intensity values mirrors that of a number of isotopic and molecular environmental-state proxies for marine circulation intensity (5 S), terrestrial nutrient runoff (5 Sr), and carbon cycle operation (8 C, C0 ). Since modern plankton biotas are effected by (e.g., circulation intensity) or effect (e.g., carbon cycle) the global environmental state, and since all explanations for marine extinction-intensity peaks involve short-term reductions in marine primary productivity, it is logical to expect a link between planktonic biodiversification and the susceptibility of marine invertebrate fauns to extinction. Evidence for this link includes (1) the Mesozoic-Cenozoic decline in overall extinction intensities and the corresponding increase in taxic richness for the primary modern phytoplankton groups (e.g., nannoplankton, dinoflagellates, diatoms), (2) that fact that increases in phytoplankton diversity are associated with the overall diversification of two of Sepkoski's three marine invertebrate evolutionary faunas, and (3) a variety of associations between Early Mesozoic plankton diversification events and macroevolutionary changes in diversification histories for a variety of marine invertebrate clades. Taken together, these patterns reveal a consistent relationship between the state of the global planktonic biota and global extinction rate controls. Furthermore, the fact that the greatest decline in background extinction rates occurs at the end of the Devonian suggests a macroevolutionary link between changes in terrestrial primary productivity and benthic marine invertebrate diversification that is most likely mediated through the marine planktonic biota. These data also imply that a stable, diversified planktonic biota was probably a consistent feature of the marine biosphere from Carboniferous-Recent, despite the fact that the taxonomy of the Late Palaeozoic members of this biota is almost wholly unknown. 34

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RAUP, D.M., and J.J. SEPKOSKI, Jr., 1984. Periodicity of extinctions in the geologic past. Proceedings of the Natural Academy of

Sciences 81, 801-805.

RAUP, D.M., and J.J. SEPKOSKI, Jr., 1986. Periodic extinction of families and genera. Science 231, 833-836.

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SOURCES OF—AND SOLUTIONS TO—ERROR IN HIGH-RESOLUTION QUANTITATIVE BIOSTRATIGRAPHICAL ANALYSES N. MACLEOD Department of Palaeontology, The Natural History Museum, Cromwell Road, London SW7 5BD, UK, [N. MacLeod@nhm. ac. uk]_ Biostratigraphy has been, is now, and will remain well into the foreseeable future the most accurate and practical method available for inferring chronostratigraphical relationships within Phanerozoic sediments. This is not to say that biostratigraphy can or should be used to accomplish this task in isolation from or in competition with other techniques that bear on the inference of time relations in rocks (e.g., magnetostratigraphy, geochronometry). Nevertheless, fossil content is the most widely distributed and inexpensively assessed set of time-related observations that can be made in most sedimentary facies. When used appropriately, the biostratigraphical time scale also offers levels of temporal resolution that are superior to those of any other method of chronostratigraphical inference and correlation. However, in order to achieve the maximum level of chronostratigraphical resolution that can be extracted from biostratigraphical datasets, various well-known sources of error must be acknowledged and controlled for explicitly. Failures to correctly assess levels of error in high-resolution biostratigraphical analyses often result in the inference of incorrect correlations, age-depth models, diversification-extinction rate summaries, and biogeographical reconstructions that, in turn, compromise palaeontologists' ability to test higher-order hypotheses. Fortunately, techniques are now being developed to address these sources of biostratigraphical error. The most common—though least discussed—source of biostratigraphical error is inconsistent taxonomy. Recent studies of micropalaeontological datasets suggest that levels of potential error due to inconsistent taxonomy are as high as 70%. The fact that the entire literature devoted to this topic consists of a dozen or so widely scattered research reports suggests that the palaeontological community has not taken this obvious source of error—that ultimately effects virtually all comparative palaeontological studies—seriously. This source of error is presently uncontrolled because of the lack of standardized taxonomies, even for wellknown fossil groups (e.g., planktonic foraminifera). Electronic taxonomic databases (e.g., PalaeoBase, PaleoBank) have demonstrated their ability to address this problem though their elaboration into a truly comprehensive research tool will require greater levels of specialist input into these types of projects than they now enjoy. The second most common source of biostratigraphical error is spurious accuracy in the spatial placement of 'observed' biostratigraphical events. As pointed out originally by Shaw (1964), the first or last recorded observation of a taxon's occurrence only rarely coincides with the taxon's true local (not to mention global) first or last occurrence. These sources of error can be controlled via the estimation of 'bestcase' and 'worst-case' models for patterns of occurrence in local sections using stratigraphical confidence intervals—the generality of which is undergoing rapid revision and improvement—and by coupling these error estimates with explicitly comparative methods of spatial trend analysis and geochronometrical calibration (e.g., multivariate graphic correlation). The third important source of biostratigraphical error is unevenness in the spatial distribution of biostratigraphical events in local sections or cores. This situation leads to subintervals that are relatively poor in observed biostratigraphical events with a consequent loss of chrono-stratigraphical resolution. There are two extant solutions to this problem (excepting the obvious solution of including more taxonomic groups in the biostratigraphical analysis). The first is the 'morpholog' approach (Reyment 1980) in which morphometrically identified characters within the taxon's fossil phenotype are tracked through the section or core. These data are then added to the taxonomic first and last appearance data to create an extended or composite palaeontological dataset for use in correlation. The second is the 'supplemented' approach (Edwards 1989) whereby nonpalaeontological (e.g., geochemical isotopic) observations are included along with palaeontological data in the analysis. The use of these methods is illustrated with examples drawn from new high-resolution analysis of Cretaceous-Tertiary boundary chronostratigraphy. EDWARDS, L.E., 1989. Supplemented graphic correlation: A powerful tool for paleontologists and nonpaleontologists. Palaios 4, 127143. REYMENT, R.A., 1980. Morphometric methods in biostratigraphy; Academic Press, London. SHAW, A., 1964. Time in stratigraphy; McGraw-Hill, New York.

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IPC2002 Oral Presentations ICHNOLOGY OF THE CAMBRIAN CAMPANARIO FORMATION IN NORTHWEST ARGENTINA AND THE RECONSTRUCTION OF EARLY PHANEROZOIC INTERTIDAL ECOSYSTEMS M. Gabriela MANGANO & Luis A. BUATOIS Conicet-Insugeo, Casilla de correo (CC), 4000 San Miguel de Tucuman, Argentina [ichnolog@infovia. com. ar]. The Cambrian Meson Group of northwest Argentina consists of thick and laterally continuous deposits and includes, from base to top, the Lizoite, Campanario and Chalhualmayoc formations. The Meson Group was historically considered as Middle to Late Cambrian in age. However, the presence of the ichnogenus Syringomorpha suggests that the group may range into the Lower Cambrian. The Meson Group is interpreted as having accumulated in macrotidal shallow-marine environments with extensive tidal-flat areas flanked seawards by subtidal sandwave complexes. In particular, the Campanario Formation comprises bioturbated, planar cross-bedded and ripple cross-laminated sandstones, thinly interbedded sandstones and mudstones, and red mudstones, representing deposition in tidal flats and very shallow subtidal areas. Hummocky crossstratified sandstones recording storm events occur locally. Tidal flat facies having abundant trace fossils offer an opportunity to examine the ecology of an early Phanerozoic intertidal ecosystem. Shallow subtidal and intertidal sand flat deposits are dominated by vertical domiciles of suspension feeders and passive predators of the Skolithos ichnofacies (e.g. Skolithos, Arenicolites, Diplocraterion). The ichnogenus Syringomorpha commonly occurs in high density, comprising monospecific assemblages in sand flat facies. Syringomorpha forms composite ichnofabrics which mostly resulted from the upward migration of the community in response to vertical accretion of intertidal sediments. The composite nature of this ichnofabric is revealed by high bioturbation indexes (bi4-bi5) and complex cross-cutting relationships. High degree of bioturbation and preferential preservation of closely-spaced, vertical components make the Syringomorpha ichnofabric analogous to Skolithos piperocks. Maximum penetration depth recorded for vertical burrows is around 40 cm. Mixed flat deposits contain horizontal feeding, locomotion and resting traces as diagnostic components. However, vertical burrows, such as Skolithos and Syringomorpha, are dominant in some wavy-bedded strata that most likely represent sand flat-mixed flat transition facies. Mixed flat facies are characterized by common sand-mud interfaces that enhanced preservation of horizontal structures, providing the absence of pervasive bioturbation by Skolithos and Syringomorpha. In these taphonomic windows a relatively low diversity Cruziana ichnofacies can be reconstructed, including trilobite trace fossils (e.g. Cruziana, Rusophycus, Diplichnites) and shallow burrows and trails of vermiform organisms (Planolites, Palaeophycus, Helminthoidichnites). The ichnospecies Rusophycus leiferikssoni is the most distinct structure of this facies, forming monospecific assemblages of clustered individuals or associated with Syringomorpha. Rusophycus leiferikssoni may occur in deposits having indicators of periodic subaerial exposure (e.g. desiccation cracks). Maximum depth recorded is approximately 4 cm at the base of cross-laminated sandstones. Its localized abundance in tidal flat deposits, the tendency to form clusters and overall morphology suggest nesting behavior. Alternatively, the association with Syringomorpha suggests that R. leiferikssoni may represent a feeding structure related to high microbial concentration in intertidal deposits enhanced by the activities of other infaunal animals. Modern tidal flats are characterized by abundant food supply derived from multiple sources, including nutrients and rich plankton brought in by the sea, terrestrially-derived organic detritus and autochthonous food production. The inhabitants of the intertidal area are exposed to a double set of predators significantly affecting community structure. During submergence they are preyed by other marine organisms and during emergence they are visited by enemies from the land and air. The picture that emerged of an intertidal Cambrian ecosystem is contrastingly different. The absence of land vegetation in the Cambrian was a major controlling factor in the composition and structure of intertidal communities. In the absence of land plants, Cambrian intertidal trophic webs were entirely based on the marine rich source and the autochthonous production. Land and air predators were absent. Depth and extent of bioturbation reveals colonization of a relatively deep infaunal ecospace mostly by suspension feeders and some unorthodox deposit feeders feeding on clean sand sediments rich in microbes and/or meiofauna. These ichnofabrics dominated by vertical domiciles record the advent of deep burrowing by coelomate metazoans during the Cambrian radiation. Assemblages of the Cruziana ichnofacies are exceptionally preserved recording the activities of very shallow vermiform animals. Trilobite nests are larger and deeper than the vermiform trace fossils, leading to increased disturbance of the original stratification. Tiering structure, however, remains simple. Trilobite excursions to Cambrian tidal flats support an early colonization of intertidal environments and indicate that representatives of the Cambrian evolutionary fauna were able to colonize very shallow water environments, thus suggesting a significant landward expansion of the Cambrian explosion.

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IPC2002 Oral Presentations LAMELLORTHOCERAS (NAUTILOIDEA, PALLIOCERATIDA) FROM THE LOWER DEVONIAN OF BOHEMIA: A CONTRIBUTION TO CAMERAL MANTLE THEORY Jaroslav MAREK Charles University, Institute of Geology and Palaeontology, Albertov 6, 128 43 Praha 2, Czech Republic; [marekj@natur. cuni. cz/ Since definition of the term "cameral mantle" by Flower (1939), the problem of its existence has been widely discussed. The problem of communication betwen the cameral mantle tissue and the cephalopod body through the connecting rings of the siphonal tube is the main objection against this theory. Finds of well preserved specimens of Lamellorthoceras in Lower Devonian limestones (Dvorce-Prokop Formation, Barrandian area, Czech Republic) solve the question of communication of the siphonal cord with the shell camerae by a long and wide opening positioned on the dorsal side of the siphonal tube. The siphonal tube thus changed into the shape of a trough situated inside the camerae, whereas within the siphonal neck it retained the classical tubular form. The cameral mantle in Lamellorthoceras is bilaterally symmetrical; it consists of numerous thin longitudinal lamellae growing from the dorsal siphonal tube opening to the outer shell wall. In cross-section the lamellae are radially arranged wsith distance apart equal to their thickness. The narrow ventral space below the siphonal tube is the only exception; it is filled by massive cameral deposits. Similar, but not so massive, deposits are present also in spaces between the cameral mantle lamellae. Cameral mantle lamellae are usually longitudinally undulating and, in some taxa, also branch irregularly to the periphery. Such branching occurs mainly on the dorsum and on the lateral sides on the adoral portion of the camerae. Because of this, different patterns of arrangement of lamellae (depending on location and orientation of the shell section) could be observed. The pattern varies from simply radiating (e.g., Gorgonoceras) to dendritic branching (e.g., Lamellorthoceras) in cross-section. Longitudinal undulation of lamellae may produce "strange" sinuose structures in longitudinal sections (e.g., Mutvei 1956, pi. 1). Several genera have been established on differences in arrangement of lamellae. Detailed understanding of lamellar morphology could impact significantly on classification of the family Lamellorthoceratidae. Overall, the cameral mantle complex is more developed in camerae adorally then adapically. The cameral mantle of each individual camera is wider adorally, thus having a conical outline. The entire cameral mantle complex of the phragmocone is made up of a series of such cones After weathering, such cephalopods may be misinterpreted as rugose corals (see the original description of Arthrophyllum Beyrich, 1850; Howell, 1942, etc.). The study was supported by Czech Ministry.

COMPOUND AND COMPLEX TRACE FOSSILS FORMED BY PLANT AND ANIMAL BEHAVIOR IN THE PLEISTOCENE OF SAPELO ISLAND, GEORGIA (USA) Anthony J. MARTIN1 & Murray R. GREGORY2 1 Department of Environmental Studies, Emory University, Atlanta, Georgia 30322 USA; [geoam@learnlink.emory.edu]; 2Department of Geology, The University of Auckland, Private Bag 92019, Auckland, NZ; [m.gregory@auckland.ac.nz]. Structures in the Raccoon Bluff Formation (Pleistocene) of Sapelo Island, Georgia (USA) show how plantproduced trace fossils later provided substrates for feeding burrows of terrestrial invertebrates. This combination of two trace fossils into structures formed by different species at different times (yet overlapping in space) qualifies them as both complex and compound trace fossils. The structures are large (1-2 m long and as much as 50-cm wide) white-sand filled tubes, circular in horizontal section and cylindrical (but tapering downward) in longitudinal section. Dark-brown (humic) haloes surround the white sand fill and connect with an overlying palaeosol. The structures were made primarily by tree roots associated with the development of a maritime forest and are morphologically comparable to those of modern pines (e.g., Pinus taeda). White sand in the structures represents a passive fill from an eolian sand containing the same sediments above the palaeosol, meaning that the root structures were temporarily open and connected with the Pleistocene ground surface. Boundaries between dark-brown haloes and white-sand fills are blurred by back-filled burrows (Taenidium); deposit-feeding insect larvae likely made the burrows after the root structures were filled. Sand-filled zones are visibly more porous and permeable than surrounding haloes, thus these root structures provided a moist microhabitat for burrowing invertebrates well after the death of the trees. The structures intrude sandy sediments near the top of a shallowing-upward sequence (Ophiomorphadominated upper shoreface to berm) that was probably formed by the ending of the Wisconsinian glacial period.

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IPC2002 Oral Presentations Analogous modern coastal and terrestrial environments and organisms on Sapelo provide excellent opportunities for testing the interpretations presented here. Nevertheless, our preliminary results imply that complex and compound trace fossils caused by plant- and animal-caused structures can contain more palaeoenvironmental information than that obtained from interpreting simple, contemporaneous trace fossils.

DUAL ORIGIN OF TRIBOSPHENIC MAMMALS: NEW EVIDENCE FROM SOUTH AMERICA Thomas MARTIN1, Oliver W.M. RAUHUT2, Edgardo ORTIZ-JAUREGUIZAR2, and Pablo PUERTA2 l lnstitut fur Geologische Wissenschaften, Fachrichtung Palaontologie, Freie Universitat Berlin, Malteserstrafie 74-100, 12249 Berlin, Germany; [tmartin@zedat.fu-berlin.de]; 2Museo Paleontdlogico Egidio Feruglio, Fontana 140, 9100 Trelew, Argentina Recently the theory of a dual origin of tribosphenic mammals was presented (Luo et al., 2001) based on a phylogenetic analysis of newly discovered mammalian mandibles from the Southern Hemisphere. Ambondro from the Middle Jurassic (Bathonian) of Madagascar (Flynn et al., 1999) and the Early Cretaceous Ausktribosphenos and Bishops from Australia (Rich et al., 1997, 2001) possess lower molars with fully basined talonids from which a functional protocone on the upper molars can be inferred. Autapomorphic characters such as talonids which are wider than longer and a wrapping lingual cingulid suggest that these Gondwanan Holotheria represent a separate lineage, the Australospenida which evolved tribosphenic molars indepedently from the Southern Hemisphere Boreosphenida (Luo et al. 2001, 2002). The discovery of Asfaltomylos patagonicus from the Middle Jurassic (Callovian) Canadon Asfalto formation in Chubut (Argentina) yields important new information on the mammalian evolution in Gondwana. Asfaltomylos patagonicus is the first Jurassic mammal from South America (Rauhut et al., 2002) and has lower molars with fully basined talonids. From wear facets within the talonids the presence of a fully functional protocone on the (unknown) upper molars can be inferred. The proportions of the talonids on the molars which are wider than longer (the talonid is the widest part of the molar in m2) and the presence of a faint lingual cingulid at the base of the paraconid of ml-m3 suggest that Asfaltomylos is a representative of the Australosphenida. This interpretation is supported by the combination of a derived dentition with a mandible that exhibits remarkable plesiomorphic characters. These are a dental foramen in a very anterior position (below the origin of the coronoid process) and a postdentary trough with faint longitudinal striations indicating the former presence of some vestigial additional bones. Such a combination of derived dental and plesiomorphic mandibular characters is unknown in (pre)tribosphenic boreosphenidans. Asfaltomylos predates the oldest Laurasian tribosphenic mammal, the recently described Tribactonodon bonfieldi Sigogneau-Russell, Hooker, and Ensom 2001 from the early Cretaceous Purbeck Limestone (Southern England) by about 20 Myr and corroborates the existence of a Middle Jurassic radiation of tribosphenic holotherians in Gondwana. The addition of Asfaltomylos to the phylogenetic analysis resolves the polytomy within Australosphenida found by Luo et al. (2001), and Ambondro and Ausktribosphenos appear as successively closer outgroups to Monotremata (including Steropodon). Interestingly, no tribosphenic mammals so far have been reported from Cretaceous strata in South America. Apparently, the Australosphenida underwent a decline since the Late Jurassic and finally evolved completely reduced dentition in contrast to their successful boreosphenidan counterparts. FLYNN, J.J., PARRISH, J.M., RAKOTOSAMIMANANA, B., SIMPSON, W.F. and WYSS, A.R. 1999. A Middle Jurassic mammal from

Madagascar. Nature 401, 57-60. LUO, Z.-X., CLFELLI, R.L. & KIELAN-JAWOROWSKA, Z. 2001. Dual origin of tribosphenic mammals. Nature 409, 53-57. Luo, Z.-X., KIELAN-JAWOROWSKA, Z., and ClFELLI, R . 2002. In quest for a phylogeny of Mesozoic mammals. Acta Palaeontologica Polonica 47, 1-78. RAUHUT, O.W.M., MARTIN, T., ORTIZ-JAUREGUIZAR, E. & PUERTA, P. 2002. A Jurassic mammal from South America. Nature 416, 165-168. RICH, T.H., VICKERS-RICH, P., CONSTANTINE, A . , FLANNERY, T.F., KOOL, L. a n d VAN KLAVEREN, N . 1997. A t r i b o s p h e n i c m a m m a l

from the Mesozoic of Australia. Science 278, 1438-1442. RICH, T.H., FLANNERY, T.F., TRUSLER, P., KOOL, L. VAN KLAVEREN, N . , a n d VICKERS-RICH, P. 2 0 0 1 . A s e c o n d t r i b o s p h e n i c m a m m a l

from the Mesozoic of Australia. Records of the Queen Victoria Museum 110, 1-10. SIGOGNEAU-RUSSELL, D., HOOKER, J.J., and ENSOM, P. 2001. The oldest tribosphenic mammal from Laurasia (Purbeck Limestone Group, Berriasian, Cretaceous, UK) and its bearing on the "dual origin" of Tribosphenida. Comptes Rendus des seances de l'Academie des Sciences Paris, Sciences de la Terre et des planetes 333, 141-147.

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IPC2002 Oral Presentations CLUSTER ANALYSIS OF DEVONIAN BRACHIOPOD FAUNAS IN NORTH AMERICA Paul S. MAYER Geology Section, Milwaukee Public Museum, 800 West Wells Street, Milwaukee, WI53080, USA [paul@mpm. edu]. Boucot, Johnson and Talent (1969a, 1969b) divided Devonian brachiopod faunas into realms and provinces. A closer look at North American brachiopod distributions (Johnson, 1970, 1971) demonstrated that a land barrier separated the Cordilleran Subprovince of the Old World Realm (OWR) in western North America from the Appalachian or Eastern America Realm (EAR) in eastern North America. Johnson (1970, 1971) noted that during part of the Early Devonian there was a decrease in provinciality, while in the later part of the Early Devonian and during the most of the Middle Devonian provinciality increased. During a major onlap of North America near the end of the Middle Devonian and through the Late Devonian, provinciality decreased again. In this study a total of 53 faunal lists were generated using a total of 382 genera based on present and absent data collected from the literature. The faunas were from seven basins (New York (NY), Michigan (MI), Hudson Bay (HUD), Iowa (IA), New Mexico (NM), Great Basin (GB), and Western Canada (WC)) and were correlated using 11 Transgression-Regression (TR) cycles (Johnson et al., 1985; Johnson and Klapper, 1992). Faunal lists from each TR cycle (TR-Ia-IIf) were compared to each other using a provinciality index (PI=C/2E) where C= number of brachiopod genera in common and E= endemic genera from the smaller of the two faunas compared. The brachiopod lists were analyzed in the software program Biodiversity Pro using Jaccard single average cluster analysis. Each code, on the right side of the cluster analysis, starts with the letter code for the basins (given above) followed by a hyphen and then the TR cycle number (Ia-IIf). The cluster analysis shows three main clusters. The bottom cluster has Early and Middle Devonian EAR faunas including the two oldest Great Basin faunas. The middle cluster has late Early, Middle and early Late Devonian OWR faunas and includes Iowa and late Middle Devonian Hudson Bay faunas. The top cluster encompasses Late Devonian EAR and OWR mixed faunas. Closer examination of the cluster analysis along with the provinciality indexes shows two types of smaller clusters. One type groups the same basin together through two or more TR cycles. This indicates the basin has a high level of provinciality and was closed off from other basins. A second type of cluster groups several different basins together all from the same TR cycle indicating that these basins had a low level of provinciality and were connected to each other.

% Similarity

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IPC2002 Oral Presentations CORAL RECORD OF TERRESTRIAL RUNOFF INTO THE INNER GREAT BARRIER REEF: QUANTIFICATION OF ANTHROPOGENIC FLUXES Malcolm McCULLOCH , Stewart FALLON , Timothy WYNDHAM , Erica HENDY , Janice LOUGH and David BARNES Research School of Earth Sciences, Australian National University, Canberra, Australia; Australian Institute of Marine Science, Townsville, Queensland, Australia. The Great Barrier Reef (GBR) has been described as the world's largest living organism, extending for over 2000 km along the northeastern coastline of Australia and containing immense physical and biological diversity. Although some sections are distal from direct terrestrial influences, inshore regions of the central and northern GBR are regularly impacted by runoff from large rivers. The river flows are highly episodic, being associated with cyclones or occasionally intense monsoonal depressions. During these high intensity rainfall events, there can be massive discharges of freshwater and suspended sediments into the GBR lagoon. The Burdekin River, for example, delivers several million tons of sediment into the near-shore GBR lagoon during single flood events. A longstanding and still highly controversial question is how has the water quality changed within the GBR lagoon since European settlement? What has been the impact of these changes on the ecology and sustainability of the GBR? It has long been suspected that the flux of terrestrially derived sediments and nutrients entering the nearshore shore regions of the Great Barrier Reef (GBR) has increased substantially since European settlement; a result of large-scale modification of the river catchments from grazing, agriculture, mining and associated activities such as land clearing. The magnitude and scale of anthropogenic induced changes on the GBR however remains highly uncertain. It will be shown how longlived (300-400 year old) corals from the inshore region of the Great Barrier Reef of Australia provide a unique, long-term quantitative record of suspended sediment loads delivered to the GBR. Based on the relatively new technique of high resolution (daily to weekly) laser ablation ICP-MS developed at RSES, it is now possible to obtain continuous scans of the trace element composition of ~3-4 metre long carbonate coral cores (growth rate of ~l-2 cm per year). It will be shown how Ba/Ca ratios in coral cores provide a proxy of long-term changes in suspended sediment loads and thus nutrients (P), that are entering inshore coral reefs prior to and following European settlement. The Ba/Ca systematics in the coral core analysed in this study reveal two distinctive patterns. For the period prior to European settlement, during the 1770's when Captain Cook explored the east coast of Australia, there is only limited evidence for floodplume related suspended sediment fluxes entering the inner GBR. Following European settlement, in the 1870's, there is a dramatic change in the Ba/Ca ratios of the coral core. This is coincident with the first grazing/clearing activities by European settlers in the Burdekin catchment. Thereafter (i.e. post 1870) during all subsequent flood plume events, the Ba/Ca peaks are present in approximate proportion to the volume of the river discharge, modulated by land-use intensity and climate changes, principally droughts. For example, following the drought of 1968/69, the suspended sediment load increased dramatically during the 1970 flood, presumably due to enhanced erosion of the highly denuded Burdekin River catchment. These results therefore provide unequivocal evidence for Burdekin River flood-plumes transporting substantially increased quantities of suspended sediment into the inner GBR reef, immediately following European settlement. The impacts of different types of land-use combined with varying climate regimes (e.g. drought) on sediment/nutrient delivery to the inner and mid GBR will also be described. 1

LATE PALAEOZOIC - EARLY MESOZOIC FLORAL SUCCESSION IN EASTERN AUSTRALIA: A GEOPHYSICAL PERSPECTIVE John L. MCKELLAR Department ofNatural Resources and Mines, Queensland Government In the Australian region, as in other Southern-Hemisphere Gondwanan areas, abrupt extinction of the Glossopteris Flora (and the attendant Striatites Microflora) occurred during the Palaeozoic - Mesozoic transition. This flora, consequent to the demise of the associated peat-swamp regime at the end of the Palaeozoic, was succeeded by the Dicroidium Flora (and the Alisporites/Falcisporites Microflora), the antecedents of which had colonised emerging uplands in the Late Permian. The Dicroidium Flora evolved and diversified in the depositional basin system during the Triassic, but was rapidly extinguished at the Period's end, or in the early Hettangian. Cheirolepidiacean conifers, which originated in the Northern Hemisphere, then dominated the landscape during most of the Early Jurassic, this being indicated by the extreme abundance of their pollen, represented by Corollina/Classopollis, in palynofloral assemblages (Corollina torosa Abundance Zone of the Callialasporites dampieri Microflora/Superzone).

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IPC2002 Oral Presentations The Glossopteris and Dicroidium extinction events, which were separated in time by approximately 46 million years, seemingly have little in common. Nonetheless, they both appear to have been strongly influenced by a feature the remnants of which are evident in Earth's present-day geoidal surface. Specifically, the long-wavelength African - eastern Atlantic residual geoid high, which extends from Greenland across Africa and the southwest Indian Ridge, controlled much of late Palaeozoic - early Mesozoic geological history (McKellar, in press, and cited references). This included not only other extinctions through the Permian Triassic transition (with compressional uplift of the Pangaean perimeter), but also widespread basin formation towards the end of the Carboniferous (-300 Ma), the ensuing mid Permian - late Middle Triassic HunterBowen Orogeny in eastern Australia (and coeval global tectonism), termination of the Carboniferous Permian Reversed Superchron in the late Middle Permian by inception of the ensuing mixed polarity regime of the Illawarra Superchron, first-order lowstand of global sea level at the Permian - Triassic boundary (with compressional uplift superimposed on thermal uplift), the emergent (thermally elevated) nature of the Pangaean platform during the Triassic, and regional climate change during the late Palaeozoic and early Mesozoic with changing palaeolatitude of the landmasses. The African - eastern Atlantic geoid anomaly and hotspots corresponds with the pre-breakup, late Palaeozoic - early Mesozoic, Pangaean assemblage of continents (see McKellar, in press, and cited references). It represents the vestiges of the massive thermal and geoid anomaly (the Pangaean thermal anomaly) that developed beneath Pangaea during the mid-late Carboniferous as a consequence of mantle heat-loss retardation by the supercontinent itself. These circumstances created a mass imbalance in Earth's rotation and caused significant relocation of the principal axis of inertia of the planet. Ensuing true polar wander (TPW) apparently occurred as the planet's physical system, in order to accommodate the changed geoid and minimise kinetic energy of rotation, began the arduous task of realigning the axes of inertia and rotation. This process necessitated equal distribution of the Pangaean thermal anomaly (and other positive geoid height anomalies and mantle mass excesses) about the equator. During the Permian and Triassic - earliest Jurassic, palaeomagnetic data indicate that Pangaea underwent an anticlockwise rotation and northwards displacement, moving the southern landmass away from the pole. In eastern Australia (southeastern Pangaea), this accords with progressive shifts in regional climate from coldand cool-temperate during the Permian (Glossopteris Flora: embracing the Gangamopteris and Glossopteris floral phases) to cool- and warm-temperate during the Triassic (Dicroidium Flora), and to warm (monsoonal) conditions during the Early Jurassic when the xeromorphic and thermophilic Cheirolepidiaceae proliferated. The Early Jurassic represents transient location of the Australian region in the lowest palaeolatitudes that it was to occupy for the entire duration of the Mesozoic Era. TPW of this scale involves considerable deformation of the mantle and lithosphere because of centrifugal forces acting on the rotating, spheroidal Earth, these effecting relocation the equatorial (rotational) bulge. The geomagnetic field is also affected, as rotation of the Earth orientates the geomagnetic dipole through the action of the Coriolis force on fluid motions in the molten-iron outer core; and increasing rates of TPW have been linked to increasing rates of field reversal (see McKellar, in press, and cited references). MCKELLAR, J.L, in press. Late Early to Late Jurassic palynology, biostratigraphy and palaeogeography of the Roma Shelf area, northwestern Surat Basin, Queensland, Australia. Queensland Geology (subtitle omitted).

FLORISTIC CHANGES ASSOCIATED WITH CLIMATIC AND OTHER ENVIRONMENTAL FLUCTUATIONS IN THE EARLY CRETACEOUS OF SOUTHEASTERN AUSTRALIA Anne-Marie TOSOLINI1, Stephen MCLOUGHLIN & Andrew DRINNAN School of Botany, The University of Melbourne, Victoria 3010, Australia;1 Present address: School of Earth Sciences, The University of Leeds, Leeds LS2 9JT, UK. Palaeomagnetic data indicate that southeastern Australia was situated at high latitudes (c. 70-85°S) during the Early Cretaceous, yet abundant and diverse floras have been preserved in the Gippsland and Otway basins. Globally warmer climates during the Early Cretaceous compared to the present apparently permitted diverse vegetation types to extend to polar latitudes. Nevertheless, oxygen isotope signatures of carbonate concretions and cryoturbation structures in fluvial sediments of the Gippsland and Otway Basins, and icerafted dropstones and glendonites in neighbouring basins provide strong indications that the region experienced seasonally frigid conditions in the Aptian and Albian, although glaciers or ice caps were not necessarily developed. A range of data from foliar physiognomy, the presence of abundant epiphyllous fungi, semi-aquatic ferns and lycophytes, and sedimentary characteristics suggest that consistently high-humidity climates prevailed during the Early Cretaceous in southeastern Australia. Marked growth rings in wood, deciduousness amongst a range of gymnosperms, diminutive leaf size and thick cuticles with papillate protection of stomates or leaf imbrication amongst various evergreen gymnosperms reflect adaptations to strongly seasonal climates at

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IPC2002 Oral Presentations these latitudes. Faunal evidence in the form of oscillatory growth in larger dinosaur bones, enlarged optic features, and evidence of periodic fish and invertebrate mass mortality also attest to a strongly seasonal environment with long periods of winter darkness. A cool but not extreme climate is indicated for the Neocomian, based on similarities to Jurassic floras. An apparent cooling trend in the Aptian was accompanied by a sharp decline in seed-fern diversity, increased abundance of ginkgoaleans, and significant turnovers in conifer species. The diversification of broad-leafed Araucariaceae in the Albian is correlated with a return to warmer, though still strongly seasonal, climates. Quantification of mean annual temperatures for the Victorian Early Cretaceous based on foliar physiognomic characters is not possible using currently available angiosperm-based criteria. However, regional trends in foliar dimensions and stomatal protection in groups such as bennettitaleans and conifers offer some scope for improved palaeoclimatic resolution across Gondwana.

LATE ORDOVICIAN/EARLY SILURIAN ARTHROPOD COLONISATION OF THE LAND EVIDENCE FROM THE TUMBLAGOODA SANDSTONE, WESTERN AUSTRALIA Kenneth J. MCNAMARA1 & Nigel H. TREWIN2 1 Western Australian Museum, Francis Street, Perth, Western Australia 6000; 2Department of Geology and Petroleum Geology, University of Aberdeen, Aberdeen, Scotland. The Early Palaeozoic Tumblagooda Sandstone, that outcrops in the spectacular gorges of the Murchison River in Kalbarri National Park in Western Australia, contains a great variety of trace fossils. These provide a unique insight into the activities of early invaders of the terrestrial environment and reveal the presence of a diverse fauna dominated by arthropods. The sandstones are more than 1 km thick and developed from mixed fluvial and aeolian sandsheet deposits in a high energy terrestrial environment. The age of the Tumblagooda Sandstone has been the subject of much debate. It has variously been assigned to the Cretaceous, Silurian, Ordovician or Cambrian. In a study of the trace fossil assemblage, Trewin & McNamara (1995) suggested a ?late Silurian age, on the basis of overall similarities between some of the trace fossils with those from the Taylor Group of Antarctica. Palaeomagnetic studies had suggested a much older, early Ordovician age. The most recent study is based on conodonts from limestones of the Ajana Formation derived from drill core. These limestones overlie red sandstone which is thought to be a lateral equivalent of the Tumblagooda Sandstone. The limestones have yielded an Early Silurian conodont. This would suggest a late Ordovician to early Silurian age for the Tumblagooda Sandstone. Two distinct, diverse ichnofaunas have been recognised. The first is the Heimdallia-Diplichnites Ichnofauna. This occurs in sands deposited in broad low sinuosity braided fluvial channels, between which were mixed aeolian and waterlain sandsheets, small aeolian dunes and flooded interdune and deflation hollows. The major bioturbator was the organism that in shallow pools formed beds of Heimdallia. Other burrows include Tumblagoodichnus, Beaconites and Diplocraterion. The Diplichnites represent arthropod trackways found on waterlain sands and foreset beds of aeolian dunes. Other tracks include Paleohelcura and Protichnites. A wide size range of tracks, from a width of a few millimetres up to nearly 20 centimentres, indicates a wide diversity of trackmakers. Digging traces, such as Rusophycus, are also known. More than 10 different types of arthropods have been recognised to date. Likely track makers include myriapods, eurypterids, euthycarcinoids, xiphosurids and scorpionids. The only body fossil found is a single specimen of the euthycarcinoid Kalbarria brimmellae (see figure left). On the basis of this discovery it has been suggested that euthycarcinoids provide a potential evolutionary link between myriapods and hexapods. The other ichnofacies is the Skolithos-Diplocraterion Ichnofauna. This occurs higher in the section in strata that represent a fluvial marine transition. Traces are dominated by Skolithos, some up to 1 m long, together with other burrows Diplocraterion, Daedalus and Lunatubichnus. Apart from rare Diplichnites, the most common trails are Aulichnites. Preservation of the rich diversity of trackways attributable to arthropods occurred because of the nature of the fluvial/aeolian regime. Tracks were made by arthropods walking out of

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IPC2002 Oral Presentations water on wet sand. Fine, wind-blown dust settled on these surfaces, preserving the finest details. At this time land vegetation was minimal, being restricted to lower plants, hence erosion rates would have been very high. This is attested to by the thick sequence of sediments in the Tumblagooda Sandstone which are thought to have been deposited relatively rapidly. How many of these arthropods had become truly terrestrial by this time is unknown. Many may have been amphibious, walking between pools of water as they dried out. These thus represent some of the earliest reported terrestrial trackways and support the view that one of the major steps in evolution, the colonisation of land by animals, may have been from rivers, rather than from the sea. TREWIN, N.H. and MCNAMARA, K.J., 1995. Arthropods invade the land: trace fossils and palaeoenvironments of the Tumblagooda Sandstone (?late Silurian) of Kalbarri, Western Australia. Transactions of the Royal Society of Edinburgh 85, 177-210.

THE OSSIFIED MECKEL'S CARTILAGE FROM THE EARLY CRETACEOUS TRICONODONT REPENOMAMUS AND ORIGIN OF THE MAMMALIAN MIDDLE EAR Jin MENG1,Yao-Ming HU2, Yuan-qing WANG3, & Chuan-kui LI3 1 Division of Paleontology, American Museum of Natural History (AMNH), Central Park West at 79th St., New York, NY 10024, USA; [jmeng@amnh.org]; institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, P.O Box 643, Beijing, 100044, China & Biology Program (EEB), Graduate School and City College, City University of New York, NY 10016-4309, USA; and AMNH; [yhu@amnh.org]; institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, P.O Box 643, Beijing, 100044, China. A groove that extends longitudinally along the medial surface of the dentary is a common but puzzling feature present in many Mesozoic mammals and their relatives known since the 19th century (Owen, 1871). The groove varies in its position, shape, and size. In some forms more than one groove are present. Simpson (1928) made the first systematic review about this structure based on his observations of jaws of Mesozoic mammals known at the time. Because the function of the groove was uncertain, Simpson (1928) employed "internal groove" as a descriptive, unambiguous yet noncommittal, term to denote the groove in question. In conclusion Simpson (1928) endorsed the view of Owen (1871) that the internal groove lodged a nerve or artery or both, probably resembling the mylohyoid groove of extant mammals. On the other hand, Simpson disfavored Bensley's (1902) view that the groove is for the Meckel's cartilage. Recent study considered that the internal groove may have accommodated the postdentary unit, which implies that a definitive mammalian middle ear (DMME) is not yet formed in some Mesozoic mammaliaforms that have the internal groove (Allin and Hopson, 1992). The ossified Meckel's cartilage has been recovered from two early Cretaceous triconodonts, Repenomamus and Gobiconodon (Wang et al., 2001), and possibly from the symmetrodont Zhangheotherium from Liaoning, China. The rod-like ossified Meckel's cartilage bridges the dentary and the ear region of the skull. Its shape and position are similar to those of Meckel's cartilage in prenatal and some postnatal extant mammals. The ossified Meckel's cartilage may have functioned as attachment site for the medial pterygoid muscle. These specimens provide direct evidence for the function of the internal groove in related Mesozoic forms, which probably lodges the Meckel's cartilage rather than a nerve/artery or the postdentary elements. The evidence shows that the definitive mammalian middle ear has evolved in triconodonts and symmetrodonts and weakens the multiple origination of the mammalian ear ossicles. It supports the prediction that a persistent or ossified Meckel's cartilage has been present in adults of the common ancestor of mammals. The new evidence does not support the mechanic model in which brain expansion and negative allometry of auditory chain are responsible for the detachment of ear ossicles in mammalian ontogeny and evolution. An alternative hypothesis is proposed that does not require brain expansion as the initial factor for the detachment of ear ossicles during mammalian evolution. The research is supported by the Ministry of Science and Technology, P. R. China (G2000077700), National Natural Science Foundation of China (49832002), and Chinese Academy of Sciences (KZCX3-J-03, KZ951-B1-410). ALLIN, E.F, and Hopson, J. A., 1992. Evolution of the auditory system in Synapsida ("mammal-like reptiles" and primitive mammals) as seen in the fossil record, pp. 587-614. In Webster, D. B, Fay R. R. and Popper, A. N. (eds), The evolutionary biology of hearing; Springer-Verlag, New York. BENSLEY, B.A., 1902. On the identification of meckelian and mylohyoid grooves in the jaws of Mesozoic and Recent Mammalia. University of Toronto Studies, Biological Series 3, 75-81. OWEN, R., 1871. Monograph of the fossil Mammalia of the Mesozoic formations; Paleontographical Society, London. SIMPSON, G.G., 1928. Mesozoic Mammalia. XII. The internal mandibular groove of Jurassic mammals. American Journal of Science, XV, 461-470. WANG, Y.-Q., HU, Y.-M., MENG, J. and LI, C.-K., 2001. Discovery of an ossified Meckel's cartilage in two Cretaceous mammals and origin of the mammalian middle ear. Science 294, 357-361.

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IPC2002 Oral Presentations

CRANIAL, POSTCRANIAL, AND FUNCTIONAL MORPHOLOGY OF A NEW GENUS OF PRIMITIVE DIPROTODONTOID FROM THE LATE OLIGO-MIOCENE ETADUNNA FORMATION OF SOUTH AUSTRALIA Robert W. MEREDITH Museum of Geology, South Dakota School of Mines and Technology, 501 E. St. Joseph St., Rapid City, SD 57701 USA The postcranial and cranial morphology of a new genus of diprotodontoid from the Oligo-Miocene Etadunna Formation of South Australia, shares many cranial and postcranial features in common with the other Etadunna Formation diprotodontoids (Ngapakaldia tedfordi, N. bonythoni, and Pitikantia dailyi). This specimen was recovered from Lake Pitikantia, stratigraphic unit 8, faunal zone C (Ngapakaldi Local Fauna). Like Ngapakaldia, this new genus possesses a plesiomorphic vombatiform skeleton similar to the phalangeriform possums but with adaptations for a larger size and a plantigrade condition for terrestrial habitus. The terrestrial life-style is clearly seen in the ankle joint, i.e. concave dorsal surface of the astragalus, reduced lateral fibular facet, and the medial tibial knob. However, the manus and pes elements of the new genus are more plesiomorphic than any known diprotodontoid postcrania. These elements are relatively less robust and more gracile suggesting a closer relationship to an arboreal ancestor. Unlike Pitikantia and Ngapakaldia, the new genus possesses a small but pronounced posterior cuspule on P3 and I1 is the largest incisor (plesiomorphic state). Current classification schemes place Ngapakaldia and Pitikantia in the subfamily Diprotodontinae. However, from an expanded cladistical analysis of cranial material based primarily on tooth morphology, the Etadunna Formation taxa including the new genus consistently group together outside and separate from the Diprotodontinae. As a result all of the known Etadunna Formation diprotodontoids should be placed in their own subfamily.

POSITION AND CORRELATION OF THE BIOSTRATIGRAPHIC PERMIAN-TRIASSIC BOUNDARY AT SHANGSI, SICHUAN, CHINA I. METCALFE1 and Robert S. NICOLL2 1 Asia Centre, University of New England, Armidale NSW 2351 Australia; 2Department of Geology, Australian National University, Canberra 0200, Australia The Permian-Triassic "event" boundary at Shangsi, Sichuan, China has been placed at the base of bed 28a, coincident with the boundary between the Dalong and Feixanguan Formations (Li et al., 1989; Wignall et al., 1995; Lai Xulong et al. 1996). This level coincides with the first occurrence of the "Triassic" bivalve genus Claraia which is soon followed by the appearance of Ophiceras. In the P-T boundary GSSP Meishan section the event boundary has been placed at the top of bed 26 (Yin et al., 2001) or bed 24e (Wang, 1999). At this event boundary level, there is a remarkably similar lithological succession in the Shangsi and Meishan sections with a change from limestone to marls and mudstones as well as several volcanic ash/clay layers. One might even speculate that Bed 27b at Shangsi corresponds to Bed 28 at Meishan and that the three clay layers in Bed 25 at Shangsi correspond to Bed 25 at Meishan. The biostratigraphic Permian-Triassic boundary is now defined by the first appearance of the conodont Hindeodus parvus (Kozur & Pjatakova) and the GSSP is located at the base of Bed 27c at Section D, Meishan, South China (Yin et al., 2001). Early work on the Shangsi section (Yang et al., 1987; Li et al. 1989) reported the first occurrence of Hindeodus parvus in Bed 30 4.5 metres above the event boundary. Our own detailed re-sampling of the boundary interval at Shangsi confirms this first occurrence. Dai and Zhang (in Li et al. 1986) described a new species of Hindeodus "Anchignathodus" decrescens Dai and Zhang. This species ranges from Bed 28c to Bed 30 according to Li et al. (1989). Lai Xulong et al. (1996) record Isarcicella turgida (Kozur, Mostler & Rahimi-Yazd), regarded by many as the descendent of Hindeodus parvus, to first appear in Bed 28c at Shangsi, suggesting that the P-T biostratigraphic boundary is at or slightly below this level. The " Isarcicella turgida " reported at this low level, is in fact Hindeodus decrescens Dai & Zhang which we do not synonomise with Isarcicella turgida. We interpret the true biostratigraphic P-T boundary at Shangsi to occur at the first occurrence of Hindeodus parvus in Bed 30, 4.5 metres above the "event" boundary, the level at which we also record the first Isarcicella turgida. Isarcicella isarcica (Huckriede), which first appears in Bed 28 at Meishan, only 8cm above the P-T boundary, first occurs in Bed 32 at Shangsi, 2.7 metres above the first occurrence of Hindeodus parvus and 7.2 metres above the "event" boundary. We also record Hindeodus latidentatus Kozur, considered by some (but not by us) as

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IPC2002 Oral Presentations the evolutionary pre-cursor to Hindeodus parvus, in Bed 28d at Shangsi. U-Pb isotope geochronological work at Meishan (Mundil et ah, 2001) has dated the Permian-Triassic boundary at 253 Ma. Recent U-Pb isotopic studies at Shangsi (Mundil et ah, this abstract volume) have dated several volcanic ash layers, which indicate that the level of the first occurrence of Hindeodus parvus at Shangsi is the same age as the P-T boundary at Meishan, confirming the biostratigraphic correlation suggested here. LAI XULONG, YANG FENGQING, HALLAM, A. and WlGNALL, P.B. 1996. The Shangsi section, candidate of the Global Stratotype Section and Point of the Permian-Triassic Boundary. Pp. 113-124 in, Yin Hongfu (ed) The Palaeozoic-Mesozoic Boundary candidates of Global Stratotype Section and Point of the Permian-Triassic Boundary. China University of Geosciences Press, Wuhan. LI ZISHUN, ZHAN LIPEI, DAI JINYE, JIN RUOGU, ZHU XIUFANG, ZHANG JINGHUA, HUANG HENGGUAN, XU DAOYI, YAN ZHENG, LI

HUAMEI (eds.), 1989. Study on the Permian-Triassic biostratigraphy and event stratigraphy of northern Sichuan and southern Shaanxi. Ministry of Geology and Mineral Resources, Geological Memoirs Series 2, 9, 428-435. MUNDIL, R., METCALFE, I., LUDWIG, K . R . , RENNE, P.R., OBERLI, F. a n d NICOLL, R.S. 2 0 0 1 . T i m i n g o f the P e r m i a n - T r i a s s i c biotic

crisis: Implications from new zircon U/Pb age data (and their limitations). Earth and Planetary Science Letters 187, 133-147. WANG CHENG-YUAN, 1999. Conodont mass extinction and recovery from Permian-Triassic boundary beds in the Meishan sections, Zhejiang, China. Bollettino della Societa Paleontologica Italiana 37,489-495. WlGNALL, P.B., HALLAM, A . , LAI XULONG a n d YANG FENGQING. 1995. P a l a e o e n v i r o n m e n t a l c h a n g e s across the P e r m i a n / T r i a s s i c

boundary at Shangsi (N. Sichuan, China). Historical Biology 10, 175-189. YANG ZUNYI, YIN HONGFU, W U SHUNBAO, YANG FENGQING, DING MEIHUA, XU GUIRONG et al., 1987. Permian-Triassic b o u n d a r y

stratigraphy and fauna of South China. China Ministry of Geology and Mineral Resources Geological Memoirs Series 2, Number 6. Geological Publishing House, Beijing. YIN HONGFU, ZHANG KEXIN, TONG JINNAN, YANG ZUNYI & W u SHUNBAO, 2 0 0 1 . T h e G l o b a l Stratotype Section a n d Point ( G S S P ) o f

the Permian-Triassic boundary. Episodes,24, 102-114.

CRETACEOUS DINOFLAGELLATE STRATIGRAPHY OF THE MAGALLANES BASIN, OFFSHORE TIERRA DEL FUEGO, SOUTHERN ARGENTINA Daniel MICHOUX TOTALFINAELF, Avenue Larribau, 64000PAU, France Exploration wells drilled in the Magallanes (or Austral) basin, offshore Tierra del Fuego provide an insight into the opening of the South Atlantic during Early Cretaceous times, along with elements allowing correlation with other southern hemisphere basins, in particular Australia and Papua New Guinea. The first sedimentary rocks overlying the volcanic tuffs of the Tobifera Fm are fluvial deposits, containing abundant pollen and spores assemblages. In some areas, transitional deposits (Arcillas Intermedias) yielded peculiar microplankton assemblages interpreted as freshwater or restricted-marine dinoflagellate cysts. These contain genera described by Backhouse (1988) such as Mooridinium and Gagiella. In the Perth Basin, these forms were recovered in the Parmelia Fm and overlying Gage Sandstone Mb of the South Perth Shale. The inception of marine conditions in the Springhill Formation is marked by the appearance of fully marine dinocyst assemblages: the genus Spiniferites is present, along with members of the Phoberocysta neocomica plexus, Aprobolocysta galeata, Kleithriasphaeridium fas datum, Avelodinium lepidum. This dinocyst suite shows affinities with the Kaiwaradinium scrutillinum Zone of Backhouse (1987, 1988) and Senoniasphaera tabulata Zone of Helby, Morgan & Partridge (1987). A Late Valanginian to Early Hauterivian age is proposed for this interval, where the Marine vs. Continental ratio remains relatively low (typically less than 10%). An upward increase in marine palynomorph frequency (from 10 to 30% or more) coincides with the appearance of common Muderongia, including M. cruris, Batioladinium micropodum and Cemicysta helbyi. Cassiculosphaeria magna can be locally abundant in the upper part of the Springhill Fm. The predominantly siliciclastic Springhill Fm is overlain by the shales of the Inoceramus Inferior Fm, whose deposition corresponds to a shift towards deeper sedimentation, highlighted by an increase in amorphous organic matter. Phoberocysta neocomica becomes extinct near the top of the Inoceramus Inferior Fm. This is an intra-Barremian event located within the Muderongia australis Zone of Helby et ah 1987. The transition between the Inoceramus Inferior Fm and the overlying Margas Verdes Fm is marked by an acme of Ascodinium sp. and the appearance of Heerendinia postprojecta. This is thought to correspond to the Ascodinium cinctum Zone of Helby et ah, which straddles the Barremian-Aptian boundary. The top of the Aptian is taken at the top of Sentusisdinium aptiense. The highest occurrence of abundant Oligosphaeridum dividuum is an intra-Aptian event. The Albian is recognised by the occurrence of Canninginopsis intermedia, Canninginopsis denticulata Protoellipsodinium spinosicristatum, Carpodinium granulatum and Discorsia nanna. It is possible to subdivide the Albian into a lower and an upper interval using extinction events: the boudanry corresponds to the extinction of the last representatives of the genus Muderongia, Dingodinium cerviculum and Canninginopsis intermedia. In Australia D. cerviculum and C. intermedia become extinct in the Muderongia tetracantha Zone of Helby et ah, which is the basal zone of the Albian in this zonation scheme.

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BACKHOUSE, J., 1987. Microplankton zonation of the Lower Cretaceous Warnbro Group, Perth Basin, Western Australia. In Jell P.A., Ed. Studies in Australian Mesozoic Palynology, Ass. Australasian Paleontologists Mem. 4, 205-226. BACKHOUSE, J., 1988. Late Jurassic and Early Cretaceous Palynology of the Perth Basin, Western Australia. Geological Survey of Western Australia Bulletin 135. HELBY, R., MORGAN R., & PARTRIDGE A.D., 1987. A palynological zonation of the Australian Mesozoic. In Jell P.A., Ed. Studies in Australian Mesozoic Palynology, Ass. Australasian Paleontologists Mem. 4, 1 -94.

COMPARATIVE VARIATIONS OF STROMATOPOROID BIODIVERSITY AND BIOGEOGRAPHY DURING THE MIDDLE AND THE LATE DEVONIAN Bruno MISTIAEN Laboratoire de paleontologie stratigraphique FLS-ISA, UPRESA 8014 du C.N.R.S., F-59046 Lille cedex [bruno. mistiaen@fls.fupl. asso.fr]. Stromatoporoids are benthic organisms, limited to reefal environments. They were abundant during the middle part of the Palaeozoic, especially during the Silurian and the Devonian (Givetian, Frasnian). But, throughout these periods, they display wide variation in biodiversity and biogeographic distribution. They occurred in profusion during the Silurian, but at the beginning of the Lower Devonian stromatoporoid diversity decreased. Authors underline especially a large recession during the Pragian and, for a long time, stromatoporoids have been considered as completely absent from Pragian strata in North America (Stock, 1990) but recently (Stearn, 2001) some new Pragian outcrops with stromatoporoid has been discovered. At the end of Lower Devonian (Emsian), stromatoporoids again developed and became almost worldwide in reef environments. During the Middle Devonian (Eifelian and all of the Givetian), stromatoporoid diversity increased greatly (Stearn, 1982), connected with spectacular development of reefs (Flugel E. & Fliigel-Kahler, 1992; Kiessling et al., 1999). Reefal environments at that time were more important globally than at any other time during the Phanerozoic (probably ten times as much as for contemporary reefs). During the Givetian, stromatoporoid diversity was particularly significant, corresponding to a polystoeic state (Lucas, 1970). During Frasnian times, generic and specific stromatoporoid diversity decreased abruptly. This corresponds to an oligostoeic state (Lucas, 1970). Some authors (Cockbain, 1989) have pointed out their decline during this period, but it seems that the abundance of individuals reached their maximum and, during Frasnian, cosmopolitanism was at a maximum for stromatoporoids. But stromatoporoids were swiftly and drastically reduced at the Frasnian/Famennian boundary ("Kellwasser events"); some authors (Mc Laren, 1970, 1982) clamed they disappeared completely. During Famennian times stromatoporoids recovered. They slowly reconquered reefal biotopes. Only at the end of Famennian, during Strunian times, did they again gain a large and quasi-worldwide development, but with very pronounced endemism, with three or four provinces being recognized (Stearn, 1987; Stearn et al., 1987; Cockbain, 1989; Mistiaen et al., 1998). Stromatoporoids disappeared completely at the DevonianCarboniferous boundary ("Hangenberg event"). COCKBAIN A. (1989) - Distribution of Frasnian and Famennian stromatoporoids. Memoirs of the Association of Australasian Paleontologists. 8: 339-345.

FLUGEL E. and FLUGEL-KAHLER E. (1992) - Phanerozoic Reef Evolution: Basic Questions and Data Base. Facies, 26: 167-278. KIESSLING W., FLUGEL E and GOLONKA J (1999) - Paleoreef Maps Evaluation of a Comprehensive Database on Phanerozoic Reefs. American Association of Petroleum Geologisst. 83 (10): 1552-1587. LUCAS G. (1970) - Formations construites; essai de classification et d'interpretation. Compte-rendu Academie des Sciences. 270 (D): 1417-1420.

MCLAREN (1970) - Bolides and biostratigraphy. Geological Society of America Bulletin. 94: 313-324. MCLAREN (1982) - Frasnian-Famennian extinction. Geological Society of America Special Paper. 190: 477-484. MISTIAEN B., MILHAU B., KHATIR A . , H o u HONGFEI, VACHARD D . & W u XIANTAO ( 1 9 9 8 ) -

Famennien terminal

(Strunien)

d'Etroeungt (Avesnois, Nord de la France) et d'Etaoucun (Guangxi, Chine du Sud). Incidence paleogeographiques des donnees relatives aux stromatopores et aux ostracodes. Annales de la Societe geologique du Nord. 6: 97-104. STEARN C. W. (1982) - The unity of the stromatoporoides. Third North American Paleontological Convention, Proceeding volume: 511516. STEARN C.W. (1987) - Effect of the Frasnian-Famennian extinction event on the stromatoporoids. Geology. 1 : 677-679. STEARN C.W., HALIM-DIHARDJA M.K. and NISHIDA D.K. (1987) - An Oil-Produicing Stromatoporoid Patch Reef in the Famennian (Devonian) Wabamun Formation, Nordmanville Field, Alberta. Palaios. 2: 560-570. STEARN C.W. (2001) - Biostratigraphy of Devonian stromatoporoid faunas of Arcticand Western Canada. Journal of Paleontology. 75: 9-23. STOCK C. (1990) - Biogeography of the Devonian stromatoporoids. In Mc KERROW W.S. & SCOTESE C.R. Eds, Palaeozoic Palaeogeography and Biogeography, Geological Society Memoir. 12: 257-265.

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IPC2002 Oral Presentations CAMBRIAN SAPROGENIC NANOBACTERIA: A MISSING LINK IN ORGANIC CARBON CYCLE Malgorzata MOCZYDLOWSKA Uppsala University, Department of Earth Sciences, Historical Geology and Palaeontology, Norbyvagen 22, SE-752 36 Uppsala, Sweden, [malgo.vidal@pal.uu.se]. The nanometric organic filaments preserved in situ and three-dimensionally on the tube of the vestimentiferan Sabellidites cambriensis are recognised as bacterial nanofossils of the earliest Cambrian age. They are slightly permineralized during the early diagenesis and are surrounded by biogenic pyrite as a metabolic by-product. Morphologically, the elongated rod-like or cylindrical non-septate filaments are persistently of an equal diameter along the length of individual specimens but the individuals have various diameters. They were flexible, softly bending and deformed like "macaroni". The surface of the filaments is smooth and their width varies between 209 and 324 nannometres. The length is generally 2 to 5 micrometers. The sporadically observed filament terminations are rounded and individuals are attached there. The elemental composition spectra of the filaments, measured in SEM energy dispersive X-ray analysis, indicate that they are composed of organic matter. The bacterial origin of filaments is consistent with their morphology, dimensions and growth environments and they are interpreted to be sulphate-reducing, and probably halophilic bacteria. The nanobacteria resemble some modern (Microcoleus) and fossil (Siphonophycus) cyanobacteria, which are associated with microbial mats, but only in the shape whereas their size is of a different magnitude and their mode of life and habitat were different. They were saprogenic, not mat building bacteria and their systematic affiliation remains undetermined. The nanobacteria infested the Sabellidites tube post-mortem and began to decompose its organic matter under the anoxic conditions in the water-sediment interface environment. They represent the awaited fossil record of decomposers, which together with primary producers and consumers constitute the biogenic cycle in of generating, converting and degrading of the organic matter in the Earth natural habitats. The bacterial decomposers must have been existed and functioned in biosphere since the origin of life, and fermenting archaea and sulphate-reducing bacteria evolved probably at the earliest in the anoxic/dysoxic or low-oxygen content environments that prevailed through the Archaean and early Proterozoic times. Yet their records could not be preserved otherwise then revealing their metabolic processes, such as biogenic minerals, biomarkers and isotopic fractionation, or in the exceptional preservational conditions as those reported herein. This first fossil record of biodegrading bacteria provides the evidence for the missing link in the organic carbon cycle between generation of organic matter by autothrophs and burial of particulate organic matter and release of organic carbon dioxide caused by the bacterial decay. After the recent investigations on the alleged Martian fossil nanobacteria ended in their final dismissal as fossils, rigorous tests of credibility that the filaments reported here are indigenous, biogenic, and of the claimed age were undertaken. The Sabellidites specimen was peeled, using hydrofluoric acid, from the shale core fragment from the Tverecius-336 borehole at a depth of 397.6 m, within the Lontova Formation in Lithuania. The stratigraphic level containing Sabellidites and associated bacteria lies within the lowermost Platysolenites antiquissimus Zone of the East European Platform and is of the earliest Cambrian age. The isotopic age of the onset of the Cambrian Period is currently established at ca. 544 million years ago, and thus the age of the specimens described may be estimated to be ca. 544-540 Ma. The possibility of contamination by modern bacteria of the exposed surface of the Sabellidites tube is excluded since no biota would survive the hydrofluoric acid treatment and the sterile specimen was coated with gold for SEM observations. The filaments are preserved in large numbers as free individuals in densely packed colonies in situ on the Sabellidites organic wall, slightly pyritized and phosphatized, and are entangled with crystals of authigenic, early diagenetic minerals (pyrite, gypsum). In the periphery of the colony, they are coated by authigenic phosphate and silica, which also fill the interstices forming a mineralized crust, which is proof that they are fossils. The sequence of events leading to the fossilization of bacteria was as it follows. The Sabellidites tube was laid down in shallow marine outer shelf with low hydrodynamics. Dysoxic conditions prevailed at the bottom level where dark, organic-rich and non-bioturbated clay accumuated with embedded, and subsequently fossilized, abundant cyanobacteria and algae. The anaerobic, sulphate-reducing bacteria infested and began to decompose the Sabellidites tube. They digested the organic matter of the tube and released hydrogen sulfide, which combined with iron ions from seawater to form pyrite as a metabolic by-product.

STUDY OF ICHNOFOSSILS AND ICHNOFACIES OF THE UPPER ORDOVICIAN IN WEST OF SHAHROUD, NORTHERN IRAN H. V. MOGADDAM and A. TAHERI

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IPC2002 Oral Presentations Department of Geology, University ofIsfahan, Islamic Republic ofIran; [avaziri730@yahoo.co.uk] Based on systematic study of the ichnofossils of the Upper Ordovician in west of Shahroud, 13 trace fossils, including: Cosmorhaphe cf. lobata, Spirophycus ichnosp., Neonerites uniserialis, Neonerites biserialis, Neonerites ichnosp., Didymaulichnus ichnosp., Lorenzina cf. kulczynski, Protopaleodictyon ichnosp., Helmintopsis ichnosp., Paleodictyon ichnosp., Phycodes palmatum, Palaeophycus cf. striatus, Palaeophycus sulcatus, Planulites ichnosp., Thalassinoides ichnosp. and Scolicia ichnosp. have been recognized. These ichnofossils represent the nereites ichnofacies and indicate that the sediments formed in a relatively deep marine condition. The sedimentary structures and field observations confirm the data obtaind from the ichnofossils. STUDY OF ICHNOFOSSILS AND ICHNOFACIES OF THE UPPER PART OF THE SHEMSHAK FORMATION AT TAZAREH AREA, NORTHERN IRAN H. V. MOGHADDAM Department of Geology, University ofIsfahan, Islamic Republic ofIran; [avaziri730@yahoo.co.uk] The upper part of the Shemshak Formation at Tazareh area consists of sandstone, siltstone, and shale beds with marine fossils. Based on systematic study of the ichnofossils in these sediments, 9 ichnogenera, in two assemblages have been identified . The first assemblage with low ichnodiversity (Skolithos, Arenicolites, Diplocraterion) occurs in the siltstone and sandstone beds. This assemblage of ichnofauna represents the skolithos ichnofacies which formed in a relatively high energy condition. The second assemblage with higher ichnodiversity (Planolites, Palaeophycus, Neonerites, Cochlichnus, Rhizocorallium, Chondrites) is very common in the shale beds. This assemblage represents the cruziana ichnofacies which formed in a relatively lower energy condition. HIGH RESOLUTION STRATIGRAPHIC, PALAEOENVIRONMENTAL AND SEQUENCE STRATIGRAPHIC PALYNOLOGICAL ANALYSIS IN THE ALBO-CENOMANIAN FROM THE EYRE SUB-BASIN, OFFSHORE SOUTHERN AUSTRALIA. Eric MONTEIL Geoscience Australia, GPO Box 378, Canberra, ACT2601, Australia; [eric.monteil@ga.gov.au]. The southern continental margin of Australia is one of the most under-explored passive margins in the world. Between 1972 and 1993 only 12 exploration wells have been drilled between Kangaroo Island in South Australia and Cape Leuwin in Western Australia. Prior to ODP drilling in 1998, geological knowledge of the Eyre Sub-basin of the Bight Basin was based solely on seismic reflection data and a single exploration well, Jerboa-1. ODP Leg 182 site 1126 targeted Cenozoic seismic sequences and a high-amplitude reflector which was considered to be Cenomanian age. Following the new sequence framework proposed by Totterdell et al. (2000) for the Great Australian Bight and prior to the future release of new blocks in the Duntroon and Otway Basins, GA felt it is essential to compare the probable Cenomanian of site 1126D with stratigraphically equivalent deposits recovered from Jerboa-1 (Bein & Taylor, 1981). The CretaceousJurassic interval of Jerboa-1 was re-sampled and new palynological analyses were performed on 110 side wall cores and 1 core. This study, which focusses on the Albo-Cenomanian interval, includes 49 of these samples. Palynological analyses were undertaken on 15 samples from site 1126D. Dinoflagellate cyst and spores and pollen distributions are compared with the palynological zonation of Helby et al. (1987) and some potential new markers are identified. A quantitative analysis of dinocysts, spores and pollen, and organic matter is carried out through IPS (Integrated Palaeontologic System) software*. These data are used to refine the new sequence stratigraphic framework proposed by Totterdell et al. (2000) and a palaeoenvironmental interpretation is proposed for both Jerboa-1 and site 1126-D. BEIN, J., and TAYLOR, M.L., 1981. The Eyre Sub-basin: recent exploration results. APEA J., 21:91-98. HELBY, R., MORGAN R., & PARTRIDGE A.D., 1987. A palynological zonation of the Australian Mesozoic. In Jell P.A., Ed. Studies in

Australian Mesozoic Palynology, Ass. Australasian Paleontologists Mem. 4, 1-94.

TOTTERDELL, J.M., BLEVIN, J.E., STRUCKMEYER, H.I.M., BRADSHAW, B.E., COLWELL, J.B. and KENNARD, J.M. (2000). A new

sequence framework for the Great Australian Bight: APPEA Journal, 95-117. * IPS software was developed by the Technical Alliance for Computational Stratigraphy (TACS) consortium at the University of Utah, under the direction of Dr. Anthony Gary. For further information visit the web-site: http://www.ig.utexas.edu/research/projects/tacs/tacs.htm.

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A GLOBAL OVERVIEW OF THE LUNDGRENI (WENLOCK, SILURIAN) GRAPTOLOID EXTINCTION EVENT Lucy MUIR Department of Geology and Geophysics, University of Edinburgh, Grant Institute, West Mains Road, Edinburgh, EH9 3JW, UK. [Lucy.Muir@glg.ed.ac.uk]. The extinction event at the end of the lundgreni biozone was one of the most severe to affect graptoloids during the Silurian. I have assembled a database from the literature of graptoloid occurrences before and after the lundgreni event. The database records species occurrences at the zonal level. Data collection from the literature is advantageous in that it rapidly provides a global overview much more quickly than could be achieved from fieldwork. However, the precision that can be achieved in a global study is not as good as that possible in some local studies. This is because the detailed zonal schemes utilised in some areas cannot be applied where the faunas are less well known. The data were used to test the hypotheses that victims of the event were geographically restricted and that life history strategy (whether a species is K- or r-selected) determines extinction probability. Ecological theory predicts that K-selected species are less likely to survive extinction events than r-selected species. Kselected species are large, long-lived and have few offspring, most of which survive; r-selected species are small, short-lived and have many offspring, few of which survive. Pristiograptus dubius is found globally and survives the lundgreni event. However, some species, for example Cyrtograptus lundgreni and Monograptus flemingii, are found globally but go extinct, implying that, for at least some species, geographical distribution is not the cause of extinction. Graptoloids can be assigned to life history on the basis of rhabdosome size. Graptoloids with a large rhabdosome are likely to be K-selected and those with a small rhabdosome are likely to be r-selected. For example, Cyrtograptus lundgreni and Monograptus flemingii both have large rhabdosomes and go extinct. Pristiograptus dubius is smaller and survives the event. Thus it appears that K-selected species went extinct, which agrees with ecological theory. In conclusion, life history strategy appears to be a more important factor than geographical distribution in determining which species are likely to go extinct. This work can be repeated for other extinctions and taxa using the same method.

U/PB AND 40AR/39AR RADIO-ISOTOPIC AGES FOR THE PERMIAN-TRIASSIC TRANSITION (SHANGSI, N SICHUAN, CHINA) Roland MUNDIL1. Paul R. RENNE h 2, Zhensheng ZHOU2 & Ian METCALFE3 1 Berkeley Geochronology Center, 2455 Ridge Road, Berkeley, CA 94709, USA; 2Dept. of Earth and Planetary Science, UC Berkeley, Berkeley, CA 94720, USA; 3Asia Centre, University of New England, Armidale, NSW 2351, Australia Both the age and tempo of the Permian Triassic (P-T) biotic crisis have recently been subjects of controversy. New U/Pb single-zircon and 40Ar/39Ar data on sanidine and plagioclase phenocrysts from ash layers intercalated within the Permo-Triassic deposits of the Shangsi section (Sichuan Province, Central China) constrain the most profound biotic crisis in the Earth's history to an age of >253 Myr (based on the U/Pb decay system). The presence (within individual ash layers) of multiple generations of older xenocrysts in combination with the effects of Pb loss result in an age-scatter which prohibits the extraction of a statistically robust age from U/Pb analysis of zircons in many cases. Only by analyzing multiple ash layers in different stratigraphic levels by single-zircon techniques, are these combined phenomena are recognizable and resolvable. Preliminary single-zircon analyses from an ash layer 4.5 m below the FAD of Hindeodus parvus (the biostratigraphic definition for the P-T boundary, see also companion abstract from Metcalfe and Nicoll) yield a mean 238U/206Pb age of 254.5 ± 0.9 Myr (95% conf.), an additional layer 7.5 m below the boundary is dated to 255.0 ± 0.9 Myr. Also, analyses from an ash layer just below the base of the final stage of the Permian (Changshingian) yield an age of 260.1 ± 0.6 Ma. All ages are consistent with the results presented in Mundil et al. (2001) obtained on ash layers from the GSSP section in Meishan. In order to mutually control ages from different isotopic systems, K bearing minerals from the same layers mentioned above (and additional ones) were subjected to 40Ar/39Ar analyses. The samples were irradiated with geometry sufficient to ensure negligible fluence gradients between standards (28.02 Ma Fish Canyon sanidine) and samples. All samples have been analyzed by total fusion of single crystals in order (to ensure the absence of inherited

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IPC2002 Oral Presentations components) and additionally by incremental heating of single- or multigrain samples with a CO2 laser. For the layers at 4.5 m and 7.5m below the FAD of H. parvus nearly irresolvable ages of ca. 250-251 Myr, in agreement with the previous 40Ar/39Ar reported by Renne et al (1995), were obtained. The layer below the Changshingian stage was dated to ca. 254 Myr. Our conclusions are twofold: (1) These new data pairs provide further evidence that 40Ar/39Ar ages are 12% younger than U/Pb ages (see also Min et al., 1999), most likely due to systematic errors in the current calibration of the 40Ar/39Ar system. If this bias is taken into consideration, our U/Pb and Ar/Ar ages are in good agreement. (2) Our estimate of 253 Myr for the P-T boundary (based on U/Pb ages) is in agreement with Ar/Ar ages of 250 Myr presented in Renne et al.{ 1995) for the Siberian Trap basalts, if systematic errors are taken into consideration. Not only is this age considerably older than previously suggested (Bowring et al., 1998), our findings concerning the tempo of the end Permian extinction challenge recent conclusions (e.g. Becker et al., 2001) about a rapid extinction caused by a bolide impact. A more protracted scenario for the biotic crisis is consistent with independent evidence for palaeoenvironmental change over a > 1 Myr time scale (Renne et al., 2001). A causal relation between the massive continental flood basalt volcanism in South China in the Late Permian (Emeishan) at the Permian-Triassic boundary (Siberian Traps) -possibly in combination with other factors -and the biotic crisis must be considered. BECKER, L., POREDA, R.J., HUNT, A . G . , BUNCH, T.E., RAMPINO, M . , 2 0 0 1 . I m p a c t e v e n t at t h e P e r m i a n - T r i a s s i c b o u n d a r y ; e v i d e n c e

from extraterrestrial noble gases in fullerenes. Science 291, 1530-1533. BOWRING, S.A., ERWIN, D . H . , JIN, Y . G . , MARTIN, M . W . , DAVIDEK, K., WANG, W . , 1998. U / P b z i r c o n g e o c h r o n o l o g y a n d t e m p o o f the

end-Permian mass extinction. Science 280, 1039-1045. MIN, K., MUNDIL, R., RENNE, P . R . a n d LUDWIG K . R . , 2 0 0 0 . A T e s t f o r S y s t e m a t i c E r r o r s in 4 0 A r / 3 9 A r G e o c h r o n o l o g y T h r o u g h

Comparison with U-Pb Analysis of a 1.1 Ga Rhyolite. Geoch. Cosmoch. Acta 64, 73-98. MUNDIL, R., METCALFE, I., LUDWIG, K . R . , RENNE, P.R., OBERLI, F. a n d NICOLL, R.S., 2 0 0 1 . T i m i n g o f the P e r m i a n - T r i a s s i c biotic

crisis: Implications from new zircon U/Pb age data (and their limitations), Earth Planet. Sci. Let. 187, 131-145. RENNE, P.R., SHARP, W . D . , MONTANEZ, I.P., BECKER, T . A . , a n d ZIERENBERG, R . A . , 2 0 0 1 . 4 0 A r / 3 9 A r d a t i n g o f L a t e P e r m i a n evaporites,

southeastern New Mexico, USA: Earth Planet. Sci. Let. 193, 539-547. RENNE, P.R., ZHANG ZICHAO; RICHARDS, M . A . , BLACK, M . T . , BASU, A . R . , 1995. S y n c h r o n y a n d c a u s a l relations b e t w e e n P e r m i a n -

Triassic boundary crises and Siberian flood volcanism. Science 269, 1413-1416.

UPPER MOLARS OF A BUNODONT MESOZOIC MAMMAL FROM AUSTRALIA (MONOTREMATA; KOLLIKODONTIDAE) Anne M. MUSSER 1 Michael ARCHER2'1, Andrew CODY2, Henk GODTHELP1, Suzanne J. HAND1, Tim FLANNERY3 & A.W. CROMPTON4 1 School of Biological Science, University of New South Wales, New South Wales 2052, Australia; 2 The Australian Museum, 6-8 College St, Sydney, New South Wales 2000, Australia; 3South Australian Museum, North Terrace, Adelaide, South Australia 5000, Australia; 4Museum of Comparative Zoology, Harvard University, Cambridge Massachusetts 02138 USA The first upper cheekteeth of a Mesozoic mammal from Australia appear to represent the bizarre Cretaceous monotreme family Kollikodontidae. The specimen, from early Cretaceous sediments at Lightning Ridge, NSW, is a partial maxilla that retains four molars and ultimate premolar referred to the early Cretaceous Kollikodon ritchiei Flannery et al. 1995. K. ritchiei is unique among mammals in having moon-shaped and mammalonated molar crowns and in exhibiting large, hemispherical depressions in the enamel that may have assisted in securing and fragmenting food. These unusual apical depressions, or pits, appear to be part of the intrinsic enamel structure of the teeth rather than formed through wear (either masticatory or thegotic), suggesting that these pits in K. ritchiei are primary rather than secondary structures, a condition not found in other mammals. The dentition is suited to crushing, rather than shearing, and K. ritchiei may have specialised in hard-shelled invertebrates including molluscs (abundant in the Lightning Ridge Local Fauna), crustaceans and perhaps aquatic insects. This specimen also represents the first known upper molars for nonornithorhynchid monotremes. Monotreme-like features of the maxilla include a large infraorbital canal; marked disjunction between molars and premolars; and laterally expanded molar toothbed. The presence of an apparent trough on the medial side of the dentary, previously unreported for this taxon, is noted. Monotreme and australosphenidan affinities will be discussed; extreme specialisation in this taxon and the fragmentary nature of the fossil material, however, limit comparisons and phylogenetic interpretations.

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IPC2002 Oral Presentations AN EARLY MIOCENE PALAEOCOMMUNITY FROM THE RIVERSLEIGH WORLD HERITAGE FOSSIL DEPOSITS Troy J. MYERS, Mina BASSAROVA and Kirsten CROSBY School of Biological, Earth and Environmental Science, University of New South Wales, Sydney, Australia, 2052 Multivariate analyses of 14 local palaeocommunities (sensu Bennington & Bambach, 1996) from the Riversleigh World Heritage Fossil Deposits, north-western Queensland, suggest the presence of at least one palaeocommunity among the suite of sites formerly assigned to Early Miocene 'System B' of Archer et al. (1994). Neville's Garden, Wayne's Wok, Upper Site and Camel Sputum local palaeocommunities (local faunas) constitute the Nambaroo-Balbaroo palaeocommunity. The fauna from Mike's Menagerie Site may also be indicative of this palaeocommunity but cannot at this stage be included due to a lack of conclusive evidence, probably stemming from insufficient sampling and/or species identifications. Other lines of evidence, such as stratigraphic, geographic and geological, support the inclusion of MM within the Nambaroo-Balbaroo palaeocommunity. Other sites, not investigated in the present study, such as Dirk's Towers, are likely candidates for inclusion in this palaeocommunity, but require further palaeoecological investigation. The existence of the palaeocommunity is supported by various multivariate analyses, including cluster, principal components, principal coordinates and de-trended correspondence analyses, on relative abundance as well as presence/absence data. Taphonomy of Camel Sputum and Mike's Menagerie Sites has been studied. Geological features indicate Camel Sputum is a cave deposit, linked to Mike's Menagerie by a fossiliferous channel. Taphonomic analysis of fossil specimens from these sites reveals no fluvial transport, no prolonged exposure of bones prior to burial and considerably little evidence of predator/scavenger activity, which indicates the local faunas are locally derived. Age-distribution analysis of Camel Sputum indicates that the deposit is a result of attritional accumulation rather than a catastrophic event. The Nambaroo-Balbaroo palaeocommunity appears to be defined by the presence of Balbaroo gregoriensis and Nambaroo sp5 (Cooke, 1997). Other species characteristic of this palaeocommunity, but not exclusive to it, include: Burramys brutyi, Ekaltadeta ima, Yarala burchfieldi, Bulungamaya delicata, Wabularoo naughtoni, as well as one undescribed species of Pseudocheirops and 5 other undescribed yaraloid bandicoots. For future local palaeocommunities to qualify for inclusion in the Nambaroo-Balbaroo palaeocommunity a significant number of the latter species would need to be present, and at particular levels of relative abundance. Discriminant function analysis, utilising a large database of extant Australian mammal communities and corresponding habitat information, suggests that the Nambaroo-Balbaroo palaeocommunity occupied a habitat similar to modern 'closed' and 'wet sclerophyll' forest. This suggested habitat is shown in the large number of arboreal herbivores present in the Nambaroo-Balbaroo palaeocommunity. At least 26 species are known from these sites, representing the Phascolarctidae and eight families of possum (Acrobatidae, Burramyidae, Ektopodontidae, Miralinidae, Petauridae, Phalangeridae, Pilkipildridae, and Pseudocheiridae). These species range in size from approximately 13g to 5.9kg. It appears that the change-over between a diet of insects, saps and nectars and that of leaves and fruit in modern species occurs between the body weights of 250g and 450g. Of the 26 species present, over a quarter have weights in this range. Differences in weight and diet will allow a large number of similar species to coexist in an area. ARCHER, M., HAND, S. J. & GODTHELP, H., 1994. Riversleigh: the story of animals in ancient rainforests of inland Australia. Reed Books, Sydney. BENNINGTON, J.B. & BAMBACH, R.K. 1996. Statistical testing for paleocommunity recurrence: Are similar fossil assemblages ever the same? Palaeogeography, Palaeoclimatology, Palaeoecology 127, 107-133. COOKE, B.N. 1997. Biostratigraphic implications of fossil kangaroos at Riversleigh, northwestern Queensland. Memoirs of the Queensland Museum 41, 295-302.

A NEW SPECIES OF PROSANSANOSMILUS (CARNIVORA, MAMMALIA), AND THE MULTIPLE ARRIVAL OF BARBOUROFELIDS IN EUROPE Doris NAGEL1. Michael MORLO2 & Stephane PEIGNE3 l lnstitut fur Palaontologie, Geozentrum, Althanstr. 14, 1090 Wien, Austria [doris.nagel@univie.ac.at] 2 Forschungsinstitut Senckenberg, Abt. Messelforschung, Senckenberganlage 25, 60325 Frankfurt, Germany Immorlo@sng.uni-frankfurt.de]; 3Staatliches Museum fur Naturkunde Stuttgart, Rosenstein 1, 70191 Stuttgart, Germany [peigne.smns@naturkundemuseum-bw.de].

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IPC2002 Oral Presentations The famous MN5 locality Sandelzhausen (Germany) yielded about 63 species during several excavation campaigns over the last 40 years (Fahlbusch et al1974, Fahlbusch & Liebreich, 1996). The latest scientific finding is Prosansanosmilus n.sp., a new barbourofelid species. It differs from all other European barbourofelid species in having the most plesiomorphic features. The species, however, is stratigraphically younger than the more apomorphic P. peregrinus, which is known from MN 4 of Germany and France (Heizmann et al., 1980). Prosansanosmilus n.sp. proves the evolution and palaeobiogeography of early barbourofelids to be less simple than previously thought. The primary evolution of this group occurred in the Early Miocene of Africa. Prosansanosmilus peregrinus and Afrosmilus hispanicus are the oldest known European members of the family. They arrived in Europe in MN 4 with other immigrants such as Hyainailouros and Gomphotherium at the so-called Creodont event (Van der Made, 1999). As the new investigation shows, these species are more apomorphic than the slightly younger Prosansanosmilus n.sp. from MN 5. Due to the fact that other African immigrants like pliopithecid primates or the tayassosuid Sanitherium are firstly recorded from Europe in MN 5 as well, we interpret P. eggeri to be a part of this later immigration, the so-called Conohyus/Pliopithecus event (Kohler, Moya-Sola, Andrews, 1999). While formerly included in Nimravidae, the dental morphology of the new species supports previous results on skull morphology of Barbourofelis that "Barbourofelinae" is not related to the Late Eocene and Oligocene Nimravinae (Bryant, 1991, Morales et al., 2001). Instead, the separation of both subfamilies on a family level should be discussed. FAHLBUSCH, V., GALL, H., SCHMIDT-KITTLER, N . , a n d DEHM, R., 1974. D i e o b e r m i o z a n e F o s s i l - L a g e r s t a t t e SANDELZHAUSEN. 10. D i e

Grabungen 1970-73. Beitrage zur Sedimentologie und Fauna. Mitteilungen der Bayerischen Staatssammlung fur Palaontologie und historische Geologie 14, 103-128. FAHLBUSCH, V. and LIEBREICH, R., 1996. Hasenhirsch und Hundebar. Chronik der tertiaren Fossil-Lagerstatte Sandelzhausen bei Mainburg, Verlag Dr. Friedrich Pfeil, Munchen. HEIZMANN, E.P.J., GINSBURG, L. and BULOT, C., 1980. Prosansanosmilus peregrinus, ein neuer machairodontider Felide aus dem Miocan Deutschlands und Frankreichs. Stuttgarter Beitrage zur Naturkunde B 58 1-27. HUNERMANN, K.A., 1999. Superfamily Suoidea, pp 209-216. In Rossner, G.E. and Heissig, K. (eds), The Miocene Land Mammals of Europe; Dr. Friedrich Pfeil Verlag, Munchen. KOHLER, M., MOYA-SOLA, S. and ANDREWS, P., 1999. Order Primates, pp 91-104. In: In Rossner, G.E. and Heissig, K. (eds), The Miocene Land Mammals of Europe; Dr. Friedrich Pfeil Verlag, Munchen. MADE, J. VAN DER, 1999. Intercontinental relationship Europe - Africa and the Indian subcontinent, pp 457-472. In Rossner, G.E. and Heissig, K. (eds), The Miocene Land Mammals of Europe; Dr. Friedrich Pfeil Verlag, Munchen. MORALES, J., SALESA, M.J., PICKFORD, M. and SORIA, D., 2001. A new tribe, new genus and two new species of Barbourofelinae (Felidae, Carnivora, Mammalia) from the Early Miocene of East Africa and Spain. Transactions of the Royal Society of Edinburgh: Earth Sciences 92, 97-102.

LIFE AFTER SNOWBALL: THE OLDEST COMPLEX EDIACARAN FOSSILS Guv M. NARBONNE1 & James G. GEHLING2 department of Geological Sciences and Geological Engineering, Queen's University, Kingston, Ontario K7L 3N6, Canada; 2South Australian Museum, Division of Natural Science, North Terrace, Adelaide, South Australia 5000, Australia The Ediacara biota represents the oldest evidence of abundant and diverse, large, complex lifeforms on Earth, including the oldest unequivocal animals. With a few possible exceptions from slightly older and younger strata, the Ediacara biota consistently occurs above the highest Neoproterozoic tillites attributed to the "Snowball Earth" and below the base of the Cambrian. The Marinoan glaciation is generally believed to have functioned as a bottleneck in eukaryotic evolution and/or as an impetus for the subsequent evolution of animals, but the substantial gap between the highest Neoproterozoic tillites and the lowest Ediacaran fossils in most sections has hindered testing of this hypothesis. Precise U-Pb dates for the Ediacara biota range from 565-543 Ma. The oldest radiometrically dated Ediacaran assemblage anywhere is from the Avalon Zone of Newfoundland, which contains a 6 km succession of strata that records the transition from deepwater basin-plain and slope deposits in the Conception and St. John's groups to coastal and alluvial deposits of the Signal Hill Group. Previous work has shown that Ediacaran fossils are abundant and diverse in the Mistaken Point Formation, which has yielded a date of 565±3 Ma for a volcanic ash that covers the most fossiliferous surface near the top of the formation, but no definite fossils had previously been reported from below the Mistaken Point Formation. Our recent work has extended the stratigraphic range of unequiovocal Ediacaran fossils in Newfoundland nearly 2 km downwards through the Briscal Formation and into the upper part of the Drook Formation. Fossils of the Briscal Formation include diminutive forms of most of the typical taxa of the Mistaken Point biota. Drook fossils include the cosmopolitan Ediacaran "index fossil" Charnia (also known from Charnwood Forest in England, the White Sea and Siberia in Russia, and the Ediacara Member in South Australia), along with the

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IPC2002 Oral Presentations enigmatic discoid fossil Ivesia (also known from low in the succession in Chamwood Forest) and several other forms. Simple considerations of stratigraphic level and U-Pb dates suggests that the Drook fossils are 570-580 million years old, and thus represent the oldest-known evidence of architecturally complex megascopic life after the meltdown of the "Snowball Earth" glaciers.

TAPHONOMY OF PREDATION: A NATURAL EXPERIMENT BASED ON PREDATORY ATTACKS ON CLYPEASTEROID ECHINOIDS James H. NEBELSICK Institute of Geology and Palaeontology, University of Tubingen, Sigwartsr. 10, D-72076 Tubingen, Germany The destructive affects of predation can have a significant influence on the preservation of organisms in the fossil record. In this study two different types of predation on Clypeasteroid echinoids from shallow water environments of the Red Sea are compared. This study aims to analyze the differential affects of various predation types on skeletal preservation and to make eventual statements relevant to preservation patterns in the fossil record. Numerous predators are known to attack a broad range of echinoid prey. These attacks lead to a variety of taphonomic signals on the echinoid test including: 1) total destruction of the skeleton, 2) non-descript predation marks which do not general allow predator recognition, 3) distinct predation marls allowing predator recognition and detailed investigations, and 4) no wounds at all. Detailed investigation associated with type 3 predation events include among others predation modes, wound description, site selectivity, stereotypic behavior, and the evolution of predation rates through time. In echinoids, consistently recognizable predation marks are boreholes produced by cassid gastropods and characteristic wounds caused by fish. The former has been relatively well documented while the latter has, so far, received far less attention. The study area (Northern Bay of Safaga, Red Sea) include three clypeasteroid genera (Clypeaster, Fibularia, Echinocyamus) which are sufficiently common as dead skeletons to allow comparisons among different states of preservations as well as from different depositional environments. Clypeaster skeletons show a wide rang of preservation including 1) pristine test with spines still attached, 2) denuded test with, however, excellent preservation of surface features 3) abraded and encrusted and, in part, bioeroded tests and 4) heavily corroded test with heavily destroyed surface features and signs of early marine diagenesis. These form a taphonomic gradient and represent increased surface residence times of the individual specimens. Obvious predation scars are common among these Clypeaster skeletons consisting of a massive lethal wounds. These wounds are found on the oral surface and are characterized by intraplate fracturing accompanied by distinct teeth marks which often occur in parallel corresponding to the teeth arrangement of the fish predator. This type of predation occurs in all of the preservational stages listed above. The comparison of predation frequencies along the taphonomic gradient suggest that these massive attacks substantially weaken the test increasing the probability that further taphonomic processes destroy the test as a complete skeleton. Predation marks found in the minute clypeasteroids Fibularia and Echinocyamus have been attributed to cassid gastropods which leave a characteristic, small, cylindrical drill hole. Previous studies have shown that there is no significant reduction or measured predation intensities along a taphonomic gradient leading from pristine tests to heavily abraded, encrusted specimens. This suggest that drilling frequencies appear to be independent of the taphonomic state of the tests. Different predation modes thus have different affects on the preservation of prey skeletons. On the one hand, they can be so benign as to allow for detailed evolutionary studies of predation patterns in the fossil record. They can, on the other hand, be so destructive as to have serious implications concerning the preservation potentials of heavily predated members of fossil communities.

EVOLUTION OF GASTROPOD SPECIES-LEYEL DIVERSITY AND TURNOVER AFTER THE END-PERMIAN MASS EXTINCTION Alexander NUTZEL1 & Douglas H. ERWIN2 1 Palaontologisches Institut, Loewenichstr. 28, D-91054 Erlangen, Germany, [nuetzel@pal.uni-erlangen.de]; Dept. of Paleobiology, MRC-121, National Museum of Natural History, Washington, DC 20560, USA; [Erwin.Doug@NMNH.SI.EDU]. 2

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IPC2002 Oral Presentations Gastropods are one of the most diverse invertebrate groups. The major mass extinctions had considerable impact on the reported genus- and family-level extinction of the gastropods. As with bivalves, but in contrast to many other clades, a relatively steady increase of published diversity during the Phanerozoic can be recognized. This rather steady development masks considerable change in the taxonomic composition and ecological structure of gastropod faunas.The destruction of typical Palaeozoic biotas and ecosystems during mass extinctions is probably one reason for the success of modern gastropods and for the differences in composition between ancient and modern gastropod faunas. The Triassic is particularly interesting because during this brief interval between two major mass extinctions there was a concentration of turnover that had considerable impact on the composition of present day faunas. In order to quantify and understand these processes, we compiled a database of more than 2050 Triassic nominate gastropod species and 360 genera. This is the first such comprehensive species-level data base for any invertebrate group in the Early Mesozoic. The data base is nearly complete for the Triassic. Simple univariate statistics produced characteristic patterns: an Early Triassic minimum is followed by a steady and rapid increase with a peek in the Carnian. Subsequently, diversity drops considerably in the Norian and remains low in the Rhaetian. The exceptionally rich gastropod fauna of the Carnian Cassian Formation (Italian Alps) possibly biases this diversity pattern to a certain degree, but every stage has an exceptionally rich fauna that contributes about 30% to 50% to the reported species diversity per stage. The species-level diversity patterns is basically similar to the genus-level pattern but there are some notable differences e.g., the Carnian peak is much more pronounced on the genus level. This is probably a consequence of the exceptionally good preservation of the gastropods from the Carnian Cassian Formation which encouraged taxonomists to propose more higher (supraspecific) taxa because more characters could be studied. On the genus level, gastropods and bivalves show a basically similar pattern but the Carnian peek and the Norian/Rhaetian diversity drop are by far not as prounounced in bivalves. Within the Gastropoda, some groups obviously have benefited more than other groups from the destruction of Palaeozoic ecosystems. As an example, modern-looking cerithiid-like gastropds are a more or less marginal group in the Late Palaeozoic to the early Late Triassic (Carnian). But since the latest Triassic (Norian/Rhaetian) modern-looking cerithioids have become more abundant and for the first time, they even dominate faunas in that period. Another example are the shell-bearing Opisthobranchia (Cephalaspidea, Cylindobullinoidea). There are no certain and only a few putative cephalaspideans in the Late Palaeozoic, but in the Early Triassic (Scythian, Olenekian) Moenkopi Formation of North America, small shell bearing opisthobranchs are most abundant. Modern gastropod faunas were clearly shaped to a high degree by the reorganization of gastropod faunas during recovery periods after major mass-extinctions. ORDOVICIAN CHITINOZOANS FROM THE CENTRAL PART OF THE RUSSIAN PLATFORM: ZONATION AND INTERREGIONAL CORRELATION Olga T. OBUT Institute ofPetroleum Geology, Russian Academy of Sciences, Siberian Branch, 630090, Novosibirsk, Russia The Ordovician sequences of the Russian Platform have been examined from bore cores. The first Ordovician chitinozoans from this region were described in 1970s but no biozonation was proposed. Recent revision of microfossil collections from the Ordovician rocks of 10 deep (1-3 km) boreholes (Danilov-10, 8, 6, D'yakonovo-4, Lezha-1, Tolbukhino-1, Tot'ma-1, 29, Pestovo-l-R, Lyubim-7), from the central part of the Russian Platform (Moscow Syneclise) reveals chitinozoan associations. Chitinozoans collected with graptolites allow alignment with the International Stratigraphic Scale. At the present stage of investigation, the associations of the chitinozoan succession are regarded as a succession of lonas (local zones). More study is required to establish real zones. Six such lonas are proposed provisionally. The lowermost lona [Conochitina incompata] coincides with the graptolite murrayi Zone of the upper Tremadocian. It is represented by an assemblage of Con. incompata Umn., Con. platifundis O.Obut, Cyathochitina laticollum Umn., Lagenochitina esthonica Eis., L. porrecta Umn., Rhabdochitina magna Eis., Eremochitina longiformis O. Obut, Desmochitina minor typical Eis., D. m. ovolum Eis. and Siphonochitina sp. The next lona [Cyathochitina primitiva] is proposed for the interval of four graptolite zones of the lower and middle Arenigian (Phyllograptoides, approximatus; balticus, densus and angustifolius elongatus). The chitinozoan assemblage includes C. primitiva Szan., C.laticollum Umn., Eremochitina longiformis O. Obut, Desmochitina minor typical Eis., D. m .ovolum Eis., Lagenochitina esthonica Eis. and Siphonochitina sp. In the upper part of this lonal interval (densus and angustifolius elongatus zones), the Conochitina decipience Subzone is defined. It is characterized by Con. decipience Taug. and Jekh., Con. brevis Taug. and Jekh., Con. kuckersiana Eis., Cyathochitina primitiva Szan., C. campanulaeformis Eis., C. calyx Eis. and Rhabdochitina magna Eis. 124

IPC2002 Oral Presentations The succeeding Lagenochitina grossum lona can be aligned with the upper Arenigian-lower Llanvirnian hirundo and "artus" zones. It is represented by L. grossum O.Obut, L. esthonica Eis., Cyathochitina campanulaeformis Eis., C. calyx Eis., Laufeldochitina stentor (Eis.) and Fungochitina fungiformis (Eis.). The succeeding Conochitina insueta lona is within the Llanvirinian (murchisoni, geminus and teretiusculus zones). Its chitinozoan association includes Conochitina insueta Umn., Con. micracantha Eis., Cyathochitina calyx Eis. and Rhabdochitina magna Eis. It should be mentioned that the murchisoni zonal interval can be recognized as the Conochitina clavaherculi sublona. It is represented by Con. clavaherculi Eis., Lagenochitina obesa Umn., L. pervulgata Umn., Cyathochitina campanulaeformis Eis., C cf. regnelli Eis., C. cf. kuckersiana Eis., Rhabdochitina gracilis Eis., Desmochitna minor Eis. and Rhabdochitina gracilis Eis. The uppermost chitinozoan lona [Rhabdochitina cf. parvicollis] is conditionally proposed for the Caradocian-Ashgillian(?) according to poor graptolites. Its chitinozoan association is represented by R. cf. parvicollis Taug., R. tublaris Umn., Con. cf. brevis Taug. and Jekh., Con. micracantha Eis., Cyathochitina campanulaeformis Eis. and Desmochitina minor Eis. Ordovician chitinozoan associations from the Moscow Syneclise have species with global distribution allowing alignment with Baltic chitinozoan zonal units. Thus, the Con. primitiva lona can be correlated to the primitiva Zone of the Baltic except its upper part. The proposed L.grossum lona coincides with the total range of the Baltic regnelli Zone; the Con. insueta lona with to the striata Zone; and the C. clavaherculi lona with the clavaherculi Zone. Similar chitinozoan associations have been obtained from Ordovician strata of the Gorny Altai area. The present study reveals some chitinozoan species occur at slightly lower stratigraphic levels than previously reported. Ranges of these species are confirmed by the graptolites found together with chitinozoans. Among them are Laufeldochitina stentor (Eis.) and Cyathochitina kuckersiana Eis. The former, previously known from the upper Llanvirnian-Caradocian of Estonia and Sweden, was obtained from upper Arenigian (hirundo Zone) of the Moscow Syneclise. C. kuckersiana, reported from the Llanvirnian-lower Ashgillian of Sweden, Estonia, Moldova and Podolia, was found in the middle-upper Arenigian (angustifolius elongatus to (?) hirundo zones). It is therefore important to re-check the stratigraphic distribution of these taxa. These studies were supported by grant RFBR 02-05-64789.

FLECTOSPIROIDES FUSIFORMIS GEN. ET SP. NOV. FROM THE LATE PERMIAN OF THE BO WEN BASIN, CENTRAL QUEENSLAND V. PALMIERI 5/63 Mc Lay St, Coorparoo, 4151, Qld Calcareous imperforate encrusting foraminifera of peculiar form and growth are present in Late Permian strata of the Bowen Basin. In 1998 they were reported by the author as Pilammina sp.; they are here considered and proposed as belonging to a new genus. Their distribution is at present restricted to: a) strata of the uppermost Barfield Formation and the lower Flat Top Formation, which is their type locality; b) strata of the lower Peawaddy Formation; and c) a sample from the Gigoomgan Limestone of the Tamaree Formation, Gympie Basin. They are associated with foraminifera belonging to the Lunucammina maioris Zone of Late Kazanian-Midian age.

SYSTEMATIZATION OF THE ORGANIC WORLD: PRINCIPLES AND REGULARITIES Yu. S. PAPIN State Oil and Gas University, Tyumen, Russia, [yuripapin@mail.ru]. The phenomenon of the nature bipolar organization reveals itself in the bini-systematization of the organic world. The living nature as the whole material world conforms to the following principles of biniology: a binialness or binomial structure of the natural objects, a contradiction and homology of the binial taxons, a presence of the third component in the structure of the whole. The main principle of biniology (binialness) is acknowledged by other paradigms of the nature organization and development such as the dialectics, symmetrology, synergetics and geometryphysics. Decisive patterns of the binomial structure can be found on all hierarchical levels: from the superkingdom up to species and even a living cell. So on the highest hierarchical level the whole organic world is divided by cell construction into two superkingdoms: Procaryota (without a nucleus of cell) and Eucariota (with a nucleus). By way of feeding

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IPC2002 Oral Presentations both the Procaryota and Eucaryota are separated into two kingdoms: Procaryota - into Cyanobionta and Bacteria, Eucaryota - into Phyta and Zoa (Animalia). In their turn there are Thallophyta and Telomophyta in the composition of Phyta, Protozoa and Metazoa in the composition of Zoa. On the following levels Metazoa is parted into primitive (Parazoa) and real (Eumetazoa) Metazoa, Eumetazoa - into radially (Radiata) and bilaterally (Bilateralia) symmetric animals, Bilateralia - into Protostomia and Deuterostomia and so on. On the hierarchical levels of types, classes, orders, families, genera and species there are indisputable and plural examples of bini-systematization as well. There is no point in giving new patterns here. It is enough to consider the structure of a living cell. It consists of the protoplasm and the nucleus, the latter - of the deoxyribonucleic (DNA) and ribonucleic (RNA) acids. In their turn DNA is presented by two filaments spirally wound round each other. Every filament is made of nucleotides of purine and pyrimidine types. On the one hand there is adenine and guanine in composition of the purine type, on the other hand there is thymine and cytosine in composition of the pyrimidine type. The aforesaid facts prove that binomial division of the organic world on different hierarchical levels into two taxons reflects not individual cases, not suitable way of classification, but the genuine regularity of construction and development of the living nature. Two parts or binitaxons forming the whole, as plus and minus, are directly contrary to each other by presence or absence of some features. The denominations of taxons of one and the same hierarchical level often reflect their principal difference. For example, they are Dicotyledones and Monocotyledones plants, Procaryota and Eucaryota superkingdoms, Agnatha and Gnathostomi vertebral animals, Gymnospermae and Angiospermae paramount plants. Homology is another regularity of the material world organization which is connected with binialness. The same examples which decisively attest that binialness and contradiction of binial taxons are a fundamental law of nature organization equally prove that they have similar variability inside themselves, i.e. they are homologous. So Procaryota and Eucaryota are homologous by way of feeding. Both Procaryota and Eucaryota are able to live using ready-made organic substance or producing it by photosynthesis. It turns out that binialness and homology exist simultaneously, complete and control each other: binial groups must be homologous and homologous groups must be formed by a binial pair of directly opposed taxons. In the structure of the whole there is the third component together with the two main ones. It is convenient to call it an intertaxon because it has intermediate features, sharply suppressed in quantity, and its evolutional development is much lower. In the organic world the most bright example of the third component is Mycetalia taxon (group of mushrooms). This taxon has an intermediate position between the Zoa and Phyta kingdoms and together with them it accounts for the Eucariota superkingdom. It is known that Mycetalia lives as the Zoa kingdom on the ready-made organic substance but it breeds by spores and has an apical growth as the Plant kingdom. At the same time there are data, in particular for Bivalvia, which allow us to consider that an intertaxon can be presented by a boundary or a boundary zone between binitaxons. The cases of conflicting with the principles mentioned above are explained by mixture of hierarchic ranks, insufficient study and artificial separation of intermediate taxons. Even those existing classifications, in which bini-phenomenon is not observed on any level, do not disprove it because in these cases there are principally different variants of taxonomy. So new variants of taxonomy of the Bivalvia class and Foraminifera subclass proved to be strictly binial. The methodological importance of biniology is evident in the nature investigation. Taking into account that binitaxons of the same hierarchic level are homologous and knowing characteristics of one of them it is possible to predict peculiarities of another taxon. On the other hand one can predict the presence of an unknown taxon on the base of a studied one which together with the first one forms the binial pair. LATE CAMBRIAN-EARLY ORDOVICIAN BREAKS IN THE TETHYAN HIMALAYAN SUCCESSIONS: FAUNAL CHANGES AND IMPLICATIONS FOR BIOCHRONOLOGY S.K. PARCHA

Wadia Institute ofHimalayan Geology, 33 GMS Road, Dehradun, India; [bswihg@sancharnet.inj

Richly fossiliferous Cambrian-Ordovician successions with relatively few breaks in sedimentation were deposited along the entire length of the Tethyan Himalaya belt. The interruptions in sedimentation include a long break, Late Cambrian-Early Ordovician, extending up to the Changshanian-Fengshanian (Early Ordovician). This time gap is mostly represented by an obvious unconformity: in the Zanskar valley of Ladakh and the Spiti valley of Himachal Pradesh. No fauna corresponding to this interval is known from anywhere on the Indian subcontinent. Several phases of transgression and regression can be discriminated during the Cambrian-Ordovician period. The Lower Cambrian in the Himalaya is a widespread transgressive facies represented by sedimentary sequences even in the Lesser Himalaya regions of the Mussoorie and Nigalidhar synclines. In the Middle Cambrian a regressive phase commenced with sedimentation restricted to the Tethyan Himalayan belt. This phase seems to have culminated in an interval of non-deposition during the 126

IPC2002 Oral Presentations Late Cambrian, followed by a complete change in lithofacies and biofacies to turbidite facies of Ordovician age. The presence of early Late Cambrian (Kushanian) trilobites in Kashmir, Spiti and possibly Zanskar (fragments only) are the only reports so far of Late Cambrian in India. Trilobites predominate in Cambrian successions of the Tethyan Himalayan regions, whereas brachiopods dominate in the Ordovician successions of Kashmir, Spiti, Zanskar and Kumaon-Garhwal. Trilobites are known from the brachiopod-dominated Ordovician of Spiti, but are not known from the Zanskar and Garhwal regions.

TAPHONOMIC TRENDS IN ORGANISM REMAINS (MOLLUSCS, CRUSTACEANS, ECHINODERMS, AND WOOD) OVER EIGHT YEARS FROM SHELF TO SLOPE DEPTHS IN THE BAHAMAS AND GULF OF MEXICO Karla M. PARSONS-HUBBARD1. Sally E. WALKER2, Eric N. POWELL3, Carlton E. BRETT4, Russell CALLENDER5, Anne RAYMOND6, & George STAFF7 1 Dept. of Geology, Oberlin College, Oberlin, Ohio 44074 USA [karla.hubbard@oberlin.edu]; 2Dept. of Geology, University of Georgia, Athens, GA 30602 USA, sHaskin Shellfish Research Lab, Rutgers University, Port Norris, New Jersey 08349 USA, 4Dept. of Geology, University of Cincinnati, Cincinnati, Ohio 45221 USA; 5NOAA, Oceanic and Atmospheric Research, Silver Spring, MD 20910 USA, 6Dept. of Geology and Geophysics, Texas A& M University, College Station, TX 77843 USA, 7Austin Community College, NRG Campus, Geology Dept., Austin, TX 78758 USA. The Shelf and Slope Experimental Taphonomy Initiative began a long-term study of taphonomic processes in 1993. Mesh bags containing crabs, two species of urchin, five species of mollusc, and six types of wood were placed along two shelf to slope transects (15 - 300 m) off the Bahamas carbonate platform. Similar experiments were placed in six different depositional environments on the shelf and slope of the Gulf of Mexico (75 - 600 m). Experiments were retrieved from Bahamas sites after one, two, and seven years and after two and eight years in the Gulf of Mexico. Upon recovery, each specimen is photographed, weighed, and measured. Then each specimen is characterized as to degree of fragmentation, disarticulation, surface condition (abrasion, dissolution, discoloration, edge condition), and infestation by endoliths and epibionts. Taphonomic loss did not significantly affect mollusc shells until after two years of exposure. Epibionts are abundant and diverse after only one year for shells within the photic zone. By years six to eight, shells above 100 m begin to deteriorate. Much of this loss is biologically mediated as endolithic algae, fungi, and sponges weaken the shell and/or attract surface grazers to accelerate shell loss. Shells deployed below 100 m are generally indistinguishable from controls after eight years with the exception of discoloration of shell surfaces in both carbonate and siliclastic settings. However, taphonomic signature in molluscs from deep cold seeps do differ from controls. These sites offer heterogeneous bottom conditions with strongly sulfidic and/or highly saline poor waters. Dissolution, breakage, and edge alteration is more common in these environments but is restricted to regions in the immediate vicinity of the seep with shells deployed as little as 15 m away showing no impact at all. Two urchin species (Eucidaris and Echinometra) and the decopod crustacean Callinectes sapidus were deployed frozen in 2-mm mesh pouches as part of each experimental array. After eight years, all urchins had lost spines and the lantern had at least partially disarticulated, although most urchins were recovered with the test intact. Broken tests were most common on the Bahamas shallow shelf, but even at 15 meters depth, some whole tests were recovered. Callinectes chelipeds were nearly always present upon collection over the eight years of the project. In many cases carapace fragments were present as well. The only sites completely lacking crab remains were two 15-m bags from the Bahamas shelf. The remarkable endurance of Echinoderm and crab remains, two groups that are commonly found living at these sites, indicates that these deeper shelf/slope settings may be appropriate analogs to the depositional environments of some fossil Lagerstatten. Results of the deployed wood show that teredinid clams (shipworms) and Limnorid isopods quickly consume wood exposed at the sediment/water interface at all sites below the photic zone. Black walnuts and oak bark seem to be most resistant to the activities of these organisms. Burial, even intermittent burial on the shallow Bahamas shelf greatly increases the likelihood of recovering wood after even 6 or 7 years of deployment. Interestingly, coverage by encrusting epibionts on shallow deployments also helped to slow the loss of wood. This long-term experimental taphonomy project continues to provide invaluable information on the fate of organism remains. Hard parts exposed at the sediment/water interface within the photic zone will likely not survive more than 6 to 10 years. Deeper shelf and slope settings exhibit a slower rate of taphonomic loss (n.b., there is an opposite trend in wood species) and have the potential to preserve rich assemblages particularly those associated with cold seeps.

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IPC2002 Oral Presentations EARLY ORDOVICIAN TRILOBITES FROM MOUNT ARROWSMITH, NORTHWESTERN N.S.W., AUSTRALIA: BIOSTRATIGRAPHIC AND BIOGEOGRAPHIC IMPLICATIONS John R. PATERSON Centre for Ecostratigraphy & Paleobiology, Department ofEarth & Planetary Sciences, Macquarie University, NSW2109, Australia. The Mount Arrowsmith area is situated approximately 200 km north of Broken Hill, in the far northwestern corner of New South Wales. The Early Ordovician sediments of Mount Arrowsmith are represented by the Mootwingee Group, comprising the Yandaminta Quartzite (lowermost unit), Tabita Formation, and Pingbilly Formation (uppermost unit). The Mootwingee Group sediments represent a minor transgressive episode or deeping-upward sequence, which were deposited in a shallow marine shelf environment. These Early Ordovician deposits form part of the Gnalta Shelf of western New South Wales, representing a remnant of the former continental margin, situated at the eastern extremity of the Larapintine Sea. The trilobite fauna from the Tabita and Pingbilly formations includes Carolinites genacinaca Ross, Prosopiscus sp. nov., and the asaphids Lycophron sp. nov., Asaphellusl sp., Basilicus (Parabasilicus) sp., and others left in open nomenclature. The associated conodont fauna is indicative of the Oepikodus evae conodont Zone, suggesting a late Bendigonian (Be3) to latest Chewtonian (Ch2) age for the trilobite fauna. Trilobite biostratigraphy and correlation of the Early Ordovician succession of Mount Arrowsmith with other contemporaneous Australian successions is based primarily on Carolinites genacinaca, but also at the generic level with Prosopiscus and Lycophron. The occurrence of C. genacinaca in eight other units across Australia demonstrates that the Early Ordovician succession of Mount Arrowsmith is coeval with parts of the following successions: Horn Valley Siltstone, Amadeus Basin; lower Nora Formation, Georgina Basin; Gap Creek Formation (Prices Creek Group), as well as the Nambeet, Willara and Wilson Cliffs formations, Canning Basin; Rollston Range Formation, Mt Windsor Subprovince, Queensland; and the lower Rowena Formation, N.S.W. The occurrence of Prosopiscus and Lycophron in both the Horn Valley Siltstone and Nora Formation further supports the correlation with Mount Arrowsmith, which is probably due to the close proximity of the successions. The Ordovician trilobite biogeography of Australasia has been recently synthesised by Webby & Edgecombe (in Webby et al. 2000). The biogeographical significance of the epipelagic telephinid trilobite Carolinites genacinaca has been thoroughly documented by McCormick & Fortey (1999), and is considered to have had worldwide distribution during the Early Ordovician, occurring on all Ordovician palaeocontinents. C. genacinaca is also regarded as being circum-equatorial, constrained to a geographic belt with margins at approximate palaeolatitudes of 30°N and 30°S (McCormick & Fortey 1999). Based on current data, Prosopiscus was restricted to, and may have originated in Australia during the Early Ordovician (Bendigonian-Chewtonian). By the Middle Ordovician (Darriwilian), Prosopiscus had dispersed to other parts of Gondwana, including the North and South China blocks, Tarim, central Himalayas, and the Argentine Precordillera (South America), and appears to have been confined to low latitudes. Lycophron is of lesser biogeographic significance, being endemic to Australia. During the Early Ordovician (BendigonianChewtonian), Lycophron was restricted to the Gnalta Shelf and the Amadeus and Georgina basins, however appears to have spread to the Canning Basin by the Middle Ordovician (Darriwilian). MCCORMICK, T. & FORTEY, R.A., 1999. The most widely distributed trilobite species: Ordovician Carolinites genacinaca. Journal of

Paleontology 73, 202-218.

WEBBY, B.D., PERCIVAL, I.G., EDGECOMBE, G.D., COOPER, R.A., VANDENBERG, A.H.M., PICKETT, J.W., POJETA Jr, J., PLAYFORD, G., WINCHESTER-SEETO, T., YOUNG, G.C., ZHEN, Y.Y., NICOLL, R.S., Ross, J.R.P. & SCHALLREUTER, R., 2000. Ordovician palaeobiogeography of Australasia. Memoir of the Association of Australasian Palaeontologists 23, 63-126.

THE POSTCRANIAL SKELETON OF TEMNOSPONDYLS Kat PAWLEY and Anne WARREN Department ofZoology, La Trobe University, Melbourne 3086 [kpawley@zoo.latrobe.edu.au] Study of the postcranial skeleton of the Palaeozoic and Mesozoic Temnospondyli is important for understanding both the lifestyle and phylogenetic relationships of the group. Generally the skulls of temnospondyls have been the basis for study, rather than the postcranial skeleton, and no recent overview of the temnospondyl postcranial skeleton has been conducted. There is wide morphological variation in the degree of ossification of the postcranial skeleton of temnospondyls, from heavily ossified and highly terrestrial, to poorly ossified and obligatorily aquatic. Most recently, Yates and Warren (2000) considered the Temnospondyli to be divided into two major groups, the 128

IPC2002 Oral Presentations highly terrestrial Euskelia, and the more aquatic Limnarchia that includes the Stereospondyli. Recent study of the postcranial skeleton of basal members of the Stereospondyli has shown that some taxa are highly terrestrial, and that the degree of ossification can vary markedly between closely related genera. This indicates that the degree of ossification of the postcranial skeleton within the Temnospondyli is highly plastic, and has implications for assessment of the lifestyles of these animals. Comparison of the postcranial skeleton of the Lepospondyli, Seymouriamorpha and basal amniotes, such as Limnosceles, with that of basal members of the Temnospondyli, such as Eryops, reveals striking similarities, and suggests a common origin for the fully terrestrial bauplan. The evolutionary transition between the paddle-like limbs of the early tetrapods (as evidenced by their L-shaped humeri, for example) and more terrestrial limbs with paddle shaped humeri and reduced dermal pectoral girdles (characteristic of the early Temnospondyli, Lepospondyli, Seymouriamorpha and basal amniotes) is a complicated evolutionary step, and it may be more parsimonious to suggest a common origin for these fully terrestrial taxa, rather than convergent evolution across the crown clades. To date, preliminary cladistic analysis (including both postcranial and cranial characters) supports this hypothesis, which disagrees with previous hypotheses concerning the phylogenetic relationships of early tetrapods (Carroll 1995, Lebedev & Coates 1995, Coates 1996, Laurin & Reisz 1997, Clack 1998, Paton, et al. 1999) in that Greererpeton, the Baphetidae and the Anthracosauria all form sister taxa to a crown clade containing the Lepospondyli, Seymouriamorpha, basal amniotes, and Temnospondyli. CARROLL, R.L., 1995. Problems of the phylogenetic analysis of Paleozoic choanates. Bulletin du Museum National d'Histoire naturelle de Paris , 4eme serie 17, 389-445. CLACK, J. A., 1998. A new Early Carboniferous tetrapod with a melange of crown-group characters. Nature 394, 66-69. COATES, M.I., 1996. The Devonian tetrapod Acanthostega gunnari Jarvik: postcranial anatomy, basal tetrapod interrelationships and patterns of skeletal evolution. Transactions of the Royal Society of Edinburgh: Earth Sciences 87, 363-421. LAURIN, M. & REISZ, R.R., 1997. A new perspective on tetrapod phylogeny. In Amniote origins- completing the transition to land, S. Sumida & K. Martin, ed., Academic Press, London, 9-59. LEBEDEV, O.A. & COATES, M.I., 1995. The postcranial skeleton of the Devonian tetrapod Tulerpeton curtum Lebedev. Zoological Journal of the Linnean Society 114, 307-348. PATON, R.L., SMITHSON, T.R. & CLACK, J.A., 1999. An amniote-like skeleton from the early Carboniferous of Scotland. Nature 378, 508-513.

YATES, A.M. & WARREN, A.A., 2000. The phylogeny of the 'higher' temnospondyls (Vertebrata: Choanata) and its implications for the monophyly and origins of the Stereospondyli. Zoological Journal of the Linnean Society 128, 77-121.

INTEGRATING MOLECULAR AND MORPHOLOGICAL INFORMATION ON THE PROBLEM OF MONOTREME AFFINITIES Matthew PHILLIPS Institute of Molecular Biosciences, Massey University, Palmerston North, New Zealand Complete mitochondrial (mt) genome sequencing has provided by far the largest molecular dataset for testing the phylogenetic relationships among the mammalian sub-classes. Phylogenetic analyses (Janke et al. 2002) subsequent to sequencing mt genomes from a platypus and an echidna supported a monotreme/marsupial (Marsupionta) grouping. I show that apparent phylogenetic signal supporting Marsupionta appears to owe to differences in DNA substitution properties among monotremes, marsupials, placentals, and outgroup taxa. Nullifying these biases results in the traditional marsupial/placental (Theria) grouping being favored. These analyses also have significant implications for relationships within Marsupialia and Placentalia, and support a sister group relationship between turtles and archosaurs, at least from among extant amniotes. It may be inferred that extensive morphological and physiological restructuring occurred over the lineage (branch) that extends from the last common ancestor (LCA) of monotremes and therians, up to the LCA of marsupials and placentals. Curiously, little mt sequence evolution occurred along this branch. Given that there is no evidence for major differences in rates of mt DNA evolution between monotremes and early therians, this branch represents perhaps less than 20 million years. Additionally, mt genome data corroborate previous molecular dating estimates of an early-mid Tertiary divergence of platypuses and echidnas. Despite mt DNA showing that platypuses and echidnas share about 100 million years of common ancestry along the monotreme stem lineage, cladistic analysis of morphological data (based on Ji et al. 1999) favors echidnas and platypuses being successive outgroups for a Trechnotheria plus Multituberculata clade. This failure to support monotreme monophyly casts doubt over the reliability of these morphological characters for determining the deeper level and more elusive overall placement of monotremes (or Australosphenida). Even with monotreme monoplyly constrained, parsimony significance tests and partition homogeneity testing show that monotreme inclusion induces extreme incongruence between anatomical region partitions (dental, mandibular, basicranial, vertebral, upper appendicular, lower appendicular). Embracing the most parsimonious compromise among the partitions cannot be justified on the basis of

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IPC2002 Oral Presentations stochastic variation, and amounts to a loss of information on the nature of apparent phylogenetic signal within and between the data partitions. Inferring monotreme affinities might be better served by selecting the placement that is most consistent with what can be established on the nature of the incongruence among the anatomical regions. A novel incompatibility analysis for examining phylogenetic signal and conflict among characters is presented. This indicates that homoplasy affecting monotreme placement evolved non-independently among characters, essentially at the level of the anatomical regions, which may be viewed as functional units. Incongruence analysis indicates that much of the homoplasy inducing the incongruence likely involved transformations along the monotreme stem lineage, rather than being "hidden" among non-monotremes. In light of the above inferences, and consideration of differences in evolutionary trends between monotremes and other Mesozoic mammals, the upper appendicular characters are considered as probable candidates for anatomical region level homoplasy. The close relationship between monotremes and therians implied by the analysis of mt DNA is consistent with reversal of upper appendicular character states along the monotreme stem lineage, though may be in conflict with recent finds suggesting early australosphenidan mandibles retained attached post-dentary units (middle ear bones). JANKE, A., MAGNELL, O., WEICZOREK, G., WESTERMAN, M. and ARNASON, U., 2002. Phylogenetic analysis of 18S rRNA and the mitochondrial genomes of the Wombat, Vombatus ursinus, and the spiny anteater, Tachyglossus aculeatus: increased support for the Marsupionta hypothesis. Journal of Molecular Evolution 54, 71-80. Jl, Q., LOU, Z. and Jl, S., 1999. A Chinese triconodont mammal and mosaic evolution of the mammalian skeleton. Nature 398, 326-330.

PALAEONTOLOGICAL MUSEUM OF TOMSK STATE UNIVERSITY AT THE BEGINNING OF THE XXI CENTURY V.M. PODOBINA Tomsk State University, Lenin Ave. 36, Tomsk 634050, Russia [podobina@ggf.tsu.ru] At the end of the XIX century, the first palaeontological collections, a precious museum heritage, came into the possession of the Tomsk State University (TSU). These collections had been presented mainly to the first Siberian University at the time of its foundation (1878) by various scientists and Maecenases. Part of these displays was manufactured by the well-known German firm "Kranz" 150 years ago. In our museum these collections have been kept intact and are now unique. Professor V.A. Khakhlov was the founder and the first scientific head of the museum when it was organized in 1926. Recently (since 1990) the museum has been substantially renovated and transformed under the direction of Prof. V.M. Podobina. Colourful displays in the museum result from enormous scientific work on the fauna and flora of all Phanerozoic systems in various places in Russia. The engtrance to the display area, the greater part of the museum, has skeletons of a fossil bison and woolly rhinoceros (reconstructed). A huge mammoth skeleton dominates the far right of the museum. It completes the museum's major complex of the Pleistocene fauna of western Siberia. Bone material for the reconstructions came from the SE part of the Tomsk region. In six showcases and on separate stands are skeltal remains of the mammoth fauna: woolly rhinoceros, bison, horse, deer, elephant (Archidiskodon trogontherii), mammoth tusks, etc. These displays have been prepared on the basis of materials from the Lower Cretaceous deposits near Shestakovo (in the SE of Western Siberia). Of extreme value was the discovery in 1999 by A.V. Voronkevich of two skeletons of a new species of the ornithischian dinosaur Psittacosaurus sibiricus Voronkevich and Averianov. Phanerozoic index plant and animal fossils as well as their reconstructions are set out in showcases and dioramas; these also display, the evolution of plants, colourful reconstruction, and aspects of their biogeographic provinces. Siberia is rich in fossil localities; the range of fauna and flora from Devonian to Neogene, mainly from the S of Western Siberia, is displayed. The Early Devonian flora consists mainly of psilophytes and algae from lagoonal deposits of the Minusinsk depressions. Excellent fish imprints from the Izykchulskian horizon in Khakasia and brachiopods, bryozoans and crinoids from the Lower Carboniferous key-section in the town of Tomsk are also displayed. Of great interest are the finds of the Jurassic plants from Kuzbass outcrops and from core samples from boreholes in the vicinity of Tomsk. Wonderful moulds of Neogene plants complete the upper part of this exposition. Remains of marine algae dated to a billion of years (the "Newlandia" problematicum, stromatolites, etc.) are the most ancient exhibits of the museum. Five showcases of the museum demonstrate unique displays of invertebrates and plants collected from stratotypes of various Phanerozoic systems. Two monographic departments of the museum have palaeobotanical, palaeozoological and micropalaeontological collections deposited and studied over many years. Professor Khakhlov's palaeobotanical collections are the basis for the first department. His collection comprises fossil plants from Carboniferous and Permian horizons of numerous coal-bearing basins of Russia and the former USSR. Of extreme value are the collections of Devonian plants made up by Prof. V.A. Ananyev and L.I. Bystritskiy (among the best in the world), and collections of Jurassic plants. Palaeozoological collections of coelenterates

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IPC2002 Oral Presentations consist of Devonian rugose corals, bryozoans and stromatoporoids. In 1997 a unique collection of Devonian to Carboniferous brachiopods from Siberia and Mongolia was deposited in the palaeontological museum. Foraminiferal collections, the basis of 10 monographs by Prof. V.M. Podobina, are the basis of the second monographic department (about 5 thousand item). The museum is constantly replenishing its collections. At present the museum's corpus of major palaeontological material includes 7 educational collections and about 80 scientific collections. The rich palaeontological material, representing almost all Phanerozoic systems, provided a basis for organizing the I and II International Symposiums "Evolution of Life on the Earth" (1997 and 2001) in Tomsk State University.

A TAXONOMIC ASSESSMENT OF DIPROTODON (DIPROTODONTOIDEA; MARSUPIALIA) AND AN INTERPRETATION OF SEXUAL DIMORPHISM WITHIN THE GENUS Gilbert J. PRICE Queensland University of Technology, School of Natural Resource Sciences, 2 George Street GPO Box 2434, Brisbane, Queensland 4001, Australia; and Queensland Museum, Department of Palaeontology and Geology, PO Box 3300, South Brisbane, Queensland 4101, Australia [gj.price@student.qut.edu.au]. Understanding phylogenetic relationships between fossilised animals is limited by the preservation of many as isolated elements, and paucity of fossil remains. However, even when fossil remains are abundant and often complete, doubts may arise regarding the taxonomic validity of species within well-known taxa. The genus Diprotodon is a case in point. Diprotodon, the largest marsupial that ever lived, is one of the icons of the extinct Australian Pleistocene megafauna. Its remains have been commonly found throughout the arid and semi-arid regions of Australia. Since erection of the genus in 1838, a controversy has arisen over the taxonomic validity of a number of subsequently erected Diprotodon species. Primarily, the argument centres around the occurrence of two distinct size classes within Diprotodon. The uncertainty regarding the taxonomic status of several apparent species, depends on whether those size classes are representative of inter- or intraspecific differences. A recent study of Diprotodon remains from the Darling Downs (southeastern Queensland) and Lake Callabonna (central Australia) indicates the existence of three morphologically distinct species. Furthermore, each appears to exhibit marked sexual dimorphism in molar tooth dimensions. The interpretation severely complicates the taxonomy of Diprotodon and has major implications for our understanding of other related fossil groups, since the possibility of sexual dimorphism has not been taken into account in several taxonomic assignments.

PALYNOCOMPLEXES AND STRATIGRAPHY OF THE PALEOGENE OF TAJIKISTAN Muhabbat PULATOVA Institute of Geology Academy of Sciences Tajikistan, Ainy 267, 734063 Dushanbe Paleogene accumulations on the Tajikistan territory are formed by sea formation and in the upper horizons by lagoon formation. The palynologic analysis of the complete section of Paleogene determined 10 palynocomplexes which replaced in the stratigraphy succession. Regional and interregional correlation in the scale of horizons is posible with the help of the above mentioned. The determined complexes are the standart ones and called according to the leading kinds. The first (hochilyorski horizon) with Triatriopollenites confusus Zakl., T. Pseudorurensis Pfl. There is typical the domination of the formal taxons group (division). There are a lot of T.concavus Pfl., T. rurensis Pfl., T. exelsus Pfl.. The coniferous and spores are of a small amount. It is confronted with the complexes of the upper -talizkaja subsuite of the Northern-Siberian lavland and with the Paleocene of the eastern part of the western Kazakhstan - Kachinski layer - the upper Paleocene. The second (givarski horizon) with Trudopollis pompeckji (R. Pot.) Pfl., Triporopollenites robustus Pfl. is characterized by the apperance of the kinds of the "mirikoid" type, Castanae, Taxodiaceae and the domination of formal taxsons of the previous complex is preserved. The composition of spores and the coniferous increases. Bachisaraiski lauer - the lower Eocene is confronted with the lower Eocene complexes of Kazakhstan and Germany. The third (alaiski horizon) with Rhoipites pseudocingulum (R.Pot.), Trudopollis pompeckji (R.Pot.) Pfl. is characterized by equal content of the pollen of formal and natural taxon. It is notable for the appearance of the angiospermea representatives of subtropics, tropics and mild zones (Fagus, Quercus, Rhus, Sterculia,

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IPC2002 Oral Presentations Platanus). The composition of spores and coniferous increases. It is confronted with the complexes from the lauer-tasaranski subsuite of Kazakhstan eocene - Simphropolski lauer - middle Eocene. The fourth (beshkentski horizon) with Castanea bajsunica, Rhus turkenstanica Pokrvskaja brunnea Boitz. The subtropical species dominate there along with the representatives of mild latitudes: Palmae, Myrica, Comptonia, Magnolia, Sterculia, Rhus, Salix, Juglans, Carya, Betula, Quercus, Castanea. The composition of formal taxons is rich on account of Pokrovskaja kind. The pollen of Ephedraceae vis of a great number. That complex is contrasted with the same ones from the middle-bodrakski layer of southern regions Russia. The fifth (ichkibulakski horizon) with Fothergilla grandis, Rhoipites villensis (Toms.) Boitz. The blossom of vartiety of the leading forms Ephedraceae are widely represented , there is a variety of artificial taxons. It is confranted with the complexes of the upper-bodrakski region of the layer of more western parts of Euroasia and with the termenbesskie layers of the western Kazakhstan. The sixth (kushanski horizon) with Ephedra fusiformis Shakhm., Quercus graciliformis Boitz. The amount of spores there is greatly increased, the coniferous and pollen - of a medium amount. There are a lot of Juglans, Betula, Quercus, Castanea. Also there appear grasses as: Chenopodiaceae, Compositae. Subtropical, ephedres and formal taxons are of the same variety. Among the latter is Triporopollenites coryloides Pfl. - prevait - Alminski layer - the upper Eocene. The seventh (nizhnesumsarski horizon) with Ephedra sumsarica, Rhus asiatica characterized by the equal composition of tropical and subtropical and mezofile arboreal kinds of boreal flora and grasses Salix, Juglans, Alnus, Acer, Tilia, Rhus, Platanus, Chenopodiaceae, Compositae, Artemisia. It is notable for abundance of coniferous plants, ephedres and for the pollen reduction of the formal taxons. It is confronted with the turanglinski layer of chiganskaja suite of the Western Kazakhstan and with the moniwalski layer of the upper eocene of Germany - Alminski layer - the upper Eocene. The eighth (verhnesumsarski horizon) with Juglans tutcaulica, Elaeagnus sp. The meaning of warmoderate kinds increases there and subtropical complexes are sharply decreased. The coniferous and grasses prevaitt there. The pollen Taxodiaceae, Juglans, Chenopodiaceae, Compositae, Artemisia prevails there. The complex is confronted with hadumski horizon of the trout Caucasus - Oligocene. The ninth (gissaraksi horizon) with Betula tutcaulica, Pocrovskaja oligocaenica is characterized by the coniferous broad-leaved boreal kinds with abundance of desert-steppe vegetable associations. The pollens, ephedres and tropical formes are rare there Taxodiaceae, Salix, Juglans, Graminea, Chenopodiacea are typical. The complex is quite close to the same one from the Rupelski layer Germany. The tenth (shuriysaiaki horizon) with Ephedra schurisaica, Ulmus guliobica is characterized by the absolute supremacy of the coniferous with broad development of Taxodiaceae as well as angiospermae Salix, Juglans, Betula, Ulmus, along side with them the pollen of clesert-steppe vegetable associations Graminea, Chenopodiaceae, Compositae, Artemisia, Ephedra - prevail. There are no representatives of tropical flora, with one dominanted in Eocene. The complex is confrouted with the complex from the Hattski layer of the upper Oligocene in Germany.

VEGETATION CHANGE AT THE CRETACEOUS-TERTIARY BOUNDARY IN NEW ZEALAND, EVIDENCE FOR ECOLOGICAL DISASTER FOLLOWING THE CHIXULUB ASTEROID IMPACT J. Ian RAINE1 & Vivi VAJDA2 institute of Geological & Nuclear Sciences P.O. Box 30368, Lower Hutt, New Zealand' Geology, Lund University, Tornavagen 13, SE-223 63 Lund, Sweden

Department of

Miospore analyses of two Cretaceous-Tertiary Boundary sections in New Zealand reveal the first record of a "fern-spike" in Southern Hemisphere Cretaceous-Tertiary Boundary sites (Vajda et al. 2001). The studied sediments derive from two sites; one in near-shore marine sediments at mid-Waipara River, northern Canterbury and the other in terrestrial sediments at Moody Creek Mine, Westland. The boundary is well constrained and in the terrestrial Moody Creek Mine section is identified within a coal seam by an iridium anomaly of 70 ppb, in combination with extinction of several miospore index-taxa. At mid-Waipara, the boundary is well constrained on geochemistry and foraminiferal stratigraphy. In both sections the K/T boundary is met with a "fern spike" or Fern Spore Abundance Anomaly, which in the marine sediments shows as an abrupt increase in fern spores from an average of 40% below the boundary to over 70% in the sediments above the boundary. In the terrestrial section the rise is even more dramatic, i.e from 40% fern spores below the boundary to 99% just above it. The fern spikes indicate disruption of the standing vegetation supporting the theory of an ecological disaster following the Chixulub impact. Also, the floral turnover at the New Zealand K/T boundary is comparable to palynological records from North America and Japan and the palaeogeographical position of

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IPC2002 Oral Presentations New Zealand, at c. 50-60° S latitude, on the opposite side of the earth to the impact site, indicates that the effects of the impact were truly global. Vegetation recovery after the asteroid impact can be distinguished in great detail in the Moody Creek Mine section where the succession of fern groups appears to represent a succession from ground ferns, through larger ferns, finally to a more diverse vegetation. The "fern spike" appears to have endured for several thousand years, and represents a fern-dominated vegetation in which most angiosperms and gymnosperms were suppressed. The duration of the period of fern-dominance is orders of magnitude greater than seen in normal serai successions following deforestation. We suggest that the observed vegetation succession is due to a prolonged period of low ambient light levels, sufficient for photosynthesis but favouring plants already adapted to these levels (such as forest ground stratum), accompanied by a moderate temperature and moisture regime. In New Zealand, the devastated vegetation slowly recovered, many of the same taxa as before the K/T event returning higher in the sequence. Rough estimations indicate that the extinction rate is below 15% but it is difficult to give exact numbers without more extensive biostratigraphic studies. Early Paleocene climate was cooler than before the K/T event, perhaps reflecting long-term consequences of the impact. VAJDA, V., RAINE, J.I. & HOLLIS, C.J., 2001. Indication of Global Deforestation at the Cretaceous-Tertiary Boundary by New Zealand Fern Spike. Science 294, 1700-1702.

THE STIRLING BIOTA - EVIDENCE FOR MOTILE, MEGASCOPIC ORGANISMS MORE THAN 1200 MILLION YEARS OLD Birger RASMUSSEN1, Stefan BENGTSON2. Ian R. FLETCHER1, Neal J. MCNAUGHTON1 Centre for Global Metallogeny, University of Western Australia, Crawley, 6009, Australia; 2Department of Palaeozoology, Swedish Museum of Natural History, Stockholm, Sweden The current controversy regarding the ages of the basal metazoan lineages emphasizes the importance of examining pre-Ediacaran Proterozoic rocks for animal-like fossils and constraining the ages of the rocks in which such fossils occur. Ediacaran-type discoidal fossils were identified a decade ago in the Stirling Range Formation, Western Australia (Cruse et al., 1993; Cruse and Harris, 1994), and used to assign an age of 540590 Ma for sedimentation, in preference to the -1340 Ma suggested by Rb-Sr data (Turek and Stephenson, 1966). New radiometric and palaeontological work on the fossil-bearing sequence indicates that its depositional age is in fact more than twice as old as the Ediacaran, that the discoidal fossils are of uncertain nature, but that associated trace-like fossils nevertheless indicate the presence of animal-like organisms (Rasmussen et al., 2002). The Stirling Range Formation is a siliciclastic sedimentary sequence, variably metamorphosed up to greenschist facies. SHRIMP U-Pb and Th-Pb analyses of detrital minerals and metamorphic monazite bracket the age of sedimentation between ca. 2000 Ma and 1200 ± 20 Ma. The discoidal fossils previously used to infer an Ediacaran age were identified by Cruse and Harris (1994) as species of Cyclomedusa and the presumed actinian trace fossil Bergaueria. The disks are simple in structure and their preservation is poor. Although an interpretation of them as imprints of disc- or bag-shaped organisms is not unlikely, other explanations, even non-biological ones, cannot be completely ruled out. The trace-like fossils, however, are decidedly biological in origin. They are preserved in convex hyporelief on the sole of a thick bed of fine-grained sandstone. They consist of fine ridges, about 0.5-1 mm wide and high, forming parallel-sided pairs, 1.5-2 mm wide and up to more than 2 cm long. The ridge-pairs may be straight, but usually curve more or less irregularly. A recurring morphology is characterized by the ridges at one end coming together in a U-shape and at the other end flaring to about 3.5 mm width before terminating. There is no evidence of deeper penetration into the underlying sediment. The ridges are interpreted as positive moulds of mucus-reinforced sediment strings formed by the surface movements of a vermiform organism. The organism had well-developed mucus-producing capacity and probably a hydrostatic skeleton and musculature to allow it to change shape. Whereas in today's biota this would be a description of an animal, it is possible that the traces were made by extinct multicellular or syncytial organism outside the clade of crown-group metazoans. Whichever type of organism made the traces, the Stirling biota offers a glimpse of a biosphere more than 1200 million years ago which was more complex than the singularly microbial-algal world that is usually assumed. CRUSE, T. and HARRIS, L.B. 1994. Ediacaran fossils from the Stirling Range Formation, Western Australia. Precambrian Research 67, 1-10.

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IPC2002 Oral Presentations CRUSE, T., HARRIS, L.B. and RASMUSSEN, B., 1993. The discovery of Ediacaran trace and body fossils in the Stirling Range Formation, Western Australia: Implications for sedimentation and deformation during the 'Pan-African' orogenic cycle. Australian Journal of Earth Sciences 40,293-296. RASMUSSEN, B., BENGTSON, S., FLETCHER, I.R. and MCNAUGHTON, N., 2002. Discoidal impressions and trace-like fossils more than 1200 million years old. Science, in press. TUREK, A. and STEPHENSON, N.C.N., 1966. The radiometric age of the Albany Granite and the Stirling Range Beds, southwest Australia. Journal of the Geological Society of Australia 13,449-456.

PALAEOPATHOLOGY IN A MATURE SPECIMEN OF TYRANNOSAURUSREX E.A. REGA1 & C.A. BROCHU2 department of Anatomy, Western University of Health Sciences, Pomona, CA 92506; 2Department of Geoscience, University of Iowa, Iowa City, IA 52242. A variety of abnormalities are present throughout the skeleton of FMNH PR2081, a mature Tyrannosaurus rex specimen popularly known as "Sue". These include healed osteomyelitis (infection) of the left fibula, healed fractures of the right and left ribs, possible well-healed osteomyelitis of the right proximal humerus, exuberant vertebral osteophyte formation, and multiple bilaterally-present erosive lesions primarily confined to the post-dentary mandibular elements. No evidence of pre or peri-mortem bite marks is present. Pathology to the left fibula most likely did not prevent locomotion. The jaw lesions are bilaterally present although not bilaterally symmetrical and may be neoplastic or fungal in origin, although the pattern and location of the lesions remains problematic for a conclusive attribution. Lesions of this nature are found in other mature tyrannosaurid specimens, and so a number of other possibilities should be entertained. While the number of these pathologies present in a single individual may superficially seem to imply that Sue was not heathy during life, the maturity of the specimen and the clear evidence of healing indicate that Sue was a robust individual who successfully survived many insults. The injured ribs suggest two traumatic events to the trunk, one of which also impacted the right pectoral complex. Functionally, the evidence of pseudoarthrosis (non-union) in two of a series of adjacent healed fractures in the right thoracic ribs suggests the potential of not-inconsiderable movement in the rib cage during healing and may imply thoracic breathing. No skeletal evidence of cause or manner of death is apparent.

SOUTHERN AFRICAN GORGONOPSIAN PHYLOGENIES REVISITED Alain J. RENAUT and Ross J. DAMIANI Bernard Price Institute for Palaeontological research, School of Geosciences, University of the Witwatersrand, Johannesburg. Private Bag 3, Wits 2050, South Africa. The non-mammalian therapsids were amongst the dominant terrestrial vertebrates for most of the Late Palaeozoic and Early Mesozoic eras. Some of the most distinctive Permian therapsids are the basal biarmosuchians and the more advanced carnivorous gorgonopsians, the focus of this paper. The exceedingly rare higher-taxon Biarmosuchia was the most recently recognised higher-level therapsid clade, and many of its taxa are considered as the most basal of the post-sphenacodont synapsids (Rubidge and Sidor, 2001). Most genera of this small carnivore are known from only one or two poorly preserved skulls, and it is difficult to confidently recognise diagnostic characters common to the group. Gorgonopsians, however, occur in relatively high abundance, particularly in the rocks of South Africa's Lower Beaufort Group. Literally hundreds of specimens have been collected, and currently at least twenty-five genera, with numerous species, are recognised. Gorgonopsians flourished during the Late Permian, despite a somewhat unsophisticated masticatory apparatus (subject of some recent research: Laurin, 1998; Tatarinov, 2000), and are recognised as the dominant large-bodied terrestrial carnivores of this period. Unfortunately, gorgonopsian taxonomy is in a singularly unsatisfactory state, posing a major obstacle to a broader understanding of their evolution. The monumental, but precladistic work of Sigogneau-Russell (Sigogneau, 1970; Sigogneau-Russell, 1989) has, until now, been the definitive word on gorgonopsian phylogeny. The lack of a clear diagnosis for each taxon, as well as the group as a whole, has meant that field specimens are often misidentified, and there is little resolution on gorgonopsian evolution and phylogeny. More recently, such subjective-based taxonomy has obscured the possible occurrence of the Russian genus Biarmosuchus in South Africa. This project seeks to shed new light on the gorgonopsians, resolve taxonomic enigmas, and determine the interrelationships within Gorgonopsia, by examining the current holotypes as well as newly collected specimens. Preliminary results suggest that the high conservatism of the cranial morphology of this group has meant that ontogenetic changes, and cranial distortion, have often been used to identify species and even genera.

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LAURIN, M. 1998. New data on the cranial morphology of Lycaenops (Synapsida, Gorgonopsidae) and reflections on the possible presence of streptostyly in gorgonopsians. Journal of Vertebrate Paleontology 18, 765-776. RUBIDGE, B. S. and SLDOR, C. A. 2001. Evolutionary patterns among Permo-Triassic Therapsids. Annual Review of Ecology and Systematics 32,449-480. SLGOGNEAU, D. 1970. Revision Systematique des Gorgonopsiens Sud-Africains. Cahiers Paleontologie, Paris. SIGOGNEAU-RUSSELL, D. 1989. Theriodontia I, pp. 123. In Wellnhofer, P. (ed), Encyclopaedia of Paleoherpetology, Part 17B; Fischer, Stuttgart. TATARINOV, L. P. 2000. A new gorgonopsid (Reptilia, Theriodontia) from the Upper Permian of the Vologda region. Paleontology Journal 34, 75-83.

MORPHOMETRY METHODS IN PALAEONTOLOGICAL RESEARCH Richard A. REYMENT Section for Palaeozoology, Natural History Museum, Stockholm 10405, Sweden Scientific interest in the quantitative analysis of shape has a long history in biology, dating back almost 100 years. It was, however, in 1917 that Thompson published his celebrated treatise on growth and form Interest in trying to reproduce Thompson's approximate (freehand) diagrams by appropriate mathematical methods expired owing to the mathematical difficulties involved. Although Thompson's treatise was reprinted many times, he never added anything to his original presentation, despite interest at large. Instead, a more accessible ad hoc algebraic approach gained ascendancy, beginning with some exploratory work by Teissier in 1938, whereby the algebraic mode of analysis by principal components surged to the fore. Teissier's results were for what we would now call allometric size-change and are quite forecastable, in that they are a natural outcome of the Perron-Frobenius theorem of linear algebra. Later workers seized upon Teissier's idea and proposed an ad hoc solution for interpreting growth in terms of size differences (the first latent vector of principal components of an appropriate covariance matrix) and subsequent latent vectors of the extraction. This simplistic approach became very popular in taxonometric connexions, despite logical flaws (e.g. the suggestion that the loadings of the first latent vector of a covariance matrix vectors are a unique representation of size-variability). The size-shape justification attached to the principal component solution is an a posteriori one, and not the outcome of any specific biometrical model. The same algebra can, and is, applied to any number of problems in the Natural Sciences. Blackith and Reyment in 1971 were the first to formalize multivariate morphometries as an analytical concept in quantitative biological work. An ingenious growth-invariant method proposed by Burnaby in 1966 was a remarkable attempt at separating size from shape. Burnaby's work derived from his studies of Carboniferous bivalves and Cretaceous foraminifers. At the core of contemporary morphometries (= the quantitative study of biological shape variation) is a synthesis of two largely divergent methodologies. One of these centres around the standard multivariate statistical analysis of covariance matrices. The other tributary, often called the geometric, emphasizes the visualization of changes in shape. The realization of a fusion of these two variants of thinking into a useful praxis for studies of biological shape was achieved in the 1980's by Bookstein when techniques from multivariate statistics, biometrics, non-Euclidean geometry and computer graphics were combined into a new system of tools for the complete regionalized quantitative analysis of landmark points together with the images of the organisms with which they are seen. In this synthesis, correspondence of landmarks (= points of reference at diagnostic sites, like "adductor muscle tubercle", "eye tubercle", "caudal process", bone prominences) across specimens is taken as a biometrical starting point. The shapes of configuration of landmarks are defined as equivalence classes with respect to the Euclidean similarity group and represented as single points in shape-space as defined by Kendall. This is a Riemannian manifold with Procrustean distance as a metric. Procrustean distance is defined as the square root of the sum of squared distances between the positions of the landmarks in two optimally superimposed configurations at centroid size. The important thing to know here is that Kendall's definition allows all conventional multivariate statistical methods to carry over to the study of shape variation and covariation when shapes are interpreted in the tangent space to the shape manifold at an average shape. In order to be able to provide a biomathematical interpretation of such analyses, one needs a basis for the tangent space which is compatible with biological reality and explanations at different scales. One also needs graphics for visualizing average shape-differences. Both of these needs are met by the thin-plate spline, a deformational function with readily accessible mathematical properties Moreover, the spline also links the biometrics of landmarks to the deformation analysis of the images from which the landmarks were selected. Fundamental to applications in biology are graphical ordinations. The practical significance of geometric morphometries in Palaeontology is self-evident. We have now in our hands a powerful tool for describing variation, including evolutionary change, in "pure shape" and hence, by extension, a means of introducing new biostratigraphical, taxonomic and phylogenetic criteria into our work. Most palaeontologists know that evolutionary lineages are often characterized by shape-changes. The problem has always been that these

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IPC2002 Oral Presentations manifestations of evolution in the phenotype have not been adequately quantifiable, and hence exploitable, other than in vague terms. Examples from ongoing work on Cretaceous ammonites and Palaeogene ostracods are used to illustrate the concepts of geometric and algebraic morphometries, both of which can supply valuable information viewed from their respective standpoints AFFINITIES OF THE AUSKTRIBOSPHENIDAE, 5 YEARS ON Thomas H. RICH and Patricia VICKERS-RICH Museum Victoria, P.O. Box 666E, Melbourne, Victoria 3001, Australia; [trich@museum.vic.gov.au]; Earth Sciences Department, P.O. Box 28E, Monash University, Victoria 3800, Australia; [Pat.Rich@sci. monash. edu. auj. On the morning of 8 March 1997, the holotype of Ausktribosphenos nyktos Rich et al. 1997 was found at the Early Cretaceous (early Aptian) site of Flat Rocks which is located near the town of Inverloch, Victoria and 120 km east-south-east of Melbourne. The holotype was a mandible with four teeth preserved. Since then, more than a dozen additional specimens attributed to the Ausktribosphenidae have been found at this site. Amongst these is the holotype of a second ausktribosphenid genus and species, Bishops whitmorei Rich et al 2001a. When first proposed, the Ausktribosphenidae were regarded as members of the Placentalia. Alternative suggestions have been that they were allied with symmetrodonts or monotremes or represented an entirely new group of mammals that that although functionally tribosphenic and possessing a number of characters typical of placentals, are not in fact placentals but rather convergent on them; e.g. Archer et al. (1999) and references therein; Foote et al. (1999), Luo et al. (2002) and references therein, Sigogneau-Russell et al. (2001). These arguments against the ausktribosphenids being placentals have been countered in a series of papers cited in Rich et al. (2001a-b, in press). Given that a dozen papers have now been published which deal with the affinities of the Ausktribosphenidae, it is unlikely that the disputants will come to a consensus as long as what is known about the family is restricted to lower jaws. The critical discovery that will provide the evidence to decide between the competing hypotheses will probably be in the form of an ausktribosphenid upper dentition and (or) petrosal. Although the sediments at Flat Rocks site were deposited in such a manner that there is a pronounced bias against these more fragile elements, skull fragments of small dinosaurs have been recovered there as well as two parietal-frontal regions of mammals (probable monotremes on the basis of their size comparable to Tachyglossus aculeatus and three to five times the dimensions expected of an ausktribosphenid). To date, about six person-months of effort mechanically breaking down the fossiliferous rock have been required in order to recover each mammalian jaw fragment at the Flat Rocks site. Despite this low rate of yield of mammalian fossils at this locality, continued work there should eventually produce the kind of specimen needed to decide between the various ideas that have been proposed concerning the affinities of the Ausktribosphenidae. Fortunately, if need be to settle the issue, the extent of the fossiliferous units at the Flat Rocks site is sufficient to make possible at least another two decades of collecting there at the current rate of excavation. 1

FOOTE, M., HUNTER, J.P., JANIS, C.M., SEPKOSKI Jr., J.J., ARCHIBALD, J.D., HEDGES, S.B., KUMAR, S., RICH, T.H., VICKERS-RICH, P. and FLANNERY, T.F. 1999. Divergence Times of Eutherian Mammals. Science on Line 285:2031.

Luo, Z.-X., KJELAN-JAWOROWSKA, Z and R.L. CIFELLI 2002. In quest for a phylogeny of Mesozoic mammals. Acta Palaeontologica

Polonica 47:1-78. RICH, T.H., FLANNERY, T.F., TRUSLER, P., KOOL, L., VAN KLAVEREN, N.A. and VICKERS-RICH, P. in press. Evidence that monotremes and ausktribosphenids are not sister groups. Journal of Vertebrate Paleontology. 22(2).

RICH, T.H., FLANNERY, T.F., TRUSLER, P., KOOL, L., VAN KLAVEREN, N.A. and VICKERS-RICH, P. 2001a. A second tribosphenic

mammal from the Mesozoic of Australia. Records of the Queen Victoria Museum 110:1-9. RICH, T. H., T. F. FLANNERY, P. TRUSLER, and P. VICKERS-RICH. 2001b. Corroboration of the Garden of Eden Hypothesis; pp. 315324, In I. Metcalfe, J.M.B. Smith, M. Morwood, I. Davidson, and K. Hewison (eds.), Faunal and floral migrations and evolution in SE Asia-Australia. A. A. Balkema, Lisse. SIGOGNEAU-RUSSELL, D., HOOKER, J.J. and P.C. ENSOM 2001. The oldest tribosphenic mammal from Laurasia (Purbeck Limestone Group, Berriasian, Cretaceous, UK) and its bearing on the 'dual origin' of Tribosphenida. Compte Rendu Acad. Sci. Paris, Sciences de la Terre et des plantes / Earth and Planetary Sciences 333:141-147.

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IPC2002 Oral Presentations PALYNOLOGICAL EVIDENCE FOR DATING A LATE FAMENNIAN EVENT IN NORTHERN U.S.A.: EXTRATERRESTRIAL OR METEOROLOGICAL? John B. RICHARDSON. W. WOODROW & D. SEVON Department of Palaeontology, Natural History Museum, Cromwell Road\ London SW7 5BD Palynological analysis of Famennian deposits in New York State and Pennsylvania has been used to date an unusual sedimentological event. The sediment, a diamictite with a distinctive profile, is known to cover much of the Appalachian area in Pennsylvania and northern Maryland. Don L. Woodrow (sedimentologist) and W.D. Sevon (Pennsylvania Geological Survey) have together plotted the diamictite through outcrops from eastern to mid-Pennsylvania and into Maryland and provided samples for palynological analysis. Sediments above and below the diamictite have all been dated to a single subzone in the upper part of the Retispora lepidophyta - Hymenozonotriletes explanantus (LE) Zone. The origin of the diamictite is enigmatic. Was it the result of a bolide plunging into the Appalachian Basin, followed by a tidal wave, or a seismic deposit, or was it the result of an enormous mudslide following an Upper Devonian Pluvial Period perhaps similar to slides found in the Chilean Andes of the Present?

ENGLISH LOWER DEVONIAN CRYPTOSPORES AND THE HABIT AND HABITAT OF THEIR PARENT PLANTS John B. RICHARDSON Department of Palaeontology, Natural History Museum, Cromwell Road, London SW7 5BD Without in situ coal deposits it is probably impossible to determine the enviroments where the parent plants of these Lower Devonian spores lived but as Muller demonstrated the spores and pollen in the Orinoco Delta were dispersed mainly by water and their spacial distribution in the deltaic sediments was sometimes irregular or local. Spores (cryptospores and miospores) occur abundantly in Lower Old Red Sandstone sediments of Hereford and Worcester and Shropshire. The sediments were deposited in floodplain environments and vary both laterally and vertically. The sequence shows offlap reflecting the progressive migration to more proximal environments and the shift of distal fluvial environments to the south. Both these factors appear to influence cryptospore distribution though it is difficult to exclude the influence of water current sorting. Distribution patterns in cryptospore assemblages reflect both the lateral and the stratigraphical changes and such variations may be used with caution to interpret potential habitats of their parent plants. Variations in the ratio of miospore/cryptospore species may reflect competition for habitats as well as dispersal. In some cases cryptospores dominated distal sediments, laid down in the distal parts of a marine-influenced coastal plain. In contrast in the proximal (upstream) sediments miospore-bearing plants appear more important. In situ Cryptospores, though they are relatively few in number, give tantalising insights into the nature of their parent plants.

A NEW GENUS OF GROENLANDASPIDID ARTHRODIRE (PISCES; PLACODERMI) FROM THE EARLY-MIDDLE DEVONIAN MULGA DOWNS GROUP OF WESTERN NEW SOUTH WALES, AUSTRALIA Alex RITCHIE Australian Museum, Sydney. The Merrimerriwa Formation of the Devonian Mulga Downs Group of western New South Wales contains locally rich and well-preserved, but dissociated, fish remains. The fauna is dominated by placoderms, especially Wuttagoonaspis, an aberrant arthrodire whose affinities are still in dispute. The widespread Wuttagoonaspis fauna, which is also known from sites in northwest Queensland and the Northern Territory, is thought to be Emsian-Eifelian in age. It also includes various dolichothoracid arthrodires one of which represents a new genus, Mulgaspis, here interpreted as an early representative of the family Groenlandaspididae. Mulgaspis gen. nov. (two species of which are present in the Mulga Downs Group in western N.S.W.) provides a link between Early Devonian phlyctaeniid arthodires (such as Dicksonosteus, Arctolepis) and the cosmopolitan Late Devonian genus, Groenlandaspis.

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IPC2002 Oral Presentations FUSULINID SEQUENCE EVOLUTION AND SEQUENCE EXTINCTION IN LOWER PERMIAN, GLASS MOUNTAINS, TEXAS Charles A. ROSS1 and June R. P. ROSS2 department of Geology, and 2Department of Biology, Western Washington University, Bellingham WA 98225 U.S.; [A.ross@biol.wwu.edu or rossjrp@cc.wwu.edu]. The Lower Permian Wolfcampian and Leonardian Series of West Texas show repeated sea level fluctuations and associated depositional hiatuses. The Wolfcampian Series comprises the Nealian and Leonoxian Stages. The Nealian Stage includes 16 relatively short term sea-level fluctuations (fourth-order depositional sequences) and contains a diverse fusulinid fauna of more than 39 species in 8 genera, characterized by inflated species of Paraschwagerina and Pseudoschwagerina, advanced species of Leptotriticites, early species of Eoparafusulina, and many species of Schwagerina. Most Nealian species range through three or four fourth-order cycles before becoming extinct and none extends into the overlying upper Wolfcampian Lenoxian Stage. The Lenoxian Stage overlies a tectonic unconformity (and hiatus) and includes three thirdoider depositional sequences. Four Lenoxian species are restricted to the lower sequence, sixteen to the middle sequence, and six to the upper sequence. Most are species of Pseudoschwagerina, Paraschwagerina, Schwagerina, Eoparafusulina, Chalarochwagerina, and, locally, Pamirinal sp. Wolfcampian fusulinid species demonstrate sequence evolution and sequence extinction as they record the appearance and disappearance of morphological species in their stratigraphic successions. The Leonardian Series comprises the Hessian (lower) and Cathedralian (upper) Stages. The Hessian includes seven third-order depositional sequences and numerous minor fourth-order and smaller parasequences. Hessian carbonate platform facies have low fusulinid species diversity and high abundances. Schwagerina is common in the lowest depositional sequence. Primitive species of Parafusulina and a species of Misellina (Brevaxina)1 are common in next higher Hess sequence. Higher sequences have progressively more advanced Parafusulina. The lower four Hessian lowstand clastic wedges of the shelf margin, slope, and basin facies include at least six species of schwagerinids, and the upper three wedges include only three species of Parafusulina. The Cathedralian Stage has one main third-oider depositional sequence and perhaps a second, which is mostly missing below the Mid-Permian unconformity below the Middle Permian Guadalupian Series. The Cathedralian has well-developed species of Parafusulina. The vertical distribution of Lower Permian fusulinid species have first appearances (sequence evolution) and last appearancess (sequence extinction) discretely packaged in this succession of carbonate depositional sequences.

SEQUENCE EVOLUTION AND SEQUENCE EXTINCTION June R. P. ROSS1 and Charles A. ROSS2 department of Biology and 2Department of Geology, Western Washington University, Bellingham, WA 98225 U.S.A. [ross@biol.wwu.edu or rossjrp@cc.wwu.edu]. Depositional sequences and sequence boundaries in the stratigraphic record preserve many significant depositional breaks and hiatuses. The fossils preserved within these depositional sequences record the sequence of evolutionary changes in species with the passage of time. The breaks at depositional unconformities mark the extinctions of many species from earlier sequences and the first appearances of new species. An example of the relationship of species occurrences, depositional boundaries, and time hiatuses is shown in Figure 1. It is based on species of the trilobite Phacops from the Middle Devonian stratigraphic succession in New York State and midwestem states areas. Phacops rana is subdivided into five subspecies and P. iowenis into three subspecies. The eastern, or Appalachian miocline, successions have the more complete stratigraphic sections. There, Phacops rana crassituberculata occurs below the hiatus between the conodont zones costatus and australis. Specimens transistional between P. rana crassitubercutata and P. rana rana are reported only in the conodont kockelianus zone. These are separated from P. rana rana by an unconformity and hiatus between the conodont kockelianus and ensensis zones. The stratigraphic range of P. rana rana extends through ensensis and lower varcus zones to the hiatus within the upper part of the middle varcus zone. Above this, the specimens become transistional between P. rana rana and P. rana norwoodensis or become questionably assigned to P. rana rana. P. rana norwoodensis is widely distributed on the craton in beds of the middle-upper varcus zone. Also mainly on the craton, P. rana paucituberculata and P. rana milleri are geographically restricted to margins of the Michigan basin and stratigraphically to the conodont ensensis zone, as are some late specimens assigned to P. rana crassituberculata . On the cratonic platform, Phacops iowensis alpenensis first appears in, and is restricted to, the depositional sequence marked by the conodont ensensis zone. P. iowensis iowensis appears above the hiatus between the ensensis and lower

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IPC2002 Oral Presentations varcus zones and ranges through the middle varcus zone. It becomes extinct at the sequence boundary before the transgression of the middle-upper varcus zone. P. iowensis southworthi, an extremely large subspecies from the eastern margin of the Michigan Basin, is reported only in the Centerfield transgression at the base of the lower varcus zone. (SEA LEVEL K-

Figure l.-The depositional sequence distributions of Phacops subspecies. Data from Eldredge, R. N., 1969, Ph.D. dissertation, Columbia University; Johnson, J.G., etal., 1985, Geol. Soc. Amer. Bull, v. 96; and Dennison, J.M., 1985, Geol. Soc. Amer. Bull, v. 96.

EXPANSION OF DEVONIAN TERRESTRIAL ECOSYSTEMS: ADAPTIVE RADIATION AND RISE OF FORESTS Stephen E. SCHECKLER Biology, Virginia Polytechnic Institute & State University, Blacksburg, VA 24061-0406, USA. Plant-based terrestrial ecosystems begin by Middle Ordovician. The typical growth plan of plants (axis construction by apical growing tips), however, was uncommon before Middle Silurian. Plants were initially small (< 0.5 m tall) and simply constructed of progressively diminishing forked axes. Robust plants are uncommon until near the end of Early Devonian and resulted from more complex branching. Main axes with lateral-branches, plus tissues capable of increased support and conductance, became common in several plant groups, e.g., trimerophytes, cladoxylopsids, cormose lycopsids (ca. 2-3 m high). Plant size increased sufficiently by early Middle Devonian so that small trees and shrubs became common and widespread. Root innovations arose that penetrated soils more deeply and stabilized floodplain habitats. Frequency, areal extent, and depth of palaeosols, and abundance of macrofossil debris, increased as forest ecosystems became permanent additions. Trees radiated more or less simultaneously from three distinct lineages: woody progymnosperms, cladoxylopsid ferns, and cormose lycopsids. Each group gave rise to new types of tree-sized descendants throughout the Late Devonian and Early Carboniferous, but used different styles of growth, branching, and tissue design. They produced patchy vegetation characterized by monotypic-stand growth where many local habitats were filled by plants with clade-specific biological adaptations of rooting, growth architecture, or reproduction. Global impacts of forests: Forest expansion stabilized stream banks and floodplains and dramatically increased sediment retention time, so that more clay was produced on floodplains. Increased depth and areal extent of rooting changed soil chemistry. Carbon sequestration (by soil silicate formation, primary production, recalcitrant plant biomolecules, and burial of trunks, roots, and branches) transformed global atmospheric chemistry (less C0 2 , more 0 2 ). Global cooling, pronounced extinctions of marine invertebrates, and the initiation of wildfire conflagrations are among the effects attributed to the Devonian rise of forested ecosystems. Early Devonian landscapes: Expansion and diversification of plants in Early Devonian protected floodplains and soils from erosion. Secondary succession became dominant over primary succession. Bank-

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IPC2002 Oral Presentations dwelling plants stabilized stream channels and promoted meandering rather than braided stream courses. These and floodplain dwellers served to delay and lessen the effects of devastating flash floods so that soil formation on interfluves was less frequently and less critically interrupted. Plants were small and formed local monotypic patches by clonal growth. Rhizomes or corms bore only tufts of rhizoids or short roots for anchorage and absorption. Mainly surface water was utilized and early plants were probably limited to habitats with nearly continuous moisture. By mid-late Early Devonian (Pragian-Emsian), however, new plant architectures emerged. Trimerophyte types had taller main axes with lateral branches. Lycopsids axes bore numerous small leaves. By Pragian, root penetration of flood plain deposits was common. Soil water and dissolved nutrients were better utilized. Slightly drier habitats were colonized. Middle Devonian landscapes: Tree-sized lycopsids with solitary, nonclonal growth were common in wetlands. Trimerophyte relatives also produced solitary trees (cladoxylopsids plus aneurophyte and archaeopterid progymnosperms). All had non-laminated 'leaves' or branchlets that allowed light penetration to the understory. Tiered ecosystems, that vertically stratified light and humidity, promoted niche diversification of understory plants and are linked to heterospory. Stabilized floodplains developed local microclimates and distinctive soils that produced horizontally complex, patchy vegetation. Late Devonian landscapes: Archaeopteris progymnosperm trees appeared in early Frasnian and rapidly spread worldwide. Most had broad leaves that made deeply shaded forests. Archaeopteris grew in well drained to waterlogged soils and formed dense streamside galleries. Drier interfluves supported trailing lycopsids, cladoxylopsid shrubs/vines, and shrubby seed plants. Archaeopteris tolerated wet to seasonally dry soils and formed extensive floodplain forests of only a few species. Tree lycopsids or zygopterid ferns occupied most wetland habitats, however. Late Devonian riparian landscapes were thus marked by abrupt, small scale, spatial heterogeneity. Extinction of Archaeopteris in Latest Devonian coincided with the rapid spread of early gymnosperm seed plants, which became widespread, but uncommon, in mid Famennian. BIOGEOGRAPHY OF EOCENE BRYOZOANS OF THE ST VINCENT BASIN, SOUTH AUSTRALIA Rolf SCHMIDT & Yvonne BONE Dept. Invertebrate Palaeontology, Museum Victoria, PO Box 666E, Melbourne, Victoria 3001; Dept. Geology & Geophysics, Adelaide University, Adelaide, South Australia 5005 1

The first extensive and stratigraphically detailed taxonomic study of fossil Bryozoa within the Middle to Late Eocene sediments of the St Vincent Basin has identified almost than 200 species of Cheilostomata and 50 species of Cyclostomata. This is probably only a part of the total bryozoan specie and thus a higher diversity than all other macrofauna present combined. Biogeographical comparisons are hampered by the absence of other detailed and stratigraphically constrained species lists for most of the Australian Tertiary limestones. Comparison with the published fossil Bryozoa of Victoria (mainly Neogene) and elsewhere revealed several biogeographic groups, namely basin endemic, Australian, and global. A significant number of species and even a genus are at this point considered endemic to this basin. Interesting is the apparent absence in the St Vincent Basin of groups which are generally common in Victorian Tertiary deposits (as well as the modern shelf), such as any species of Selenaria. The Cellariidae (articulated branching colonies) are a very common component of most Australian Teriary deposits, but the actual species are highly dissimilar, with 13 of the 17 species being new. Such endemism may be the result of the restricted nature of the St Vincent Basin during much of the Tertiary caused by a basement high centered on what is now Kangaroo Island. Most of the other species are very similar to the ones found in the Oligo-Miocene of Victoria, but have consistently smaller zooidal measurements. This may be environmentally influenced, indicating cooler temperatures in the Eocene. One species is almost identical with Rhamphosmittina lateralis (MacGillivray), which occurs in the Victorian Miocene and is the still extant in New Zealand. This indicates a species time range of 40 million years, which is exceptionally long among bryozoans. The global Eocene component indicates that significant biogeographic links with outside of Australia still existed at this time. The Phidoloporidae ("lace corals") represent the most diverse and ubiquitous group, at a geological time which is at their estimated time of origination. Contemporaneous sediments in Antarctica, Eastern Europe and North America, however, also have a diverse fauna of this family, pointing to a Tethyan origin and rapid dispersal. Similarily, a new genus of Romancheinidae shows strong links with similar species of the Eocene Eastern Europe and North America as well as recent New Zealand and Japan. A new genus of Onychocellidae appears very similar to ones that dominated much of the Cretaceous Tethyan faunas but are subsequently very rare during the Cenozoic. These similarities indicate that the last stages of Tethys still could have acted as a dispersal center. This interchange and similarity ends in the Oligocene (probably

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IPC2002 Oral Presentations due to the change on the oceanic circulation system), after which the Australian Bryozoa appear to have become as endemic as other phyla. The large number of new species and several new genera described further adds to the high global diversity of the Late Eocene.

SHELLS OF THE SHALLOW-MARINE BIVALVE, PHACOSOMA JAPONICUM, MID-HOLOCENE SEASONAL CLIMATE CONDITIONS IN JAPAN

RECONSTRUCT

Bernd R. SCHONE1. Kazushige TANABE1, David L. DETTMAN2, Yasumitsu KANIE3 department of Earth and Planetary Sciences, University of Tokyo, Hongo 7-3-1, Tokyo 113-0033, Japan; [bernd.schoene@excite.com]; department of Geosciences, University of Arizona, 1040 East 4th Street, Tucson, AZ 85721, USA; sYokosuka City Museum, Yokosuka 238, Japan What was the climate like during the mid-Holocene in subtropical settings? Seasonal climate variability during the past 10.000 years, especially during times of profound climatic changes, is the focus of many modern climate-change studies. In general, data on seasonal climate variability (of the Recent past) can improve atmosphere-ocean general circulation models (GCMs, e.g., Manabe & Stouffer, 1988). More precise GCMs are essential to assess the role of humans on global climate change and to predict future evolution of the atmosphere and ocean circulation and thermodynamics. Recently, the middle Holocene, roughly 6000 years BP, proved to represent an era of substantial global climate change. Climate was perhaps generally warmer than today, i.e., summers in the Northern Hemisphere were generally warmer, and winters probably cooler. However, little is known, for instance, about seasonal climate variation in subtropical regions. We also know little about the severity and duration of the monsoon and typhoons seasons, or how long a specific temperature regime lasted. Those questions can be answered by analyzing bivalve mollusk shells. Bivalve mollusk shells provide ultra-high-resolution climate proxies in their shells. Daily growth patterns and the oxygen isotope composition of Recent juvenile, shallow-marine bivalve mollusk shells of Phacosoma japonicum (Reeve) from Japan were analyzed and cross-calibrated with environmental parameters. Our results indicate that growth is mainly controlled by temperature: Growth ceases below 14.2°C (age two) and 16.8°C (age four) and is most rapid between 24.6°C and 27.2°C. Salinity changes have no profound effects on growth rates of this species. It appears that P. japonicum calcifies in oxygen isotopic equilibrium with the ambient sea-water. The annual oxygen isotope profiles of the shells reflect the temperature cycle and the varying amounts of freshwater added to the sea-water by precipitation. Most negative values of -3.15%o occur during the rainy season, i.e. during the monsoon and typhoon seasons. Strongly reduced growth rates at some localities during the second half of the year were explained by nutrient deprivation. Preliminary results of a program of continuing analyses of mid-Holocene shells indicate completely different life history traits and different growth conditions. Many specimens exhibit in average 15% longer growing seasons than today. Shell growth commenced perhaps even during most parts of the coldest season of the year. True winter breaks were not found. Apparently, winter temperatures did not drop below 14°C. Growth rates were high during spring and autumn. Other shells at the same locality exhibit growth interruptions in late summer and early autumn. There is still no clear-cut explanation for this feature— occurring in juvenile and mature specimens. Our study demonstrates the utility of accretionary skeletons for high-resolution climate and environmental reconstructions.

AFFINITIES OF LOWER AND MIDDLE DEVONIAN TRILOBITES BETWEEN N-GONDWANA AND LAURUSSIA Gunnar SCHRAUT Institut des Sciences de VEvolution, Laboratoire de Paleobotanique et Paleontologie, Universite Montpellier II, Place E. Bataillon; FR-34095 Montpellier, France Affinities of Lower and Middle Devonian trilobite associations between the northern margin of Gondwana, the terranes of Armorica, Avalonia and Laurussia are investigated (IGCP-Project 421). All including data of geology, geophysics and palaeontology are used for interpretation of palaeogeography for continents, microcontinents, terranes and their dynamic of movement in space and time.

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IPC2002 Oral Presentations Because of - in analogy of the short planctonic-pelagic stage of recent deep-sea crustacean larvae - the early benthic stage of Larvae (see Speyer & Chatterton 1989) trilobites are especially sensitive for deducing oceanic and climatic barriers and therefore conclusions of movements of crustal blocks including shallow marine environments of the continental shelfs. Good correlations with index-fossils of biostratigraphy (e.g. conodonts, tentaculites and / or ammonoids) makes trilobite very useful for interpretation of short-time movement of tectonic blocks between different regions. Because of their high diversity (e.g. more than 1000 species in the Lower Devonian) and the hughe amount of published datas it is necessary to use a database stabled by computer programs. New data and interpretation of palaeomagnetism indicate a large ocean of more than 3500 km width between Laurussia in the north and the northern margin of Gondwana in the south during mid-Devonian times (e.g. Tait et al. 1997; Tait et al. 2000). Results which comes from the trilobites are not fitting this modell because affinities on genera and especially on the specific level are much too high and distinctiv. SPEYER, S.E. & CHATTERTON, B.D.E., 1989. Trilobite Larvae and Larval Ecology. Historical Biology 1989, 3,27-60. TAIT, J.A., BACHTADSE, V., FRANKE, W. & SOFFELT, H.C., 1997. Geodynamic evolution of the European Variscan fold belt: palaeomagnetic and geological constraints. Geologische Rundschau 86, 585-598. TAIT, J., SCHATZ, M., BACHTADSE, V. & SOFFEL, H., 2000. Palaeomagnetism and Palaeozoic palaeogeography of Gondwana and European terranes. pp. 21-34. In Franke, W. & Haak, V., Oncken, O. & TANNER, D. (eds.), Orogenic Processes: Quantification and Modelling in the Variscian Belt; Geological Society of London, Special Publications 19; London.

BENTHIC FORAMINIFERA OF GULF OF MEXICO COLD SEEPS Barun K. SEN GUPTA1, Emil PLATON2 & Melissa K. LOBEGEIER3 department of Geology and Geophysics, Louisiana State University, Baton Rouge, LA 70803, USA, [barun@geol.lsu.edu]; 2Energy and Geoscience Institute, University of Utah, 423 Wakara Way, Salt Lake City, UT 84108, USA, [eplaton@egi.utah.edu]; 3Department of Geology and Geophysics, Louisiana State University, Baton Rouge, LA 70803, USA, [melissa@geol.lsu.edu] Diverse benthic Foraminifera survive the ecological constraints of bathyal/abyssal hydrocarbon seeps of the northern Gulf of Mexico, but unlike their molluscan and vestimentiferan counterparts, none of the foraminiferal species identified so far is endemic to these restricted environments, and cannot be considered as exotic elements of the fauna. Samples collected from submersibles in a depth range of 600-2200 m (and stained by Rose Bengal) indicate a reduction in species diversity, compared to the diversity in isobathyal, non-seep sediments from the same area. A bathymetric influence on the community composition is also discernible (as in the case of non-seep Foraminifera), with agglutinated taxa (e.g., Trochammina) being present in much greater percentages in abyssal depths. In the well-surveyed Green Canyon area of the Gulf of Mexico slope (depth -600-700 m), numerous foraminiferal species have been found in oxygen-poor sedimentary microhabitats associated with mats of the large chemolithotrophic bacterium Beggiatoa, and with chemosynthesis-based communities of mussels, clams, and tubeworms. Judging by the presence of living individuals in subsurface sediments (to 3 cm below the sediment-water interface), several species (e.g., Bolivina albatrossi, B. ordinaria, Cassidulina neocarinata, Gavelinopsis translucens, Osangularia rugosa, and Trifarina bradyi) are considered to be microaerophiles or facultative anaerobes. Among these, Bolivina albatrossi shows the greatest tolerance to oxygen deprivation and the presence of H2S. One potential source of stress for this foraminiferal community is the liquid and gaseous petroleum present in the bottom water and the sediments, but we have not detected any drastic effect of these natural pollutants. Samples with an extraordinary amount of oil were not barren of foraminifera, and did not contain deformed individuals. Stratigraphic records of Gulf of Mexico cold-seep Foraminifera (dead individuals) offer clues to the seepage history. A 24-cm push core, taken through a Beggiatoa mat on a methane-hydrate mound (depth 567 m) reveals assemblage changes in the past 1800 years at a site of present-day hydrate dissociation and gas expulsion. It shows a very sharp upward reduction of assemblage density (individuals/gm of sediment) and a slightly less pronounced reduction in equitability (derived from species richness and Shannon-Wiener diversity) in the 15-19 cm stratigraphic interval. This change probably reflects an intensification of hydrate dissociation and methane enrichment of habitat waters. The species richness is highly variable (10-46), but with the exception of the surface-sediment sample, values higher than 27 are confined to levels below 15 cm. Preliminary data from an undated abyssal push core through another Beggiatoa mat (Alaminos Canyon, depth 2221 m) also demonstrate an upcore reduction in species diversity, probably linked with the onset or intensification of seepage. Although Trochammina sp. dominates the assemblage throughout this core, high relative abundances of many other species, including Ioanella tumidula, Nuttallides decorata, and Hoeglundina elegans, in the lower section of the core indicate an environmental change at the 6-cm level. An

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IPC2002 Oral Presentations unusual feature of the modern assemblage here is the conspicuous presence of encysted living individuals of the porcelaneous species Cornuspira involvens in the seepage-affected top 3 cm of the core. This work has been supported by the U.S. Minerals Management Service through the Coastal Marine Institute at Louisiana State University (Cooperative Agreement No. 1435-01-99-CA-30951, Task Order 18182), and by the NOAA National Undersea Research Program.

PEDAL RETRACTOR SCAR OF TRIGONIOIDACEA (NON-MARINE LATE MESOZOIC BIVALVIA) AND ITS CLASSIFICATORY AND FUNCTIONAL SIGNIFICANCE Jingeng SHA Nanjing Institute of Geology and Palaeontology, Academia Sinica, Chi-Ming-Ssu, Nanjing 210008, China Trigonioidids are a special group of the Late Mesozoic non-marine unionid bivalves widely distributed in Asia. These bivalves have a minute but very depressed anterior pedal retractor scar. This pedal retractor scar is reniform in outline, occurs at the dorsal margin of the anterior adductor but distinctly separates from, posterior to and above the anterior adductor scar. It is the key feature that distinguishes Trigonioidacea from all other non-marine bivalves. Trigonioidids have been reported from Asia (China, Korea, Japan, Thailand, Laos and Russia), Europe (England), America (Colorado), Africa (Sudan, Algeria) and Oceania (Australia). However, there is not any anterior pedal retractor scar separating from the anterior adductor scar that has been recognized from the published figures of the so-called trigonioidids from America, Africa and Oceania to date. Those "trigonioidids" outside Asia and Europe are, therefore, probably not real trigonioidids, implying that trigonioidids were limited in Asia and Europe during the Late Mesozoic. The deeply impressed pedal retractor scar and separation of anterior pedal retractor from anterior adductor have declared that the trigonioidids have a special muscle system of strong retraction, and the functional division between closing shell and retracting the foot was very clear, because the anterior pedal retractor must have been able to function independently. The strong pedal retractors presumably were able to withdraw the foot within the shell before it was closed. When the valves rapidly closed by contraction of the strong adductor muscle; the tip of the foot swelled into a bulb and water contained in the mantle cavity was expelled and liquefied the sediment adjacent to the shell, the anterior pedal retractor contracted rapidly, pulling the shell anteroventrally downward. As a result, the animal was lifted upward and the anteroventral part of the shell entered the sediment.

LOPINGIAN (LATE PERMIAN) STRATIGRAPHY, SEDIMENTATION AND PALAEOBIOGEOGRAPHY IN SOUTHERN TIBET SHEN Shu-zhong1, CAO Chang-qun1, G.R. SHI2, WANG Xiang-dong1, MEI Shi-long3 and JIN Yu-gan1 1 Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, 39 Eastern Beijing Road, Nanjing, 210008, P.R. China [szshen@nigpas.ac.cn]; 2School of Ecology and Environment, Deakin University, Melbourne Campus, 221 Burwood Highway, Burwood, Victoria 3125, Australia;3School of Geosciences, China University of Geosciences, Beijing Campus, 100083, Beijing, P.R. China. Investigations into the Permian-Triassic sections and limestone blocks scattered in the Indus-Tsangbo Suture Zone in southern Tibet show widespread distribution of the Lopingian strata. The Lopingian deposits mostly contain rich brachiopod fossils and a characteristic conodont Mesogondonella sheni Zone of latest Changhsingian age in the topmost part. Brachiopod assemblages are largely comparable with those known from the upper Wargal and Chhidru Formations of the Salt Range, Pakistan, the Zewan Formation of Kashmir, the upper part of the Kuling Group in Spiti of India and the Hardmen Formation of Western Australia. A revised Lopingian (Late Permian) Epoch is proposed for the Selong Group and its equivalents in southern Tibet. The Lopingian deposits in southern Tibet can be grouped into three different sedimentary types, each of which reflects different sedimentary environments from coastal to continental shelfal settings on the northern peri-Gondwanan margin. The 'Qubu-type' sequence represents marine coastal and proximal barrier-lagoon sediments during a gradual sea-level rise. Micaeous sandstone and shale of regressive origin, with abundant palynomorphs and acritaches, were developed during the Late Lopingian sea-level lowstand, which is followed by a major rapid transgression at the very end of Permian. The 'Selong-type' sequence in the Selong area consists of bioclastic limestone and calcareous shale in the lower part, and crinoid grainstone in the upper part. The latter part is believed to have been formed in a high-energy inner shelf shoal setting and was

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IPC2002 Oral Presentations accompanied by sedimentary starvation. In this fades, the Late Lopingian regression event is indicated by a caliche bed. Above the caliche bed, a coeval rapid transgression is suggested by a fining-upward lithological shift from crinoid grainstone to pyritic packstone across the P-T boundary. The fChitichun-typef sequence, sporadically distributed along the Indus-Tsangbo suture zone as small limestone blocks, consists of pure bioclastic sparite with the ammonoid Cyclolobus fauna. It is interpreted as the break-up products of seamounts and/or small isolated carbonate platforms developed on the outer shelfal settings. Palaeobiogeographically, the faunal compositions in different sedimentary types clearly indicate palaeolatitudinal variations in climate. In the Qubu- and Selong-type Lopingian strata close to the continental margin, faunas consist of typical Gondwana-type, bipolar, bi-temperate and cosmopolitan elements, whereas typical Tethyan elements are totally absent until the very end of Permian when some Tethyan taxa invaded northern Gondwana in response to climatic warming. Basinwards, the Chitichun-type Lopingian developed on the outer shelfal environments evidently demonstrates palaeobiogeographical mixed character in faunal composition between the Cathaysian and Himalayan provinces.

BIOGEOGRAPHICAL CHARACTERISTICS AND PALAEOGEOGRAPHICAL IMPLICATIONS OF MARINE BIOTAS AT THE JUNCTION BETWEEN WARM-WATER AND COLD-WATER REALMS: A CASE STUDY OF THE PERMIAN MARINE FAUNAS OF SOUTH PRIMORYE, FAR EAST RUSSIA G. R. SHI School of Ecology and Environment, Deakin University, Melbourne Campus, 221 Burwood Highway, Burwood, Victoria 3125, Australia The biogeographical features and associated biostratigraphical/palaeogeographical implications of fossil biotas from the interface regions of two or more palaeobiogeographical realms of contrasting environmental settings remain under-studied. The South Primorye region of Far East Russia is such an area with distinctive Permian transitional biotas of mixed biogeographical affinities. In this paper I will review the Permian faunas, especially Brachiopoda, of South Primorye based on my own field observations and collections, as well as a critical examination of published literature. The Permian marine faunal succession of South Primorye, as typically represented by Brachiopoda, is clearly threefold: a late Early Permian low-diversity fauna with proportionally high number of endemic taxa, a middle Middle Permian (Wordian) fauna with an usually high diversity and mixed Cathaysian/Boreal biogeographical affinities and the unique bi-temperate Monodiexodina fusulinacean fauna, and a late Middle Permian to early Late Permian Cathaysian-type warm-water fauna of moderate diversity with some reef development. This faunal succession can be closely compared with the Permian faunal sequences of southeast Mongolia, northeast China, and the Kitakami Mountains and Hida Gaien Belt of Japan. Various interpretations have been proposed to explain the marked change of marine provinciality of the Permian faunas in East Asia. In particular, a controversy still prevails over the origin of some Gondwanatype Permian marine taxa found in South Primorye and adjacent regions. In this paper, I argue that the origin of the mixed Boreal/Palaeoequatorial Permian marine faunas in South Primorye (and adjacent regions) is most likely a result of the combined effect of three factors: its middle palaeolatitudinal position during the Permian, its possession of surface ocean current connections with both the cold Arctic sea to the north and the warm Eastern Tethys (Cathaysia) sea to the south, and increased plate convergence and ultimate terminal collision between the Sino-Korea and Bureya blocks. It is suggested that South Primorye was located in a middle latitude setting, estimated to be about 25°-35° in the northern hemisphere, on the eastern side of the Bureya block and proximal to and slightly northeast of the Sino-Korea block, during the Permian. As such, South Primorye would have had ocean current connections to the temperate and polar Arctic sea to the north and the warm-water Eastern Tethys to the south in a geographical and climatic situation analogous to the Sea of Japan today. Marked change of marine provinciality within the Sino-Mongolian seaway through the Permian, as evidenced by the change of faunal successions, suggest that the Sino-Korea and Bureya blocks were converging rapidly through the Permian, resulting in the shrinking of the Sino-Mongolian seaway in the middle, which in turn facilitated and enhanced the intermingling of Boreal and East Tethyan (Cathaysian) faunas.

IPC2002 Oral Presentations PALAEONTOLOGY AND MUSEUM STUDIES AT MACQUARIE UNIVERSITY Andrew SIMPSON1. Ruth MAWSON2 and John A. TALENT2 division of Environmental and Life Sciences, Macquarie University 2109, Australia [asimpson@els.mq.edu.au]; 2Macquarie University Centre for Ecostratigraphy and Paleobiology, Department of Earth and Planetary Sciences, Macquarie University 2109, Australia; [rmawson@els. mq. edu. au; jtalent@els. mq. edu. au] The science of palaeontology connects most broadly across society via the work of museums. Every significant state or national museum anywhere in the world will have some form of palaeontological collection and programs that elucidate, interpret and communicate earth history (deep time) through fossils. As part of the overall decline in teaching of earth sciences in Australian universities, palaeontology programs have declined significantly since the mid-1990s with several institutions abandoning it completely. Similarly, with a declining public sector investment in research, collections-based natural history research programs have not attracted adequate funding to sustain an energetic and expanding research agenda. This sclerosis is not assisted by competitive funding structures that dissuade students from exploring intellectual arenas outside of their undergraduate major. Macquarie University has therefore introduced a double degree program, the BSc with BA in Natural History, Culture and Museum Studies, to allow students to combine coherent study patterns with a core museological component. This is Australia's first undergraduate museum studies degree program. Students are required to complete three coherencies, either two in the Arts and one in the Sciences, or one in the Arts and two in the Sciences. Palaeontology is a compulsory science coherency. Other Science coherencies may be taken in biology and geology, and arts coherencies in, inter alia, Ancient Mediterranean cultures, Australian history, indigenous studies, and environmental and cultural geography— traditional areas from which curatorial and other museum personnel are drawn. Other Arts and Science coherencies are currently being negotiated. Whereas not everyone undertaking the degree will secure or even seek museum employment, the program equips students with a broad range of valuable generic information management skills. Furthermore, through Arts and Science exposure they are engaged by a more liberal education than is possible in most other undergraduate programs. The double degree program also has the added benefit of introducing a wider range of students to the value of the collections-based science of palaeontology. Broad public understanding of the value of the science of palaeontology is required to ensure the viability of future research programs.

DENTITION CHARACTERS AS A CONTRIBUTION TO GNATHOSTOME AND PLACODERM PHYLOGENY Mova Meredith SMITH1 & Zerina JOHANSON2 Craniofacial Development, Dental Institute KCl, Guy's Campus, London Bridge, SE1 9RT, UK; 2Earth Sciences, Australian Museum, 6 College Street, Sydney 2000, Australia [Moya.smith@kcl.ac.uk]. Among jawed vertebrates, the fossil group Placodermi is generally resolved to the base of the gnathostome phylogeny and the current opinion is that teeth, homologous to those of acanthodians, chondrichthyans and osteichthyans, are not present in this group (Reif, 1982; Donoghue et ai, 2000; Young et al., 2001). This assertion is based on the absence in placoderms of recognisable teeth, that is, lack of structural evidence that a patterned tooth-generating system exists, and the presence in the gnathal denticles of a characteristic dermal tubercle histology. To test the theory that teeth evolved together with jaws at the origin of gnathostomes, it is important to establish if teeth homologous with those of chondrichthyans and osteicthyans are present in placoderms, or at least in the basal groups of the clade. The placoderm dentition is one in which the dentition is not replaced, and in which basal growth of dental tissue replaces worn gnathal biting surfaces (statodont condition). However, descriptions of ordered rows of teeth along the gnathal edges in coccosteid arthrodires, require an explanation of their development and growth. We present data that these patterns in the adult dentition, include ordered sets of teeth in which the newest tooth is added out of the bite, in advance of need, and in a sequential and regulated position relative to other teeth of the set. These are characteristsics of teeth in a gnathostome dentition as proposed by Reif (1982) to distinguish them from oral denticles. 0rvig (1980) described in some detail the position and growth of these teeth in the arthodire placoderm Plourdosteus, with individual "true teeth" newly added to a "dental field" with growth of the gnathal bone. This occurred on both the anterior and posterior supragnathal plates of the upper dentition, and on the infragnathal of the lower jaw. Although these patterned dental morphologies are only in one group of placoderms (the Arthrodira), they can be related to tooth sets in other gnathostomes (Smith and Coates, 2001) and described as lyodont tooth addition. This is contrary to Reif s

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IPC2002 Oral Presentations (1982) opinion that tooth families are absent from placoderms because of the lack of tooth spirals at the jaw margin. However, within the Placodermi it is necessary to determine if growth is from a consistent direction in all dentitions and by a mode of unitary addition of teeth. We attempt to fit new morphological data into theories of gnathostome tooth families, the 'tooth whorl' concept, discontinuous dental laminae, and tooth primordia forming from clonal models of tooth patterning programmes (Smith & Coates, 2001). We also aim to establish the phylogenetic sequence in which these characters of the dentition are expressed within placoderms. In particular because in some primitive arthrodires (phlyctaeniids) the gnathalia are said to support crowded denticles comparable to tuberculate ornament on the external plates of the head and trunkshield (Young et al. 2001). The importance of this is because new data from the fossil record is challenging the accepted idea that teeth are present at the base of the gnathostome clades in all phyla. The group with clearly recognised tooth addition, the brachythoracid arthrodires, are a derived taxon within the Placodermi, and on this basis the origin of teeth in placoderms occurs late in the phylogeny so that these teeth cannot be considered as homologues with those of other gnathostomes. However, the histology of these teeth shows that they are composed of regular dentine formed around a pulp chamber and different from the semidentine of the dermal tubercles. The origin of teeth in this group of derived placoderms implies that more basal forms adopted other strategies, some of these may co-opt dermal denticles at the jaw margins. However, it also supports the separate evolution of jaws and teeth and is highly significant because these conclusions can be tested on each gnathostome clade to determine by cladistic methods where the origin of teeth occurred in each higher level taxon. 0RVIG, T., 1980. Histologic studies of Ostracoderms, Placoderms and fossil elasmobranchs. Zoologica Scripta 9, 141-159.

REIF, W-E., 1982. Evolution of dermal skeleton and dentition in vertebrates: the odontode-regulation theory. Evolutionary Biology 15,

287-368. DONOGHUE, P., FOREY, P.L. and ALDRIDGE, R.J., 2000. Conodont affinity and chordate phylogeny. Biological Reviews 75, 191-252. YOUNG,G.C., LELIEVRE, H. and GOUJET, D. 2001. Primitive jaw structure in an articulated brachythoracid arthrodire (placoderm fish: Early Devonian) from southeastern Australia. Journal of Vertebrate Palaeontology 21, 670-678.

SMITH, M.M. and COATES, M.I., 2001. The evolution of vertebrate dentitions: phylogenetic pattern and developmental models, pp. 223240. In Ahlberg, P. E. (ed.). Major Events in Early Vertebrate Evolution. Taylor and Francis, London.

ROADIAN-WORDIAN BRACHIOPODS FROM EASTERN PENINSULAR MALAYSIA WITH UNEXPECTED SIBUMASU/PERI-GONDWANAN AFFINITIES AND THEIR PALAEOBIOGEOGRAPHIC IMPLICATIONS Masatoshi SONE and Ian METCALFE Asia Centre, University ofNew England, Armidale 2351, Australia During the Middle Permian (Guadalupian), Tethyan biotic provincilism was most pronounced. The East Malaya terrane includes the eastern half of Peninsular Malaysia and extends eastwards offshore. It has often been considered to be an extended part of the Indochina block and has broadly been referred to as a unit of the tropical Cathaysian biogeographic province throughout the Permian (eg. Metcalfe 1998, Shi & Archbold 1998). This view is questioned in the light of new biogeographic data here presented. Middle Permian marine faunas of East Malaya are dominated by warm-water Tethyan elements, although Roadian faunas are not well understood. Early Capitanian brachiopods of East Malaya exhibit strong affinity to the coeval fauna of western Cambodia but its specific linkage to those of South China is weaker or not clearly definable (Sone et al. 2001). Recent investigations on two East Malayan brachiopod faunas (in Pahang and Johore) of probable Roadian-Wordian age reveal the presence of some genera suggestive of Sibumasu/Cimmerian or peri-Gondwanan affinities. These genera include Caricula, Pseudoleptodus, Neochonetes (Nongtaial), Retimarginifera and Magniplicatina. In particular, Johore species of Caricula, Pseudoleptodus and Transennatia are closely comparable to those of the Rat Buri Limestone, southern Thailand. In addition to the brachiopod evidence, there are also some mid-Permian cephalopods, corals and small foraminifers, which are distributed through Indochina/East Malaya, Cimmeria and western periGondwana. The Bentong-Raub suture zone of Peninsular Malaysia is widely accepted as representing the PalaeoTethys in SE Asia, and as representing the biogeographic boundary between the Gondwanan and Cathaysian floral provinces (Metcalfe 2000). This is in good agreement with general distributions of faunal and floral groups, but for some marine faunas the Gondwana-Cathaysia divide between Sibumasu and East Malaya/Indochina appears not to have inhibited some faunal exchange during the mid-Permian. Preliminary results presented here suggest that there was some specific interchange or one-way migration between shallow-waters of East Malaya and Sibumasu across or around the Palaeo-Tethys ocean during the mid-Permian. This may imply the presence of particular ocean currents facilitating such faunal traffic

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IPC2002 Oral Presentations between the two terranes, and/or East Malaya being an independent terrane off Indochina, acting as a biotic station for stepping-stone migration. In either case, the mid-Permian Palaeo-Tethyan seaway between Sibumasu and East Malaya/Indochina must have been narrow enough to allow such faunal traffic. Hence, a large Palaeo-Tethys ocean between Sibumasu and East Malaya/Indochina reconstructed by Baud et al (1993) or Stampfli (2000) is highly unlikely. The Mid-Permian marine biota of East Malaya is not exclusively of tropical Cathaysian affinity, but to some degree displays a palaeobiogeographically transitional character between the Sibumasu and Cathaysian provinces and reflects sub-tropical to temperate climatic conditions, at least during the RoadianWordian period. Sone's study is supported by both an International Postgraduate Research Scholarship and a University of New England Research Scholarship. BAUD, A . , MARCOUX, J., GUIRAUD, R., RICOU, L. E. and GAETANI M., 1993. Late Murgabian ( 2 6 6 - 2 6 4 Ma), pp. 9 - 2 0 . In Dercourt, J.,

Ricou, L. E. and Vrielynck, B. (eds), Atlas Tethys Palaeoenvironmental Maps; Gauthier-Villars, Paris. METCALFE, I., 1998. Palaeozoic and Mesozoic geological evolution of the SE Asian region: multidisciplinary constraints and implications for biogeography, pp. 25-41. In Hall, R. and Holloway, J. D. (eds), Biogeography and Geological Evolution of SE Asia; Backhuys Publishers, Leiden. METCALFE, I., 2000. The Bentong-Raub Suture Zone. Journal of Asian Earth Sciences 18, 691-712. SHI, G. R. and ARCHBOLD, N. A., 1998. Permian marine biogeography of SE Asia, pp. 57-72. In Hall, R. and Holloway, J. D. (eds), Biogeography and Geological Evolution of SE Asia; Backbuys Publishers, Leiden. SONE, M., LEMAN, M. S. and SHI, G. R., 2001. Middle Permian brachiopods from central Peninsular Malaysia — faunal affinities between Malaysia and west Cambodia. Journal of Asian Earth Sciences 19, 177-194. STAMPFLI, G. M., 2000. Tethyan oceans. In Bozkurt, E., Winchester, J. A. and Piper, J. D. A. (eds), Tectonics and Magmatism in Turkey and the Surrounding Area, Geological Society London Special Publication 173, 1-23.

SOME TERTIARY PALYNOFLORAS FROM THAILAND WITH CLIMATIC CHANGE EVIDENCES Wickanet SONGTHAM1. Benjavun RAT AN ASTHIEN1, and Dallas C. MILDENHALL2 department of Geological Sciences, Faculty of Science, Chiang Mai University, Thailand; 2Institute of Geological and Nuclear Sciences, Lower Hutt, New Zealand. Two palynological assemblages were recognized from Tertiary basins of Thailand, temperate and tropical. The temperate elements include Dacrydium, Pinus, Picea, Tsuga, Taxodium, Sequoia, Podocarpus, Acer, Alnus, B etuia, Carya, Corylus, Fagus, Juglans, Liquidambar, Lonicera, Quercus, and Salix. The tropical elements include Ammania, Avicennia, Bomb ax, Browlowia, Caesalpinia, Calophyllum, Cardamine, Crudia, Dipterocarpus, Excoecaria, Hopea, Lagerstroemia, Nypa, Radermachera, Rhizophora, Sonneratia, Thespesia, and Xylocarpus. The temperate assemblages are assigned as the Oligocene to Early Miocene meanwhile the tropical ones are Middle Miocene. The climate of Thailand changed from temperate to tropical conditions during Oligo-Miocene.

THE GREAT ORDOVICIAN BIODIVERSIFICATION EVENT BASED ON ECHINODERM SPECIES James SPRINKLE1 and Thomas E. GUENSBURG2 department of Geological Sciences, University of Texas, Austin, TX 78712 USA; 2Physical Science Division, Rock Valley College, Rockford, IL 61114 USA. Echinoderms diversified greatly during the Ordovician as new and more advanced members of the Palaeozoic Evolutionary Fauna (PEF) added to or replaced older members of the Cambrian Evolutionary Fauna (CEF). Echinoderm diversity increased from 8-9 classes in the CEF to a peak of 16 classes and 29 cladelike groups in the PEF by the early Late Ordovician. The echinoderm component changed from small eocrinoid and cornute stylophoran-dominated faunas in the Late Cambrian to much larger crinoid, rhombiferan, or diploporan-dominated faunas during the Ordovician. This radiation began near the base of the Early Ordovician before that of many other metazoan groups in the PEF and continued until the early Late Ordovician when echinoderms had developed nearly all of their Palaeozoic ways of life. Group diversity then declined during the rest of the Late Ordovician as less diverse PEF echinoderm classes or groups dropped out of the record. Several distinctive patterns show up in the newly plotted species-level diversity and range diagrams for Ordovician echinoderms. These include: 1) the Early Ordovician appearance of 21 of the 30 echinoderm

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IPC2002 Oral Presentations groups; 2) the lack of diversity change in most echinoderm groups at the Early-Middle Ordovician boundary, when many other metazoan groups diversified, and at the Middle-Late Ordovician boundary; 3) the dramatic diversity increase in crinoids and many other echinoderm groups in the early Late Ordovician (middle Caradoc or Mohawkian); 4) the dropoff in diversity and scarcity of echinoderms in the latest Ordovician (Hirnantian), even though 23 of the 27 Late Ordovician groups survived this glacially driven extinction interval; 5) the "stepped" appearance of sequentially more advanced echinoderm groups during the Ordovician, perhaps indicating their likely time of branching and rapid morphological change; and 6) the unusual diversity patterns shown by diploporans, which had an earlier diversity peak than most other echinoderm groups, and by cornute stylophorans that also peaked early and then were surpassed in diversity by closely related mitrate stylophorans before finally becoming extinct. AEDUELLIDS (ACTINOPTERYGII) FROM THE LOWER PERMIAN BASINS OF THE BOHEMIAN MASSIF Stanislav STAMBERG Regional Museum, Eliscino nabrezi 465, 500 02 Hradec Kralove, Czech Republic; [info@muzeumhk.cz]. Actinopterygians of the order Aeduelliformes are abundant in the Permocarboniferous basins of the French Massif Central. In particular, the type genus Aeduella, well described by Heyler (1969), commonly occurs in the Muse Formation (Bassin d'Autun) and at Buxieres-les-Mines (Bourbon l'Archambault Basin) and well as other localities. Aeduella has subsequently been described from the Saar Basin in Germany, from Northern Switzerland and the similar genus Bourbonella also from New Mexico, USA. The actinopterygian faunas from the Permocarboniferous freshwater basins of the French Massif Central and the Bohemian Massif are very similar. In both Permocarboniferous formations, the genera Paramblypterus, Progyrolepis and Igornichthys occur and even the family Haplolepididae. Until now, the only member of the order Aeduelliformes to be described from the Czech basins was Spinarichthys dispersus from the Stephanian C of Central Bohemia (Stamberg 1986), but the type genus Aeduella has not previously been reported from the Permocarboniferous of the Bohemian Massif. Extensive new collections of actinopterygians from several Lower Permian freshwater basins in Bohemia and Moravia have yielded several specimens undoubtedly belonging to Aeduella. These finds of Aeduella come from the Krkonose Piedmont Basin and Boskovice Furrow. Aeduella occurs in the Krkonose Piedmont Basin in two horizons. The lower one is the Rudnik Horizon (Lower Permian, Vrchlabi Formation). It lies near the base of the Lower Permian and two localities have produced ten very young specimens of Aeduella, the smallest of which is only 27 mm long. This specimen has not yet developed scales neither on the trunk nor on the caudal peduncle. In contrast, all the fins are welldeveloped and the diagnostic maxilla is visible. The largest specimens from the Rudnik Horizon are 74 mm long and their scale count is already identifiable. The Kalna Horizon (Lower Permian, Prosecne Formation) is the second, slightly higher, horizon producing Aeduella. Fragments of seven species have been collected from the Klasterska Lhota locality. The relatively large bones and thick scales suggest that these were adult specimens up to 14 cm long. The Boskovice Furrow is the second freshwater basin to have produced new finds of Aeduella. Hundreds of actinopterygian specimens have been collected from the Lower Permian of the northern region of the Furrow. Nearly all specimens have paramblypterid features and, so far, only two are assignable to Aeduella. Both are adult specimens with well-developed scale cover, and diagnostic elements such as the maxilla, operculum and suboperculum are visible As well as the actinopterygians, the horizon produces specimens of the tetrapod Discosauriscus. Several characteristic features, previously described by Heyler (1969), are used for diagnosis of the Aedelliformes and especially of Aeduella. Of particular value are the configurations of the maxilla, operculum and suboperculum, the small number of branchiostegal rays, the course of the supraorbital sensory line, the shape of the cleithrum and the scale count. The fragmentary specimens from Klasterska Lhota also demonstrate that the shape of the clavicle, with its dorsally elongated vertical branch, is of diagnostic value. These records of Aeduella in the Lower Permian of the Krkonose Piedmont Basin and Boskovice Furrow document an eastern extension of its known range. However, the frequency of specimens is different from that in the Permocarboniferous basins of French Massif Central. While Aeduella specimens clearly outnumbered the other actinopterygians in some localities of the French Massif Central, paramblypterid are always more abundant in the Lower Permian basins of Bohemia and Moravia. It appears that Aeduella has a relatively wide stratigraphical range, but some elements of the associated fauna vary through its range. In the Upper Carboniferous and Lower Permian of the French basins, Aeduella is always associated with acanthodians. Aeduella is not yet known from the Upper Carboniferous of the Czech basins, but in the Lower Permian of the Rudnik Horizon, it is accompanied by acanthodians. However 148

IPC2002 Oral Presentations in the slightly higher layers of the Kalna Horizon and the horizons in the northern part of the Boskovice Furrow, it occurs without acanthodians.

COMMENTS ON LAND-DERIVED CRYPTOSPORES AND TERRESTRIALIZATION Paul K. STROTHER Boston College Weston Observatory, Department of Geology & Geophysics, Weston, Massachusetts, U.S.A. Given that the mesofossil plant record extends only to the Wenlock, we are dependent upon the microfossil record of cryptospores for tangible evidence of plant life during the earliest Palaeozoic. Cryptospores are broadly defined to include the spore-like remains of early land plant ancestors and other plant-like autotrophes adapted to subaerial habitats. Although chlorophytes possess the ability to produce sporopollenin-like compounds, only the embryophytes are known to form resistant-walled spores in dyads and tetrads - evidence of their derivation from meiotic division of diploid sporocytes. The cryptospore record extends from the Middle Cambrian through the Early Devonian, but composite taxon diversity curves demonstrate a shift from cryptospore to trilete spore dominance during the later half of the Silurian Period. Timing of this shift converges with palaeobotanical evidence for the origin of tracheophytes and provides a strong case for rejecting molecular phylogenies that posit tracheophyte origins near 700 Ma. Cryptospores are abundant in Middle Cambrian rocks from near-shore sequences in North America. These assemblages include polyads and spore clusters, many kinds of tetrads and dyads, and numerous monads. Resistant, enclosing envelopes, often in multiple layers are common. Rare tissue fragments of Nematothallaceae occur in addition to spore clusters associated with homogeneous tissue layers. These diverse palynological assemblages contain cryptospore dyads and tetrads that are morphologically indistinguishable from Silurian cryptospores with unmistakable links to younger embryophytes. They indicate conclusively that a subaerial mesoflora was extant by Middle Cambrian time. As presently understood, the stratigraphic distribution of cryptospores leads to three possible scenarios: i) spore characters in ancestral lineages developed much earlier than embryogenesis itself [preadaptation], ii) meiospores evolved in unrelated extinct protoctist lineage(s) adapting to subaerial habitats [convergence], or, iii) true plants existed by Middle Cambrian time. Even though the exact composition of the mesoflora is not known, evidence from microfossils indicates that the Cambrian landscape was advanced well beyond a surface cover limited to microbial mats. This condition has far-reaching consequences for the evolution of the atmosphere, as a Cambro-Ordovician subaerial mesoflora would have played a significant role in the drawdown of atmospheric C0 2 during the Early Palaeozoic. The Cambrian "explosion" of metazoan evolution may have been linked to the rise of this terrestrial flora through carbon runoff affecting the trophic structure of near-shore marine ecosystems.

THE SIGNIFICANCE OF ABUNDANT AND DIVERSE CRYPTOSPORES FROM THE MIDDLE CAMBRIAN ROGERSVILLE SHALE, CONASAUGA GROUP, TENNESSEE, USA. Paul K. STROTHER1 & Gordon D. WOOD2 Boston College Weston Observatory, Department of Geology & Geophysics, Weston, Massachusetts, U.S.A.; 2 the irf group, Katy, Texas, U.S. The Rogersville Shale was deposited as part of an inner clastic belt that received sediment eroded from the Laurentian craton. The presence of abundant and diverse cryptospores, and the rarity of acritarchs, suggests that freshwater flow onto the near shelf was substantial during Rogersville time. The cryptospores display considerable morphological range. Many forms are somewhat irregular in shape, most enclosed in envelopes, and sculpture is minimal (laevigate to scabrate). Dyads are particularly abundant and include new genera of paired dyad sets, in addition to forms clearly related to Abditusdyadus and Dyadospora. Larger polyads are similar to forms from the Middle Cambrian Bright Angel Shale (Grand Canyon, USA). Perfectly tetrahedral tetrads are rare, but tetrads overall are quite diverse. Both tetrahedral tetrads and dyads have their closest affinities to the embryophytes, either these spore characters evolved prior to the charophyte-embryophyte split, or embryophytes were a component of Cambrian subaerial floras. The great variation between samples throughout the Rogersville indicates that the plant communities producing cryptospores of this age were as diverse as younger Ordovician and Silurian bryophytic mesofloras. Middle Cambrian cryptospores are also geographically widespread. They have been recovered from Idaho, Arizona, and Texas. Although plant mesofossils have not yet been reported from Pre-Silurian

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IPC2002 Oral Presentations sediments, the microfossil record of cryptospores indicates that subaerial (terrestrial) habitats were occupied from at least the Middle Cambrian. FORAMINIFERA FROM TUROSS ESTUARY AND COILA LAKE: INDICATORS OF ESTUARINE EVOLUTION Luke STROTZ Centre for Ecostratigraphy and Paleobiology, Macquarie University, NSW 2109, Australia; [Lstro002@student. mq. edu. au] Tuross Estuary and Coila Lake are adjacent estuaries situated on the New South Wales South Coast. Tuross Estuary is an extremely convoluted, complex estuary, characterised by numerous sandbars, variable depth and is open to the Pacific Ocean via a narrow channel. Coila Lake, in contrast, is a relatively simple, shallow estuary, closed off from the ocean by a large barrier beach. Both are drowned river valleys, filled with sediments of Holocene age (Roy and Peat 1976). Cores, up to 1.6 metres in length, obtained from both estuaries were sampled for foraminifera in attempt to chart the evolution and development of both estuaries during the late Holocene. At each coring site, surface samples of living foraminifera were also collected to provide a baseline for comparison with fossil material collected from the cores. Following sampling, cores were impregnated in resin and thin sectioned in order to document details of the sedimentological changes that have taken place in each estuary. Radiocarbon dating of suitable wood and shell material found within the cores reveal the foraminiferal assemblages span a maximum range of approximately 2,300 years. Forty-one species of foraminifera were identified from both the surface and core samples obtained from the two estuaries. Much of this diversity is concentrated at sample sites located in the eastern or seaward portion of the Tuross Estuary and consists predominantly of rotaliine genera such as Rosalina, Ammonia, and Elphidium. Coila Lake, and the western half of Tuross Estuary, are characterised by a low diversity fauna dominated by the agglutinated genera Reophax and Ammobaculites. Abundance is low throughout both estuaries ranging from 0 to 450 tests per 10 grams of dry weight sediment but generally only reaching » 50 tests in most samples. Analysis of water chemistry from both estuaries suggests that the environment is ecologically suitable for foraminifera so a high sedimentation rate is the likely culprit for this low abundance. The foraminiferal and sedimentological evidence obtained from core material suggests that both estuaries are in-filling. Past facies typically resemble those present in the deeper portions of the two estuaries today and contain assemblages more indicative of an open water environment. This trend complies with a model for estuarine evolution proposed by Roy (1984) that a typical estuary will show a decrease in water area and depth with time. ROY, P. S., 1984. New South Wales's estuaries: their origin and evolution, pp. 99-121. In Thom, B. G. (Ed), Coastal Geomorphology in Australia; Academic Press, Sydney ROY, P. S. and Peat, C., 1976. Bathymetry and bottom sediments of Tuross Estuary and Coila Lake. Records of the Geological Survey of New South Wales 18(1), 103-134

LATE PALAEOZOIC TERRESTRIAL VERTEBRATE ASSEMBLAGES OF EUROPE AND NORTH AMERICA: TOWARD GLOBAL UNDERSTANDINGS OF EARLY PERMIAN BIOGEOGRAPHY AND THE EVOLUTION OF VERTEBRATE TERRESTRIAL ECOSYSTEMS Stuart S. SUMIDA , David S BERMAN , Amy HENRICI 'David A. EBERTH department ofBiology, California State University San Bernardino, 5500 University Parkway, San Bernardino, California 92407 USA, [ssumida@csusb.edu]; Section of Vertebrate Paleontology, Carnegie Museum ofNatural History, 4400 Forbes Avenue, Pittsburgh, Pennsylvania 15213, [BermanD@carnegiemuseums.org and HenriciA@carnegiemusuems.org]; Royal Tyrell Museum of Palaeontology, Box 7500, Drumheller, Alberta TO J OYO, Canada 1

Lower Permian correlation between North America and Europe. Permian vertebrate assemblages are represented worldwide; however, until very recently different parts of the world were considered to preserve differing age and type assemblages. The majority of semiaquatic, semiterrestrial, and terrestrial assemblages are known from redbed exposures of North America, whereas more completely aquatic assemblages are better known from Europe. Late Permian assemblages are predominantly terrestrial in nature and are best known from Russia and South Africa. The Lower Permian Bromacker locality in central (formerly eastern) Germany's Tambach Formation has been known as a footprint locality for over a century. The more recent 150

IPC2002 Oral Presentations documentation of skeletal fossils at this locality provides the best record of terrestrial vertebrates of Early Permian age from continental Europe. This locality preserves both unique taxa, as well as numerous taxa in common with North American redbed assemblages in north-central New Mexico, southeastern Utah, northcentral Texas, and northern Oklahoma. A completely terrestrial Early Permian vertebrate assemblage from central Germany. Careful stratigraphic interpretation of the German Bromacker locality indicates that it is unique, as it represents an exclusively terrestrial environment that was deposited in an upland setting near the center of a small, internally drained palaeograben. Excellently preserved fossils, many of them completely articulated, indicate subaerial exposure times of very short duration with little or no reworking. In the case of articulated specimens, death and burial were probably coeval events, most likely caused by flooding. When not being flooded, the internally drained basin was extremely calm as evidenced by finely preserved mud and clay drapes marking dune forms continuously (as opposed to being restricted to back or lee sides). This setting has produced an assemblage dominated by the terrestrial herbivore Diadectes (and close relatives of that taxon), frequent representatives of terrestrial amphibians such as Seymouria and trematopids, as well as rare occurrences of medium to large carnivorous synapsids. The locality preserves caseosaurian synapsids, the first known record of Dimetrodon in Europe, and Eudibamus, the most complete bolosaurid reptile known and the earliest known facultative biped. Significantly, twenty-five years of excavation indicate a complete lack of aquatic or semi-aquatic vertebrates. Correlation, biogeography, and palaeoenvironmental interpretation. The presence of taxa heretofore considered as North American at the Bromacker allows the beginning of stratigraphic correlation between rock units in North America and continental Europe. The presence of Seymouria sanjuanensis, Diadectes, and trematopid amphibians suggests strongly that the Tambach Formation in central Europe is of Lower Permian, Wolfcampian age. The common taxa also suggest that some routes of dispersal must have existed between what is now North America and central Europe during the Early Permian. Combining both unique taxa and those also known from North America results in an assemblage list that is completely terrestrial in nature: trematopid and seymouriamorph amphibians, large terrestrial herbivores such as Diadectes, a new diadectid, and caseosaurian pelycosaurs, as well as bolosaurid and protorothyridid reptiles. Though restricted in number as compared to more extensive North American redbed assemblages, the Bromacker locality's exclusively terrestrial nature allows the strictly terrestrial component of Late Palaeozoic ecosystems to be identified and dissected out of more general models. That terrestrial component is dominated by large terrestrial, high-fibre herbivores with rare medium to large bodied carnivores. The contention that Palaeozoic assemblages had nearly one-to-one ratios of predators to prey is quite likely incorrect. The research presented here has been supported by the National Geographic Society, the North Atlantic Treaty Organisation, The College of Natural Sciences of California State University San Bernardino, the California State University Tyrannosaurus rex Initiative, and the Graham Netting Fund of the Carnegie Museum of Natural History.

PERMO-TRIASSIC EXTINCTION AND RECOVERY OF BRACHIOPODA IN SOUTH CHINA SUN Dongli and SHEN Shuzhong Nanjing Institute of Geology and Paleontology, Chinese Academy of Sciences, 39 Eastern Beijing Road\ Nanjing, 210008, P. R. China Since there are many continuous Permian-Triassic sections containing abundant brachiopod faunas, South China is considered to be one of the best areas for the study of the Permo-Triassic extinction and recovery patterns of brachiopods. A database of 288 genera of 99 families of Permian and Triassic Brachiopoda in South China was analyzed at stage/substage level using several statistical measures to unravel the changing patterns of diversity through Permian and Triassic. It was revealed that Brachiopoda suffered two most pronounced mass extinction respectively at the end-Changhsingian of Permian and the Rhaetian of late Late Triassic. Unlike other benthic organisms such as fusulinids and corals, the end-Maokouan extinction widely recognized on the Pangean continental shelf is only expressed by life-depleted early Wuchiapingian in South China in terms of Brachiopoda, but much less pronounced than the end-Changhsingian mass extinction. The end-Changhsingian mass extinction eliminated more than 73% families and 80% genera of Brachiopoda in South China. Only 13 Permian-type brachiopod genera, associated with some long-ranged disaster taxa such as Lingula and some bivalves, lasted into the earliest Triassic, thus constitutes a distinct survival interval of early Griesbachian age. Three new Triassic brachiopod genera occurred during the interval between the middle Griesbachian and the Olenigian, suggesting an unusually long recovery stage of Brachiopoda spanning the entire Early Triassic. The true onset of distinct radiation of Brachiopoda began in the Middle Triassic, as suggested by 26 brachiopod genera found in the Anisian Stage. The Triassic radiation reaches a peak in Late Triassic Norian in South China.

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IPC2002 Oral Presentations The possible end-Maokouan decline of Brachiopoda is most likely related with the short-lived regression, but immediately recovered to the same or even higher diversity in the late Wuchiapingian following a transgression in South China. The cause of end-Changhsingian mass extinction remains enigmatic. Associated with the mass extinction, a rapid transgression has been documented just prior to the PermianTriassic boundary as indicated by a dramatic drop of 8 C, the occurrence of framboidal pyrites, a lithologic shift from thick-bedded biosparite into middle/thin-bedded argillaceous limestone and a brachiopod community shift from parent-reef forms to stress-tolerant forms. Evidence of volcanic eruption is indicated by the occurrence of several clay layers of illite/smectites with microspherules. The Late Triassic extinction of Brachiopoda is considered to be related the regression at that time. 13

SEARCHING FOR AN ADEQUATE SECTION AND POINT TO DEFINE THE INITIAL BOUNDARY OF THE TERMINAL PROTEROZOIC SYSTEM SUN Weiguo , ZANG Wenlong and ZHOU Chuanmin 1

Nanjing Institute of Geology and Palaeontology, Nanjing, P.R. China; Geological Survey, Minerals Group, Department ofPrimary Industry and Resources, South Australia 2

The primary task of establishing a globally recognized Terminal Proterozoic System is to select and define an adequate section and point for the GSSP of its initial boundary. The current consensus is that the GSSP will be placed at a position associated with the cap carbonate above a : 50%c(PDB) 8VMPDB) 11 * • DDDHHH 9-b 9-a Marinoan/Varanger/Nantuo tillite. WD H DDHH 75-b In the eastern Yangtze Gorges, the type region of the ^m * DDHH 35-a Sinian System in China, the terminal Proterozoic succession is represented by the Doushantuo and Dengying Formations. 19 18 This succession, immediately above the Nantuo tillite, is 17—c 17—b carbonate-dominant, well exposed, essentially continuous, 17—a 16 15b~b virtually unmetamorphosed, richly fossiliferous and easily 15b~a 15fl ' £ (, £ accessible. Thus, it is favored as a candidate for the stratotype 15a 14—c of the Terminal Proterozoic System. The cap-dolomite unit at 14—b 14—a the base of the Doushantuo Formation in the Jinguadun 13—a 12 9—b section provides a superb case for defining the initial 9—a 8—b boundary of the Terminal Proterozoic System. Litho8—a 7 stratigraphically, at least three reference points can be 6—b 6—a recognized: Point A is at the base of the Doushantuo Fm., i.e., 5—b 5—a the unconformable contact between the basal conglomerate, 0 4—b 4—a 3b - lm thick, and the underlying glaciogenic diamictite; Point B 3a 2—c is at the base of the cap-dolomite, which is about 5m thick; 2—b ® T 2—a and Point C is at the top of the cap-dolomite, which is 1—c 1—b followed by the lowest level of black shale deposits. 1—a Sequence-stratigraphically, the first maximum flooding surface is located within the cap-dolomite, about 2m above the Fig. 1. Variations of C and O isotopes bottom. Bio-stratigraphically, the first occurrence of large and through the cap-dolomite at the base of the complex acanthomorphic acritarchs is, by correlation, about Doushantuo Fm. 8m above the top of the cap-dolomite. And isotopicstratigraphically, as shown in Figure 1, significant variations in carbon and oxygen isotopes through the cap-dolomite occur at Point 1 of a distinct rise in§ C (sample 8a, S C -0.716 and 5 0 -4.191), 40cm below the first maximum flooding surface; Point 2 of the C-isotopic minimum (sample 19, 5 C -5.830), 20cm below the top, and Point 3 of a very prominent rise in both 8 C and 5 0 (sample 20, 5 C 1.414 and 5 O -0.542) at the top of the cap-dolomite. So, an integrated approach is vitally significant in defining the initial boundary of the Terminal Proterozoic System. Isotopic indicators, e.g., Point 2 in the Jinguadun section, may be chosen as the stratotype point. A distinct signal of isotopic carbon variation may be accepted as an appropriate substitute for the first appearance of a particular fossil species. Reference points from other disciplines may help complete definition and promote global correlation. This research is supported by Ministry of Science and Technology of China (Project G2000077700) and All-China Committee on Stratigraphy. I3

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IPC2002 Oral Presentations INTRASPECIFIC VARIATION OF EARLY INTERNAL SHELL FEATURES IN CRETACEOUS AMMONITES Kazushige TANABE . Neil H. LANDMAN and Yuki YOSHIOKA department ofEarth and Planetary Science, University of Tokyo, Hongo 7-3-1, Tokyo 113-0033, Japan [tanabe@eps.s.u-tokyo.ac.jp; yuki7676@gbs.eps.s.u-tokyo.ac.jp]; Division ofPaleontology (Invertebrates), American Museum ofNatural History, Central Park West at 79th Street, New York, NY 10024, U.S.A. [landman@amnh. org] 1

Since Branco (1879-80) first synthesized the general characteristics of early shell features of some Palaeozoic and Mesozoic ammonoids, many works have been carried out to describe the external and internal shell features at the early ontogenetic stage of various taxa by means of optical and scanning electron microscopy. These previous works have demonstrated that the external and internal shell features at the embryonic and early postembryonic stages appear to be stable at higher taxonomic levels, suggesting that the character states of these features can be used for analysis of higher level systematics (see Landman et al. 1996 for a recent review). However, most previous descriptions on early shell features were made on a small number of specimens for each species, and few studies have examined the intraspecific variability of various characters relying upon sufficient material. In this study, we have analyzed the intraspecific variation of quantitative and qualitative characters of early internal shell structures in 15 species of Cretaceous ammonoids that are distributed in the Phylloceratina, Lytoceratina, Ammonitina and Ancyloceratina. The material utilized came from the Upper Cretaceous of Hokkaido (Japan) and U.S. Western Interior Province, and the samples for each species were recovered from individual calcareous concretions, each containing 8 to 104 individuals. Microscopic observations and measurements of early internal shell features were made on polished and slightly etched median-sections by means of a NIKON profile projector with a digital micrometer (accuracy lDm) or a scanning electron microscope with a Quartz PCI program for measurements calibrated to a standard sample. Our observations show that within species, there is modest variation in the dimensions of the initial chamber and the dimensions and spiral length of embryonic shell in the samples examined (coefficient of variation ranges from 2.5 to 8.6). In contrast, there is almost no variation within species with respect to qualitative characters such as the shape of the prosiphon, the presence or absence of secondary prosiphon, the shape of the caecum, and the initial position of the siphuncle. This study clearly demonstrates that these qualitative characters are stable within a species; hence they can be used for phylogenetic analysis. Wide intraspecific variation in the length of the prosiphon reported in two Jurassic oppeliids by Rouget and Neige (2001) is presumably due to secondary breakage or shrinkage during fossilization because of the delicate and elastic organic nature of the prosiphon. BRANCO, W., 1879-80. Beitrage zur Entwicklungsgeschichte der fossilen Cephalopoden. Palaeontographica 26, 15-50 (1879), 27, 17-81 (1880).

LANDMAN, N.H., TANABE, K. and SHIGETA, Y., 1996. Ammonoid embryonic development, pp. 343-405. In LANDMAN, N.H., TANABE,

K. and DAVIS, R.A. (eds.), Ammonoid Paleobiology; Plenum, New York. ROUGET, I. And Neige, P., 2001. Embryonic ammonoid shell features: Intraspecific variation revised. Palaeontology 44, 53-64.

USING SPORE WALL ULTRASTRUCTURE TO TRACE THE NATURE AND EVOLUTION OF THE EARLIEST LAND PLANTS Wilson A. TAYLOR Department ofBiology, University of Wisconsin - Eau Claire, Eau Claire, Wisconsin, 54701, USA This presentation will begin by reviewing the history of early land plant research, focusing on the definition, distribution and search for affinities of cryptospores and early trilete spores. One fruitful body of data, wall ultrastructure, provides some clues. Most notably, cryptospores with highly lamellated walls bear a strong resemblance to the spores of some modern liverworts. This fact, in combination with the discovery of certain cryptospores in sporangia of Upper Silurian rhyniophytoid mesofossils from Wales, lends support to the position that the liverworts may have been represented in the prevascular flora. Further evidence in the form of molecular phylogenies suggested that the liverworts might be the basal embryophytes among extant land plants. However, some recent molecular analyses favor a different group of extant land plants to be basal the hornworts. This contention can and will be tested against newly gathered information on hornwort wall ultrastructure. Finally, the record of land derived cryptospores of uncertain affinity stretches back in time to at least the Middle Cambrian, with some of the recovered microfossils bearing a remarkable similarity to much younger cryptospores. Once again, these are amenable to analysis with transmission electron

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IPC2002 Oral Presentations microscopy (ultrastructure), and consideration of this suggests an unsurprising (given the age of the fossils) intermediacy between algal and land plant spore walls in terms of structure and degree of robustness.

SHORT-LIVED BURST OF POLYMORPHISM IN PLIOCENE POPULATIONS OF GLYCYMERIS AMERICANA (RIVALVIA: ARCOIDA), ASSOCIATED WITH RAPID ENVIRONMENTAL CHANGE IN THE WESTERN ATLANTIC R.D.K. THOMAS Department of Geosciences, Franklin & Marshall College, Lancaster, Pennsylvania 17604-3003, U.S.A.; [r_thomas@email.fandm. edu]. The living species Glycymeris americana occurs offshore on sandy bottoms, on the continental shelf of the southeastern United States. This species ranges back to the early Pliocene. Its direct antecedents occur in Middle and Early Miocene strata, so the lineage has a range of at least 15 million years. The shells of these animals are quite variable in form and adult size from one population to another, especially on different substrates. In this and other respects, they are quite typical of Glycymeris s.s. In the mid-Pliocene, a series of variants with distinctive patterns of aberrant shell sculpture suddenly appeared in populations of G. americana. These variants occur together with normal shells in faunas that were broadly contemporaneous, within limits of correlation, from North Carolina to south Florida. These faunas are preserved in sands and shell beds deposited during a major transgression. This event, which has been attributed to high glacio-eustatic sea level, extended from the end of planktonic foraminiferal zone N19 into zone N20. Aberrant shell morphotypes have not been observed in subsequent late Pliocene and Pleistocene populations of G. americana. The aberrant shells bear oblique or irregularly concentric folds or ridges, in most cases affecting only the outer shell layer. Four distinct variations are recognized. (1) Oblique dorsal rugae, variable in number and intensity of expression, occur just posterior or anterior of the umbo. (2) Irregularly concentric rugae extend across the entire shell, which is unusually long relative to its height. (3) Irregularly concentric rugae occur on the juvenile shell, but these are suppressed in the adult, which reverts toward the normal shell shape. (4) Anterior and posterior oblique rugae diverge away from a medial area without rugae. These characters and the timing of their development can be linked to a plausible model, based on a single mutation with variable expression in different genetic (pleiotropic) and environmental contexts. Frequency distributions suggest that the most aberrant forms were highly deleterious in some but not all circumstances. Rapid population growth, prompted by expansion of favourable habitats due to the transgression, is inferred to have facilitated the survival and spread of the mutation, which had limited negative consequences for heterozygotes. Genetic polymorphism in G. americana was originally proposed by Nicol (1953), on the basis of morphotype (1) and wildtype shells. Here, morphotype (4), assigned to a distinct species by Nicol, and forms unknown to him are all shown to belong to G. americana. The scope of its polymorphism was much greater than he realized. This proliferation of aberrant morphotypes in populations of G. americana coincides with the appearance of unusual morphologies in several other taxa, in the same faunas. Sea bottom temperatures off the southeastern United States increased dramatically at this time and the ranges of subtropical taxa expanded further to the north than at any other time in the Neogene. These events seem to have been prompted by substantial changes in oceanic circulation, nutrient availability, and other environmental effects arising from the last stages of closure of the Isthmus of Panama. NICOL, D., 1953. A study of the polymorphic species Glycymeris americana. Journal of Paleontology 27, 451-455.

GIANT DINOSAUR TRACKS IN THE BROOME SANDSTONE (LOWER CRETACEOUS) OF WESTERN AUSTRALIA Tony THULBORN Vertebrate Palaeontology Lab, Department of Zoology & Entomology, The University of Queensland, Queensland 4072, Australia The world's largest footprints, up to 1.75 m long, were made by sauropod dinosaurs traversing lagoonal deposits of the Broome Sandstone (Lower Cretaceous, c. 130 Myr) in the Canning Basin of Western Australia. The clastic sediments of the Broome Sandstone accumulated in a patchwork of environments, including lagoons, deltas and swamps, and they contain a rich and varied suite of dinosaur tracks -

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IPC2002 Oral Presentations constituting practically the entire fossil record of dinosaurs in the western half of the Australian continent. The tracks include those of theropods, ornithopods and thyreophorans provisionally identified as stegosaurs, but the most conspicuous among them are tracks of sauropods. Most of the exposed sauropod tracks are transmitted prints, but some are demonstrably original impressions showing, for example, clear imprints of fleshy pads beneath the track-makers' feet. The pes prints are often subcircular or oval in outline, between 40 and 120 cm in length, though the smallest yet discovered is 21 cm long and the largest five have lengths between 150 and 175 cm. These measurements were obtained from original prints, not from transmitted prints. Where present, and not overtrodden by the pes, the manus prints are shallow and much smaller, with semicircular or crescentic outline. The trackway pattern is usually wide-gauge, with broad straddle and short strides; only a single narrow-gauge trackway has been discovered to date. Some better-preserved tracks are referable to the ichnogenus Brontopodus, originally defined for sauropod tracks in the Glen Rose Formation (Lower Cretaceous) of Texas, USA, and attributed to sauropods of the family Brachiosauridae (Pleurocoelus, Brachiosaurus) - which included some of the largest known dinosaurs. The possibility that similar animals produced some of the Broome Sandstone tracks is sustained by stray occurrences of brachiosaurid-like bones in the Cretaceous of Queensland. It is difficult to estimate the size of dinosaurs from the evidence of footprints. One widely-used rule of thumb takes length of pes to represent one-quarter of hindlimb length (roughly equivalent to height at the hip in standing pose). According to this generalisation, the largest of the Broome Sandstone sauropods might have stood about 7 m high at the hip. The largest brachiosaurids represented by skeletal remains were about 5.4 m high at the hip and are estimated to have weighed 45 to 55 tonnes. However, some related sauropods the titanosaurids Argentinosaurus and Paralititan - had shorter limbs but appear to have been more robust, perhaps weighing as much as 90 tonnes. By comparison the largest of the Broome Sandstone sauropods are likely to have weighed 70-75 tonnes. The most conspicuous sauropod tracks in the Broome Sandstone are those occurring in thinly and evenly bedded substrates of lagoonal origin, along with occasional theropod tracks, ripple-marks and desiccationcracks. (Ornithopods seem rarely, if ever, to have entered those lagoonal settings; their tracks are confined mainly to more sheltered landward environments, now represented in the Broome Sandstone by beds rich in plant debris.) The lagoon floor sediments were sometimes surprisingly firm and coherent: the sauropod footprints impressed into them are quite shallow and the bedding beneath those prints is compressed, but neither crumpled nor contorted. In such firm but flexible substrates the footprints are sometimes encircled by broad conical zones of depression: each print lies, as it were, at the centre of a gigantic dimple. These impact structures, both footprints and surrounding dimples, were transmitted into the underlying beds as stacks of nested underprints. In trackway sequences the dimples enclosing successive footprints tend to coalesce into broad zig-zag channels, often several metres in width; these channels resemble miniature synclines with flanks dipping at angles up to 40° and are easily mistaken for minor tectonic features. At some points repeated impacts of sauropod feet liquefied the substrate, which consequently slumped into gigantic pools or load-casts. These structures are recognisable as steep-walled and flat-bottomed basins containing remnants of collapsed sauropod tracks; they resemble kiddies' paddling pools and occasionally reach a diameter of more than 5 m, thus qualifying as some of the largest trace fossils on earth. MODELLING PHYTOPLANKTON DIVERSITY FLUCTUATIONS FOR PALAEOECOLOGICAL ANALYSIS M. TONGIORGI and A. DI MILIA Dipartimento di Scienze della Terra, Universita degli Studi di Pisa, Italy Poorly diversified acritarch assemblages, not rarely dominated by only one species, mostly are disregarded or quickly cited in the literature. Hence, potentially important information is lost. Studies on the distribution of dinoflagellate cysts in the sediments of modern seas ascertained that the species diversity generally increases towards low latitudes and becomes higher with increasing depth and distance from shore (Odum and Copeland, 1974; Wall et al., 1977). On the contrary, the absolute number of cysts per gram of rock is of ambiguous interpretation, because the density of dinoflagellate cysts in modern sediments is directly controlled by sedimentological factors at the sea-bottom (e.g., the sedimentation rate) rather than by the primary productivity inside the overlying water column. For a generalized and palaeontologically orientated interpretation, Wall et al. (1977) adopted a model already presented by Bretsky & Lorenz (1970), which predicts that the more highly specialized, stenotopic, K-selected phytoplankton species, tend to be localized in the stable and predictable open oceanic domain, particularly in cool and warm water sectors. Conversely, opportunistic, r-selected organisms are adapted to the more unstable, unpredictable and/or severe shallowerwater habitats along the continental margins of a wide range of latitudes. Thus, the present-day cyst-

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IPC2002 Oral Presentations producing phytoplankton diversity increases along both latitudinal and inshore-offshore trends, from polarcoastal/estuarine to tropical, oceanic habitats. If climatic changes through time are introduced in Wall et al"s (1977) model, the same diversity variability may be read as a function of the variation in time from globally colder and more stressed marine ecosystems to warmer and more uniform ones. Since 1987, Hallock elaborated a further model, which correlates trophic resources and phytoplankton diversity and abundance in time. Integrating all the above mentioned models, we propose a new synthetic model that considers the dominance/diversity values of the phytoplankton assemblages to be directly controlled by the trophic levels, which are in turn (particularly on low latitude platforms within the subtropical oceanic gyres) a direct function of eustatic transgressiveregressive trends related to climatic changes. This model is to a large extent compatible with Jeppson's (1990) Primo- and Secundo Episode model. With this approach, the compositional fluctuations of the acritarch assemblages from the subtropical lower Yushanian to lower Zhejiangian (Dawan Formation, Arenig) of South China (Daping section, Yichang area) have been studied in detail. The sea level curve resulting from the dominance analysis conform with the global sea-level curve provided by Nielsen (1992). The Correspondence Analysis based on the same data confirms that during transgressions the spectrum of trophic environments tends to expand and stronger gradients are created across the platform, though oligotrophic environments prevail. BRETSKY, P.W. and LORENZ, D.M., 1970. Adaptive response to environmental stability: a unifying concept in paleoecology, pp. 522550. In North amer. paleont. Conv., Chicago, III, 1969, Proc. E, Chicago. HALLOCK, P., 1987. Fluctuations in the trophic resource continuum: a factor in global diversity cycles? Paleoceanography 2 (5), 457471. JEPPSSON, L., 1990. An oceanic model for litological and faunal changes tested on the Silurian record. J. geol. Soc. London 147, 663674. ODUM, H.T. and COPELAND, B.J., 1974. A functional classification of the coastal systems of the United States. In Odum, H. T., Copeland, B. and MacMahan E. A. (eds), Coastal ecological systems of the United States, 1(1): 1-90, New York. NIELSEN, A.T., 1992. International correlation of the Arenigian (Early Ordovician) based on the sequence and ecostratigraphy, pp. 367380. In: Webby, B. D. and Laurie, J. R. (eds), Global perspectives on Ordovician geology. Proceedings of the sixth International Symposium on the Ordovician System, University of Sidney, Australia, 15-19 July 1991; A. A. Balkema, Rotterdam. WALL, D., DALE, B., LOHMANN, G.P. and SMITH, W.K., 1977. The environmental distribution of dinoflagellate cysts in modern marine sediments from regions in the north and south Atlantic oceans and adjacent seas. Marine Micropaleont. 2, 121-200.

FIRST REPORT ON MIOCENE DECAPOD FAUNA (CRUSTACEA) FROM CENTRAL IRAN, A PRELIMENARY STUDY ON THEIR ENVIRONMENTAL AND ECOLOGICAL FACTORS Hossein TORABY & Mehdi YAZDI Department of Geology, University of Isfahan, Islamic Republic of Iran; [h.toraby@sci.ui.ac.ir] A Miocene Crustacean fossil assemblage was collected from Qum Formation in several parts of Central Iran (Isfahan, Kashan and Ardestan). Collected exemplars related to this assemblage can be assigned to: Necronectes iranensis (new species) and Necronectes tajinensis. The environment and living condition related to this assemblage can be proposed as: near shore, reef, and patch reef to shallow water. Two specimens (Necronectes iranensis, new species) were collected from Miocene sequences near Isfahan city. First specimen was collected from Kuh-e-Donbeh (5km east of Isfahan). The Kuh-e-Donbeh resembles a Miocene bioherm. Since in this locality corals, algae and remains related to fauna that levied within or near reef (including Miocene crabs), we propose that, this site is important regarding to palaoecology related to Miocene crabs. The second fossil related to crabs was collected from Abegarm Area (70km northeast of Isfahan) and west Ardestan. The data related to the preservation of these specimens can be used for reconstructing the whole feature of their bodies. Collected specimens from other outcrops (Kashan & Ardestan) can be assigned to? Necronectes tajinensis. Qum Formation has been divided into members from A to F. All collected fossils came from member F. (Early Miocene). Recovered foraminifers (within thin sections) associated with Miocene fossils are: Astergerina sp., Amphistegina lessonii. Heterostegina antillea. Lepidocyclina elephantine and Eulepidina dilitata. Based on recovered foraminifers the age of Miocene crabs can be reported as: Aquitanian to Burdigalian. This is the first report on the Miocene crabs from Iran. Further research should be done on the phylogenetical study on this clad in future. Fossilized crabs from Isfahan are similar to those that had been reported by Vega, et al. 1999 from eastern of Mexico. The similarity between Iranian crabs and Mexican fossils can be used for international corellation and phylogenetical study related to fossilized crabs and living decapods. VEGA, F.J., FELDMANN, R.M., VILLALOBOS-HIRIART, J.L. & R. GIO-ARGLEZ. 1999. A New Decapod fauna from the Miocene Tuxpan Formation, Eastern Mexico. Journal Of Paleontology, 73 (3): 407-413.

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IPC2002 Oral Presentations

FIRST REPORT ON THE OLIGOCENE - MIOCENE CORALS FORM CENTRAL IRAN (WEST ARDESTAN AREA) Hossein TORABY Department of Geology, University of Isfahan, Islamic Republic of Iran; [h.toraby@sci.ui.ac.ir] A considerable number of coral specimens were collected form Oligo- Miocene of west Ardestan area. "Several species of this fauna (Antiguastrea Iucasiana, Tarbellastraea profundata, Astrocoeniu palmuta, Caulastraea pseudoflabellum) are typical Paleogene (Eocene - Oligocene) species of the Mediterranean Tethys. There is only one species (Favites insingnis) which is also known from Sind (Pakistan). Most of the species are typical Zooxanthellate, constructional taxa, which most probably occurred in the upper 20-30 m of water depth. Genera that are also common in slightly deeper or badly illuminated (due to fine sediment) water are the solitary corals and Cyathoseris ^."(F.Schuster. personal Communication 2001). Lithostratigraphical research by had been then on the Oligo - Miocene deposits of Ardestan area. Alternation of marl and limestone is dominant in the area. Based on the age of foraminifers associated are with corals the sequence in the area can be dated as Chattion to Aquitanin. International correlation can be fixed based on this research in future.

A NEW GENUS OF PTYCTODONTID FISH (VERTEBRATA, PLACODERMI) FROM THE LATE DEVONIAN GNUEDNA FORMATION, WESTERN AUSTRALIA. Kate TRINAJSTIC1 and John LONG2 department of Geology and Geophysics, University of Western Australia, Perth, Western Australia, 6000; 2 Department of Earth and Planetary Sciences, The Western Australian Museum, Francis Street, Perth, Western Australia, 6000. The Gneudna Formation has yielded a diverse fossil assemblage, comprising of both vertebrate and invertebrate taxa. However, the majority of vertebrate fossils found are as micro-remains, that is isolated teeth and scales (Long and Trinajstic, 2000). The only macrofossils discovered to date are a single lungfish jaw and several isolated placoderm shield plates (Long and Trinajstic, 2000). The only articulated macroremains recovered are those referred to a new genus of ptyctodontid, Gneudnaodus williamburyensis gen et sp. nov.. The articulated remains are preserved in a single bed towards the base of the section but isolated, shield-plates and tooth-plates have been found throughout the section. As most of the known ptyctodontid taxa are based solely on tooth-plates the Gneudna material represents an important addition to this group. The three dimensional preservation of the plates has enabled G. williamburyensis to be fully reconstructed, with the exception of the pineal plate which is missing. Reconstruction has been possible with two other species from Western Australia, Cambellodus decipiens Miles et Young 1977 and Austroptyctodus gardineri Long 1997. Unlike the loose fit between the skull roof bones encountered in these two genera, the bones of the skull roof in G. williamburyensis fit closely together, a character also seen in Ctenurella gladbachensis 0rvig 1960. As in C. gladbachensis there was no median gap between the preorbital plates. The nuchal plate of the skull roof is contacted laterally by the centrals, and forms the posterior indented margin of the skull roof. In this respect it is similar to C. decipiens, A. gardineri and Rhynchodus tetrodon and unlike C. gladbachensis in which the central plates meet posterior to the nuchal plate. The head shield is broader than long, being broadest across paranuchal plates. Immediately posterior to the large orbits, the postorbital plates are as broad as the paranuchal plates. In lateral view, the skull roof shows a narrow postorbiotal fenestra. There is a narrow overlap area along the margin of the paranuchal plate where it connects with the marginal plate. The trunk shield has also been preserved. It comprises of large anterior lateral plates, paired anterior lateral and dorsolateral plates, median dorsal plate with a median ventral keel, paired spinal and interolateral plates and an anterior medial ventral plate. Unlike the other Western Australian species G. williamburyensis lacks dermal scales. In addition much of the endocranial ossification has been preserved. The new specimen shows the occipital and orbital ossification perfectly preserved in three-dimensional form, corroborating the foramina and morphological features with those preserved in other ptyctodontids. In the past inadequate material has limited systematic analyses of the ptyctodontids. However recent new discoveries are re-description of taxa are contributing more data for character analyses (Long 1997). A cladistic analysis of the ptyctodontids is presented here.

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IPC2002 Oral Presentations LONG, J.A. 1997. Ptyctodontid fishes (Vertebrata, Placodermi) from the Late Devonian Gog Formation, Western Australia, with the

revision of the European genus Ctenurella 0rvig, 1960. Geodiversitas 19 (3) 515-555.

LONG, J.A. & TRINAJSTIC, K.M., 2000. An overview of the Devonian microvertebrate faunas of Western Australia In Palaeozoic

Vertebrate Biochronology and Global Marine / Non-Marine Correlation A. Blieck & S. Turner (eds.) Courier Forschungsinstitut Senckenberg

MILES, R.S. and YOUNG, G.C., 1977. Placoderm interrelationships reconsidered in the light of new ptyctodontids from Gogo Western Australia. Linnean Society Symposium Series 4: 123-98. 0RVIG, T., 1960. New finds of acanthodians, arthrodires, crossopterygians, ganoids and dipnoans in the Upper Middle Devonian

Calcareous Flags (Oberer Plattenkalk) of the Bergisch-Paffrath Trough. (Part 1). Palaont. Z. 34: 295-335.

POLLEN OF DROSERACEAE FROM TERTIARY SEQUENCES IN EAST ANTARCTICA Elizabeth M. TRUSWELL & Michael K. MACPHAIL department of Geology, Australian National University; Consultant Palynological Services, Canberra 1

We report here the first record of pollen of the carnivorous family Droseraceae from Antarctica. Distinctive pollen tetrads representative of this family were recovered from Late Eocene sequences on the east Antarctic continental margin within Prydz Bay, drilled during Leg 188 of the Ocean Drilling Program. The primary objective of this cruise was to determine the age of onset of continent-scale glaciation in Antarctica, and to obtain a record of subsequent fluctuations in the ice sheet. Site 1166, drilled on the continental shelf, penetrated pre-glacial rocks and allowed the documentation of the transition to full glacial environments. In the sequence penetrated at this site, sediments dated as Mid to Late Eocene on the basis of their contained dinocysts, unconformably overlie Late Cretaceous carbonaceous sandstones and claystones. The Eocene sediments are interpreted as marginal marine, possibly deltaic deposits, and are rich in spores, pollen and dinocysts, considered to be in situ. The uppermost part of this sequence contains claystones with dropstones probably of glacial origin and high dinocyst frequencies suggest more open marine conditions. Late Eocene sequences are also known from shallow coring on the Mac.Robertson Shelf, to the west of Prydz Bay. Within the sequence at Site 1166, pollen tetrads referable to Droseraceae occur as a sparse component of the spore and pollen suites in both the deltaic and glacio-marine sediments. They are also reported from sites on the Mac.Robertson Shelf. Although some tetrads were observed, many specimens are fragmentary, but still recognizable. Individual grains within the tetrads show a strongly arched distal face, with an extremely thick exine and scattered coni, and 7 or 8 apertures arranged in a ring-like configuration on the proximal face. The specimens differ in detail from the only formally described Australian species, Fischeripollis halensis, known from Eocene deposits in the Tertiary Hale Basin of central Australia. Similarly robust forms are known to occur in Early Eocene to Oligocene sediments in basins in southern Australia. In Antarctica, the associated spore and pollen suite is interpreted as reflecting a 'scrubby rainforest' vegetation, with dominance of Nothofagus and conifers. The presence of Droseraceae suggests that there may have been some heathlands with nitrogen-poor soils. GYRACANTHIDES VERSUS GYRACANTHUS: NEW GYRACANTHIDID REMAINS FROM THE CARBONIFEROUS OF QUEENSLAND Susan TURNER . Carole J BURROW and Anne WARREN Queensland Museum, P.O. Box 3300, South Brisbane, QLD 4101; Department of Zoology & Entomology, University of Queensland, QLD 4072; department of Zoology, La Trobe University, MELBOURNE, VIC 3086 1

Gyracanthidid pectoral and unpaired fin spines, plus other, rarer elements ("carpal bones", "tubercles") have long been known to occur commonly in Carboniferous non-marine assemblages (typically coal measures) in Europe and North America. The discovery of the only gyracanthidid species based on complete specimens, Gyracanthides murrayi Woodward 1906, in the presumed earliest Carboniferous of Mansfield, Victoria, Australia, has been followed in recent decades by more finds of Devonian and Carboniferous specimens which have been found increasingly in the Southern Hemisphere. Warren et al. (2000) reviewed G. murrayi using the type, new and comparative material, briefly considering its status and significance. They concluded that the systematic position of the family Gyracanthidae remained unclear, being retained within the Climatiiformes only on the basis of the broad-based, fin spines with nodose ornament. The redescription of the Victorian specimens was a necessary prerequisite to description of a rich cache of disarticulated gyracanthidid material from Middle Paddock, near Emerald, Queensland, in the Lower Carboniferous (mid-

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IPC2002 Oral Presentations Visean) Ducabrook Formation. The latter specimens, being preserved in three dimensions, allow an even better understanding of the anatomy than does the Mansfield taxon. The new Gyracanthides material exhibits the different morphologies of the pectoral, pelvic, dorsal and anal spines, as well as enabling inference of the spatial relationships of dermal structures and endoskeletal shoulder girdle elements. In Queensland, fragmentary Gyracanthides spines from the Lower Carboniferous Raymond, Bulliwallah and Ducabrook formations of the Drummond and Georgetown Basins, had previously been referred to or compared with G. murrayi (Turner & Cook 1999, Turner et al. 2000, Burrow & Turner 2002 submitted). The abundant new material which can now be referred to a new taxon of Gyracanthides was discovered in the restricted outcrop of a tetrapod-bearing member of the Ducabrook Formation at the Middle Paddock locality QML1117, east central Queensland. The new species is based on isolated three-dimensionally preserved elements. The specimens comprise paired and unpaired spines and pectoral girdle elements, and include growth series at least for pectoral spines, procoracoids and scapulacoracoids. The morphology, especially of the shoulder girdle bones and the form and tubercular ornamentation of the paired fin spines, is used to distinguish the new taxon. A reconstruction of the new fish is based on our interpretation of how the isolated elements articulated combined with examination of the wear on fin spines. Gyracanthides sp. nov. is compared with other Australian and overseas gyracanthidid material, plus taxa from Iran, Canada, USA, England and Scotland, some of which are referred to the genus Gyracanthides. This genus was primarily a Gondwanan genus, which ultimately gave rise to Gyracanthus in a presumed vicariant event, apparently after the docking of northern Gondwana with the Laurentian continent along the Appalachian/maritime Canadian boundary some time in the Late Devonian, late in the Frasnian or early in the Famennian. Gyracanthus s.s. remains a typical Late Carboniferous "northern" genus. The family appears to have had its greatest, almost worldwide, distribution in the latest Devonian to Early Carboniferous. Comparison of the Australian taxa with those from North and South America, Antarctica, Iran, and Europe has not yet clarified the systematic position of the Gyracanthidae, although the uncertainty is mainly due to the need for a revised analysis of all acanthodians and acanthodian-like fishes. A Euramerican (Laurentia, Laurussia, Baltica) origin for the Gyracanthidae is not supported. AAW & ST acknowledge ARC Large grant no. A00000629. BURROW, C.J. & TURNER, S., 2002 submitted. Unusual preservation of vertebrate remains from the Carboniferous of north Queensland. Abstracts IPC 2002, Sydney, x. TURNER, S. & COOK, A.G., 1999. Carboniferous fish remains from the far-northern Drummond Basin. Memoirs of the Queensland Museum 43,786. TURNER, S., BASDEN, A. & BURROW, C.J., 2000. Devonian vertebrates of Queensland. In Final Report IGCP 328 (1991-1996), A. Blieck, & S. Turner, eds. Courier Forschungsinstitut Senckenberg 223, 487-521. WARREN, A.A.W., CURRIE, B.P., BURROW, C.J. & TURNER, S., 2000. A redescription of Gyracanthides murrayi Woodward 1906 (Acanthodii, Gyracanthidae) from the Lower Carboniferous of the Mansfield Basin, Victoria, Australia. Journal of Vertebrate Paleontology 20, 225-242.

THEORETICAL MORPHOLOGY OF BIVALVE LIGAMENTS Takao UBUKATA Institute of Geosciences, Shizuoka University, 836 Oya, Shizuoka 422-8529, Japan The ligament of the Bivalvia seems to be an example of complex developmental systems in higher organisms. Various types of ligaments have been found in extant species, and they can be reconstructed in most fossil bivalves from their traces implanted on the shell. The taxonomic distribution of a ligament type has, therefore, been attracted considerable attention from palaeontologists and malacologists by means of phylogenetic evolution. On the other hand, the ligament serves for opening of valves on relaxation of the adductor muscles, thus it has been taken for granted as a highly adaptive structure in the Bivalvia. However, little attention has been paid to the morphogenetic aspect of the various geometric patterns of ligaments. Modeling the pattern formation of bivalve ligaments will help us to understand wide varieties of bivalve ligaments in terms of evolution of developmental processes. In the present paper, I introduce a theoretical morphologic model designed to generate hypothetical images of most of the diverse patterns of bivalve ligaments. A theoretical morphospace of ligamental patterns in bivalves is visualized based on the model. Ligament systems of bivalves are classified into several types based on their arrangements of two different layers: the lamellar layer and the fibrous layer. Growth of a bivalve ligament consists of two elements, namely, growth of each ligament layer and introduction of new layers. In the present model, the ligament is assumed to be formed on a growing triangle which maintains its shape during growth. At first, the hypothetical ligament consists of one fibrous and a single or a pair of lamellar layers. As a ligament layer grows and increases its length, new ligaments are introduced within the layer. If more than one chevron of lamellar layers occur in a ligamental area, the fibrous layer between the halves of neighboring chevrons reduces its length as the chevrons grow. As the ligament grows further, the anterior and posterior halves of

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IPC2002 Oral Presentations neighboring chevrons of lamellar layers may come closer and in contact with each other, and then may become extinct. Then, a theoretical morphologic model exhibiting ligament formation can be defined based on the following three parameters: relative growth rate of the fibrous ligament (/), the rarity of insertion of new ligaments (w), and the relative growth rate of the fibrous layer inside a chevron of lamellar layers (r). Most of the diverse patterns of bivalve ligaments were successfully modeled by computer simulations. Naturally occurred ligaments do not fulfill the theoretical morphospace but occupies a restricted region in the morphospace. The model of the ligament with a large value of w tends to have a single fibrous layer below the umbo. It represents the alivincular ligament if it is amphidetic, or it can be regarded to be the parivincular or planivincular one if it is opisthodetic and the ligamental area is slender in shape. An iterative pattern such as the multivincular or duplivincular ligament is formed when w is small. A multivincular pattern is found characteristically around the w-axis of the low-w region in the f-w morphospace. The duplivincular pattern, by contrast, occupies the high-/ region of the morphospace, where lamellar layers hardly grow and form a chevron. The effect of r is significant especially in the high-/ duplivincular region. In the duplivincular region, the angle of the chevrons becomes more acute with decreasing r, as a result of insertion of lamellar layers not only below the umbo but also near the anterior or posterior margin, as in Area. When r= 0, the ligament shows a multivincular-like pattern with vertical lamellar layers situated in a ligamental groove within the fibrous ligament, as is observed in noetiids. Wide intraspecific variation of the ligamental pattern is observed in a arcid species Tegillarca granosa. In some individuals, lamellar layers are introduced at various portions of the ligamental area showing an irregular appearance. The angle of the lamellar chevron and the frequency of newly added lamellar layers are quite variable among individuals in this species; both tend to increase with growth showing an "allometric densing pattern". The positive allometry of the shell weight in T. granosa requires an allometric densing pattern to maintain the ligament strength to the shell weight. An allometric densing pattern is formed by allometric change of parameters r and w during ontogeny, which tends to produce a considerable variability of the ligamental pattern. In sum, the functional demand to keep up the ligament strength with the shell weight throughout ontogeny seems to be an indirect cause of occurring peculiar varieties of the ligamental pattern typically observed in T. granosa.

ICHNOLOGICAL EVIDENCES OF OXYGENATION CHANGES IN THE LOWER CRETACEOUS FLYSCH DEPOSITS OF THE SILESIAN UNIT, WEST CARPATHIANS, POLAND Alfred UCHMAN Institute of Geological Sciences, Jagiellonian University, Oleandry 2a; 30-063 Krakow, Poland; [fred@ing. uj. edu.pl/. The Lower Cretaceous deposits of the Silesian Unit contain: (1) Cieszyn Limestone (Upper TithonianBerriasian, 100-250 m thick, turbiditic sandy calcarenitic and calcilutitic limestones interbedded with marly shales); (2) Upper Cieszyn Shale (Valanginian-Hauterivian, 300 m thick, dark-grey marly mudstones intercalated with thin-bedded sandstones); (3) Grodziszcze Beds (Upper Hauterivian-Barremian, 95-140 m thick, grey marly shales intercalated with rare thin calcareous sandstone beds and marlstones, replaced locally by more sandy facies, locally with blocks); (4) Verovice Shale (Barremian-lowermost Albian, 200 m thick non-calcareous black mudstones interbedded with rare cross-laminated thin sandstone beds); (5) Lgota Beds (Albian-Cenomanian, 300-350 m thick, thin- and medium-bedded turbiditic sandstones and greenish grey spotty mudstones, locally thick-bedded sandstones in the lower part, and spiculites in the upper part). Trace fossils and ichnofabrics show significant vertical changes from the unit 1 to the unit 5. The Cieszyn Limestone displays a moderate diverse trace fossil assemblage dominated by Chondrites targionii, Thalassinoides, and Helminthopsis. Other trace fossils (e.g., Lorenzinia, Glockerichnus, Paleodictyon) are rare. Upper part of turbidites is bioturbated up to 6.5 cm from the top. All these features, together with overall relatively light colour of shales, indicate well-oxygenated environment Trace fossils of the Upper Cieszyn Shale are relatively abundant and diverse. Chondrites intricatus, Helminthopsis, and Planolites are the commonest ichnotaxa. Extent of bioturbation from the top of turbidites is very limited, and commonly does not exceed 1 cm. This proofs decrease of oxygenation of sediments in comparison to the Cieszyn Limestone. In some beds or packages of beds, the bioturbated horizons do not occur. This is related to temporary anoxia. The Grodziszcze Beds (the shaly facies) display relatively diverse trace fossil assemblage. Chondrites, Phycosiphon, Helminthopsis, Taenidium are common. Other trace fossils (e.g., Belorhaphe, Urohelminthoida, Paleodictyon) are rare. It is worthy to note the occurrence of Diplocraterion, which is a very rare trace fossil in deep-sea deposits. The bioturbated layers are thicker (up to 6 cm) than in the underlying Upper Cieszyn Shale. This suggests improved oxygenation of sediments.

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IPC2002 Oral Presentations The black deposits of the Verovice Shale would be easily considered as an example of Lower Cretaceous anoxic deposits, but they contain lighter, thin bioturbated horizons occurring at the top of some sedimentary events. Phycosiphon incertum, Chondrites intricatus, and Planolites are the dominant ichnotaxa. Below the horizons, Protovirgularia pennata and Protovirgularia obliterata occur in a few centimetres thick zone. They have been produced by probably chemosymbiotic bivalves in anoxic sediment. The occurrence of trace fossils in anoxic zone below Chondrites, which commonly occupies the deepest tier in fine-grained deposits, is a unique situation among trace fossil communities. Such a trace fossil tiering expresses adaptation of macroinfauna to the poorly oxygenated environments during the Early Cretaceous. At the few top meters of the Verovice Shale, a few centimetre-thick layers of greenish, bioturbated, spotty shales occur. They contain Planolites, Chondrites and Thalassinoides. Their occurrence indicates general improvement of oxygenation. The Lgota Beds contain low diverse trace fossil assemblage dominated by Planolites, Chondrites and Thalassinoides. Arthrophycus tenuis is common on sole of some turbiditic beds. The oldest occurrence of Scolicia in the Flysch Carpathians, which is the trace fossil produced by irregular echinoids, is noted here. Below some turbidites, shales are dark and barren trace fossils. There are not evidences of significant erosion. This indicates short anoxic events, however oxygenation of the sediments was generally better than in the underlying Verovice Shale. The decrease of sediment oxygenation during sedimentation of the Upper Cieszyn Shale and the Verovice Shale can be related to the widely known Lower Cretaceous anoxic events. Ichnological analyses help very much in determination of short- and long-term oxygenation changes. The black deposits are not necessary anoxic through all the section as in the case of the Verovice Shale.

PALYNOLOGICAL ZONATION AND ITS ECONOMIC APPLICATION TO MISSISSIPPIAN ROCKS OF ATLANTIC CANADA John UTTING1 and Peter S. GILES2 1 NRCan, Geological Survey of Canada (Calgary), [JUtting@NRCan.gc.ca]; 2NRCan, Geological Survey of Canada (Atlantic), [Pgiles@NRCan.gc.ca] Eight palynological zones and three subzones have been established for marine and non-marine Mississippian rocks of Atlantic Canada. The ages determined for the spore zones rely heavily on correlations with spore zones of western Europe, which have more stratigraphic control from associated marine faunas than do those in Atlantic Canada. However, some of the resulting age determinations are older than those suggested by other fossil groups. In spite of differences in age determinations the palynological zones permit regional palynostratigraphic correlations in a variety of sedimentary facies of the Horton, Windsor and Mabou groups of Nova Scotia, and the Anguille and Codroy groups and the Searston and Rocky Brook formations of Newfoundland. The lower five zones contain spore assemblages similar to those from the Tournaisian (Courceyan) to upper Visean (lowest Asbian) of northwestern Europe. The upper three zones have some features in common with spore assemblages from the upper Visean (Brigantian) to lower Namurian (Arnsbergian) of northwestern Europe, but there are significant differences in microfloral assemblages. Some Mississippian rocks in Atlantic Canada are of economic interest because they contain oil and gas, and a variety of minerals including lead, zinc, potash, rock salt and gypsum. The new palynological zonal scheme indicates that most of the lead and zinc deposits are late Tournaisian (Chadian) to early Visean (Chadian to Arundian) age, whereas the evaporite deposits are Visean (Arundian) to early Namurian (Pendleian). In contrast rocks containing the alga Botryococcus, from which liquid hydrocarbons have been derived, may have a considerable age range. Many are of Tournaisian (Courceyan) age, although some are latest Tournaisian to earliest Visean (Chadian), and some early Namurian (Pendleian). These age differences increase the complexity and challenge of petroleum exploration.

THE LAST OF THE "MOHICANS"? A NEW SIPHONOTRETID BRACHIOPOD FROM THE SILURIAN OF NEW SOUTH WALES James L. VALENTINE and Glenn A. BROCK Centre for Ecostratigraphy and Paleobiology, Department of Earth and Planetary Sciences, Macquarie University 2109, Australia; [jvale002@student.mq.edu.au]. Siphonotretid brachiopods first appeared during the upper Middle Cambrian (Myaian stage) in the SaianAltai region of southwest Siberia. Slowly diversifying throughout the Late Cambrian and Early Ordovician,

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IPC2002 Oral Presentations the siphonotretids reached a peak diversity of 13 genera during the Late Arenig as part of the great Ordovician diversification event. Their diversity, however, steadily decreased throughout the Middle and Late Ordovician due to the radiation of the Palaeozoic Evolutionary Fauna in shallow-water, near shore environments. Until recently, siphonotretids were believed to have disappeared, along with most of the Cambrian Evolutionary Fauna, during the end-Ordovician extinction event (Bassett et al. 1999) with Multispinula drummuckensis Harper, from the upper Ashgill of the Drummuck Group, Scotland, generally acknowledged as the youngest species. A number of supposed Silurian siphonotretids have been documented from Europe, Russia, North America and Australia, particularly during the mid 1800s to early 1900s. However, following the introduction of the Ordovician System, most of these taxa were reassigned to strata of Ordovician age. Of the three known post Ordovician occurrences, 'Siphonotreta' australis Chapman and 'Siphonotreta' plicatella Chapman from Ludlow strata in Victoria, Australia can now confidently be rejected as members of the Siphonotretida. "Siphonotreta" anglica Morris from the Wenlock of Dudley, England is poorly known, but is provisionally accepted as a member of the Siphonotretida. Recently, Mergl (2001a, b) recorded fragmentary material which he identified as belonging to four indeterminate siphonotretid species from the Early Silurian to Early Devonian of central Bohemia. Recent investigation of linguliformean brachiopod assemblages from Boree Creek, central western New South Wales, has revealed a new genus and species of Silurian siphonotretid brachiopod that ranges through the late Llandovery (amorphognathoides Zone) early Wenlock (ranuliformis Zone) boundary. The siphonotretid taxon is characterised by an elongate pedicle track extending forward through resorption and covered posteriorly by a convex plate; hollow spines of uniform size arranged in concentric rows close to the valve margins; a smooth, unpitted larval shell and an irregular, but densely dimpled post-larval shell (Valentine et al. in press). These features indicate a close affinity with the post-Ordovician siphonotretids "Siphonotreta" anglica, Siphonotretine sp. from the Ludlow Kopanina Formation of Reporyje (Mergl 2001b) and Schizambonine sp. A from the Pragian Dvorce-Prokop Limestone of Klukovice (Mergl 2001b). Rickards and Wright (2002) noted that the graptolite faunas from the Silurian of western NSW were holdovers from the Late Ordovician indicated this region was refugia for survivors of the End Ordovician Extinction. The presence of a Silurian siphonotretid in the same region supports this contention. BASSETT, M.G., POPOV, L.E. and HOLMER, L.E., 1999. Organophosphatic brachiopods: patterns of biodiversification and extinction in

the Early Palaeozoic. Geobios 32, 145-163.

MERGL, M., 2001a. Extinction of some lingulate brachiopod families: new stratigraphical data from the Silurian and Devonian of central

Bohemia, pp. 345-351. In Brunton, C. H. C., Cocks, L. R. M. and Long, S. M. (eds), Brachiopods past and present; Systematics Association Special Volume 63, London. MERGL, M., 2001b. Lingulate brachiopods of the Silurian and Devonian of the Barrandian (Bohemia, Czech Republic). Acta Musei Nationalis Prague, Series B, Historia Naturalis 57, 1-49. MORRIS, J., 1849. Note on the genus Siphonotreta, with a description of a new species. Annals and Magazine of Natural History 4, 315321. RICKARDS, R.B. and WRIGHT, A.J., 2002. Lazarus taxa, refugia and relict faunas: evidence from graptolites. Journal of the Geological Society, London 159, 1-4. VALENTINE, J.L., BROCK, G.A. and MOLLOY, P.D., in press. Linguliformean brachiopod faunal turnover across the Ireviken Event at Boree Creek, central-western New South Wales, Australia. Courier Forschungsinstitut Senckenberg.

ACRITARCH EVOLUTION IN THE HIGH-LATITUDE "PERIGONDWANA PROVINCE" FROM LATEST CAMBRIAN TO LATEST ORDOVICIAN TIMES AND ITS PALAEOECOLOGICAL SIGNIFICANCE Marco VECOLI and Alain LE HERISSE Domaines oceaniques, UMR 6538 du CNRS, Universite de Bretagne Occidentale, Av. Le Gorgeu, B.P. 807, 29285 Brest cedex, France. Morphological diversity of acritarchs and related forms (e.g., prasinophycean phycomata) increased dramatically during latest Cambrian through Ordovician times. Successive introductions of innovative cyst morphologies occurred during short periods of diversification bursts (e.g., at the Cambrian-Ordovician transition and during early Arenig times), followed by periods of slowed evolutionary rates. Some morphologies which evolved during early-middle Ordovician times (e.g., Veryhachium-like and Dactylofusa/Eupoikilofosa-liko) proved highly successful, surviving to succeeding major episodes of mass extinctions such those associated with the end-Ordovician, end-Devonian, and end-Permian biological crises. The present analysis shows that certain associations of morphological characters were reproduced cyclically in Early Palaeozoic acritarch evolution, possibly in response to the cyclical establishment of particular palaeoecological conditions (e.g., glaciation/deglaciation, transgressive/regressive cycles). Lazarus phenomena and punctuated bursts in polymorphisms are also thought to be triggered by changes in

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IPC2002 Oral Presentations palaeoecological/palaeoclimatic situations which in turn may be linked to major palaeogeographical modifications. The detection, accurate description, chronostratigraphical constraining of acritarch assemblage evolutive dynamics is therefore pivotal to an enhanced understanding of acritarch palaeoecological behaviour and also to improving the biostratigraphical value of these microfossils. The most important steps of acritarch evolution during latest Cambrian through Ordovician times are: 1. The microphytoplankton turnover during latest Cambrian times which caused the gradual disappearance of numerous forms such as Ladogella, Timofeevia, Trunculumarium, Phenacoon, Ooidium, accompanied by the introduction of new morphologies which will thrive and greatly diversified during Tremadoc times such as Stelliferidium and Cymatiogalea, various diacrodian forms such as Acanthodiacrodium and Dasydiacrodium. The Cambro-Ordovician transition is characterized by an increase in diversity. 2. The early Arenig introduction of numerous innovative morphologies such as the polygonal, striated forms (Arkonia, Striatotheca, Frankea, Coryphidium), the morphologically complex peteinoid clade, the Orthosphaeridium and Ordovicidium clades, and the first great diversification of the Verhyhachiids. 3. A general increase in acritarch diversity during Llanvirn times with the development of strong bioprovincialism between high latitude („Peri-Gondwanan") and low latitude („Baltican") assemblages. 4.An acceleration in extinction rates starting during early Caradoc times and continuing into the Ashgill, accompanied by a breakdown in microphytoplankton bioprovincialism. 5. A period of increased turn-over rates during the last part of the Ashgill (Hirnantian), during which the extinctions of typical Ordovician taxa (e.g., Villosacapsula, Ordovicidium) was paralleled by a gradual introduction of taxa characterized by innovative morphologies which will further develop during Early Silurian times, such as Evittia, Oppilatala, Leprotolypa, Neoveryhachium. Consequently, acritarchs do not record a marked extinction event during the end-Ordovician but rather a turnover which occurred during a relatively long period of time (most part of the Ashgill). Large-scale acritarch dynamics appear to be controlled by the interplay of numerous parameters including palaeoclimatic and palaeogeographic changes which in turn influenced palaeoceanographic conditions. For example, it is possible to note that the periods of maximum rate of specific diversification and morphological innovation roughly coincided with periods of widespread marine transgressions during which oceanographic and climatic conditions favoured cyst production. Superimposed on the above main evolutive trends, lazarus taxa and intraspecific polymorphism observed in the stratigraphic sections seem to be associated with variation to local and/or global palaeoenvironmental conditions. For example, the extreme polymorphism within Netromorphic and Veryhachiid acritarchs, occurring in Late Ordovician glacial-related sediments of North Africa, suggests that these might represent opportunistic species, capable of high reproduction rates in stressed environments. Various examples of Lazarus taxa are evident among Ordovician acritarchs like for example the Ladogella-Barakella complex, appearing in Late Cambrian times, then disappearing around the Cambrian-Ordovician boundary, and finally reappearing during the early Arenig. Similar patterns are observed for the Arkonia-Striatotheca complex which appeared and greatly diversified for the first time during the Middle Ordovician, and re-occurred intermittently not only during the remaining part of the Ordovician but also during Silurian and Devonian times.

THE BEGINNINGS OF BIOMINERALIZATION IN THE SOUTHWESTERN GREAT BASIN OF THE WESTERN UNITED STATES Ben WAGGONER Department of Biology, University of Central Arkansas, Conway, AR 72035-5003 USA The southwestern part of the Great Basin, including southwestern Nevada and southeastern California, USA, includes two well-studied late Proterozoic and Cambrian sections: the northern White-Inyo facies and the southern Death Valley facies. The Death Valley section contains a small assemblage of soft-bodied Ediacaratype fossils found immediately below the local base of the Cambrian. Mineralized and agglutinated fossils are preserved in both facies, in both carbonates and shales. In the Death Valley region these include unidentified smooth circular and conical forms, as well as the circular Cloudina, the square tube Corumbella, the agglutinated tubes Archaeichnium and Onuphionella, and the elongated conical fossil Lapworthella. The White-Inyo facies includes cloudiniids, agglutinated fossils, and the conical form Wyattia. In fact, the southwestern Great Basin currently has the greatest diversity of mineralized fossils of any late Proterozoic locality. At least two genera cross the Precambrian-Cambrian boundary. This gives us a detailed look at the regional evolution of biomineralized taxa, and allows the comparison of this section with other areas where mineralized fossils are found on both sides of the Precambrian-Cambrian boundary. Describing their stratigraphic succession may provide important clues both to the regional and global stratigraphy and to the global appearance of biomineralization.

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SHELF-TO-SLOPE TRENDS IN BIOLOGICAL TAPHONOMY ASSOCIATED WITH EXPERIMENTALLY-DEPLOYED GASTROPOD SHELLS, LEE STOCKING ISLAND, BAHAMAS Sally E. WALKER1, Karla PARSONS-HUBBARD2, Carlton BRETT3, and Eric POWELL4. J Dept. of Geology, University of Georgia, Athens, GA 30602 USA, [swalker@gly.uga.edu];2Dept. of Geology, Oberlin College, Oberlin, Ohio 44074 USA; Dept. of Geology, University of Cincinnati, Cincinnati, Ohio 45221 USA; Raskin Shellfish Research Lab, Rutgers University, Port Norris, New Jersey 08349 USA Biology taphonomy encompasses, in part, the study of encrusting and bioeroding organisms (bionts) associated with calcareous hardparts and organisms that secondarily use and alter hardparts (such as hermit crabs). Predation records, such as shell repair and peeled shells, are also biological components of taphonomic analysis. To examine the components of biological taphonomy with depth and with time, clean and empty gastropod shells were experimentally deployed in 1993 as tethered shells and as shells within bagged sets across a bathymetric gradient encompassing shallow shelf (15-30 m), shelf/slope break (70 m), and slope (88-260 m) environments off Lee Stocking Island, Exuma Cays, Bahamas. Experiments were retrieved in 1994, 1995, and in 1999 using SCUBA and submersibles (Clelia and Nekton Gamma). Results indicate that the type of experimental array (bagged vs. tethered) affects the relative abundance of encrustation; tethered shells exhibited fewer bionts than bagged shells because of abrasion. These differences disappeared with depth, however. Within the first year, foraminiferans and invertebrates were relatively abundant, and were most abundant at the shelf/slope break (70 m). Fewer bionts occurred below this depth, and were chiefly encrusting foraminiferans. After two years of deployment, shells had a higher diversity of encrusters, including the addition of bioeroders. By far the most numerically dominant and preservableencrusting organisms were foraminiferans after two years of deployment at all depths. After six years of deployment at the shallow shelf sites, the majority of the shells were smothered by one type of encrusting foraminiferan (Gypsina), and not invertebrate encrusters as we had expected. Thus, although the shells were deployed longer, they had less diversity because of a spatially-dominant protist. Tethered shells were "preyed upon" by shell-peeling crabs and/or molluscivorous or crustacean-eating fish (predators may have been attracted to hermit crabs that had inadvertently exchanged their shells to live in tethered arrays). Predation occurred down to slope depths on tethered shells; bagged shells were not preyed upon. In summary, biological taphonomy was quite evident on the experimental arrays after two years of deployment. Most encrusting diversity occurred at the shelf/slope break for experimentally-deployed gastropod shells; over time, this diversity decreased due to the dominance of a particular species of protist (Gypsina) at shelf sites; slope sites temporally maintained foraminiferal diversity. For the fossil record, diversity of encrusters is not tied to shallow water, but may also indicate shelf/slope environments. Encrusters (especially protists) are useful bathymetric indicators with high preservation potential. Encrusters may also be protists, which are often overlooked in modern and fossil biont studies. Predation, while common in shallow settings, also occurs at slope depths, suggesting that the record of predation can be studied on deep-water gastropod fossils.

FURTHER OBSERVATIONS ON THE ULTRASTRUCTURE IN G-TYPE TRACHEIDS OF EARLY LAND PLANTS De-Ming WANG and Shou-Gang HAO School of Earth and Space Sciences, Peking University, Beijing 100871, P. R. China; [dmwang@geoms.geo.pku. edu. cn] In early land vascular plants, the conducting cells (tracheids) are divided into S-, G- and P-types (Kenrick and Crane, 1991, 1997). Recently, two plants, Huia gracilis Wang et Hao 2001 and Hsiia Li 1992, were documented from the Lower Devonian (late Pragian-early Emsian) Xujiachong Formation of Qujing District, eastern Yunnan, China. By their anatomical research, the innovation in method resulted in improved understanding of the ultrastructure in G-type tracheids. Under the scanning electron microscope (SEM), we simultaneously compare coalified tracheids through chemical maceration and permineralized tracheid lumen casts. This method reveals some ultrastructure in walls and perforations of G-type tracheids: 1) In Huia gracilis, the enclosing wall of tracheidal perforation contracts toward the lumen and possesses secondary perforations (Wang and Hao, 2001); the perforation has a thickened border facing the tracheid lumen; 2) In Hsiia, the lignified layer of secondary wall is composed

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IPC2002 Oral Presentations of uneven material further divided into S h S2 and S3 layers; 3) Instead of longitudinal rows of pits as suggested by Li (1992), the lignified tracheid secondary wall of Hsiia possesses many irregularly distributed simple perforations—with the smooth enclosing wall, the perforation is internally dumbbell-shaped. These anatomical studies add to knowledge of G-type conducting cells: 1) It proves the theory of two depositional processes for the secondary wall (.sensu Bierhorst, 1960): the discontinuous cellulose layer is laid down before the continuous lignified layer; the former layer is prone to be broken down, whereas the latter is highly decay-resistant. 2) It suggests that the lignified layer of secondary walls of tracheids is perforate. 3) The wall structure of G-type tracheids is diverse. At genus level, the secondary wall differs in the distribution, internal shape and structure of the perforations. 4) Some G-type tracheids combine the characters of S-type tracheids in distribution, density and diameter of perforations. This work was supported by the National Natural Science Foundation of China (Grant No. 49972009) and Major Basic Research Projects of the Ministry of Science and Technology, China (Grant No. G2000077700). BIERHORST, D.W., 1960. Observations on tracheary elements. Phytomorphology 10, 249-305. KENRICK, P. and CRANE, P.R., 1991. Water-conducting cells in early fossil land plants: implications for the early evolution of tracheophytes. Botanical Gazette 152, 335-356. KENRICK, P. and CRANE, P.R., 1997. The origin and early diversification of land plants: a cladistic study. Smithsonian Institute Press, Washington, DC. Li, C.S., 1992. Hsiia robusta, an Early Devonian plant from Yunnan Province, China and its bearing on some structures of early land plants. Review of Palaeobotany and Palynology 71, 121-147. WANG, D.M., and HAO, S.G., 2001. A new species of vascular plants from the Xujiachong Formation (Lower Devonian) of Yunnan Province, China. Review of Palaeobotany and Palynology 114, 157-174.

LATE PALAEOZOIC CORALS OF TIBET (XIZANG) AND WEST YUNNAN, SOUTHWEST CHINA: SUCCESSIONS AND PALAEOBIOGEOGRAPHY X. D. WANG1 and S. Z. SHEN1, T. SUGIYAMA2 & R. R. WEST3 1 Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, P. R. China; 2Faculty of Earth System Science, Fukuoka University, Fukuoka 814-0180, Japan; department of Geology, Kansas State University, Kansas 66506, USA A dynamic pattern of coral faunal provincialism in the Carboniferous to Permian is preserved in Tibet-West Yunnan. During the Early Carboniferous, an undifferentiated Eurasian province was present, containing the Kueichouphyllum, Keyserlingophyllum-Siphonophyllia, and Cyathaxonia faunas that reflect major environmental differences relative to previous interpretations. During the Late Carboniferous-Early Permian, the Indoralian province and the Cathaysian province can be distinguished. The former is recognised by absence of Late Carboniferous-Asselian corals and by presence of the Sakmarian-Artinskian Cyathaxonia fauna. The latter contains the Late Carboniferous and Early Permian compound corals Nephelophyllum and Kepingophyllum. As many blocks drifted northward beginning in the late Early Permian, the Indoralian province had evolved into two discrete provinces: the Himalayan and Cimmerian provinces. The Himalayan province as a relic of the Indoralian province was On the northern margin of Gondwanaland. The Cimmerian province between the Himalayan and the Cathaysian provinces consists of the present tectonic blocks: Lhasa, Qiangtang, Tengchong, and Baoshan in Tibet and West Yunnan. It is characterised by Roadian nondissepimental solitary corals and Wordian—Capitanian compound Waagenophyllidae, as well as some endemic Cimmerian taxa such as: ThomasiphyHum and Wentzellophyllum persicum. The cathaysian province is dominated by Szechuanophyllum and Ipciphyllum. During the Late Permian, the Himalayan province and the Cathaysian province can be recognised. The former contains only small solitary corals referred to as the Lytvolasma fauna; the latter is identified by Liangshanophyllum, a fasciculate waagenophyllid.

A RARE AND VALUABLE BIOTA - THE GUANLING BIOTA WANG Xiaofeng, CHEN Xiaohong, XU Guanhong , MENG Fansong, CHEN Lide, ZHANG Zhenglai, CHEN Huiming, WANG Chuanshang & CHEN Long Centre of Stratigraphy and Paleontology, China Geological Survey, Yichang, Hubei, China The Guanling biota is characterized by numerous well-preserved marine reptiles and crinoids together with ammonoids, bivalves, conodonts, brachiopods and a few fossil fishes and plants. Such a rich, diversified and perfectly preserved palaeontologic assemblage is rarely encountered globally. Preliminary study indicates that the principal marine reptiles are ichthyosaurs—Qianichthyosaurus zhoui Li (1999), thalattosaurs— Anshunsaurus huanguoshuensis (Liu, 1999) and Xinpusaurus suni (Yin et al., 2000), placodonts—

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IPC2002 Oral Presentations Sinocymodus xinpuensis Li (2000) and some new unidentified taxa. The crinoids are dominated by Guizhoucrinus hsui (Mu) and G. guanlingensis (Yu et al.) revised in the present paper, and several new forms needing further study. Associated fossils comprise conodonts of the Neogondolella polygnathiformis Zone, ammonoids of the Trachyceras multituberculatus Zone, bivalves of the Halobia-"Daonella" bifurcatus Assemblage Zone, the brachiopods Koninckina guizhouensis and K. zhengfengensis, and newly discovered fish Asialepidotus sp. nov., and plants—Equisetites arennaceus and Ctenozamites sarrani. Comprehensive analysis of the above-mentioned fossil suggested that the age of the Guanling biota should be of early Carnian (Late Triassic). Systematic exploration indicates that the Guanling biota is distributed mainly through an interval of 5-11 m above the base of the Lower Member of the Xiaowa Formation (formerly "Wayao Formation") around Huangtutang, Xiaowa, Maowa and Bamaoling of Xinpu Village and Baiyan of Gangwu Village, Guanling County—covering about 200 sq. km. Combined eco-, sequence- and chemo-stratigraphic researches indicate that this rare biota was probably formed in a relatively stagnant basin or gulf near the active shelf margin of the SW Sichuan-Yunnan basin during the early Carnian transgression, following the Middle Triassic Ladinian global regression.

limestone

PALYNOFLORAL ASSEMBLAGE ACROSS THE TERRESTRIAL PERMIAN - TRIASSIC BOUNDARY AT DALONGKOU, XINJIANG, NW CHINA WANG Xiaofeng1. ZHANG Zhenlai1, Ian METCALFE2 and Clinton FOSTER3 1 Centre for Stratigraphy and Paleaontology, CGS, Yichang, Hubei, China; 2Asia Centre, University of New England, Amidele, NSW, Australia; 3Geoscience Australia, Canberra, Australia Internationally important terrestrial Permian-Triassic transition sedimentary sequences are found within the Guodikeng Formation in the north and south limb sections of the Dalongkou anticline and the Lucaogou section near Wulumuqi (Urumqi) in the southern Junggar Basin, Xinjiang, NW China. The Guodikeng Formation contains well-preserved palynofloras together with megaspores, fossil plants and vertebrates in some beds. From detailed study of a suite of samples collected by Metcalfe et al. (2001) a minimum of three palynomorph assemblages, rather than two assemblages (Hou & Wang, 1990; Ouyang & Norris, 1998), can be recognized in the formation. They are in ascending order the Klausipollenites schaubergenProtohaploxypinus-Tympanicysta stoschiana (= Reduviasporonites chalastus) Assemblage (A.l), the Cordaitina-Hamiapollenites-Vittatina Assemblage (A.2) and the 'Lundbladispora -LunatisporitesAlisporites Assemblage (A.3). The A.l Assemblage occurs in the upper lower Guodikeng from 95m-132 m below the base of overlying Jiucaiyuan Formation in the Dalongkou north section. It is dominated by gymnospermous pollen (43- 75%) with minor pteridophytic spores (7.5-25%), abundant algal remains T. stoschiana (27%- 33%) and rarer monosaccate pollen. Of the gymnosperm pollen, the non-striate disaccate Klausipollenites schaubergeri accounts for 12-33%, and striate bisaccate taxa, represented by Protohaploxypinus and Lunatisporites, account for 9-19%. The FA of the megaspore Otynisporites eotriassicus within the Al assemblage indicates it is of latest Permian age (Lozovsky et al. 2001). The A.2 Assemblage is found in the middle Guodikeng Formation, from 57-95m below the base of the Jiucaiyuan

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IPC2002 Oral Presentations Formation. It is similar to A.l in the abundance of gymnosperm pollen (60%). The differences are as follows: a. The monosaccate taxa, represented by Cordaitina (s.l.: over 20%, occasionally reaching 40%), and Crucisaccites (1%) increase in quantity, and constitute a marked feature of the assemblage, b. Striate bisaccate pollen are more abundant than non-striate bisaccate pollen although Hamiapollenites spp. (8.1%17.9%) and Vittatina spp.(3%) are relatively more abundant, c. Unlike in Al, K. schaubergeri and T. stoschiana are rarely observed in the A.2, not exceeding 0.5- 3% and 0.7% respectively, d. The pteridophytic spores relatively increase up to 37.8% in proportion. The A.3 Assemblage occurs in the upper part of the Guodikeng Formation, covering the interval of 0-46m below the base of the Jiucaiyuan Formation. By comparison with A. 1 and A.2, A.3 is characterized by the dominance of pteridophytic spores, and appearance of species of'Lundbladisporaknown previously from the early Triassic Jiucaiyuan Formation. In particular 'Lwatangensis and 'L '.foveotus are quite common ( 3% on average and up to 9%). Striate bisaccate pollen of Lunatisporites spp. become more abundant, reaching 10%, but the monosaccates (Cordaitina spp.)and striate bisaccate pollen of Hamiapollenites spp. decrease markedly in number, and Vittatina is very rare. Our study has not identified the Early Triassic index species of Aratrisporites. It was reported by Ouyang & Norris (1998) from a palynoflora 45m below the base of the Jiucaiyuan Formation, but this record needs reevaluation. These features indicate that A.3 is distinct from A.2 and A.l in palynofloral composition, but similar to those from the overlying Early Triassic Jiucaiyuan Formation. Among vertebrates from the upper 20m of Guodikeng Formation Lystrosaurus is more common than Dicynodontia and are assumed to be of Early Triassic age (Cheng 1986). The P/T boundary must therefore be located between this level and the top of Assemblage Al: further work is required to locate this boundary precisely. CHENG, Z. W., 1986. Vertebrates, pp.207- 218. In Institute of Geology, CAGS and Institute of Geology, XBGMR(eds.), Permian and Triassic strata and fossil assemblages in the Dalongkou area of Jimsar, Xinjiang. Geological Publishing House, Beijing. HOU, J.P. and WANG, Z., 1990. Spore-pollen assemblages from the Permian of northern Xinjiang, pp. 12-36. In Permian to Tertiary strata and palynological assemblages in the north of Xinjiang. Chinaa Environmental Science Press, Beijing. LOZOVSKY, V . R . , KRASSILOV, V . A . , AFONIN, S . A . , BUROV, B . V . , YAROSHENKO, O . P . , 2 0 0 1 . T r a n s i t i o n a l P e r m i a n - T r i a s s i c d e p o s i t s in

Eyropean Russia, and non-marine correlations. "Natura Bresciana" Ann. Mus. Civ. Sc. Nat., Brescia, Monografia N.25, 301-310. OUYANG, S. and NORRIS, G.,1998. Earliest Triassic (Induan) spores and pollen from the Junggar Basin, Xinjing, northwestern China. Review of Palaeobotany and Palynology 106, 1-56. METCALFE, I., NICOLL, R . S., MUNDIL, R . , FOSTER, C . , GLEN, J., LYONS, J., WANG, X . , WANG, C . , RENNE, P . R . , BLACK, L.,QU, X . a n d

MAO, X., 2001. The Permian-Triassic boundary & mass extinction in China. Episodes 24(4), 239-244.

A NEOTENIC SALAMANDER FROM THE LOWER CRETACEOUS OF NORTHEASTERN CHINA Yuan WANG1. Ke-qin GAO2 & Christopher S. ROSE3 institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, China; [ywangl@ihw.com.cn]; 2Division of Paleontology, American Museum of Natural History, New York 10024, USA; 3Department of Biology, James Madison University, Virginia 22807, USA A fossil salamander is described based on a few dozen specimens from the Late Mesozoic of Ningcheng, SE Inner Mongolia, NE China. The fossil-bearing strata are correlated with the lower part of the Yixian Formation of the Jehol Group which, according to recent isotopic dating, is Early Cretaceous, though a Middle Jurassic age for this salamander-yielding horizon has also been suggested. Further study is needed to resolve this problem. The new salamander, recently named Jeholotriton paradoxus, represents a neotenic form as indicated by the presence of external gills, tooth-bearing coronoids, underdeveloped maxillae in combination with extensive medial contact of the nasals, and the presence of posteriorly directed tooth rows in the palate. This taxon is distinguished from other Mesozoic salamanders by having 17 presacrals, proximally expanded unicapitate ribs, pterygoids with anteromedially directed rami, vomers well-separated, large tooth patches anteriorly, longitudinal dentigerous "tails" posteriorly, premaxillae with prominent alary processes, short transverse processes of the vertebrae, and phalangeal formulae of 2-2-3-2 for manus and 2-2-3-3-2 for pes. Upon discovery of Jeholotriton, together with Liaoxitriton, Laccotriton and Sinerpeton, four taxa of Mesozoic salamanders have now been found in China, all members of the Jehol Biota. All specimens of Jeholotriton paradoxus are well preserved as impressions of articulated skeleton, a type of preservation that is unusual in Mesozoic strata globally, and provides important anatomical details of this early salamander. The great diversity of fossil salamanders from the Late Mesozoic of NE China, combined with similar findings in Japan, implies that East Asia is an important centre of early evolution of urodeles. These finds bring the total number of Mesozoic salamanders known from the world to 33 taxa, which includes 26 diagnosed species in 24 genera.

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IPC2002 Oral Presentations DONG, Z.-M. and WANG, Y., 1998. A new urodele (Liaoxitriton zhongjiani gen. et sp. nov.) from the Early Cretaceous of western Liaoning Province, China. Vertebrata PalAsiatica 36, 159-172. EVANS, S. E. and MILNER, A. R., 1996. A metamorphosed salamander from the Early Cretaceous of Las Hoyas, Spain. Phil Transactions of the Royal Society of London B 351, 627-646. GAO, K.-Q. and SHUBIN, N., 2001. Late Jurassic salamanders from northern China. Nature 410, 574-577. MILNER, A.R., 2000. Mesozoic and Tertiary Caudata and Albanerpetontidae, pp. 1412-1444. In Heatwole, H. and Carroll, R.L. (eds),

Amphibian Biology, 4, Surrey Beatty, Chipping Norton, Australia. ROSE, C.S., 2002. The developmental morphology of salamander skulls, pp. 1686-1783. In Heatwole, H. and Davies, M. (eds), Amphibian Biology, 5, Surrey Beatty, Chipping Norton, Australia. WANG, Y., 2000. A new salamander (Amphibia: Caudata) from the Early Cretaceous Jehol Biota. Vertebrata PalAsiatica 38, 100-103.

MAMMALS FROM THE EARLY CRETACEOUS JEHOL BIOTA, WESTERN LIAONING, NORTHEAST CHINA Yuan-qing WANG , Chuan-kui LI and Yao-ming HU ' ' institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, P.O Box 643, Beijing, 100044, China, [wangyuanqing@ivpp.ac.cn; lichuankui@ivpp.ac.cn]; Biology Program, Graduate School and City College, City University of New York, NY 10016-4309, USA; division of Paleontology, American Museum of Natural History (AMNH), Central Park West at 79 St., New York, NY 10024, USA. [yhu@amnh. org]. The Early Cretaceous Jehol Biota in Northeast China has yielded a variety of vertebrates, invertebrates and plants, including the well-known primitive birds, feathered dinosaurs, etc. Mammals reported from the biota indicate a fairly high diversity of mammals in eastern Asia during the Early Cretaceous. Zhangheotherium quinquecuspidens, a spalacotheriid, was named on the basis of a well-preserved skeleton that was firstly known for the spalacotheroids (Hu et al., 1997). Its dental formula is 3-1-2-5/3-1-2-6. Its dentition resembles the upper dentition of Peralestes and the lower of Spalacotherium tricuspidens, respectively, confirming Simpson's (1928) consideration that the latter two are based upon upper and lower molars of the same species. Its petrosal has a cylindrical and finger-like promontorium, similar to those of Sinoconodon, Morganucodontids, triconodonts and multituberculates, which suggests an uncoiled cochlea. Its separate interclavicle, rod-like clavicle, therian-like scapula, and mobile clavicle-interclavicle joint suggest a shoulder girdle structure intermediate to those of living monotremes and living therians. Jeholodens jenkinsi, with a dental formula of 4-1-2-3/4-1-2-4, is based upon a nearly complete skeleton preserved as two counterparts, which is the first fully articulated specimen of triconodonts (Ji et al., 1999). Its dental morphology is typical of eutriconodonts. Its shoulder girdle and forelimbs have derived, therian-like features and is characterized by a derived scapula, a somewhat mobile clavicle-interclavicle joint, and an incipient ulnar trochlea on humerus. In contrast, its pelvic girdle, hind limb and pes share many plesiomorphic characters with Morganucodontids and cynodonts, e.g., the morphology of calcaneum and an offset between metatarsal V and the cuboid. The mosaic of primitive and derived characters indicates that homoplasies are common in the postcranial evolution of Mesozoic mammals. Repenomamus robustus is probably the largest mammal (measured skull length: 108 mm and 114 mm) known from the Mesozoic age over the world (Li et al., 2000). Its dental formula is 31-2-4/31-2-5 and its cheek teeth are most similar to those of gobiconodontids. A rod-like ossified Meckel's cartilage, lodging in the internal groove, was recognized on two specimens of Repenomamus, which provides direct evidence for the function of the internal groove in related Mesozoic mammals and diminishes the possibility for multiple origination of the definitive mammalian middle ear (Wang et al., 2001). Sinobaatar lingyuanensis is represented by a subadult skeleton preserved as clear impressions on two counterparts (Hu and Wang, 2002). Its dental formula is 3-7-5-2/1-0-3-2. Its dental morphology, especially of the cheek teeth, is similar to that of eobaatarids from the Early Cretaceous of Mongolian. The proportionally longer p4, the conical lower incisor with complete enamel coverage, and the cusp pattern of upper premolars make Sinobaatar distinguishable from all the other eobaatarid genera. The postcranial skeleton of Sinobaatar is not greatly different from that of later forms, suggesting that the postcranial morphology of multituberculates did not go through great changes during their history. The research is supported by the Ministry of Science and Technology, P. R. China (G2000077700), National Natural Science Foundation of China (49832002), and Chinese Academy of Sciences (KZCX3-J-03, KZ951-B1-410). 1

1 2 3

Hu, Y.-M. and WANG, Y.-Q., 2002. Sinobaatar gen. nov.: first multituberculate from the Jehol Biota of Liaoning, Northeast China. Chinese Science Bulletin 47(5), 382-386 (Chinese edition); 47(12) (English edition). Hu, Y.-M., WANG, Y.-Q., Luo, Z.-X. and Li, C.-K., 1997. A new symmetrodont mammal from China and its implications for mammalian evolution. Nature 390, 137-142. Ji, Q., Luo, Z.-X. and Ji, S.-A., 1999. A Chinese triconodont mammal and mosaic evolution of the mammalian skeleton. Nature 398, 326-330.

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IPC2002 Oral Presentations Li, J.-L., WANG, Y., WANG, Y.-Q. and Li, C.-K., 2000. A new family of primitive mammal from the Mesozoic of western Liaoning, China. Chinese Science Bulletin 45, 2545-2549 (Chinese edition); 2001. 46, 782-785 (English edition). SIMPSON, G.G., 1928. A catalogue of the Mesozoic Mammalia in the Geological Department of the British Museum. London: Oxford Univ. Press, 1-215. WANG, Y.-Q., HU, Y.-M., MENG, J. and LI, C.-K., 2001. An ossified Meckel's cartilage in two Cretaceous mammals and origin of the mammalian middle ear. Science, 294, 357-361.

EXPERIMENTAL FRAGMENTATION PATTERNS OF LIVING NAUTILUS SHELLS AND THEIR IMPLICATIONS FOR FOSSIL CEPHALOPOD TAPHONOMY Rvoii WANI National Science Museum, 3-23-1, Hyakunincho, Shinjuku-ku, Tokyo 169-0073, Japan; [ryoji_wani@hotmail. com]. The shells of living Nautilus pompilius collected in the Philippines were experimentally fragmented. The fragmentation patterns produced by different mechanisms are distinct. Supposed mechanisms are: (1) transport with sediment; (2) sediment loading; (3) collision with flotsam; (4) impact of washing ashore; and (5) predation. Thus, comparison between these results and the fragmentation patterns of fossil ectocochleate cephalopods (nautiloids and ammonoids) allows the identification of the specific fragmentation mechanisms and a more complete reconstruction of the taphonomic history. Each fragmentation pattern mentioned above is respectively summarized as follows: (1) Fragmentations are concentrated along the venter. The aperture is, however, characteristically pristine. (2) Fragmentation occurs only on the flank of body chambers, especially adorally of the last septum. The fractured edges are almost straight. The aperture and phragmocone have retained their original morphology. (3) Floating shells collected in natural sea are entire. Shells are broken only in the artificial situation, such as the high density of flotsams. Fragmentation initially occurs at the apertures, and continues until most of the body chamber was destroyed. The fractured edges are irregularly angular and eroded. (4) The flanks of the body chamber remain remarkably intact. The fractured edges are sharply angular. (5) The body chamber displays substantial breakage. There is no damage on the phragmocone. The fractured edges are irregularly angular. As a case study, the fragmentation patterns of the ammonoids in the Upper Cretaceous of northwestern Hokkaido, Japan, are compared with the experimental results. The fragmentation patterns of most ammonoids are summarized as (1) fragmentation concentrated on the flank of body chambers, especially adorally of the last septum; (2) almost straight fractured edges; (3) intact phragmocones; and (4) no encrustation, abrasion, and corrosion of the shell surfaces (Wani, 2001). These attributes are extremely similar to the experimental result of sediment loading. Thus, the fragmentation mechanism of most ammonoids is supposed as sediment loading. WANI, R., 2001. Reworked ammonoids and their taphonomic implications in the Upper Cretaceous of northwestern Hokkaido, Japan. Cretaceous Research 22, 615-625.

CLIMATE INFLUENCED OCCURRENCES OF OSTRACOD CLADES: INSTANCES OF PUNCTUATED BIOGEOHISTORY FROM THE UPPER CENOZOIC OF SOUTHEASTERN AUSTRALIA Mark T. WARNE School of Ecology and Environment, Deakin University (Melbourne Campus), 221 Burwood Highway, Burwood, Vic., 3125 Fossil Ostracoda indicating a shift to warmer palaeoclimates within the upper Cenozoic of southeastern Australia occur during the mid Miocene and the latest Miocene (and/or earliest Pliocene). There were slight differences in aquatic temperatures between these two south-east Australian warm phases, with the mid Miocene having experienced relatively higher marine water temperatures than the latest Miocene. The intervening period experienced relatively cool palaeoclimates (McGowran et.al, 2000). Some ostracod clades present during these two warm periods and which display strongly punctuated temporal distribution patterns, exhibit discontinuous morphological variations in carapace structure between member taxa. Different members of these clades found in mid Miocene and latest Miocene strata respectively are therefore interpreted as representing distinct species. Generally both mid Miocene and latest Miocene members of these clades occurred in inner shelf palaeohabitats (carbonate and / or quartz sand substrates). An

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IPC2002 Oral Presentations example of an ostracod clade with this type of temporal south-east Australian distribution pattern is one which includes upper Cenozoic species of the genus Neobuntonia Hartmann, 1981. Populations of some other ostracod species occurring during these warm phases display more minor temporal deviations in morphology with slight, although discontinuous variation mostly involving small changes in adult size and strength of ornament. These variations are interpreted as representing different subspecies of species with relatively long time ranges. In general, members of this faunal group inhabited slightly deeper water palaeoecological niches during the mid Miocene (mid-outer shelf range, clayey substrate) than during the latest Miocene (inner shelf depth range, sandy substrate). They also have a less punctuated distribution pattern, also being small components of ostracod assemblages from relatively cooler intervening periods in southeastern Australia. An example of a species with this type of subspecies distribution pattern is Cytheropteron microfornix Whatley and Downing, 1983. The association of some ostracod clades with particular palaeoclimatic regimes has given rise to a punctuated temporal distribution pattern of member species through the upper Cenozoic of southeastern Australia. The availability of extensive continental shelf regions along which south-east Australian ostracod species could migrate north or south in response to water temperature / climate fluctuations perhaps facilitated the maintenance of consistent habitat preferences for member species of these semi-thermophilic taxonomic clades. HARTMANN, G., 1981. Die Ostracoden der Ordung Podicopida G.W. Miiller, 1894, der subtropisch - tropischen Ostkiiste Australiens (zwischen Eden im Suden und Heron Island im Norden). Teil 7. Mitteilungen aus dem Hamburgischen zoologischen Museum und Institut 78, 9 7 - 1 4 9 . MCGOWRAN, B., ARCHER, M . , BOCK, P. DARRAGH, T . A . , GODTHELP, H., HAGMAN, S., HAND, S.J., HILL, R., LI, Q., MAXWELL, P.A., MCNAMARA, K.J., MACPHAIL, M . , MILDENHALL, D., PARTRIDGE, A . D . , RICHARDSON, J., SHAFIK, S., TRUSWELL, E . M . and

WARNE, M., 2000. Chapter 9, Australasian palaeobiogeography: the Palaeogene and Neogene record in Palaeobiogeography of Australian Faunas and Floras (Editors: A.R. Wright, G.C. Young, J.A. Talent & J.R. Laurie). Memoir of the Association of Australasian Palaeontologists 23, 405 - 470. WHATLEY, R.C. and DOWNING, S., 1983. Middle Miocene Ostracoda from Victoria, Australia. Revista Espanola de Micropalaeontologia 15 (3), 3 4 7 - 4 0 7 .

DUCABROOK TETRAPOD: 2002 Anne WARREN1 and Susan TURNER2 department of Zoology, La Trobe University, Melbourne, Victoria, 3086. [a.warren@zoo.latrobe.edu.au]; 2 Queensland Museum, P.O. Box 3300, S. Brisbane, Queensland 4101 Little is known of the history of early tetrapods between the latest Famennian and the later part of the Visean, a period of some 30 million years, known as Romer's Gap (Coates & Clack 1995). Latest Famennian taxa from Euramerica are diverse, and the best known anatomically; Ichthyostega and Acanthostega from East Greenland, are likely to have been primarily aquatic, at least in the case of Acanthostega (Coates & Clack 1991). After the gap at least partly terrestrial members of both the Amphibia and Amniota are preserved in faunas from Euramerica, especially that from East Kirkton, Scotland (Smithson et al. 1994). It follows that important events in tetrapod history occurred in the period of the gap: the crown group Tetrapoda with its primary division into Amphibia and Amniota appeared in the fossil record and tetrapods invaded the land. A mid Visean fauna of fish and tetrapods that falls towards the end of Romer's Gap was discovered in 1995 in Queensland, Australia (Thulborn et al. 1996). Two other occurrences of Gap tetrapods are now known: a number of bones have been recovered from the late Tournaisian at Horton Bluff, Nova Scotia (Clack & Carroll 2000) and a single articulated specimen from earlier in the Tournaisian of Scotland has yet to be described (Clack & Finney 1997, Clack 2001). The Queensland fauna, from the Ducabrook Formation in the Drummond Basin, consists of typically near-marine fish with rare tetrapod bones, all disarticulated although a skull table suggests more complete material might be recovered. Elements were transported and deposited near the mouth of a fluvial system by a twin-peaked flood event (Parker 2001). Individual tetrapod bones are well preserved in three dimensions. At present there is no evidence that there is more than one tetrapod taxon at the Ducabrook site. This hypothesis is based on the fact that only one type of tetrapod ornamentation is present on the external surface of the cranial, mandibular and pectoral girdle fragments. The postcranial material has predominantly primitive characters. Cladistic analysis shows that the Ducabrook tetrapod belongs to a clade of stem tetrapods first shown by Clack (2001) to include the Tournaisian tetrapod from Scotland and Whatcheeria deltae, a tetrapod from later in the Visean of Delta, Iowa, USA. Inclusion of the Late Devonian Tulerpeton from Russia in the analysis removes Tulerpeton from the reptiliomorphs to a position stemwards of the new Early Carboniferous clade. A dichotomy in the crown group tetrapods into Amphibia and Amniota is well supported. Our analysis suggests the existence of a clade of tetrapods in the Early Carboniferous distributed world wide, at least in

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IPC2002 Oral Presentations low latitudes. On the other hand, the shared characters of this clade could merely be a reflection of a parallel transition to a partly terrestrial habitat before the origin of the crown clades. We thank the owners of the field site, Middle Paddock, our field and laboratory crews and the Australian Research Council. CLACK, J.A., 2001. Stepping into the Tournaisian: five toes and two fingers for early tetrapods. Palaeontological Association 45th Annual Meeting, Abstracts Volume, 6. CLACK, J.A. & CARROLL, R.L., 2000. Early Carboniferous tetrapods, pp. 1030-1043. In Heatwole, H. and Carroll R.L. (eds), Amphibian biology Volume 4, Palaeontology. Surrey Beatty and Sons, Chipping Norton, NSW. CLACK, J. A. & FINNEY, S.M., 1997. An articulated tetrapod specimen from the Tournaisian of Western Scotland. Journal of Vertebrate Paleontology 17, supplement to number 3, 38A. COATES, M.I. & CLACK, J.A., 1991. Fish-like gills and breathing in the earliest known tetrapod. Nature 352, 234-6. COATES, M.I. & CLACK, J.A., 1995. Romer's gap: tetrapod origins and terrestriality. Bulletin du Museum national d'Histoire Naturelle, Paris 17, 373-388. PARKER, K.E., 2001. Australian Lower Carboniferous site: taphonomy and geology. Journal of Vertebrate Paleontology 21 Supplement to no. 3, 87A. SMITHSON, T.R., CARROLL, R.L., PANCHEN, A.L. & ANDREWS, S.M. 1994. Westlothiana lizziae from the Visean of East Kirkton, West Lothian, Scotland, and the amniote stem. Transactions of the Royal Society of Edinburgh: Earth Sciences 84, 383-412. THULBORN, R . A . , WARREN, A . A . , TURNER, S. & HAMLEY, T., 1996. Early C a r b o n i f e r o u s t e t r a p o d s in Australia. N a t u r e 381, 7 7 7 - 7 8 0 .

PALAEOECOLOGICAL STUDIES IN THE LATE PERMIAN, BROUGHTON FORMATION, SOUTHERN SYDNEY BASIN, AUSTRALIA E.A.WELDON School of Ecology and Environment, Deakin University, Melbourne Campus, 221 Burwood Highway, Burwood, Victoria, Australia, 3125. [eweldon@deakin.edu.au]. Macrofossils, particularly brachiopods and bivalves, are abundant at a number of localities in the lower twothirds of the Late Permian, Broughton Formation, southern Sydney Basin. The Broughton Formation is the youngest formation in the Shoalhaven Group. It is subdivided into three predominantly shallow marine volcaniclastic sandstone members and five shoshonitic lava flows. Flows have been collected and in some instances described and illustrated, from notable localities in the Illawarra region throughout the past 150 years. These localities include: Black Head, Gerringong Harbour, Flagstaff Point, Springhill Cutting and Albion Park. The fossil assemblages at these localities are characterised by a low diversity of cool water fauna. The fauna responds to an environment affected by seasonal sea ice, volcanism and bathymetric changes in a storm and tidal dominated shallow marine setting. Palaeoecological studies of two disparate macrofossil assemblages at Black Head, Gerroa and Springhill Cutting, Wollongong are being undertaken. Black Head is in the Westley Park Sandstone Member, a greengrey sandstone, with glacial erratics representing a regressive, shoreface facies. The fossil assemblage at Black Head includes: Tomiopsis, Notospirifer, Sulciplica, Terrakea, ?Fletcherithyris, Aviculopecten, Myonia, Vacunella, Megadesmus, Pyramus, Stenopora, Platyschisma, Mourlonopsis, and Warthia. The fossil assemblage examined from Springhill Cutting is dominated by Terrakea. It also includes Pyramus, Vacunella, Notospirifer, Fenestella and Stenopora. The exact stratigraphic position of the sequence at Springhill Cutting is unclear. However, it is inferred that a north-south trending fault has upthrown this area and the Springhill Cutting assemblage may also be a part of the Westley Park Sandstone Member. Very little palaeoecological analysis has been previously undertaken on the Broughton Formation. Focussing on two localities, this study examines: 1. the difference in the abundance and diversity of species between palaeocommunities; 2. population structure and dynamics (eg. survivorship curves); 3. faunal spatial relationships; 4. taphonomy (eg. calcite shells preserved in a reducing environment); 5. lithology and sedimentary structures and; 6. morphological adaptations to the environment. As a product of this analysis changes in community structure as a response to environmental change will be discussed.

RECENT ADVANCES IN UNDERSTANDING OF THE MICROFOSSIL RECORD OF EARLY LAND PLANTS Charles H. WELLMAN Department of Animal & Plant Sciences, University of Sheffield, Alfred Denny Building, Western Bank, Sheffield S10 2TN, UK It is more than 30 years since Gray and Boucot first suggested that spore tetrads recovered from Early Silurian deposits provided the earliest evidence for land plants. This hypothesis was initially controversial,

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IPC2002 Oral Presentations but has subsequently received triumphant support as various lines of evidence has been investigated, and is now generally accepted. This contribution will critically review recent advances in understanding of the microfossil record of early land plants and will discuss current controversies. Pertinent new information will be provided based on newly discovered spore assemblages from the Ordovician of Oman and further examination of Jane Gray's collections, and includes new information on wall ultrastructure in spores and phytodebris. Currently the earliest generally accepted evidence for land plants are spores from the Llanvirn (Ordovician). Recently presented evidence for an earlier origin of land plants is: (i) fossil evidence consisting of purported Middle Cambrian land plants spores; (ii) molecular clock evidence for a Precambrian origin of land plants. I consider that: (i) the Middle Cambrian fossils do not bear sufficient resemblance to land plant spores to unequivocally indicate embryophyte affinities, rather they probably derive from terrestrial algae; (ii) the molecular clock data should be discounted as it is flawed in terms of the methodology utilized. Gray's initial suggestions that the early land plant spores derived from plants at a bryophyte-like grade of organization was based on morphological similarities. Subsequent investigations have supported bryophyte affinities. Initially this was in the form of phylogenetic analyses (based on morphological and/or molecular characters from fossil and/or extant plants) that suggested that bryophytes were basal with respect to tracheophytes. More recently other evidence has been provided, including studies of spore wall ultrastructure and examination of in situ spores. Initial studies of wall ultrastructure in early land plant spores were indicative of liverwort affinities for some morphologies. These studies have now been extended, and all of the main spore morphotypes have been ultrastructurally examined, and a diversity of ultrastructural types have been demonstrated. Recently obtained results on material from the Ordovician of Oman extend the diversity of wall ultrastructure reported. Comparisons with spore wall ultrastructure in extant bryophytes explains much of this variation, but some characters are more reminiscent of those present in extant vascular plants. Since the mid-1980's Edwards and co-workers have been describing assemblages of exceptionally preserved plant megafossils discovered in latest Silurian-earliest Devonian deposits of the Anglo-Welsh Basin. These minute plants are semi-compressed with excellent cellular preservation, often including sporangia with in situ spores. Most of the plants are rhyniophytes/rhyniophytoids and contain in situ trilete spores. Rare examples, however, contain in situ cryptospores. It has been suggested that these plants represent relict floras representative of those present during the Ordovician-Early Silurian. These studies have allowed many of the cryptospore morphologies to be related to their parent plants. Interestingly, the plants often exhibit strange character combinations, and their affinities are often uncertain, although some include bryophytic characters. There has also been progress in identifying the affinities of enigmatic dispersed phytodebris (cuticles and tubes). Many of the younger cuticles can be linked with higher land plants. Some, however, possibly derive from nematophytes. Chemical analysis clearly demonstrates that "nematophyte" cuticle is chemically different from that from coeval higher land plants. The tubes are more problematic. Some are clearly fungal in origin, but others probably derive from nematophytes. Recent findings by Edwards of plants infested with tubes suggest that they may derive from pathogens or decomposers. Intriguingly, Hueber has suggested that the giant nematophyte Prototaxites is indeed a fungus. More recently it has been suggested that some of the phytodebris may represent fragments generated by the disarticulation of bryophyte plants. Initial observations of size and symmetry seem to preclude such an origin, but this is an intriguing avenue of research and should be explored further. Research on the microfossil record of early land plants is vibrant and a number of diverse avenues of research are being explored. It is generating much new information on the origin and nature of the earliest land plants.

BIOSTRATIGRAPHIC, PALAEOGEOGRAPHIC, AND BIODIVERSIFICATION TRENDS OF ORDOVICIAN ACRITARCH ASSEMBLAGES FROM LAURENTIA Reed WICANDER Department of Geology, Central Michigan University, Mt. Pleasant, Michigan, U.S.A. 48859; [reed. wicander@cm ich. edu]. Acritarchs include all organic-walled microfossils of unknown biological affinity. Most palynologists accept that acritarchs are the cysts of diverse marine organic-walled microphytoplankton groups. As the primary producers, acritarchs represent the base of the marine food chain, and thus, fluctuations in their abundance and diversity played a major role in the evolution of the Ordovician marine ecosystem. In order to better understand the biodiversification of the Ordovician marine microphytoplankton, an analysis of the taxonomy, biostratigraphy, and palaeogeographic distribution must be undertaken.

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IPC2002 Oral Presentations As part of IGCP Project No. 410, a compilation of all described Ordovician acritarchs was made to enable palaeontologists to examine global changes and trends in acritarch biodiversity during the Ordovician. Based on published data, more than 100 genera and 300 species of acritarchs have been reported as occurring in Ordovician strata from Laurentia (North America). Of these, at least 25 genera and 150 species were new when originally described. The degree of similarity between Ordovician Laurentian acritarch assemblages and those elsewhere reflects both evolutionary changes and oceanic circulation patterns as well as revealing centers of origination and subsequent dispersal of individual taxa and assemblages. Sections in which well-preserved and independently age-dated Laurentian Ordovician acritarch assemblages have been described include Alberta and eastern Newfoundland, Canada for the Early Ordovician; the St. Lawrence Lowland area of Ontario and Quebec, Canada, as well as Indiana, New York, Ohio, and Oklahoma, U.S.A. for the Middle Ordovician; and the St. Lawrence Lowland area of Ontario and Quebec, Canada, Anticosti Island and Gaspe, Quebec, Canada, and Indiana, Kansas, Kentucky, Michigan, Missouri, New York, Ohio, and Oklahoma, U.S.A. for the Late Ordovician. The Early Ordovician Laurentian acritarch assemblage from Alberta has little in common with assemblages from southern Europe, North Africa, southern Britain, and eastern Newfoundland, while the eastern Newfoundland acritarch assemblage is similar in composition to age-equivalent assemblages from England, Algeria, and Morocco. The major components of the eastern Newfoundland acritarch assemblage consist of diacromorph genera such as Acanthodiacrodium, Actinotodissus, Arbusculidium, Cymatiogalea, Dasydiacrodium, Stelliferidium, and Priscotheca, while the Alberta assemblage has a large component of Aryballomorpha, Athabascaella, and Lua. The Middle Ordovician Laurentian assemblages are dominated by acanthomorphic, netromorphic, and polygonomorphic genera such as Baltisphaeridium, Peteinosphaeridium, Poikilofusa, and Veryhachium, but lack many of the characteristic genera such as Arkonia, Frankea, and Striatotheca that have been reported from southern Britain and Bohemia. The Late Ordovician Laurentian assemblages are very diverse with the following genera represented: Baltisphaeridium, Dorsennidium, Eupoikilofusa, Leiofusa, Lophosphaeridium, Multiplicisphaeridium, Orthosphaeridium, Peteinosphaeridium, Polygonium, Veryhachium, and Villosacpasula. Many of the species occurring in Upper Ordovician strata from Laurentia (e.g., Dorsennidium hamii, Excultibrachium continuum, Orthosphaeridium insculptum, O. rectangulare, and Villosacapsula setosapellicula) are also found elsewhere and are proving to be useful for both regional and global correlation. Despite the seemingly large number of Ordovician taxa reported from Laurentia, there still remains much basic descriptive, taxonomic, and biostratigraphic work to be done. This is particularly true for the Early and Middle Ordovician of this region, where only a few sections have been analyzed. Furthermore, the total number of species, and hence trends in biodiversification, may be misleading, because some of the species named were based on only a few specimens, or morphological variation within the population was not considered when erecting new species. Nonetheless, changes in composition of the Laurentian acritarch assemblages both temporally and spatially are evident even at this early stage of analysis.

THE OLDEST TERRESTRIAL DIPLOPODA: MUDDYING THE WATERS OF MILLIPEDE PHYLOGENY Heather M. WILSON Department of Entomology, 4112 Plant Sciences Building, University of Maryland, College Park, MD 20742, USA [wilsonhm@wam.umd.edu] The Palaeozoic fossil record of millipedes is very patchy, with only a handful of specimens known from localities other than Carboniferous Lagerstatten such as Mazon Creek and Nyrany. All of the SiluroDevonian specimens have been found in Scotland, bar a couple specimens from the Maritime Provinces of Canada. The oldest known millipedes are from the mid Silurian (late Wenlock-early Ludlow) Cowie Formation of Scotland. These specimens represent the oldest known terrestrial arthropods, as evidenced by the presence of spiracles and eversible vesicles. Their trunk ring architecture comprises tuberculate, paranotabearing diplopleurotergites each associated with a pair of broad, free sternites with paramedian eversible vesicles. Similar trunk ring architecture is present in Lower Devonian Archidesmida and also in Carboniferous Euphoberiida, placed together here in Archipolypoda. A specimen from the Silurian Cowie Formation and a specimen of Archidesmus macnicoli have modified legs on the 8th trunk ring resembling gonopods (modified legs in male millipedes used for sperm transfer), the 11th and 10th legs respectively. Two of the morphological characters that have repeatedly been used in generating hypotheses of millipede phylogeny are the presence or absence of gonopods on the 7th trunk ring and trunk ring architecture. The use of both these characters has become less straight-forward in light of the character states preserved in SiluroDevonian millipedes in combination with the distribution of character states in extant millipedes. The exact

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IPC2002 Oral Presentations leg pair modified as gonopods in extant millipedes varies between and among orders (Fig. 1). The use of the character 'gonopods present on the 7th trunk ring' to diagnose Helminthomorpha needs to be reevaluated given no demonstrable homology between gonopods modified from different leg pairs, no demonstrable sperm-transfer function in colobognath gonopods, and the presence of modified anterior appendages on the 8th trunk ring in Siluro-Devonian forms. The ground-plan post-thoracic trunk ring architecture of millipedes is generally accepted to consist of a diplotergite associated with a pair of free diplopleurites and two free sternites. The presence of fused diplopleurotergites has been considered a synapomorphy of Eugnatha (Chilognatha exclusive of Colobognatha). Given their trunk-ring architecture and possession of modified anterior appendages, it is possible that Archipolypoda is the sister group to Eugnatha. One implication of this phylogenetic hypothesis is that it places the last common ancestor of Archipolypoda + Eugnatha in at least the early to mid Silurian, whereas verifiable Eugnatha are currently only known from the Upper Carboniferous. The alternative is that fusion of trunk ring components evolved in parallel in several millipede lineages, as did the modification of anterior appendages for use in mating, at which point the phylogenetic position of Archipolypoda becomes very murky.

unmodified leg

gonopod

modified leg

modified in some taxa

gonopod in some taxa ? gonopod function?

Figure 1. Helminthomorph millipede phylogenetic tree of Enghoff et al. (1993) and distribution of modified anterior legs in extant Helminthomorpha, Archidesmida and a new order from the mid Silurian. In Chordeumatida either the 8th or 9th leg pair is modified as gonopods, not both simultaneously. ENGHOFF, H., DOHLE, W. and BLOWER, J. G., 1993. Anamorphosis in millipedes (Diplopoda)—the present state of knowledge with some developmental and phylogenetic considerations. Zoological Journal of the Linnean Society 109: 103-234.

A DIVERSE EARLY-MIOCENE (15-20MA) TERRESTRIAL FAUNA FROM NEW ZEALAND REVEALS SNAKES AND MAMMALS Trevor H. WORTHY1, Alan J. D. TENNYSON2, Craig JONES3, James A. MCNAMARA4 1 Palaeofaunal Surveys, 2A Willow Park Drive, Masterton, New Zealand. [twmoa@wise.net.nz]; 2Museum of New Zealand Te Papa Tongarewa, P.O. Box 467, Wellington, NZ. [Alant@tepapa.govt.nz];3Institute of Geological and Nuclear Sciences, PO Box 30368, Lower Hutt, NZ. [C.Jones@gns.cri.nz]; 4South Australian Museum, North Terrace, Adelaide, Australia. [McNamara.Jim@saugov.sa.gov.au] New Zealand was once part of Gondwana, but has been an archipelago since its separation from Australia and Antarctica around 82 Ma. The Recent indigenous terrestrial flora and fauna is highly distinctive and attests to a Gondwanan influence with Nothofagus beech trees; arthropods such as peripatus (Onycophora) and giant weta (Orthoptera); and vertebrates such as leiopelmatid frogs (6 spp); tuatara (Sphenodontidae); moa (Aves: Dinornithiformes). Some 245 breeding species of bird and lizards (Scincidae, c.35 spp; Gekkonidae , c.29 spp) dominate the Recent fauna, with land mammals represented only by 3 species of bats. While New Zealand has a very rich late Quaternary terrestrial fossil vertebrate record, it boasts one of the world's poorest pre-Quaternary records. Except for fragmentary Late Cretaceous (80-71 Ma) dinosaur material and isolated moa bones from marine sediments, up to 2.5 Ma, the terrestrial record older than IMa is very limited. A single undescribed fauna from the Manuherikia Group, containing two anatids and undetermined fish was discovered in 1978, and a single crocodilian angular from the same formation was discovered in 1989. The Manuherikia Gp sediments near St Bathans in central Otago comprises quartz gravels, carbonaceous mudstones, thin silts and clays deposited in a lake and river system approximately 1520 m.y.a. We have recently begun a reinvestigation of the Manuherikia Gp sediments employing wet sieving

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IPC2002 Oral Presentations techniques in search of fossil vertebrates and report here the preliminary results of fieldwork from 3 sites. Terrestrial vertebrate fossils include the first snakes and possible non-volant land mammals known from New Zealand, and the first Tertiary record of sphenodontids and bats from New Zealand. Fish bones, abundant in the deposits, represent small (up to 30 cm long) fish that appear to belong to a single taxon. This taxon is not of any freshwater fish family now in New Zealand, and no bones of the present dominant galaxiid group were identified. Reptiles are represented in the deposit by rare bones. A single fragment of tooth row is the first preHolocene fossil record for sphenodontids in New Zealand. Crocodilian remains include 3 teeth and 2 scutes, and indeterminate fragments. Two fragments of tooth bearing bones indicate the first fossil occurrence of a snake in New Zealand. The better preserved, is similar to that of the madtsoiids, an extinct Gondwanan group (J. Scanlon pers. comm.). Bird bones dominate the vertebrate fauna, with at least 300 bones identifiable to a taxon level. Most bones are anatids (c. 5 spp.). One common taxon is a diving duck, but none are described. Waders (Charadriiformes) are represented by c. 2 spp., rails (Rallidae) by many bones of 1 sp., parrots (Psittacidae) by 1 sp., and passerines by c. 4 spp. Other than these, fragments of longbones indicate at least one goosesized species. Eggshell of several thicknesses is abundant and is assumed to be mostly anatid, however, shell c. 1.5 mm thick is as thick as that of Emeid moa, and if confirmed as ratite indicates that moa ancestors were large and flightless at this time. Thus a minimum of 15 avian taxa are represented. Mammals. A single symphysis of a bat mandible is very similar to the recently endemic mystacinids of New Zealand, which are now known to have a Miocene presence in Australia in the form of Icarops (3 spp.). Two other bones, a ?distal tibia and a ?partial mandible, could indicate another so far undetermined mammal taxon, which would be the first non-volant terrestrial mammal from New Zealand prehuman deposits. The Manuherikia Gp sediments provide the first terrestrial vertebrate fauna of Tertiary age for New Zealand. They allow a glimpse of the fauna living in New Zealand after the Oligocene submergence, when land area was reduced to about 20% of present. This event is hypothesised to have been a bottleneck to species diversity based on DNA divergence dates for various taxa. Although preliminary, our results show that some previously undetected taxa survived on New Zealand after separation from Gondwana, and that there has been substantial changes to New Zealand's vertebrate community since the late Early Miocene.

TERRESTRIAL CARNIVORE ECOLOGY IN AUSTRALIAN FOSSIL FAUNAS AND FACTORS INFLUENCING THEIR DIVERSITY: THE MYTH OF REPTILIAN DOMINATION AND ITS BROADER RAMIFICATIONS S. WROE1,2'3 institute of Wildlife Research, University of Sydney, School of Biological Sciences, A08, University of Sydney, 2006; 2 Centre for Research into the Evolution of Australia's Total Ecosystems, Mammal Section, Australian Museum, 6-8 College St, Sydney, NSW, Australia, 2000;3 Vertebrate Palaeontology Laboratory, School of Biological Sciences, University of New South Wales, Sydney, Australia, 2052; [s.wroe@unsw.edu.au or thylacoleo@optusnet.com.edu]. The notion that Australia's middle Tertiary to Pleistocene large, terrestrial carnivore faunas were dominated by reptiles has gained wide acceptance in recent decades. Simple but sweeping hypotheses have been developed seeking to explain this perceived ecological phenomenon. However, a review of the literature does not support these interpretations which are based on largely speculative, and in many cases, clearly erroneous assumptions. Few size estimates of fossil reptilian taxa are based on quantitative methodology, and regardless of method, most are restricted to maximum dimensions. For species of indeterminate growth, this practice generates misleading perceptions of biological significance. In addition to misconceptions with respect to size, much speculation concerning the lifestyles of large extinct reptiles has been represented as fact. In reality, it has yet to be demonstrated that the majority of fossil reptiles underpinning the story of reptilian domination were actually terrestrial. No postcranial evidence suggests that any Australian mekosuchine crocodylian was less aquatic than extant species, while a semi-aquatic habitus has been posited for madtsoiid snakes and even the giant varanid, Megalania. Taphonomic data equivocally supports the hypothesis that some Australian mekosuchines were better adapted to life on land than extant crocodylians, but still semiaquatic and biologically tied to major watercourses. On the other hand, the accelerating pace of discovery of new large mammalian carnivore species has undermined any prima facie case for reptilian supremacy regarding pre Pleistocene Australia, that is, if species richness is to be used as a gauge of overall impact. However, species abundance and consumption, not richness, are the real measures. On this basis, even in Pleistocene Australia, where species richness of large mammalian carnivores was relatively low, available data exposes the uncommon and geographically restricted large contemporaneous reptiles as bit players. In short, the parable of a continent subject to a Mesozoic rerun, wherein diminutive mammals trembled under

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IPC2002 Oral Presentations the footfalls of a menagerie of gigantic ectotherms, appears to be a castle in the air. However, there may be substance to some assertions. Traditionally, erratic climate and soil-nutrient deficiency have been invoked to explain the perception of low numbers or relatively small sizes of fossil mammalian carnivore taxa. But, these arguments assume a simple and positive relationship between productivity, species richness and maximum body mass and either fail to recognise or inappropriately exclude other factors. Productivity has almost certainly played a major role, but mono-factorial paradigms cannot account for varying species richness and body mass among Australia's fossil faunas. Nor can they explain differences between Australian fossil faunas and those of other landmasses. Other factors that have contributed in part, or in whole include sampling bias, a lack of internal geographic barriers, competition with large terrestrial birds and aspects of island biogeography unique to Australia, such as landmass area and isolation, both temporal and geographic.

MULTIPLE TAPHONOMIC WINDOWS IN THE DOUSHANTUO FORMATION AND THE NEOPROTEROZOIC EVOLUTION OF ALGAE AND ANIMALS Shuhai XIAO Department of Geology, Tulane University, New Orleans, Louisiana 70118, USA The Neoproterozoic Doushantuo Formation (550 - 600 Ma) in South China, deposited immediately after the Nantuo (possibly equivalent to the Marinoan) glaciation but perhaps before the diversification of complex Ediacaran animals, contains three extraordinarily preserved biotas: a phosphatized microbiota at Weng'an, a silicified microbiota in the Yangtze Gorges area, and a carbonaceous macrobiota at Miaohe. Similarly preserved biotas also occur elsewhere in South China. Together, these fossils provide a more complete picture of the Neoproterozoic algal and animal diversity, in both microscopic and macroscopic regimes. Algal diversity. Microscopic (mm-sized), cellularly preserved, multicellular algae occur in Doushantuo phosphorites and cherts; more than ten multicellular algal taxa have been described so far. Some of these algae display a level of cellular/tissue differentiation and reproductive complexity comparable to some fossil and modern florideophyte red algae. They may represent stem-group coralline red algae related to the Solenoporaceae. Macroscopic carbonaceous compressions occur in Doushantuo shales at Miaohe Village, Yangtze Gorges area. These carbonaceous compressions are similar to the Burgess Shale and Chengjiang biotas in taphonomic style and preservational quality, thus providing a taphonomic test of possible Neoproterozoic evolution of macroscopic metazoan body plans. About two dozen taxa can be distinguished in the Miaohe biota; most of them are macroscopic algae, displaying features such as dichotomous branching, hold-fasts, and apical meristematic growth. Animal diversity. A few macroscopic compressions in the Miaohe biota have been interpreted as sponges and bilaterians. These putative Miaohe animals, however, can be alternatively interpreted as benthic algae. So far, no bilaterian animals have been unambiguously identified in the Miaohe biota despite intensive collection by several groups. The contrast in animal diversity between the Miaohe and Burgess Shale Chengjiang biotas is significant given that the Miaohe taphonomic facies has the potential to preserve nonmineralized or lightly mineralized animals of macroscopic forms. This taphonomic test indicates that the evolution of macroscopic bilaterian body plans and associated pattern formation mechanisms is largely a Cambrian event. Molecular clock analyses suggest that cladogenesis within the Kingdom Animalia and the clade Bilateria began more than a billion years ago, long before the Doushantuo time. Some developmental biologists have argued that the early history of bilaterians was represented only by microscopic, larva-like organisms that left no fossil record. Together, they allows a distinct possibility that soft-bodied micrometazoans have an extended history in the Proterozoic, before the evolution of macroscopic animals. Such a hypothesis evades a palaeontological test even with some of the best Lagerstatten such as the Miaohe biota. Doushantuo phosphorites, however, capture the micrometazoan diversity in the Neoproterozoic. Submillimeter-sized animal embryos, tabulated tubes, and other problematic microfossils that may represent stem group eumetazoans, cnidarians, or bilaterians, occur in Doushantuo phosphorites. Although this confirms a moderate diversity of micrometazoans in the late Neoproterozoic, the Doushantuo metazoans fail to agree with some specific prescriptions of larva-like micrometazoans as envisioned by developmental biologists. For example, the size of Doushantuo (and Lower Cambrian) embryos suggests that they were lecithotrophic developers, departing from the planktotrophic developers hypothesized by some developmental biologists. Lecithotrophy is perhaps also an adaptation to low-productivity oceans during Neoproterozoic glaciations, if animals did evolve a billion years ago. The three Doushantuo taphonomic windows therefore make it possible to test various hypotheses about Proterozoic algal and animal evolution.

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FEATHERED DINOSAURS FROM CHINA Xing XU Institute of Vertebrate Paleontology and Paleoanthropology, Beijing, 100044 In the last few years spectacular remains of fossils preserving soft tissues, including dinosaurs with feathers, have been collected from Lower Cretaceous sediments of western Liaoning, China, and have caused a worldwide sensation. We have already published numerous reports of these discoveries in prominent scientific journals such as Nature and Science, and many articles have been published in the popular press. Important discoveries include seven new species of theropod dinosaurs closely related to birds: Sinosauropteryx, Protarchaeopteryx, Caudipteryx, Beipiaosaurus, Sinornithosaurus, Microraptor, and Sinovenator. These discoveries provide new information important for understanding coelurosaurian evolution and have significantly advanced the study of coelurosaurian interrelationships and paleobiology. They have changed coelurosaurian phylogenetic patterns proposed by previous studies and advanced significantly the study of character evolution for the lineages. Discoveries of feathered dinosaurs are significant because they provide the most compelling evidence supporting the hypothesis that birds are descended from dinosaurs, and also improve our understanding of the origin and early evolution of feathers and the origin of bird flight by indicating that feathers evolved before powered flight, and might have been used to help gliding, thus supporting the "tree-down" hypothesis of avian flight origin. The recent dinosaurian discoveries from Liaoning have provided the most comprehensive evidence yet of dinosaurian soft tissues, and will undoubtedly produce many more insights in the future.

FIRST TRIASSIC STARFISH FOSSILS (ASTEROIDS AND OPHIUROIDEA) FROM IRAN Mehdi YAZDI Department of Geology, University of Isfahan, Islamic Republic of Iran; [m.yazdi@sci.ui.ac.ir] A complete and well-preserved fossil of Ophiuroidea was collected from Elika Formation (Early Triassic) in the Khoshyielagh area (near Ghoznavi village, eastern Albourz). According to the stratigraphical position of this bed (first bed of Triassic system) the living condition of this marine animal can be proposed as near shore to shallow water. This well-preserved single specimen is the oldest Ophiuroidea fossil is reporting from the Early Triassic of Iran. Based on the shape of central disc and long arms (semi-rounded at the end of arms) the Iranian starfish can be reported as a new species (Palecom iranica n. sp.) A sandy and near shore key bed in the Gheshlagh and Olang coal Mine areas (near Azadshahr, northeast of Iran) was controlled for the living environment related to the Late Triassic Ophiuroidea for the first time. According to the environment related to the fossilized trees in the Gheshlagh and Olang areas and discovery of a key bed with fossilized starfishes a paralic to near shore can be proposed for the east of Albourz at the time of end of Triassic. Based on the position of the fossilized and petrified trees in Gheshlagh Mine, the Autochtaneous (in situ) model can be proposed for the time of Late Triassic flora in East Elbourz, Iran.

LATE CARBONIFEROUS TO EARLY PERMIAN MASS EXTINCTION IN EAST AND CENTRAL IRAN Mehdi YAZDI1 and Neil W. ARCHBOLD2 department of geology, University of Isfahan, Islamic Republic of Iran, Iran; [m.yazdi@sci.ui.ac.ir]; School of Ecology and Environment, Burwood Campus, Deakin University Burwood, 3125 Victoria, A ustralia; [narchie@deakin. edu. au]. 2

The discovery of Early Permian Fusispirifer (Spiriferidae Brachiopoda) from Iran for the first time, similar to those species from Afghanistan and Western Australia reported by Archbold & Thomas 1987, is the main point of this report. The redeposited fauna at the base of the Jamal Formation (Permian) in several parts of Iran has confirmed that uplifting and epirogenetic movement related to the Hercynian affected east and Central Iran. Several genera related to the Late Carboniferous biota and flora were wiped out within or at the beginning of Westphalian stage (Carboniferous) to end of Asselian Stage (Permian System). Gastrioceras sp. is present in the Shotori Range (Kale Sardar and Howz-e-Dorah, eastern part of Iran) of approximately Westphalian age. Continental sequences such as: aluminosilicates, conglomerate, sandstone, coal and

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IPC2002 Oral Presentations gypsum are dominant in several sections. Reworked and replaced fauna (changed into aluminosilicates) in the Soh area at the base of Permian system is another example of uplifting and evidence related to the Hercynian epirogenetic movement in Central Iran. Oolitic and oncolitic limestone beds rich in redeposited foraminiferids at or within the base of Permian of Iran are evidence for a harsh or unfavourable environment related to the beginning of Permian time. In situ and redeposited Carboniferous to Early Permian faunas in the Shotori Range include brachiopods, gastropods, bivalves, crinoids, bryozoans and corals. Close to the base of Permian, several marine faunal elements disappeared in central and east of Iran. Changing environments from land to shallow water and then uplifting close to the base of Permian system in several parts of Iran are two reasons for mass extinction close to the end of the Carboniferous and beginning of the Permian systems. An increasing percentage of siliceous grains in sediments from the Westphalian stage to the base of Permian system in several parts of Iran may be related to the changing of palaeo-climate from warmer conditions to cooler conditions. Disappearance and extinction of several genera related to the fauna near the end of Carboniferous in several parts of Iran can be correlated to other parts of adjacent countries. The relocated fauna close to Early Permian includes various faunal elements including brachiopods, bivalves, foraminiferids and gastropods. The redeposited fauna can be traced in several sections in eastern and central Iran before the start of the Permian system in Iran. The geological gap, missing beds and erosional surface in several sections from Late Carboniferous to different stages in the Permian system in Iran is due to the Hercynian movements. ARCHBOLD, N.W., & G.A. THOMAS. 1987. Fusispirifer (Spiriferidae, Brachiopoda) from the Permian of Australia and Afghanistan. Alcheringa 11, 175-203.

EARLY ORDOVICIAN TRILOBITES FROM THE NORTH DAMGHAN AREA, EASTERN ALBORZ RANGE, NORTHERN IRAN Mehdi YAZDI & S.M. Hosseini NEJAD department of Geology, Isfahan University, Isfahan, Iran; Depatment of Geology, Damghan Universuity of Sciences, Damghan, Iran 1

The Mila Formation outcrops in the Alborz Zone of northern Iran. In the type section it is subdivided into five members and is noteworthy for persistence of these lithologic units over considerable distances. It can be traced from the type area in the E Alborz through the central Alborz, the Soltanieh Mountains and the Takab area to as far as the Lake Orumieh area in Azerbaijan. About 10 km N of Damghan, Member 5 of the Mila Formation (concealed in the type section) outcrops as a richly fossiliferous interval of more than 100 m of dark grey, thin-bedded shale. Abundant fossils include brachiopods, graptolites and trilobites including Megalaspides blackwelderi (Weller, 1907), Asaphellus homfrayi (Salter, 1866) [=Hemigyraspis (Raymond, 1910)], Megalaspidella kayseri (Kobayashi, 1937) [= Plesiomegalaspis Thoral and Ogygitella Harrington and Leanza, 1957]. Based on the trilobites, Member 5 of the Mila Formation is considered to be Lower Ordovician (Arenig). Faunal similarities are with China (e.g. Lu, 1975), Sweden (e.g. Tjernwik, 1965), and Australia (e.g. Legg, 1976). Field evidence all indicate these sediments were deposited in a relatively deep marine environment.. LEGG, D.P., 1976 Ordovician trilobites and graptolites from the Canning Basin, Western Australia. Geologica et Palaeontologica, 10, 158. Lu, H.H., 1975. Ordovician trilobite faunas of central and southwestern China. Palaeont. Sin. Ser. B, 11, 1-463. TJERNWIK, T.E., 1965 on the Early Ordovician of Sweden, stratigraphy and fauna. Bull. Geol. Inst Univ. Uppsala 36,107- 284

VERTEBRATE BIOGEOGRAPHY AND TECTONIC EVOLUTION OF THE MID-PALAEOZOIC IN CHINA ZHAO Wen-iin and ZHU Min Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, P. O. Box 643, Beijing 100044, China A review of the mid-Palaeozoic fish fossils in China indicates that three major eastern Asian blocks (i.e. the South China, North China and Tarim blocks) share a highly endemic vertebrate fauna, namely "the Cathaysian Galeaspid Fauna". Vertebrate faunal evolution within these three blocks and increasing interchange of the Cathyasian Galeaspid Fauna with East Gondwana, Euramerica, and Kazakhstan have been analyzed in the light of the global tectonic background and the tectonic evolution of the China blocks during

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IPC2002 Oral Presentations the mid-Palaeozoic. It was proposed that the global palaeocontinents during the Palaeozoic might be divided into three landmass groups, i.e. Gondwana, Laurasia and Pan-Cathaysian landmass groups. The latter, including all three major blocks in China characterized by the Tethys warm fauna and the aggregation of many small plates, was situated between the Gondwana and Laurasia landmass groups. Based on vertebrate biogeographic information, other faunal and terrestrial floral evidences, and a large corpus of palaeomagnetic data available, we can draw the following conclusions on tectonic evolution during the Silurian-Devonian in China: (1) The South China Block including the Yangtze and Huanan terranes, is not a uniform block until the end of the Silurian. In addition, the North China Block and Qilian Microplate also began to dock at the end of the Silurian; (2) The three major blocks of China can be attributed to PanCathaysian landmass groups, with the Tarim Block closer to the South China Block than the North China Block during the Silurian. On the basis of palaeomagnetic and palaeoclimatic information, the Tarim and South China blocks were located across the equator, whereas the North China Block may have had a position in moderate to low northern latitudes. Absence of Middle Ordovician to the Middle Carboniferous strata (with the exception of Ningxia and eastern Liaoning) was due to regional tectonic movements. At the end of the Silurian, the South and North China blocks began to collide at their eastern ends, whereas plate splits occurred along their western margins resulting in the Tarim Block drifting northward and away from the South China Block; (3) During the Early Devonian, all three major China blocks of the Pan-Cathaysian landmass group were located in moderate to low northern latitudes. Though the South China and the North China blocks gradually came together from east to west, their western regions did not close and the remnant narrow ocean between them still existed at the end of the Devonian. Complete suturing seems to have occurred after the Middle Triassic. During the Devonian the distance between the Tarim and the South China blocks gradually increased. In the late Late Carboniferous, the Tarim Block perhaps collided with Kazakhstan, and the collision with the North China Block may have happened after the Late Permian.

ORDOVICIAN CONODONT BIOGEOGRAPHY - RECONSIDERED Yong-yi ZHEN1'3 and Ian G. PERCIVAL2 3 division of Earth & Environmental Sciences, The Australian Museum, 6 College Street, Darlinghurst, N.S. W. 2010, Australia [yongyi@austmus.gov.au];2 Specialist Services Section, Geological Survey of New South Wales, P.O. Box 76, Lidcombe, N.S.W. 2141, Australia [percivai@minerals.nsw.gov.au]; 3Honorary Research Associate, Centre for Ecostratigraphy & Paleobiology, Macquarie University, N.S. W. A new scheme of biogeographical divisions for Ordovician conodonts is proposed, based on modern ocean biogeography. Interpretation of conodont biogeography is heavily dependent on understanding of the life mode of conodont animals. It is believed that the majority of conodont animals were benthic or nektobenthic, while most of the simple coniform taxa are interpreted as pelagic. Geographical barriers, such as deep oceans, are generally regarded as the primary causes of provincialism for marine benthic and nektobenthic organisms inhabiting different shelf regions which are connected through open ocean surface waters. Pelagic forms were mostly cosmopolitan, and the only significant barrier for them would be ecological - the surface water temperature. The observed spatial and temporal relationships of conodont distribution strongly suggest that water temperature, depth, and salinity were the most important controlling factors on their distribution. Some taxa (cosmopolitan forms) could tolerate a wider range of these parameters, while others (most endemic forms) were limited by their restricted habitat preferences. A striking faunal difference coincident with the shelf break has long been recognised as the most important biogeographical boundary between the Shallow-sea Realm and the Open-sea Realm. These major biogeographical entities are further subdivided herein into Domains (tropical, temperate and high-latitude) and then regional Provinces. Due to the complexity of coastal morphology and sea floor topography, input of sediments and fresh-water draining from adjacent land masses, and their isolation from each other by vast open oceans, provincialism is most apparent in the regions of the Shallow-sea Realm. In the High-latitude domains, faunal differences between the two realms and their subdivisions cannot be easily discerned, since the distribution of biofacies zones and different habitats were also highly condensed spatially and temporally. In contrast, faunal differences are most amplified in the tropical regions, where the traditional North American Midcontinent Province (NAMP) and North Atlantic Province (NAP) were originally defined. The NAMP sensu stricto is more or less equivalent to the Laurentian Province which is defined herein as shallow water regions fringing Laurentia, but NAMP was also widely used in a more broader sense to include all the provinces of the Tropical Domain within the Shallow-sea Realm. The NAP was previously used to include the Open-sea Realm and the Temperate and High-latitude domains of the Shallow-sea Realm. The NAMP has also been employed in the past in a purely ecological sense. To avoid confusion, we recommend that use of these two traditional biogeographical divisions (NAMP and NAP) be discontinued, in favour of the more detailed scheme proposed here.

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IPC2002 Oral Presentations Since conodonts are very useful for regional and international Ordovician biostratigraphical correlation, focus has historically been on cosmopolitan and widespread taxa, to the relative neglect of endemics. Recognition of endemic taxa, and analysis of their distribution by using an integrated approach of ecological and historical methods, is essential to reconstructing conodont biogeography, especially at the provincial level of the Shallow-sea Realm. On this basis at least six conodont biogeographical provinces, namely BaltoScandian (in the High-latitude Domain), Laurentian (Tropical Domain), Australia (Tropical Domain), North China (Tropical Domain), South China (Temperate Domain), and also Precordilleran Argentina (Temperate Domain) can be recognised in the Early Ordovician Shallow-sea Realm. These were separated by the Ordovician oceans, which acted as effective barriers to isolate endemics. During the mid-late Early Ordovician, conodonts experienced their highest provincialism and diversity of the period. Along with the closure of the Iapetus Ocean towards the end of Ordovician, the Balto-Scandian Province shifted from the High-latitude Domain in the Early Ordovician to the Tropical Domain in the Late Ordovician, when the landmass drifted towards the Equator. The Open-sea Realm is dominated by cosmopolitan or widespread taxa, and further formal subdivision is yet to be achieved through detailed studies. We predict that analysis of conodont faunas preserved in deep-water cherts will provide the key to distinguishing domains and provinces within this Realm. Percival publishes with permission of the Director General, N.S.W. Department of Mineral Resources.

A NEW TETRAPODOMORPH FISH FROM THE UPPER DEVONIAN OF CHINA ZHU Min, ZHAO Wenjin and JIA Liantao Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, P. O. Box 643, Beijing 100044, China A new tetrapodomorph fish has been recovered from the Upper Devonian (late Famennian) Remigolepisbearing deposits of North China for the first time. It is suggestive of tristichopterids in its skull-roof pattern and the absence of cosmine, but differs in possessing rhombic scales, and a row of large teeth on the coronoids in addition to marginal denticulate coronoid band and coronoid fangs. A preliminary phylogenetic analysis places the new form, the tristichopterids, and the lineage of elpistostegids + tetrapods in an unresolved trichotomy. The new form represents the first tetrapodomorph fish at the grade of tristichopterids or elpistostegids found from Asia, thus providing new evidence for the character acquisition of crownward tetrapodomorphs and bearing the biogeographic significance.

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Poster Presentations

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IPC2002 Poster Presentations CARBON-ISOTOPE, AMMONOID, AND INOCERAMID STRATIGRAPHY OF THE UPPER CRETACEOUS IN THE OBIRA AREA, HOKKAIDO, JAPAN Yoshihiro ABE1, Hironori FUNAKI1, Norimasa SHIDA1, Tsubasa MATSUMORI2, Hiromichi HIRANO2 Division of Geology, Graduate School of Science and Engineering, Waseda University, 1-6-1 Nishiwaseda, Shinjuku-ku, Tokyo 169-8050, Japan, [yoshi_rookie@hotmail.com]; department of Earth Sciences, School of Education, Waseda University. In this study, carbon-isotope stratigraphy of the Upper Cretaceous sequence in the Obira area, Hokkaido, Japan is shown together with ammonoid and inoceramid biostratigraphy. Geological Setting. The Cretaceous sequence interpreted as fore-arc basin deposits is distributed in the central part of Hokkaido with a simple geological structure. The Upper Cretaceous in Obira area is about 3000m thick, and composed of mudstone and turbiditic alternating bed of sandstone and mudstone. Ammnoids and Inoceramids occur abundantly. Method. Stable carbon-isotope ratio is determined by analyzing organic matter "kerogen," which is included in mudstone. Wherever possible the sampling interval is less than 30-50m in average. Result. Rock Eval analysis indicates that the origin of organic matter is terrestrial and the organic matter had not suffered serious thermal degradation and migration. Therefore the carbon-isotope curve shown in this study should reflect the change of isotopic composition of atmospheric C0 2 . The samples should preserve original value of carbon-isotope ratio. In this curve, two remarkable excursions are discernible; (1) a positive excursion by 1.8%o, (2) a positive excursion by 1.0%o. Discussion. This study reveals both the result of correlation of the carbon-isotope stratigrapy and that of biostratigraphy Inoceramus between in this study area and type section in the Western Europe, are coincident with each other. This means that the both of ages based on Inoceramus biostratigraphy and the carbonisotope stratigraphy are coincident. (1) can be correlated to the well-documented Cenomanian / Turonian boundary "spike". (2) also can be correlated with the broad positive excursion in the Lower Coniacian to the Lower Santonian. In the Obira area, Inoceramus kamuy Matsumoto and Asai and Vascoceras sp. are obtained at 50m above (1). The former is domestic index of Lower Turonian. The latter also indicates the Lower Turonian. Cremnoceramus rotundatus (Fiege), an index for the Lower Coniacian, is obtained from as the same horizon as the start of (2).

MEGADIG Lee ADENDORFF1 & Peter MURRAY2 Australian Museums and Galleries OnLine; 2Museum and Art Gallery of the Northern Territory Every year a team of scientists from the Museum and Art Gallery of the Northern Territory (MAGNT) work at the isolated Alcoota site to uncover a rich deposit of Late Miocene megafauna fossils. They have worked this site for several years and have built up a considerable knowledge of the site's contents, many of which are on display at the museum in Alice Springs. In July 2001 Australian Museums and Galleries Online (AMOL) and MAGNT conducted a webcast from the dig site. The webcast was aimed at primary school-aged children. They could email questions to the scientists on site who would respond within a few hours via a satellite link with the AMOL team. It gave the children an insight into the practice and processing of a real dig site through personal contact with the scientists. Their questions and the scientists' answers appeared on a website called 'Megdig' which also provided background information about the dig site, video interviews with the scientists, a daily dig diary with photographs and animated panoramas as well as an interactive game where children could build their own exhibition about megafauna using real museum objects from MAGNT's collection. This presentation will demonstrate the Megadig website and the technology that was used to make the project happen. It will also look at the potential of live community events to interrogate scientific practice and the opportunity they provide for museums to achieve educational and outreach objectives.

MICROBIOTA FROM LOWER TAL PHOSPHORITE-CHERT MUSSOORIE SYNCLINE: ITS AGE AND PALAEOECOLOGICAL IMPLICATIONS Arun D. AHLUWALIA Centre of Advanced Study in Geology, Panjab University, Chandigarh 160014, India [adahl@pu.ac.in].

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IPC2002 Poster Presentations

Though earlier thought to Mesozoic due to a tragedy of stratigraphic errors/ erroneous lithological correlations, Tal Phosphorite-Chert was a source of microbiota from 1970 onwards, not correctly identified till late seventies/early eighties. High resolution petrographic studies of this critical Lesser Himalayan horizon has yielded a wealth of skeletal algae Obruchevella, acritarchs, sponges, multicellular algae and multiple forms of microproblematica which are yet to be identified even though the task is crucial in delimiting the Precambrian-Cambrian boundary in the Krol Belt of Lesser Himalayas. It is the aim of present poster illustration to attract experts to this crucial microbial assemblage in IPC 2002 so that a credible tool which is available unlike trace fossils independent of facies control, can be put to a logical use. It has been felt that the demarcation of Pc-C boundary at the first appearance of Phycodes pedum is in error because the preservation of any trace fossil is a matter of suitable facies plus chance which does not afford a reliable criteria in stratigraphy. The forms displayed in this poster are more wide in their distribution and not necessarily confined to any particular lithology and occur in association as an assemblage. Such data should normally inspire more confidence. Prof. Andrew H Knoll of Harvard is of the opinion that the forms show a diversity of small acanthomorphic acritarchs belonging to taxa that in the eastern Europe first appear in the Platysolenites antiqiuissimus Zone( Lantova Stage, probably upper Nemakit-Daldyn). According to him Yin Leiming has described similar assemblages from basal Cambrian cherts in China.

PLEISTOCENE EXTINCTION OF NEOGASTROPODS IN THE JAPAN SEA: FROM THE VIEWPOINT OF BIOGEOGRAPHY Kazutaka AMANO Joetsu University of Education, 1 Yamayashiki-cho, Joetsu, Niigata 943-8512, Japan; [amano@juen.ac.jp]_ Many muricid and buccinid gastropods are recorded from the Plio-Pleistocene in the Northeast Japan (Amano et al., 1993, 1996; Amano, 1997; Amano and Vermeij, 1998a, b; Amano and Watanabe, 2001). They are subdivided into two taxonomic groups based on their living depth. Ancistrolepidinae, Neptunea and Buccinum (L group) mainly live in the water deeper than lower sublittoral zone while most species of Nucella, Ceratostoma, Ocinebrellus and Lirabuccinum (U group) are upper sublittoral rocky-bottom dwellers. Distributional pattern. In the L group, a total of six distributional types (Types A-FJ) are recognized among 36 species. Eleven extinct species comprise the type FJ, which is endemic to the Japan Sea borderland. Type A (9 species) is for species that are extinct in the Japan Sea, but are still living in the Sea of Okhotsk and Bering Sea. Type B species (5 species) are known as fossils only along the Japan Sea margin, and now live in the northern Japan Sea as well as in the Northwest Pacific and the Sea of Okhotsk. Type C (3 species) have been recorded as fossils from the Pacific and the Japan Sea coasts and still live in both coasts. Type D species (6 species) live only on the Pacific side, and are recorded as fossils only from there. Type E species (2 species) occur as fossil and living specimens only in the Japan Sea. On the other hand, among 10 species of U group, only two species were extinct (Type FJ ). Six species are belonged to types B (2 species) and C (4 species). One species (Type C') is known as fossils only along the Pacific coast, and now live in both the Japan Sea and the Pacific. Nucella shiwa Chinzei is a extinct species (Type FP), which is confined to the the Pacific side. Discussion. Based on observation of deep-sea sequences, Tada (1994) pointed out the formation of low salinity water and anoxic deep one during the Pleistocene glacial lowstands when the Japan Sea almost isolated. The type FJ species of the U group suffered extinction by the decreased salinity of surface water (Amano and Vermeij, 1998a). Species in both types A and FJ species of the L group underwent extinction owing to the anoxic condition (Amano et al., 1996). The type E species survived in the lower sublittoral to upper bathyal waters of the Japan Sea (ca. 100-400m) which had normal salinity and were oxic (Amano and Watanabe, 2001). Based on the presence of the type A and FJ species and the low-salinity surface water of the glacial age, it is reasonable to consider that the populations of species in types B and C became extinct in the Japan Sea, but survived on the Pacific side. As most B and C type species of both the L and U groups are shallow water dwellers,the modern populations of types B and C species in the Japan Sea may represent recent invasions through its shallow northern entrance.

184

IPC2002 Poster Presentations PRELIMINARY NOTES ON THE BRYOZOANS OF THE EMSIAN REFERENCE SECTION IN THE SHINE JINST AREA, SOUTHERN MONGOLIA Ya. ARIUNCHIMEG Palaeontological Centre, Mongolian Academy ofSciences, Ulan Baatar, Mongolia; [jariun@mongol.net] The Emsian in the Tsakhir reference section of the Shine Jinst area (between N44° 22.119', E99° 27.130' and N44° 22.201', E99° 26.906') is subdivided into three brachiopod regional zones. Bryozoans are scarce in the lower zone, but their taxonomic diversity gradually increases and attains its maximum in the upper part. The studied bryozoans came from the middle zone of Spinatrypa (Spinatrypa) galinae-Cyrtinopsis nalivkini in dark gray argillaceous limestone beds just below beds with Polygnathus inversus, and P. perbonus (Alekseeva etal., 1996). According to previous data from this beds, Fistulipora sp. and Semicoscinium sp. were determined. Preliminary analyses of samples from the Tsakhir section reveal bryozoans of the genera Fistuliramus, Amurodictya, Nematopora and Hexites. The genus Fistuliramus is known from Upper Silurian and Lower to Middle Devonian rocks of Russia and China. Amurodictya was originally described from the Russian Far East in sediments assigned to the end of the Pragian and beginning of the Emsian and have been found in the eastern part of Mongolia (Romantchuk, 1979). A few representatives of the family Artrostyllidae were reported from Mongolia; another two have been identified. Species of the Nematopora were described from the Devonian only: from Eifelain and Givetian sediments; it is now reported from Emsian horizons. Until now, only type species of the Hexites was known and it was from Lower Carboniferous rocks (Gorjunova, 1985). These discovery may have ramifications regarding stratigraphic and geographic distributions, mechanism of migration, and possibly identifying the centres of first appearance of the above-mentioned genera. R.E., et al. 1996. Emsian and Eifelian reference sections of Mongolia, pp.51-56. In Stratigraphy and GeologicalCcorrelation, Vol.4, No.l.

ALEKSEEVA,

ROMANTCHUK, T.V., 1979. Some new Early Devonian Bryozoa of the upper Amur basin. Paleont. Journ. 4,40-46. GORJUNOVA, R.V., 1985. Morphology, system and phylogeny of bryozoans (order Rhabdomesida).

THE FIRST FIND OF ARTHROSTYLIS IN THE UPPER ORDOVICIAN TSAGAAN DEL SECTION, MONGOLIA Ya. ARIUNCHIMEG Palaeontological Centre, Mongolian Academy of Sciences, Ulan Baatar, Mongolia; [jariun@mongol.net] The Upper Ordovician rocks in Tsagaan Del section (between N46° 03.38 , E100° 14.38' and N46° 03.33', El00° 14.33') are relatively well developed and considered to be a type area for the Ashgil stage by Rozman & Minjin (1979). The section is subdivided into 7 intervals with total thickness of 320 m. Bryozoans are restricted to interval 6 (25 m) consisting of green, brown argillaceous limestone yielding many brachiopods, corals, crinoids, trilobites, and conodonts. Last summer IGCP 410 visited this section and made fossil collections Research on the bryozoans has resulted in discovery of many representatives of the family Arthrostylidae, a family of small articulated Rhabdomesida, very rare in Palaeozoic sediments of Mongolia. Some representatives of Nematopora were identified in Devonian and Carboniferous rocks. The Tsagaan Del section has produced two genera of this family. One, a species of Arthrostylis, is dendroid and branching, with several slightly curved subpolygonal segments with diameter 0.4-0.5 mm and 5 to 7 longitudinal rows of apertures. Prominent longitudinal ridges with capillaries occur between the rows of apertures. Arthrostylis, originally described from the Upper Ordovician of North America, also occurs in Ordovician and Silurian rocks of Greenland and the Baltic region. The Mongolian forms, the first report of the genus from Asia, differ in having large colonies with more rows of apertures. The second genus was observed only in thin sections and zooecial apertures are not preserved. In longitudinal section rarely thin diaphragms can be observed. Cross section is elongated with long diameter of 0.6 mm and short of 0.3 mm. This genus still not determined. Associated bryozoans previously reported (Kopaevich, 1983) are Pachydictya ambigua Ross, Stictopora mutabilis Ulrich, Batostoma crassitunicatum Kopaevich, Eridotrypa multiseptata Kopaevich, Homotrypa aberrans Kopaevich, Nicholsonella amplexa Kopaevich and Amplexopora inacifera Kopaevich The Tsagaan Del section is correlated with the Dietken horizon of the Altai-Sayan folded area and the Pirgu horizon of Estonia (Xone of Dicellograptus complanatus). 1

ROZMAN, Kh.S. & MINJIN, Ch., 1979. To the stratigraphy of Ashgilian Stage in western Mongolia, pp. 69-78. In Notes of USSR

Academy of Sciences, Geology 3.

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IPC2002 Poster Presentations KOPAEVICH, G.V., 1983. Generic and species assemblages of Ordovician bryozoans of Mongolia, pp.45-49. In New species of fossil invertebrates of Mongolia. JSMPE Transactions, vol.20.

MIGUASHA NATIONAL PARK: A UNESCO WORLD HERITAGE SITE Marius ARSENAULT, Sylvain DESBIENS & Paul LEMIEUX Museum of Natural History, Miguasha National Park, Parks Quebec, Quebec, Canada Since its discovery by Abraham Gesner in 1842 and its rediscovery by R.W. Ells in 1879, the Miguasha fossil site has been intensively excavated. The expeditions by William Patten and Erik Stensio in the early 20th century are examples of the work done by collectors from abroad. Local collectors like Antoine and Euclide Plourde helped them and it is estimated that over 15,000 fish specimens from the Escuminac Formation are now kept at different institutions around the world. Nearly 8,000 are at the Museum of Natural History of the Miguasha National Park. This number is swelled each year by some 500 new fish, invertebrate, and plant specimens. These specimens are enhancing our current knowledge about a fauna and flora considered to be exceptional. The estuarine environment revealed by the Miguasha Lagerstatten provides a unique window on the Frasnian fishes that preceded the Late Devonian extinction. It also sheds invaluable light on the water-to-land transition of vertebrates that took place also by the end of the Devonian. The site has yielded 20 fish species that fall into 19 genera, 15 families, and 11 major fish groups. The Escuminac Formation has yielded specimens of the last anaspids, the only ones known from the Devonian, and the last osteostracans, both groups being jawless fish. Two genera, the antiarch Bothriolepis and the arthrodire Plourdosteus represent placoderms. Spiny fishes (Acanthodii), with 3 genera and 4 species, are common and preserved in fine detail. One species, Triazeugacanthus affinis, attests to sporadic mass die-offs in the population. Cheirolepis canadensis is among the most primitive ray-finned fishes (Actinopterygii) and is the sister group of the other actinopterygians. The Escuminac Formation reveals its full importance in its diversity of lobe-finned fishes (Sarcopterygii), including actinistians, lungfishes, porolepiforms, osteolepiforms, and elpistostegids. It boasts the most representative sample of these fleshyfinned fishes from the Devonian. Miguashaia bureaui is one of the largest species from the Palaeozoic and one of the most primitive of the actinistians. Scaumenacia and Fleurantia are lungfishes belonging to two distinct dipnoan families. Also present are two genera representing the porolepiforms—a relatively undiversified group. The best known of the lobe-finned fishes is Eusthenopteron foordi. With the bone structure of its paired fins, the pattern of its cranial roof, and its rhachitomous vertebrae, this species forms an intermediate evolutionary link between fish and the first tetrapods. Presently, the discovery of new Elpistostege specimens is among our collecting priorities. This elpistostegid, whose paired fins and tail morphology are unknown, shares many characters with Panderichthys of Latvia. Elpistostege is at a turning point in the phylogeny leading to the appearance of the tetrapods. It is about 8 million years younger than Panderichthys and a few million years older than Elginerpeton of Scotland, and Obruchevichthys of Latvia and Russia, which are among the first presumed tetrapods. The Escuminac Formation has also yielded many specimens of the progymnosperm Archaeopteris and material from the barynophytale Protobarynophyton. Spores diversity, with more than 70 species, indicates a much more diverse range of terrestrial plants. Invertebrates are represented by one of the oldest land scorpions, an eurypterid and a small chonchostracan. Acritarchs have also been described. In recognition of the evolutionary and environmental representativeness of its animal life forms, their abundance, and the exceptional quality of their preservation, the Miguasha site was officially inscribed on the UNESCO World Heritage List in December 1999. A major expansion to the Museum of Natural History will be completed during 2002, giving much more importance to research and collection facilities. New core samples will provide a basis for a revised stratigraphic standard of the whole Escuminac Formation. Among other things, it will improve and refine our understanding of the sedimentology of this formation and the palaeo-environment of Miguasha palaeo-estuary and its fauna.

RECOVERY OF QUATERNARY ELEPHANTID REMAINS FROM WESTERN IRAN Majid Mirzaie ATAABADI1, Mehdi YAZDI1 and Kamal TAHERI2 department of Geology, Faculty of Sciences, University of Esfahan, Iran; 2Regional water organization, Kermanshah, Iran

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IPC2002 Poster Presentations Farchad and Sahabi (1961) first reported and described elephantid remains from the Early Quaternary alluvial deposits in the Lorestan area, west central Iran. The specimens, including a molar and several postcranial elements, were assigened to Elephas namadicus, a widespread species in east and central Asia. Here we report the discovery of a new molar from the Quaternary deposits of the Rawansar area, Kermanshah province, western Iran. The recovery of new molars also comparable to Elephas namadicus reveals the wide distribution of Elephantidae in the Quaternary period through the Zagros area, west and southwest Iran. We thank Mr Reza Faraji for providing the fossil material. FARCHAD, F. and SAHABI, Y., 1961, La presenc d'un elephant dans le quaternaire de l'lran, Comptes rendu sommaire de la socitegeologique de France 15, 304-305. MIRZAIE ATAABADI, M., 2001, Preliminary study of Elephant teeth remains from the Quaternary deposits of Rawansar region, pp. 7277, In Taheri, K. (ed), The Rawansar region: Archeology, Geology, Geography and Culture, Taq Bustan publications, Kermanshah. (in Farsi)

DINOSAUR TRACKS AND TRACES IN IRAN: A REVIEW OF OLD AND NEW DISCOVERIES Majid Mirzaie ATAABADI Department of Geology, Faculty of Sciences, University of Esfahan, Iran De Lapparent and Davoudzadeh (1972) reported the first dinosaur tracks in Iran from Early Jurassic terrestrial deposits in the Kerman area, east central Iran. They described 23 footprints subdivided into 5 types (4 attributed to ornithopods and 1 attributed to theropods). Later, de Lapparent and Nowgolsadat (1975) reported a new carnosaurian track from the Zirab area, northern Iran. They proposed the name Iranisauripus zerabensis for this new tridactyl footprint. Klyver et al. (1983) found Late Cretaceous tracks, attributed to ornithomimids in the Lakarkuh area, eastern Iran. Recently the author reported a new ornithopod dinosaur track from the Late Jurassic red beds of the Kerman area (Mirzaie Ataabadi 2001). Probable gastroliths are also discovered in the Middle Jurassic terrestrial deposits of the same area. KLYVER, H . M . , GRIFFIS, R. J., TIRRUL, R., CHANCE, P. N . and MEIXNER, H. M., 1983, Explanatory of Lakar k u h quadrangle m a p 1:250

000, Geological Survey of Iran, 175 P. LAPPARENT, A. F. de and DAVOUDZADEH, M., 1972, Jurassic dinosaur footprints of the Kerman area, central Iran, Reports of the Geological Survey of Iran 26, 5-22. LAPPARENT, A. F. DE and NOWGOLSADAT, M. A., 1975, une trace de pas de dinosaure dans le lias de l'Elbourz, en Iran, C. R. Acad. Sci. Paris, D 280, 161-163. MIRZAIE ATAABADI, M., 2001, A new dinosaur footprint from Iran, p.26. In Proceedings of the 19th Symposium on Geosciences, Tehran, Geological and Mining Exploration Survey of Iran.

FIRST REPORT OF PERMIAN GONIATITDAE FROM CENTRAL IRAN (ISFAHAN, CHAHRESEH AREA) Nazanin BAGHERY & Mehdi YAZDI Department of Geology, Factulty of Sciences, University of Isfahan, Isfahan - Iran. [nazaninl3@ yahoo.com; m.yazdi @ sci.ui.ac.ir]. Goniatitdae from a section northeast of Isfahan are simillar to those that were reported by Zakharov (1999) as Epijuresanites pilnikovensis and Meishanensis nautilida . This species has been reported in China. The presence of the above mentioned Goniatitdae is very important regarding International Geological Correlation . According to Zakharov (1999) , the age of Epijuresanites pilnikovensis is lower Permian. This is the first report of lower Permian Goniatitdae from central Iran. The sequence in the Chahriseh area that yeilded the goniatites is composed of sandy limestone. Within the sequence, several macro fauna abound including, Gastrophoda, Brachiopoda, Porifera, Cnidaria, Pelecypoda, and Trilobita .This fossiliferous horizon can be traced to the East (Shotori Range) and northeast of Iran (East Alborz). ZAKHAROV,YD.D., A . U . OLEINIKOV,G.V. KOTLYAR,V.I. BURAGO,V.S. RUDENKO, and E.A. DORUKHOVSKAYA,1999, First Find o f

Early Permian Goniatite in SouthrenPrimorie,Geol.of pac.Ocean,vol.l4,PP.805-816 .

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IPC2002 Poster Presentations DIVERSITY AND DISTRIBUTION OF ACANTHODIAN REMAINS IN THE UPPER DEVONIAN OF THE SOUTH TIMAN (RUSSIA) Pavel BEZNOSOV Institute of Geology, Komi SC, UD, RAS, Syktyvkar, Komi Republic, Russia; [Beznosov@geo.komisc.ru]. Acanthodian remains are not abundant in the Upper Devonian of South Timan. They are mostly represented by isolated scales and rarely by fin spines and jaw bones. These remains have not previously been studied in detail. The diversity and distribution of acanthodians in the Upper Devonian of the South Timan is given, based on a summary of previous and new data. Persacanthus sp. Jaw bones, length up to 3 cm. Upper Member of Timan Formation - Lower Member of Uste Yarega Formation (see Table). Haplacanthus sp. Spines. Distribution as for Persacanthus sp. (after Ivanov & Luksevics, 1996). Devononchus sp. Spines. Timan (Upper Member) and Savinobor formations, (after Ivanov & Luksevics, 1996). Devononchus sp. Scales, usually 0.4-0.7 mm. The crown is covered by numerous longitudinal converging ridges. The neck is moderately high and thick. The histological structure is of "Acanthodes" type. Lyaiol Formation. Acanthodes? sp. Scales, ranging 0.15-0.7 mm. The crown is flat and smooth, rhombic to oval in shape. The surface of the crown is covered with numerous microtubercles (about 1-2 jum in diameter) and becomes like shagreen. Micropores are absent. The histological structure is of "Acanthodes" type. These scales are most numerous and abundant among the acanthodian remains and probably belong to several species. Uste Yarega (Upper Member), Domanik and Lyaiol formatoins. Acanthodidae gen. indet. Large scales (up to 1 mm) with smooth rhombic crown. The scale base is relatively flat and usually with two sockets along the posterior edge. The neck is very low. The surface of the crown has rare micropores of different size. Microtubercles are absent. The histological structure is of "Acanthodes" type. They are probably a new genus. Izhma Formation, cf. Cheiracanthus sp. Scales. They are relatively large (up to 0.8 mm) with wide parallel longitudinal ridges on the crown. The neck is high. The base is convex. The histology has not been studied. Izhma Formation. STAGE K)RMATICN

FAMENIAN

FRASNIAN

Timan

Uste Yarega

Lyaiol Domanik

Vetlasyan

Sirachoy

Ukhta

Savinobor

Izhma

Table. Upper Devonian subdivisions of the South Timan. IVANOV, A. & LUKSEVICS, E. 1996. Late Devonian vertebrates of the Timan. Daba un Muzejs, 6,22-33. Riga.

SILURIAN BRACHIOPOD ASSEMBLAGES IN THE TIMAN-URALS REGION Tatyana BEZNOSOVA Institute of Geology of the Komi Science Center Ural Division RAS, Syktyvkar Silurian brachiopod assemblages have been found to occur in specific facies environments of the basin. Brachiopod selectivity manifested itself in relation to depth, hydrodynamics, water salinity, nature of the ground, and proportion of terrigenous material. Llandovery and Ludlow assemblages were dominated by pentamerids. The major role in the early and middle Llandovery was played by Virgiana, Borealis, Pentamerus, Pseudoconchidium, and Virgianella, that became widespread due to a large late Ordovician/early Silurian transgression in the Timan-Urals Region. Sections in the Subpolar Urals, closest to the deep-sea part of the basin, and sections in the Northern Timans, remote from it, show similar ecologic assemblages, all included in A.Boucot's third bathyal assemblage. This suggests that Northern Timans used to be part of the early Silurian basin deepening north-northeast. Shallowing of the Timan-Urals basin in the early Wenlock favoured accumulation of littoral and lagoonal muddy sediments. Brachiopod assemblages were ousted almost entirely by abundant algae. Rise of the sea level in the late Wenlock resulted in the appearance of Spirinella nordensis and Atrypoidea linguata brachiopod assemblages. The Ludlow brought about dramatic biota changes, a result of vast regression and active formation of reefs, limiting the shallow shelf in the east. These changes gave rise to brachiopod assemblages of two types: those of the flat bottom, inhabiting shelf lagoonal environments with limited hydrodynamics, and reef assemblages. Pentamerous assemblages were only reef-confined. The following assemblages of pentamerids are known from the Timan-Urals Region: Conchidium tegularis in the Polar Urals, Conchidium nocosemelicum and C. biloculare in the Northern Urals, and C. novosemelicum in the Subpolar Urals.

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IPC2002 Poster Presentations Littoral sediments of the regressive stage in the evolution of the Silurian basin hosted the following assemblages: Greenfieldia, Didymothyris, Atrypoidea, Lenatoechia, Morhynorhynehus. Brachiopod assemblages in the Pridoli developed under conditions of repeatedly changing facies, open shelf environments being the most favourable. The palaeobasin was open for fauna migration as suggested by presence of taxons widespread in coeval sediments in the Timan-Urals Region, Baltia, Podolia, arctic islands of Russia and North America. These are Atrypoidea, Howellella, Collarothyris, Hemitoechia, Grebenella. Representatives of taxon Atrypoidea were best adapted to the varying conditions of sedimentation and survived throughout the widest stratigraphic range (Wenlock, Ludlow, Pridoli).

TAXONOMY AND MINERALOGICAL COMPOSITION OF FOSSIL AND RECENT CHEILOSTOME BRYOZOANS Yu.A.BORISENKO1. and V.I. GONTAR2 1 Geology and Geography Department, Kharkiv National University, Svobody Square, 4, Kharkiv, 61077, Ukraine [bor@sky.net.ua]; laboratory of Marine Research, Zoological Institute of RAS, University Quay, 1, St Petersburg, 199034, Russia. The taxonomy of the Bryozoa is incomplete, and criteria for describing higher taxa are varied and often subjective. Very little attention has been paid to microstructure and the composition of the bryozoan skeleton and its phylogenetic importance. Therefore, analysis of mineralogical peculiarities of cheilostome bryozoans is suggested as a potentially important taxonomic character. On the basis of our own analyses and data in the literature on the mineralogical composition of different taxa we have shown the following patterns of distribution of mineralization types in taxa of cheilostome bryozoans. It is highly probable that the more primitive bryozoans among both the Anascina and Ascophorina have only calcitic skeletons, whereas evolutionary advanced bryozoans change their skeletal composition from calcite to aragonite, including intermediate forms with different proportions of these two minerals which may by termed bimineralic. Considering the insufficient level of mineralogical study of bryozoan colonies, we can characterize the mineralogical compositions only of large taxa, for example superfamilies, although in many cases it is possible to obtain accurate characteristics for individual families. In particular, in spite of the fact that mineralogical belonging of Labiostomella and Aetea genera is unknown, considering data on other genera, the whole order of Membraniporida can be referenced to bryozoans with calcitic type of skeletal mineralization according to Morozova and Viskova's system or equivalent to them four first suborders according to Gordon's system. But here the relative resemblance of the specified two systems comes to an end. In Morozova and Viskova's system the superorder Eurystomellidea is quite heterogeneous in mineralogical relation. In it orders Bugulida, Cellariida, Cribrilinida are calcitic (C) and Flustrida and Microporida are bimineralic ones (AC). There is approximately similar distribution of mineralization type among Anascina in Gordon's system. In suborder Neocheilostomatina Buguloidea and Cellarioidea superfamilies are calcitic and Calloporoidea and Microporoidea superfamilies are bimineralic. In Morozova and Viskova's system Ascophorina find themselves in a large on the whole bimineralic order Eurystomellida. More differentiated distribution we can get in Gordon's system in Ascophorina suborder: first 2 infraorders (Acanthostegomorpha and Hippoothomorpha) are calcitic, the other 2 (Umbonulomorpha and Lepraliomorpha) are bimineralic. By Morozova and Viskova, 1988, 1992 Superorder Membraniporidea Order Membraniporida C Scrupariida C Aeteida ? Superorder Eurystomellidea Order Flustrids AC Cribrilinida C Eurystomellida AC Microporida AC Cellariida C Skyloniida ? Bugulida C Catenicellida ?

By Gordon 1996 Suborder Protocheilostomatina ? Inovicellina ? Scrupariina C Malacostegina C Neocheilostomatina: Superfamily Calloporoidea AC Buguloidea C Microporoidea AC Cellarioidea C Suborder Ascophorina: Infraorder Acanthostegomorpha C Hippothomorpha C Umbonulomorpha AC Lepraliomorpha AC

Comparison of systems of Cheilostome bryozoans while mineralogical composition of skeleton (C-calcite, A-aragonite)

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DIVERSIFICATION OF CARBONACEOUS BIOMINERALIZION IN PELECYPODS AND GASTROPODS AT DIFFERENT TAXONOMICAL LEVELS Yu.A. BORISENKO Geology and Geography Department, Kharkiv National University, Svobody Square, 4, Kharkiv, 61077, Ukraine; [bor@sky.net.ua]. The origin of a carbonaceous shell (skeleton) at the early beginning of Palaeozoic was the reaction of molluscs to essential geochemical changes of environmental habitation. The skeletogeny became a major stage in evolution of molluscs and has served as a reliable basis for their taxonomy. It has been historically established, that originally in the systematic purposes for the morphological features of shells were used for pelecypods, and for gastropods - predominantly information about a constitution of a soft body, then other data were added to them , including microstructure, but the belonging of shells' matter to one or another way of biomineralization was not taken into account. This was promoted much by belief, that the matter of shells in many cases has no stable composition, can vary greatly at diagenesis, and due to this its count at phylogenetic constructings seemed optional. Biomineralization principally differs from carbonaceous sedimentation. If inorganic genesis of one or another mineral phase is controlled mainly by chemical property and temperature of seawaters, in biological systems the role of an organic matrix is still essential . The origin of shells different in a microstructure and mineral composition is treated nowadays as a result of stereochemical interaction of organic matters of extrapalliallic fluid with dissociated carbonaceous ions, concentrated in specific positions to give rise to a germing of a relevant mineral phase. For the majority pelecypods and gastropods calcareous layers consist of aragonite, and this composition never varies, if only it does not recrystallize in calcite in the result of fossilization and diagenesis. A smaller group is made by layered bimineralic, calcite - aragonite shells with variable quantity of calcite, which can vary, depending on conditions of a molluscs' existence, from zero point up to complete predominance. Unlike pelecypods among gastropods there are practically no pure calcite shells, usually a part of aragonitic matter remains in them. The bimineralic indication has different taxonomical level. In some cases it applies to a family, superfamily or suborder, order and even of subclass, for example, subclass of prosobranchial gastropods has both types of shells, and opisthobranchiates and pulmonates have extremely aragonitic skeleton. Among pelecypods rather nonuniform by phylum of biomineralization are the orders of Cyrtodontida, Hippurida, Venerida, Conocardiida, Pectinida. Data on several hundred of mineralogical definitions of shells of fossil and recent molluscs, both own, and those taken from the literature, have shown, that the system traditionally used by palaeontologists in a number of cases unites superfamilies, nonuniform as to the type of biomineralization requiring revision with the use of larger volume of material. In our opinion, species with aragonitic shells should not be united with bimineralic. However, the contemporary mineralogical level of knowledge of molluscal shells in particular the extinct ones is still poor. Quite often primary mineralization of fossils remains absolutely vague. Many taxa, referred nowadays on single definition to aragonitic group, at more detail analysis could be bimineralic. There are reasons to suppose, that the sceletal forms of molluscs, formed during geologic history, did not essentially change their genetic code and the corresponding type of biomineralization for each taxon. Thus, the mineral composition of shells of molluscs supplemented with the data on a microstructure, can be considered as an additional sign to be considered in the specification of systematic groups.

REVISION OF THE PALAEOTHEMPERATURE ABILITIES OF BELEMNITES Yu.A. BORISENKO Geology and Geography Department, Kharkiv National University, Svobody Square, 4, Kharkiv, 61077, Ukraine; [bor@sky. net. ua]. Rather compact structure of the rostrums of Mesozoic belemnites, their frequent occurrence and the fact that it is easy clean rostrums from enclosing rocks created the illusion of exceptionally good preservation of fossil shell matter. It became the main reason of initial choosing rostrums among other fossils as the principal objects of biogeochemical research and the proportion of oxygen isotopes in shell matter of Maestrichian Belemnitella was determined as a standard when calculating the palaeotemperature of water conditions. However, later there arose some doubts as to the invariability of initial microelemental and isotopic

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IPC2002 Poster Presentations composition of the shell matter of belemnites. And, consequently, the evaluations of temperature made on the basis of shell belemnite composition are doubtful and in a number of cases they did not correspond to the general palaeogeographic situation. Such discrepancies became the motive for the present generalization of the geochemical data on belemnites which have been accumulated for half a century. Interpretation of the mineral composition of rostrums which have no direct analogues in recent molluscs turned to be the main and the most difficult task. Having analyzed all published data on rostrum matter composition the author can suppose that the internal belemnite skeleton initially was not a hard formation, it was a compound porous weak-mineralized organogenous hydrostatic apparatus. The long existing opinion about initial exclusively calcite composition of rostrum is disproved nowadays by finding aragonite of different age and unique preservation. Different parts of organogenous rostrum included in former times regularly distributed thin crystals of aragonite and/or low-magnezial calcite. The bimineral composition of skeletons was genetically determined and initially formed during their growth, and the changes of palaeothemperature could noticeably regulate the amount of low-magnezial calcite as it occurs in gastropods and bivalves. After the rostrums had been buried, aragonite gradually but rather quickly transformed into calcite and metastable low-magnezial calcite was subjected to recrystallization, pores were cemented and the degrading organic matter was replaced by secondary calcite. The initial microstructure with different organogenous admixtures in dark- and light-coloured layers were preserved. Taking into consideration that the recent calcite composition of rostrums is the product of the secondary transformation, one has to consider with regret that belemnites can not be taken as unique indicators of palaeotemperatures. The differences in microelements quantity and ratios of stable isotopes caused by possible influence of temperature are changed essentially during diagenesis process and under the influence of subsoil water. In connection with this, hardly interpretable quantitative heterogeneity of the composition of belemnite rostrums can be used only when carrying out comparative evaluation of the stage of the secondary transformation of shell matter and enclosing rocks.

TWO EXCEPTIONALLY-PRESERVED ORDOVICIAN SPONGE FAUNAS FROM AVALONIA Joseph P. BOTTING Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3BU, UK; [josephOO@esc. cam. ac. uk] The Palaeozoic sponges of Avalonia have been barely studied for over a century, and it is normally assumed that fossils are so rare and non-diverse as to be of little importance. This poster introduces two Middle Ordovician faunas from disparate palaeoenvironments of central Wales, with comments on their significance. The Llandegley Rocks site (middle Llanvirn: murchisoni Biozone) contains at least 15 species of spicular and aspicular demosponges, hexactinellids and a heteractinid from very shallow, coarse siliciclastics, preserved as silicified external moulds. In two specimens, silicification was sufficiently rapid to preserve parts of the proteinaceous skeleton. The problematic Australian genus Pseudolancicula Webby and Trotter is recorded for only the second time, and related taxa are described in articulated condition, allowing interpretation as poecilosclerid demosponges. A supposed root tuft, Pyritonema, dominates the fauna, but the presence of axially-incorporated crinoid pluricolumnals and the preservation of the protein skeleton in one specimen imply that this interpretation is incorrect; they are re-interpreted as monaxonid hexactinellids derived from lyssakids by functional expansion of the root spicules and loss of hexactines. The Llanfawr Quarries site (basal Caradoc: gracilis Biozone) preserves about 15 species (dominantly reticulosid hexactinellids, and a hazeliid demosponge) in shelf mudstones. Spicules are replaced by iron oxides, presumably after pyrite, and often include thin pyritic deposits over the area of soft tissue. The fauna occurs at several horizons, with differing taxonomic composition, and includes Asthenospongia Rigby, King and Gunther, and a strongly spinose relative, and two species of reticulosid possessing a wall of acanthohexactines. One species shows the development of thick walls and spicule modification prior to complete loss of the regular protospongiid array, and suggests an alternative evolutionary origin of thickwalled hexactinellids to that from the dictyosponges or hintzespongiids.

A NEW SPECIES OF NUMMULITES (LATE LUTETIAN) FROM JABAL HAFIT AND AL FAIYAH: WESTERN SIDE OF THE NORTHERN OMAN MOUNTAINS, UNITED ARAB EMIRATES Mohamed BOUKHARY1, Osman ABDELGHANY2 and Salah BAHR1

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IPC2002 Poster Presentations Geology Department, Faculty of Science, Ain Shams University, Cairo, Egypt; [mboukhary@hotmail.com]; Geology Department, Faculty of Science, United Arab Emirates University, Al Ain, P.O.Box 17551, United Arab Emirates; [Osman.abdelghany@uaeu.ac.ae] 2

Nummulites n. sp.(Group: Nummulites distans) is taxonomically analysed and described from fossiliferous limestones on the western limb (Tle4) of Jabal Hafit anticline, Al-Ain area, and from Al-Faiyah Range Mountains (northeast of Jabal Al Aqabah, U.A.E.). This species evolved in parallel lineage with the phyletic line of Nummulites maximus d'Archiac, 1850. The phylogeny of the lineage of Nummulites n. sp. is from tight to lax while the opposite trend is found in the lineage of Nummulites maximus. This species conforms well with that described from Turkey by Decrouez & Selcuk (1981) as Nummulites aff. maximus.

CHITINOZOA AND ACRITARCHS AT THE SILURIAN/DEVONIAN BOUNDARY: EXAMPLES FROM THE BARRANDIAN AREA Rainer BROCKE1, Volker WILDE1, Oldrich FATKA2 and Ulrich MANN3 Research Institute Senckenberg, Palaeobotany, Senckenberganlage 25, D-60325 Frankfurt/Main, Germany, [rbrocke@sngkw.uni-franlrfurt.de; vwilde@sngkw.unifranlrfurt.de]; 2 Charles University, Institute for Geology and Palaeontology, Albertov 6, 12843 Praha 2, Czech Republic; [fatka@natur.cuni.cz]; 3 Research Centre Julich, Institute for Chemistry and Dynamics of the Geosphere, JiXlich, Germany; [u.mann@fzjuelich.de]. The Silurian/Devonian (S/D) boundary stratotype near Suchomasty (Barrandian, Czech Republic) was revisited by drilling a new shallow, fully cored borehole adjacent to the stratotype Klonk itself. The core was studied palynologically with respect to the exact position of the boundary in a multidisciplinary approach, including geochemistry and sedimentology. The stratotype Klonk and two further auxilliary sections (Karlstejn, U topulu) have also been investigated for comparison. Within the S/D boundary interval the distal marine palynological assemblages consist of chitinozoans, scolecodonts, acritarchs and prasinophytes. Phytodebris and first spores occur later in the Lochkovian, reflecting more proximal environmental conditions. The present study was focussed on chitinozoa and acritarchs. For stratigraphic purposes chitinozoans turned out to be most indicative. The S/D boundary can be fixed by the FAD of Angochitina chlupaci and the LAD of Linochitina klonkensis. Further characteristic species are Urnochitina urna, Eisenackitina bohemica and Calpichitina annulata. In all of the respective sections a mass occurrence of C. annulata has been noted in the S/D transition zone with a maximum close to the boundary and a disappearance in the lowermost Devonian. This peak is stratigraphically significant for the Barrandium and may represent some kind of an ecologically controlled „event" at least for this area. The study was funded by the German Research Foundation (DFG) as part of the projects MA 1861/2-2 and BR 1943/4-1, and the Humboldt Foundation (V-8121/TSR/1007014).

TRILOBITE RESEARCH ON TERRITORY OF THE CZECH REPUBLIC: A HISTORICAL REVIEW (18™ TO THE 21™ CENTURIES) Jana BRUTHANSOVA1, Oldrich FATKA2, Petr BUDIL3 and Jiri KRAL4 1 Palaeontological Department, National Museum, Vaclavske nam. 68, Praha 1, CZ -115 79, Czech Republic. 2 Department of Geology and Palaeontology, Faculty of Science, Charles University, Albertov 6, Praha 2, CZ -128 43, Czech Republic; [fatka@natur.cuni.cz];3Czech Geological Survey, Klarov 3, Praha 1, CZ -118 21, Czech Republic; 4Department of Genetics and Microbiology, Faculty of Science, Charles University, Vinicna 5, Praha 2, CZ -128 44, Czech Republic. In several European regions the trilobite-bearing rocks are widely distributed. For instance, Cambrian to Carboniferous sediments containing diferent trilobites, cover more than 20 percent of territory of the Czech Republic. Diversified trilobite assemblages have been established in four main regions: I. Central Bohemian Region (Middle Cambrian to Middle Devonian, including the Barrandian area) II. Krkonose-Jizera Cristalline Unite (Upper Devonian) III. Moravo-Silesian Region (Lower Devonian to Lower Carboniferous) IV. Allochtonous erratic boulders (Cambrian to Silurian). In some of these regions (e.g., in the Barrandian area), favourable preservation of different fossil groups, including trilobites, combined with the common occurrence of complete specimens attracted attention and resulted into intensive collecting of trilobites already during the 18th century. The earliest published

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IPC2002 Poster Presentations information on fossils come from the last quarter of the 18th century (Zeno, 1770), the first version of stratigraphical division has been proposed to the end of the first half of the 19th century (Barrande, 1846). Such a long history, resulted into more than 400 papers focussed on the Bohemian trilobites. Although short overviews on trilobite research were added in several books, no comprehensive list of papers about Bohemian trilobites has been published. The goal of the paper is to summarize the overall up-to-date information about the trilobite research on territory of the Czech Republic from the 18th century to the end of the year 2001 and to provide a comprehensive list of publications. The short characterisation of regional units with trilobite-bearing rocks is complemented by a brief historical review of trilobite studies, discussion of development of trilobite assemblages, informations on the most important trilobite collections. Development of trilobite assemblage. Specific palaeogeographical history of individual regions had a crucial impact on the composition and changes of trilobite assemblages. In general, the development was strongly dieted by the shift and rotation of the whole Gondwanan supercontinent on the southern hemisphere in areas I-III. It started in low periequatorial palaeolatitudes (Lower-Middle Cambrian) being succeded by a quick shift to high polar palaeolatitudes (Upper Ordovician) and than followed by a gradual transfer through the cold and warm temperate belts (Silurian) up to the sub-tropical and tropical environments (Devonian and Carboniferous). The assemblages embraced under the area IV. come from erratic boulders transported by Quarternary ice from the subtropical to tropical Baltica and thus represent exotic assemblages within the Bohemian Massif. Barrandian area and its importance. In the Barrandian area several levels serve as international standards, three GSSP and several other sections of global importance have been established here: Silurian - Devonian boundary at Klonk near Suchomasty, Pridoli - the fourth series of the Silurian System at Pozary near Reporyje, Lower - Middle Devonian boundary parastratotype at Holyne - Prastav Quarry, Lochkovian - Pragian boundary stratotype at Praha - Velka Chuchle. History of the trilobite research. Joachim Barrande (1799-1883) played a fundamental role in the history of palaeontological study in the Palaeozoic not only in Bohemia or Austro-Hungarian empire but in general. Four chief periods in study of trilobites in the Barrandian area are distinguished: 1. Period before the appearance of Barrande, 2. Period of Joachim Barrande's work, 3. Period after the Barrande's death, 4. Period after the Second World War. Index of publications. Each citation is accompanied by the English translation, if the paper was published in other language than English, complete citation of the journal name, volume and pages. At the end of each citation we added, if possible, the abbreviation of the geological times in which these trilobites lived. The study of O.F. was supported by the Grant of Ministry of Education No. MSM 113100006.

UNUSUAL PRESERVATION OF VERTEBRATE REMAINS FROM THE CARBONIFEROUS OF NORTH QUEENSLAND Carole J BURROW1 and Susan TURNER2 department of Zoology & Entomology, University of Queensland, QLD 4072; 2 Queensland Museum, P.O. Box 3300, South Brisbane, QLD 4101 Fragmentary remains from acanthodian, palaeoniscoid and sarcopterygian fishes preserved in claystone nodules have been collected from the freshwater Bulliwallah Formation (Carboniferous, Vis&an) near Plain Creek, south of Charters Towers in north Queensland. An initial note by Turner & Cook (1999) reported a fauna comprising a Gyracanthides sp. fin spine, lAcanthodes fin spines and scales and palaeoniscoid remains. Further collecting from the site has yielded more small nodules encasing palaeoniscoid and acanthodiform remains, plus sarcopterygian dermal bones, a ?chondrichthyan fin spine, acanthodian jaw cartilages and an Acanthodopsis-tyipe dentigerous jaw bone. Many of the nodules are barren; no invertebrate fossils have been found. The vertebrate bones are extremely friable in most of the small specimens. Identification and description of the vertebrates is hampered by this poor preservation combined with the water-degradable nature of the nodules, which discourages clearing the bone with HC1. The fauna is of equivalent age and of similar composition in terms of higher taxa to the mid-Visean tetrapod-bearing unit of the Ducabrook Formation to the west of Emerald in central Queensland. TURNER, S. & COOK, A.G., 1999. Carboniferous fish remains from the far-northern Drummond Basin. Memoirs of the Queensland Museum 43, 786.

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DIPLACANTHID ACANTHODIANS FROM THE AZTEC SILTSTONE (LATE MIDDLE DEVONIAN), ANTARCTICA Carole J BURROW1 & Gavin C YOUNG2 department of Zoology & Entomology, University of Queensland, QLD 4072; 2Department of Geology, Australian National University, Canberra ACT 0200. One articulated and several partial, semi-articulated specimens of a diplacanthid acanthodian were collected in 1970 from the freshwater deposits of the Aztec Siltstone, Portal Mountain, South Victoria Land, Antarctica during a Victoria University of Wellington Antarctic Expedition (Young 1989). The fish were preserved in a finely laminated, non-calcareous siltstone which yielded a fauna comprising acanthodians, palaeoniscoids, bothriolepid placoderms and abundant conchostracans. The diplacanthid has anterior dorsal, posterior dorsal and anal fin spines, plus one pair each of pectoral, admedian, prepelvic and pelvic fin spines; unpaired fin spines with a long insertion area; three or four pairs of branchiostegal rays; circumorbital bones; mandibular splints; scapulocoracoids with a tall rod-like shaft; bipartite pelvic girdles; and scales ornamented with numerous sub-parallel ridges running the whole length of the crown. The fin spines show features which are identical to those of the fin spine fragments from moraine deposits of the Aztec Siltstone at Granite Harbour, Antarctica which Woodward (1921) assigned to Byssacanthoides debenhami. Though markedly smaller, the spines also resemble those of Antarctonchus glacialis White, 1968 from the outcrops of the same formation in the Boomerang Range and Lashley Mountains. The scales on the articulated fish appear similar to isolated scales which Woodward (1921) assigned to Cheiracanthus sp. Several features on the most complete of the new fish specimens - in particular, the apparent lack of an enlarged cheek plate - suggest a revision of the diagnosis for the Diplacanthidae. WHITE, E.I., 1968. Devonian fishes of the Mawson-Mulock area, Victoria land, Antarctica, Trans-Antarctic Expedition 1955-1958. Scientific Reports, Geology 16, 1-26. WOODWARD, A.S., 1921. Fish-remains from the Upper Old Red Sandstone of Granite Harbour, Antarctica, British Antarctic (Terra Nova) Expedition, 1910. Natural History Report (Geology) 1, 51-62. YOUNG, G.C., 1989. The Aztec fish fauna of southern Victoria Land - evolutionary and biogeographic significance. In Origins and Evolution of the Antarctic Biota, J. A. Crame, (ed., Geological Survey of London Special Publication 47,43-62.

LATE DEVONIAN (FAMENNIAN) BIOTA AND THE REFUGIUM IN WEST JUNGGAR BASIN, NORTHERN XINJIANG, CHINA CHEN Xiuqin Nanjing Institute of Geology and Palaeontology, Academia Sinica, Nanjing, 210008, P. R. China [chenxq@publicl .ptt.js. cn] Late Devonian sediments, widespread in northern Xinjiang, consist mainly of volcaniclastics, lavas and clastics with, in some areas, limestones. The Hongguleleng Formation, first named by a joint expedition from the Xinjiang Geological Survey and the Chinese Academy of Geological Sciences in 1973, has its type locality 3 km W of Boulongour Reservoir, and 30 km N of Hoxtolgay in the Mogolian Autonomous County of Hoboksar. Conodonts from the lower and upper parts of the Hongguleleng Formation with, inter alia, Ancyrognathus bifurcatus, Polygnathus semicostatus, Icriodus cornutus and Palmatolepis minuta minuta indicates a Lower-Middle Famennian age, crepida to marginifera zones (Zhao & Wang, 1990). Many organisms went into extinction during the Kellwasser Events, especially the Upper Kellwasser Event at the Frasnian-Famennian bundary, but many taxa thought to have gone into extincion at that time occur among the abundant conodonts, brachiopods, corals, miospores, acritarchs and subordinate bryozoans, trilobites and gastropods found in the Hongguleleng Formation. Quantitative data are becoming available for the Honguleleng faunas. Brachiopods are characterized by 27 species in 17 genera (Zhang et al., 1983), rugose corals by 12 species in 11 genera (Liao & Cai, 1987), conodonts by 22 species in 7 genera (Wang et al., 1990; Xia, 1996), miospores by 21 species (9 indeterminate) in 12 genera (Xu et al., 1990; Lu, 1999), acritarchs by 37 species (6 indeterminate) in 23 genera (Xu et al, 1990), echinoderms by 6 blastoid and 19 crinoid species (Lane et al., 1997), bryozoans by 7 species (one inderminate) in 6 genera (Lu, 1999). Based on the Famennian echinoderms collected by Maples and Waters, Kerr (1994) suggested that seas covering NW China could have been the long-sought echinoderm refugium. Rong et al. (1996, p. 264) suggested the West Junggar area was a refugium for various groups which survived the mid-Late Devonian life crisis. The abundant fossils record from the Hongguleleng Formation provides further evidence that a

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IPC2002 Poster Presentations biotic refuge could have existed in W Junggar (northern Xinjiang) during the Kellwasserr Events, surviving in that region to subsequently spread widely again.

SEDIMENTOLOGY AND PALAEOECOLOGY OF A NAMURIAN A TETRAPOD SITE, BUFFALO WALLOW FORMATION, WESTERN KENTUCKY Donald R.. CHESNUT1,2. Stephen GREB1, Glenn W. STORRS3, William J.GARCIA4 & Jack BELLAN5 Kentucky Geological Survey, 228 MMRB, 2University of Kentucky, Lexington, KY 40506-0107, [drches01@pop.uky.edu]; 2Kentucky Geological Survey; 3Cincinnati Museum Center, 1301 Western Ave., Cincinnati, OH, 45203; department of Geology, University of Cincinnati, Cincinnati, OH 45221-0013; 5 Department of Earth Sciences, Eastern Kentucky University, Richmond, KY 40475-3102 An exposure of the Buffalo Wallow Formation in western Kentucky has yielded a variety of Carboniferous tetrapods, the oldest such fossils in the Illinois Basin. Limestones at the base of the exposure are correlated to the Menard Limestone, and those at the top to the Kinkaid Limestone, making the tetrapods Namurian A (Elviran or upper Chesterian) in age. At this location, clastic units in the Buffalo Wallow consist of heterolithic palaeochannels and lateral floodplain facies; dark shale-filled scour fills; small, heterolithic scour fills; and numerous palaeosols. Palaeosols are more common at this location than farther west toward the axis of the basin, suggesting decreased accommodation along the basin margin, and possibly atop a local horst block. Decreased accommodation also resulted in complexes of laterally crosscutting palaeochannels, and the loss of a Clore-equivalent limestone found down basinal dip where complete Chester-style cyclothems are generally preserved. The Menard Limestone consists of limestone and shale containing an abundant and diverse marine fauna including articulate brachiopods, crinoids, the blastoid Pentremites, bryozoa including Archimedes and rugose horn corals. Complex palaeosol development in small graben-like structures at the top of the Menard indicate syndepositional structural movement, which also influenced sedimentation within the overlying Palestine Sandstone-equivalent palaeochannel. The "Palestine" channel is interpreted to be a mixed-load, meandering channel, with pervasive palaeoslumps. Thick-thin laminae alternations in some crossbeds, rhythmites, and abundant shale drapes on laminae are suggestive of tidal conditions. Lycopod rooting, and rhizodont and anthracosaur bones suggest dominantly fresh water conditions, placing the channel in an upper estuarine or fluvio-estuarine transitional position. A large semiarticulated embolomere (1.0-1.3m) was found near the toe of a slumped coset. It is unclear whether slumping killed and preserved the animal or whether it just transported the remains of a predeceased animal to the base of the channel. Additional embolomere, temnospondyl and to-be-named tetrapod remains were found in overlying lacustrine, floodplain and palaeosol deposits developed on top of the palaeochannel. These strata, in turn, were overlain and truncated by dark shale-filled scours, interpreted as abandoned, poorly oxygenated oxbows or chute-channel fills in a possible marsh setting. A localized thin coal and pyritic/calcareous lycopod coal balls found at the base of the scour indicate a vegetated setting prior to infilling with dark muds. Vertebrates preserved in dark shale-filled scours include Gyracanthus, xenacanths, palaeoniscoids, lungfish (in burrows), rhizodonts, a colosteid and an embolomere. Invertebrate fossils have not been noted. The fauna indicate largely fresh-water conditions. Deposition of the dark muds may reflect increased base level, probably laterally equivalent to the "Clore" marine transgression seen further down basinal dip. Allocyclic (eustatic cycles in this case) and autocyclic processes (such as channel switching), enhanced by limited accommodation space, appear to have controlled sediment preservation in this coastal setting and were probably important for the preservation of vertebrates at this site.

PEDERPES FINNEYAE, A WHATCHEERIID FROM THE TOURNAISIAN OF WESTERN SCOTLAND Jennifer A. CLACK University Museum of Zoology, Downing St., Cambridge CB2 3EJ UK I illustrate in this poster details of the anatomy of a new whatcheeriid, Pederpes finneyae, that represents the only articulated tetrapod material from the Tournaisian, and the first Lower Carboniferous tetrapod from western Scotland (Clack in press). It fits, temporally, morphologically and phyogenetically between the aquatic Late Devonian tetrapods, and the terrestrial forms of the mid-Visean. The whatcheeriids, first known from the Visean of Iowa, USA, have now been discovered to be a very early yet widely distributed clade, contrasting with the high degree of endemism seen among Late Devonian forms. Pederpes shows evidence

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IPC2002 Poster Presentations consistent with retention of Polydactyly in its manus, while its pes is similar to that of later pentadactyl Carboniferous forms in showing asymmetrical metatarsals. Pederpes has the following autapomorphies: trunk ribs with at least vertebrae numbers 4-9 bearing accessory processes and/or foramina at dorsal edge of acutely triangular terminal expansions and about numbers 10-12 with flared ends; short presacral ribs with accessory processes; minute lateralmost digit on manus; deep striations on anterior edge and anterior region of external surface of stem of clavicle and cleithrum; ovoid dorsal blade of cleithrum with fimbriated edge. It is distinguished from Whatcheeria deltae (Lombard and Bolt 1995) by the following: low but distinct ornament on dermal bones including shoulder girdle, punctate and pitted on tabular, postparietal and supratemporal (other skull table bones not known); downturned occipital flange of tabular and postparietal set off from rest of skull table by lack of ornament; jugal narrower below orbit than Whatcheeria deltae (less than 20% in Pederpes, about 30% in W. deltae) with only a narrow spike anterior to orbit (cf. antorbital expansion in W. deltae); lacrimal contributes at least a quarter of anterior orbit margin (cf. possible short contribution in W. deltae); no conspicuous thickening of prefrontal orbit margin cf. W. deltae', suspensorium greatly elongated (about same length as maximum orbit width in W. deltae, about 25% longer than maximum orbit width in Pederpes); postorbital contributes more than half of distance between temporal embayment and posterior orbit margin; no lateral lines visible in grooves on skull roof (exposed only in pores cf grooves on jugal and postorbital of W. deltae); interclavicle with thin parasternal process (of unknown length) but not thickened and robust cf. W. deltae', cleithrum without conspicuous posterior notch (cf. W. deltae)\ ilium with dorsal blade and short posterior process (cf broadened blades in W. deltae); metatarsals and pedal phalanges longer than broad (cf broader than long in W. deltae); conspicuous, high latissiumus dorsi process on humerus resembling that of Baphetes; unossified pubis; ventral armour of numerous elongate oval gastralia (none in W. deltae). The family Whatcheeriidae can be diagnosed as follows: Derived: Narrow, steep-sided skull with orbit deeper than wide; massive tooth on maxilla about position 5 or 6; light dermal skull ornament; dorsal branch of mandibular lateral line running along surangular; very broad interclavicle with acutely angled lateral corners. Primitive: grooved, denticulated parasphenoid; closed palate with denticulated surface; supratemporal-postparietal contact, fang pairs on vomers, palatines and ectopterygoids with a row of some smaller accessory teeth on each; row of coronoid teeth nearly continuous; at least some lateral lines in tubes through bone; rhachitomous vertebrae; no differentiated sacral neural arch, ilium with posterodorsal process and dorsal iliac blade. Uncertain polarity: supratemporal with deeply interdigitated suture to squamosal; small tabular with 'button' terminating in ornamented surface; steeply angled suspensorium with deeply excavated temporal notch, pronounced angle between skull table and cheek in transverse section; scapulocoracoid ossified in two portions; about 28 presacral vertebrae; trunk ribs with expanded distal flanges. CLACK, J.A. in press. First footing in the Carboniferous: an early tetrapod steps into Romer's Gap. Nature LOMBARD, R.E. & BOLT, J.R. 1995. A new primitive tetrapod, Whatcheeria deltae, from the Lower Carboniferous of Iowa. Palaeontology 38,471-494.

BOLBOFORMA AS MONITORS OF CENOZOIC PALAEOCEANOGRAPHIC CHANGES IN THE SOUTHERN OCEAN Penelope J. COOKE1. Dorothee SPIEGLER2, Martin P. CRUNDWELL1 and Campbell S. NELSON1 department of Earth Sciences, University ofWaikato, Private Bag 3105, Hamilton, New Zealand; 2 GEOMAR, Wischofstrasse 1-3, D-24148, Kiel, Germany Bolboforma distribution in space and time is analysed from a circum-Antarctic belt of lower Eocene to uppermost Miocene sediments from the Southwest Pacific, Southeast Pacific (Bellinghausen Basin), Maud Rise and South Atlantic, and Indian Ocean (Kerguelen Plateau). A correlation panel using established Cenozoic planktic foraminiferal and calcareous nannofossil Zones is linked to the Bolboforma zonation scheme for the Southern Ocean. Evolution of surface watermasses and their boundaries, the major oceanic fronts, are tracked using the microfossil distributions and general sediment characteristics, and are in turn linked to the Bolboforma distribution. Specifically, the migration of both the Antarctic Polar Front and Subtropical Front northwards from continental Antarctica, starting in the earliest Oligocene and culminating in the Late Miocene establishment of 'modern' conditions, links the bolboforms in the Southern Ocean with subantarctic watermass conditions between the equivalent of todays Subantarctic and Subtropical Fronts. The occurrence of bolboforms in sediments including subtropical microfossil assemblages from north of the subtropical front, as in the Tasman Sea, is anomalous. We suggest that they were transported into the region by subsurface (intermediate depth) waters generated by subduction of subantarctic surface water at

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IPC2002 Poster Presentations southern oceanic fronts. The distribution of bolboforms more widely outside the Southern Ocean may define the pathways of Southern Component Intermediate Water (Antarctic Intermediate Water) during the Tertiary, and account for their bipolar distribution. Bolboforms exhibit a circum-Antarctic distribution prior to the development of a full circum-Antarctic circulation system following the opening of both the Tasmanian and Drake gateways. It is inferred that a West Antarctic Seaway between the Ross Sea and Weddell Sea embayments may have afforded oceanic connection between the Southwest Pacific and the southern Atlantic during the Eocene-Oligocene, facilitating dispersal and such a distribution.

ON THE USE OF MATHEMATIC METHODS IN PALAEOECOLOGY AND SEQUENCE STRATIGRAPHY Pierre CUGNY Geologie, Ecologie Quantitatives, Universite Paul Sabatier, 118 route de Narbonne, 31062 Toulouse cedex, France. Using examples from Cretaceous series, the author shows how the association of mathematic methods such as Correspondence Analysis, Dynamic cluster analysis, Hierarchical classifications, Time series and Timedelay method with the classic methods of Geology (sedimentology, palaeontology, micropalaeontology) can objectively reveal eustatic sea level fluctuations.The conditions good use are discussed. The organization of the various steps is: I. Bringing up a gradient correlated with the eustatic sea level changes (available space). Distribution of fossil organisms and their host layers; Palaeoenvironnemental succession in time. Factor correlated to available space variations (example: Distal -proximal gradient). II. Analysis in function of the time (stratigraphic order) of the layer coordinates according to this factor. Assimilation of the successive values to a chronic (chronologic series). Weighting if necessary (distance between successive layers according to the sedimentation rate), Filtering the series of values : mobile average method. Elimination of the random fluctuations, Rest :general trend and systematic fluctuations. Adjustment of a polynomial model, General trend, Analysis of the systematic fluctuations '.sequence test, time delay method. Cyclic or non cyclic sequences. III. Synthesis of the contributions comming both from mathematic methods and sequence stratigraphy IV. Interpretations in terms of various order cycles or sequences. The method can be successfully used only when: we have a good stratigraphy of continuous series, we have at our disposal precise sedimentological and palaeontological data; palaeontological organisms are not ubiquist and not cosmopolitan., i.e: The axis of Factor Analysis is really correlated with eustatic sea level changes. If these conditions are not realized, it is impossible to make the distinction between ecosequence and sequence-stratigraphy.

DEEP-WATER PULMONATES FROM THE MIOCENE LAKE PANNON, CENTRAL EUROPE Istvan CZICZER1 -Sandor GULYAS1 - Imre MAGYAR2 1 University of Szeged, Department of Geology and Paleontology H-6722 Szeged Egyetem u.2-6; fcziczer@yahoo.com]; 2MOL Hungarian Oil and Gas Company, H-1039 Budapest Batthyany u.45. The Late Miocene Lake Pannon is one of the few examples of fossil long-lived lakes. It harbored a very spectacular endemic fauna with multiple sources of origin during its 7 million years of lifetime. Following a salinity crisis many pulmonates including planorbids and Radix moved into the lake from the surrounding ponds, marshes and rivers occupying the empty new niches in the lacustrine basin. From the originally small planorbids relatively large species developed; presently determined as Gyraulus tenuistriatus Gorj-Kramb and conquered deeper parts of the basin. According to seismic profiles of delta systems these guys come from prodelta silts and clays with depths around 250-300 ms. They form a complex deep water assemblage with other large bivalves and gastropods like the rounded flat, plate-like Valenciennesius originating from the pulmonate gastropod Radix. According to the sedimentological analyses the fossil bearing deep-water layers were well oxigenated and based on the anatomy of present day pulmonates we might suppose a special type of deep-water adaptation process in case of these gastropods. However some authors question the benthic lifestyles of these species and propose a nekton or pseudonekton lifestyle for these specimens. These and other palaeoecological questions will be investigated in details via isotope geochemical analysis of the shells

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IPC2002 Poster Presentations and micromineralogical analysis of embedding sediments. Our work is supported by OTKA Grant T029342 and NSF Grant EAR9706230. PRELIMINARY RESULTS OF SEDIMENTOLOGICAL AND PALAEOECOLOGICAL INVESTIGATIONS ON THE LAKE PANNON FAUNA OF THE TATA BRICKYARD Istvan CZICZER , Sandor GULYAS , Imre MAGYAR , Miklos SZONOKY University of Szeged, Department of Geology and Paleontology H-6722 Szeged Egyetem u.2-6; [cziczer@yahoo.com]; MOL Hungarian Oil and Gas Company, H-1039 Budapest Batthyany u.45. 1

The prodelta, delta slope deposits of the Szak Claymarl Formation from the Miocene Lake Pannon are exposed in the pits of the Tata brickyard. Our recent investigations in the area aim at giving an overall sedimentological, geochemical and palaeoecological evaluation of these deposits covering the NW foreland of the Hungarian Transdanubian Mts. Further outcrops of the formation are found in the brickyards of Szak (stratotype), Kisber, Neszmely, Tapolcafo and Tata. The deposits are composed of silty clay and claymarl as well as clayey silt with very thin sand intercalations, deposited on the delta slope and front of a prograding lacustrine fossil delta system. The deposits are mainly homogenous lacking any major traceable bedding. The high carbonate content is showing an upwards decrease in the profile with a simultaneous increase in the clay content. At some horizons intercalations of highly limonitic coquinas with the broken shells of a typically shallow water fauna (dominated by Congeria ungulacaprae Miinst.) are present indicating the activity of major stroms in the area responsible for the reworking and transport of shallow water sediments and fauna elements onto the slope via wave and current action. The presence of sedmentary faults in the layers indicate the compressional cracking of the deposits after the uplift of the surrounding mountains in the Pliocene and Quaternary. The deposits are highly fossiliferous with a dominance of the malacofauna. According to the latest stratigraphic classifications they belong to the Congeria czjzeki-Congeria zagrabiensis and the Spiniferites paradoxus, Spiniferites validatus biozones. The absolute age of the deposits is around 9.5 Ma. So far a lot of molluscs have been collected from the outcrop, the majority of which has already been determined as well. However, there are a lot of unique, formerly unknown limnocardiids in these deposits - possibly new endemic species. There is a dominance of bivalves in the fauna with Congerias being the most frequent species (Congeria czjzeki M. Homes, Congeria partschi Czjzek, and Congeria ungulacaprae (Mtinster) in the coquinas of storm deposits.) The second most rich group is that of Limnocardiids which will possibly yield a lot of new endemic species in the future. Furthermore, endemic deep-water pulomates are also present with the dominance of Planorbids, Radix and its descendants the endemic flat, plate-like Valenciennesius (Taktakishvili 1967). Numerous fish otoliths have come to light as well. This work is supported by OTKA Grant T029342. CAMBRIAN BIOSTRATIGRAPHY IN IRAN Mohammad DASTANPOUR, Department of Geology, Shahid Bahonar University, Kerman, Iran Cambrian rocks are well developed throughout NE and central Iran. Cambrian sequences outcrop from S of Kerman city to about 200 km to the north with two especially well-exposed sequences at Durah-Shahad, about 20 km SE of Kerman, and Kuhanian (Kuhanian Formation) about 180 km to the north of Kerman. In both areas there is about 150 m of fossiliferous limestone with interbedded sandstone and dolomite with trilobites including Lioparella sp., Anomocarella sp., Redlichia chinensis, Iranopsis sp., Iranoleesia pisiformis and Iranochuangia sp. Recent studies have produced new data facilitating better stratigraphic alignments with Cambrian sequences in the Alborz and Tabas areas of N and E-central Iran respectively. Biofacies studies indicate that most regions of Iran experienced transgression by Palaeotethys during the Cambrian. EFFECTS OF ANTHROPOGENIC ACTIVITIES ON FORAMINIFERAL DISTRIBUTION IN BACUIT NAY, EL NIDO, PALAWAN, PHILLIPINES Marietta M. DE LEON, & Luz D. DOMA,

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IPC2002 Poster Presentations National Institute of Geological Sciences, College of Science, University of the Philippines, Diliman, Quezon City 1101, Philippines; [mmdeleon@pacific.net.ph, luz.doma@eudoramail.com] Recent foraminiferal assemblages in Bacuit Bay, El Nido, Palawan, Philippines, are characterised and an attempt made to determine possible effects of the onset of anthropogenic activities on the faunas. Analyses of 34 grab samples used for this project reveal the presence of 110 species of foraminifers in 43 genera—almost entirely benthic forms with rotaliids the most numerous group. Very few planktic species were found; this is attributed to the shallow depths where the samples were taken: 5 to 30 m. Since the study area has the most pristine coral reefs in the country, most of the foraminifers are usually associated with reefal environments. Two assemblages are inferred, the first with abundant Pararotalia ozawai, P. domantayi, and Calcarina calcar. Although they are well distributed in most parts of the bay, they are notably numerous in regions that are 1) nearer to shore; 2) composed of fine to coarse-grained sand; and 3) surrounded by coral reefs. One particular example is the area E of Cadlao Island. Samples with finer-grained sediments from Bacuit Bay contain numerous Nonion subturgidum, a species inhabiting areas of greater depth and mud content. Cellanthus craticulatus and various forms of Quinqueloculina and Elphidium are the next most abundant bottom-dwellers, and are present in almost all the samples analysed. Other significant foraminifers are Ammonia beccarrii and Assilina ammonoides. Other planktic species in the samples are Globigerinoides ruber and Globigerinella aequilateralis. It is possible that logging operations as well as other livelihood and man-related projects in this portion of the bay have been major factors in this distribution. Extensive denudation of the forests of Bacuit Bay and the other portions of the province of Palawan has led to frequent flooding and rapid sedimentation, thereby adversely affecting the coral reefs and other marine fauna in the area.

FORAMINIFERA AND MACROFAUNA WITHIN HETEROZOAN CARBONATES FROM AN EARLY PERMIAN HIGH-LATITUDE INTERIOR SEA, WESTERN AUSTRALIA. Matthew DIXON School of Earth and Geographical Sciences, The University of Western Australia; [mdixon@geol. uwa. edu. au] Overlying thick glacially influenced sediments, the Sakmarian to early Artinskian Callytharra Formation is one of Western Australia's most fossiliferous units, containing over 220 recognised fossil species (foraminifera, brachiopods, bryozoans, crinoids, bivalves, ostracods, conodonts, corals, blastoids, gastropods, annelids, ammonoids, and nautoloids). Previously, little has been published on the stratigraphic and palaeoenvironmental distribution of these fossils. Most forms occur within the characteristic facies association of the unit which consists of alternating indurated limestone and softer bioclastic-sandy mudstone. This unusual stratigraphy has lead to varied palaeoenvironmental interpretations (from a 'shallow' sea with areas of carbonate shoals; to a 'moderately deep' sea with areas of wave induced carbonate banks; to a deep marine setting subject to turbidity currents). However, detailed sedimentological and palaeontological study suggests that the mainly autochthonous fossils inhabited a storm dominated, normal-marine environment below normal wave-base. Transitional with this palaeoenvironment, two other facies associations are recognised: a near-shore, lower salinity facies association (the Carrandibby Formation), and a normal salinity, below maximum stormwave base facies association (often represented by recessive mudstone intervals within the Callytharra Formation). As these facies associations conformably underlie and overlie the characteristic Callytharra Formation facies association, an approximate transect is provided, from near-shore to relatively offshore conditions in the basin. Near-shore environments are dominated by bivalves, particularly Eurydesma, and simple organic cemented siliceous agglutinated foraminifera, such as Psammosphaera and Hyperammina. In contrast, offshore areas are characterised by diverse agglutinated foraminifera, with rare fenestrate bryozoa and brachiopods (mainly Chonetids). In between, storm-wave dominated environments contain abundant and diverse agglutinated-, hyaline- and porcelaneous foraminifera, brachiopods, bryozoans and crinoids, with lesser abundances of the other fossil groups. High resolution analysis of the distribution of the 75 commonly occurring species (excluding fenestrate bryozoa) within this facies association allows the recognition of depth-dependant assemblage zones. While there are often minor shifts in the relative proportions of different fossil groups, such as a peak in abundance and diversity of crinoids and hyaline foraminifera towards maximum storm-wave base, zones are better defined by species and genera, particularly of foraminifera and brachiopods (the most diverse fossil groups). The application of these zones, together with biostratigraphical age control, allows for a better understanding of the development of the shallow interior basin. Although there is often very little depth control on the

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IPC2002 Poster Presentations distribution of Palaeozoic organisms when seen as a group (eg Spirifirids, tabulate corals etc.), species level analysis provides more sensitive environmental indicators.

THE LATE CARBONIFEROUS PHRAGMOCONE-BEARING ORTHOCONIC COLEOIDS WITH INK SACS : THEIR ENVIRONMENT AND MODE OF LIFE LARISA A. DOGUZHAEVA1, Royal H. MAPES2, Harry MUTVEI3, and Roger K. PABIAN4 l Paleont. Inst., Russian Acad. Sci', 117867 Moscow, Profsoyuznaya St., 123, Russia, [planetbond@mail.ru]; Ohio Univ., Dept. Geol. Sci., Athens, OH 45701, USA [mapes@ohiou.edu]; 3Swedish Mus. Nat. Hist., Dept. Palaeozool., SE-10405 Stockholm, Sweden [Harry.Mutvei@nrm.se]; 4Conservation and Surv. Div., I.A.N.R., Univ. Nebraska, Lincoln, NE 68588, USA 2

Up-to-now the most ancient coleoid known to have an ink sac has been the middle Triassic Phragmoteuthisl ticinensis from Switzerland (Rieber, 1970). The recovery of Late Carboniferous (Pennsylvanian, Missourian; = Kasimovian) coleoids with ink sac is reported herein. The assignment of these orthoconic cephalopods to the Coleoidea is based on gross shell morphology and ultrastructure examined with SEM. Their probable environment and mode of life are discussed. Five phragmocone-bearing orthocones with well-shaped ink sacs and four other orthocones without ink sacs are from the Stark Shale (Missourian- Pennsylvanian) in Nebraska, USA. All the shells (19-38 mm in overall lengths on bedding planes) are thin compressions. Despite the shell crushing, the ink sacs have retained three-dimentional shape. The shells are replaced by phosphate material. They were deposited with rare, small-sized ammonoid Neoaganides and numerous articulated fishes and sharks of different sizes in oxygen deficient environment. The phragmocones show a thin shell wall, closely spaced septa, long mural parts of septa and small marginal siphuncle. The number of preserved septa in the phragmocones varies from 4 to 11. The ink sacs are long-necked flasks with the neck tapering into a long, narrow conduit. The rounded posterior end of the sac is located near the middle or at the terminal septum of the phragmocone. One specimen with a large quantity of preserved shell shows that the ink sac is both underlain and covered by shell material indicating the presence of a living chamber. However, some other specimens show only faint traces of a mineralized shell that may represent the traces of either a proostracial covering or a living chamber. None of the specimens preserve a rostrum or arm hooks. Under SEM the shell wall is multilayered and has a granular ultrastructure that seemed to be a result of diagenetic phosphate replacement of originally organic rich layers. One specimen shows two patches of golden-brown striated material interpreted to be fossilized fragments of mantle tissue. Similar colored material with similar striations intrepreted to be mantle tissue has been observed in the Jurassic teuthid Loligosepia (unpublished observations by Doguzhaeva, Mutvei and Donovan). The Stark ink-bearing specimens can be separated into several different taxa on the basis of the presence of a long versus short body chamber/proostracum length and the length ratio of the ink sac to the body, and the amount of shell mineralization. The ink material differs in both texture and color relative to the black shale matrix. Under SEM fossilized ink shows a massive aggregate of different sized (approximately 0.5-3.0 jum) sphaeres each of which is a globular mass of smaller-sized particls. The globular ultrastructure was also observed in ink of Loligiosepia (unpublished data by Doguzhaeva, Mutvei and Donovan). In order for the ink to be sufficiently solid to resist compaction, the ink must have solidified after the animals demise prior to crushing. The rapid solidification can be explained as a resultant chemical reaction (Fox, 1966) of a slightly acid or neutral (as opposed to alkaline) bottom water condition, which caused the melanin (the main ink component providing black colour) to precipitate into a solid while still in the coleoid body. If alkaline bottom water conditions had been present, the melanin would have been dispersed colloidally, and the ink would not be preserved in the coleoid body. Based on the above information, some aspects of the life mode of the coleoids in the Pennsylvanian ocean can be inferred. Because there was an anoxic bottom condition present at the death site, these coleoids must have been mid to upper level swimmers that were agile and capable of comparatively active mobility, and they had the ability to utilized ink release as a foil to escape predators. These coleoids were probably "tasty tidbits" to larger fish predators, as are the squids in today's oceans. RIEBER, H. 1970. Phragmoteuthis? ticinensis n. sp., ein Coleoidea-Rest aus der Grenzbitumenzone (Mittle Trias) des Monte San Giorgio (Kt. Tessin, Schweiz). Paldont. Z, 44, 1/2, 32-40. Fox, D. L..1966. Pigmentation of Molluscs, pp. 249-274. In Wilbur, K. M. and Younge, C. M. (eds) Physiology of Mollusca. Acad. Press, New-York, London.

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IPC2002 Poster Presentations RIPHEAN OF THE BAIKAL MOUNTAIN AREA (SOUTHERN SIBERIA) Tatjana A. DOLNIK1, Svetlana A. ANISIMOVA2 East-Siberian Scientific Research Institute of Geology, Geophysics and Mineral Resources. Dekabrskih Sobitiy St., 29, 664007, Irkutsk, Russia; 2 Ins titite of the Earth*s Crast Siberian Branch Russian Academy of Sciences. Lermontova St., 128, 664033, Irkutsk, Russia. The sediments of the Riphean of the Baikal Mountain area are subdivided into six regional horizons (from below): purpolsky, medvegevsky, ballaganakhsky, dalnetayginsky, jouinsky and yudomsky. Two bottom horizons are allocated on the basis of geological, lithological and palaeontological data. Four regional complexes of stromatolites are allocated representing the most complete investigation of the sections in the Patomsky upland: mariinsko-baracunsky, kalanchevsky, jouinsky and yudomsky. The complexes are divided by boundaries of mass occurrence new groups and forms of stromatolites. Most ancient mariinsko-baracunsky complex characterizes the top part ballaganakhsky and bottom part dalnetayginsky horizons. Structure of this complex includes sixteen regional and interregional forms of stromatolites, from which are most abundant are Anabaria visenda Dol., Baicalia mariinica Dol., B. reticulata Dol., Stratella goloustenella Dol., Compactocollenia sarmensis Korol., C. tchajensis Dol., Conophyton garganicus Korol., C. cylindricus Masl., Stratifera baracunica Dol. The latter four forms have interregional importance. Kalanchevsky complex is characterized at the top part of dalnetayginsky horizon (valuhtinsky formation, Patomsky upland). Structure of this complex includes twelve forms of stromatolites: Baicalia baicalica Kryl., B. valuchtenia Dol., B.rara Semikh., B. aff. lacera Semikh., B. nitchatica Dol., Conophyton metula Kiritch., Conophyton cadilnicus Korol., Jacutophyton ramosum Schap., J. multiforme Schap., Parmites aimicus (Nuzhn). Schap., Svetliella ovgolica Dol., Stratifera sarmensis Dol. From them Baicalia rara, Conophyton metula, Jacutophyton ramosum, J. multiforme, Parmites aimicus have interregional importance. Jouinsky complex characterizes the same horizon. On the boundary between kalanchevsky and jouinsky complexes the group structure of stromatolites includes seven forms: Inzeria tchentcha Dol., I. gigantea Dol., Inzeria aff. tjomusi Kryl., Patomia ossica Kryl., Tinnia patomica Dol., T. punctata Dol., T. tchaja Dol. The forms Inzeria tchentcha Dol. (the synonym Inzeria dgegimi Raab.), Tinnia patomica Dol. Are important for interregional correlation. Yudomsky complex characterizes the same horizon. It includes sixteen forms of stromatolites, which belong in the basic groups not characteristic for jouinsky horizon. It is groups Linella, Boxonia, Collumnaefacta, Stratifera. In this complex are widely distributed a pore stromatolite. The coordination of regional horizons of Southern Siberia to general stratum to a scale late of a PreCambrian is decided on a basis biostratum and geological correlation with sections of Yudomo-May area (hypostratotype of a Riphean) and to a lesser degree of Southern Ural (stratotype of a Riphean). Yudomsky of sediments of Southern Siberia and Yudomo-May area practically are unequivocally correlated by all researchers from Russia. They are united by many general forms of stromatolites and microfitolites. Jouinsky the horizon of Southern Siberia is correlated with uiskiy by horizon and ignikanskay formation of lakhandian horizon of Yudomo-May area on the basis of presence at both areas of stromatolites Inzeria tjomusi (I.aff.tjomusi) Kryl. and Tinnia patomica Dol. Dalnetayginsky the horizon is correlated with kerpilsky and bottom part lakhandian (neruenskay formation) in Yudomo-May area on to stromatolites Baicalia rara Semikh., B. lacera Semikh., Conophyton metula Kiritch., Jacutophyton multiforme Schap., J. ramosum Schap. Compactocollenia tchajensis Dol., Gongylina zonata Kom., Katavia molca Dol., Stratifera baracunica Dol., Parmites aimicus (Nuzhn.) Schap. Ballaganakhsky and medvegevsky horizons of Southern Siberia are compared with aimchanian by horizon of Yudomo-May area. In connection with that the horizons of Yudomo-May area have as palaeontological, and isotope characteristic and are adhered to a general scale of a Pre-Cambrian, the offered correlation determines them with horizons of Southern Siberia the following age of horizons of this region: purpolsky horizon - Late Riphean; medvegevsky, ballaganakhsky and bottom part dalnetayginsky of horizon - Middle Riphean; the top part dalnetayginsky of horizon and jouinsky horizon - Early Riphean; yudomsky horizon - vendian.

ECHINODERM LAGERSTATTEN IN WESTERN EMILIA, ITALY, AND THEIR RELATIONSHIP TO CLIMATE AND TECTONIC SETTING Stefano DOMINICI1 & Andreas KROH2 Dipartimento di Scienze della Terra, Universita di Firenze, via La Pira 4, 50121 Firenze, Italy; Iprestonow@hotmail.com]' 2Institute of Geology and Paleontology, Karl-Franzens-University Graz, Heinrichstr. 26, A-8010 Graz, Austria [discometra@gmx.at] 1

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IPC2002 Poster Presentations The Early Pleistocene sediments of the padan foredeep basin of Western Emilia are siliciclastic successions characterised by fining upwards cycles. Within the individual cycles sandstones with shallow water benthic communities, often preserved in form of densely packed shell beds, are overlain by mudstones with muddy bottom benthic communities, of a slightly deeper setting. Two types of muddy bottom communities occur: (1) an aerobic Venus-community and (2) a dysaerobic Arctica-community. The cycles are interpreted to be related to periodical hyperpycnal flows and turbidity currents generated by river floods. The local climatic conditions, together with the increased sediment availability and higher slope of the adjacent backland, caused by the advancing thrust front, highly increased the probability of such flows. The echinoderm lagerstatten are associated with the basal sandstone units of each cycle in the Stirone, Taro and Arda sections. The echinoderms are mostly preserved as fully articulated specimens. Four different assemblages with different modes of preservation and taxonomic composition can be distinguished: (1) Echinocardium shellbed, (2) Astropecten assemblage, (3) Ophiura assemblage, and (4) mixed assemblage. The Echinocardium shellbed is characterised by a monospecific layer of densely packed Echinocardium cordatum coronas. Both whole coronas and less common fragments are present, each specimen touching the neighbouring ones. The specimens show no preferred orientation and both right-side-up and upside-down, as well as specimens lying on their side are present. The chaotic orientation of the coronas, the fragmented specimens and the denuded coronas suggest that this shellbed is a transported assemblage rather than an insitu accumulation. Density currents or storms could have been the cause of erosion and transport of these burrowing echinoids. The Astropecten assemblage is characterised by monospecific accumulations of fully articulated specimens of Astropecten cf. irregularis. Rare specimens of Ophiura sp. are associated with the asteroids. All specimens are preserved in life-position and show no signs of decomposition or dislocation by scavengers. Up to 50 specimens/m of a wide range of size classes are preserved. This deposit is interpreted as an obruption deposit of a living population. The Ophiura assemblage is characterised by accumulations of Ophiura albida and Ophiura texturata. Similarly to the Astropecten assemblage, the specimens are preserved fully articulated in life position, without any signs of transport or scavenging. It is also interpreted as obruption deposit of a living population. The fact that neither in this assemblage, nor in the Astropecten assemblage escape structures or signs that the animals attempted to work their way through the sediment are present, leads to the conclusion that the sediment covering the animals must have been very thick, or that they must have been killed by the same event that caused the obruption or immediately before. Two scenarios are plausible: (A) the animals were killed by the hyperpycnal flows, which brought freshwater into the marine environment or (B) benthic hypoxia preceded or coincided with the obruption. The mixed assemblage is characterised by the common occurrence of Schizaster canaliferus, Echinocardium cordatum, Astropecten cf. irregularis and Ophiura texturata, as well as Arctica islandica, Corbula gibba and other molluscs, most of which are still articulated. Most of the echinoderms are fully articulated, although they show some signs of transport such as overturning. The association with mollusc taxa which show a high tolerance for reduced oxygen conditions, lack of traces of scavengers, the slight relocation of the some of the specimens suggests that this deposit is related to periodic hypoxia. Echinoderm mass accumulations with exceptional preservation are nearly always related to special conditions favouring the generation and preservation of the such deposits. Three factors are needed to form echinoderm lagerstatten: (1) high densities of echinoderms firsthand (i.e., favourable environmental conditions), (2) an event, which leads to a mass mortality, and (3) a setting, which favours the preservation of such deposits. The technically active setting and the particular climatic conditions of the study area supported all three factors: (1) rich benthic communities were present in the shallow water of the padan foredeep, (2) periodic hyperpycnal flows and benthic hypoxia, which both have the capability of causing mass mortalities and (3) turbidity currents, which carried in high sediment volumes and buried the echinoderm mass accumulation. It seems likely that the conditions which caused the periodic hyperpycnal flows were also related to the benthic hypoxia, since low oxyen levels at the seabottom are in many cases caused by phytoplankton blooms, due to higher nutrient input through higher runoff from the backland. 2

DISTRIBUTION OF DEVONIAN CONODONTS IN ACTIVE MARGIN ROCK ASSEMBLAGES FROM THE SOUTH URALS Svetlana DUBININA, Alexey RYAZANTSEV, and Denis BORISENOK Geological Institute, Russian Academy of Sciences, 7 Pyzhevsky pereulok, 109017 Moscow, Russia; [dubinina@geo. tv-sign. ru, ryazan@geo. tv-sign. ru, borisenok@geo. tv-sign. ru] The volcanic/chert and condensed chert assemblages exposed in the Sakmara and Prisakmara-Voznesensk zones, South Urals, are shown to record an active margin setting of the Eastern European craton. They compose sheets and olistoliths in olistostromes from a Devonian accretionary prism.

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IPC2002 Poster Presentations The volcanic/chert assemblage is compositionally similar to the widespread Silurian and Ordovician ones. The basalts, interbedded with cherts and felsic effusives, predominate. Occasionally, the assemblage is represented by a basalt-rhiolite suite. The volcanic/chert assemblage as a whole is derived from an oceanic trench and a volcanic arc. In the eastern part of Sakmara Zone, west of Khmelevka, from bottom upward, one finds (i) aphyric basalts interbedded with cherts with Pragian Pandorinellina exigua philipi (Klapper), (ii) cherts with Late Emsian P. exigua exigua (Philip), and (iii) cherts with Late Emsian- Early Eifelian P. expansa Uyeno et Mawson. Exposed thickness of this Pragian-Lower Eifelian succession is 4.00 m. Recently, in the western part of Sakmara Zone, east of Novokursk, in cherts structurally associated with basaltic rocks, we have found Late Givetian-Early Frasnian Mesotaxis cf. falsiovalis Sand., Ziegl., and Bultynck. Earlier (Maslov et al., 1993), in the western Sakmara Zone, a fragment of a succession was dated to the Emsian-Eifelian. The condensed chert assemblage might be derived from a frontal part of an active margin. Presently, it occues in an allochthonous thrust sheet in the vicinity of Rysaevo and Sarbaevo. The cherts are intercalated by carbonaceous black shales. A thrust sheet, from base to top, consists of (i) cherts with the Lochkovian Ancyrodelloides transitans (Bischoff et Sannemann), (ii) cherts with Mid-Givetian Polygnathus xylus Stauffer, and (iii) cherts with Mid-Frasnian Polygnathus dubius Hinde, Ancyrodella ex gr. gigas Mill, et Young, Palmatolepis sp. The total thickness of this Lochkovian-Mid-Frasnian succession is no more than 1.20 m. In an olistostrome horizon, the cherts contain Early Silurian, Late Llandoverian-Early Wenlockian Kockelella ranuliformis (Walliser), Aspelundia jluegeli (Walliser), Ozarkodina excavata excavata (Branson et Mehl). Besides, in the Guberlya R. basin, the Upper Devonian cherty olistoplaques include redeposited Ordovician conodonts. Consequently, we have good reason for the reconstruction of the Ordovician-Frasnian condensed chert assemblage. The olistostromes are represented by the siliciclastic, polymictic, and ophiolitoclastic varieties, which succeed each other stratigraphically and laterally. Evidence exists for establishing Mid- and Upper Devonian levels. The first level is represented by the Mazovskaya Fm., Akchurinskaya Fm., and other siliciclastic Formations, which formed through destruction of rocks of a condensed chert assemblage. Olistoplaques of this level contain Lower and Middle Devonian conodonts. The youngest forms, such as Late Eifelian-Early Givetian Polygnathus xylus ensensis Ziegler et Klapper and Late Eifelian Tortodus kockelianus kockelianus (Bischoff et Ziegler), were found north of Blyavtamak and east of Khmelevka, respectively. In the polimictic olistostrome, in the Guberlya R. basin, the youngest olistoplaques are dated by the Early-Mid-Frasnian Polygnathus asymmetricus ovalis Glen, et Klapp. and the Early Famennian Palmatolepis triangularis Sannem. Lastly, the matrix of the ophiolitoclastic olistostrome, in the vicinity of Khmelevka, yielded the Devonian conodont imprints having apparently Frasnian appearance. The work is supported by the Russian Foundation for Basic Research, project nos. 00 05 64 104 and 00 05 64 513. MASLOV, V.A., CHERKASOV, V.L., TISCHENKO, V.T. et al1993. Stratigraphy and correlation of the Mid-Paleozoic volcanic complexes from the main MS regions of South Urals, 217 p. Ufa Science Center of the Russian Academy of Sciences, Ufa.

FIRST RECORD OF VEGETATIVE SHOOTS OF A CONIFER ASSOCIATED WITH SEED CONE AND WOOD IN THE LATE TRIASSIC OF SOUTHERN BRAZIL Tania L. DUTRA and Ubiratan F. FACCINI Universidade do Vale do Rio dos Sinos - UNISINOS, Av. Unisinos, 950- 93022-0000, Sao Leopoldo, RS, Brazil; [tania@euler. unisinos. br] Vegetative shoots that could be compared both with the form genera Pagioplyllum Heer and with those present in adult foliage of modern Araucariaceae were found recently in Upper Triassic beds of Rio Grande do Sul state, southern Brazil. They mark a distinct level in a pelitic interval (representative of floodplains) related to a dominant sandy fluvial system (Caturrita Formation, Rosario do Sul Group). A seed cone, roots and small pieces of wood, not yet described, complete the fossil assemblage and offer the opportunity of plant reconstruction and could represent new information on the late Triassic heyday of gymnosperms and to the dawn of present world. Distinct levels of the same outcrop produce shells of freshwater invertebrates (conchostracans), a mandible of a probable primitive mammal, and a skull of a sphenodont reptile exhibiting some advanced characters. The fossils are preserved as casts in iron oxides maintaining part of the original tissues in the inner portion. The branches show ovate to triangular, elongate, and spirally arranged leaves (in sequences of three to four rows of leaves on each side of the branch) apparently terminated in tuffs of branchlets. This unique taphoceonosis differs from that of the lower unit (Santa Maria Formation, AnisianCarnian in age) that contains an abundant Dicroidium Flora (impressions of leaves) and many Rhynchosauria, Thecodontia and Therapsida. The exposure is also unique when compared with more

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IPC2002 Poster Presentations westerly occurrences of probably younger age (Mata Sandstone) wherein fluvial channels include large allochthonous pieces of wood referred to Araucarioxylon and Ginkgoales. These fossils are of great stratigraphic, palaeogeographic and evolutionary significance because of: a) associate vegetative and reproductive organs that provide an opportunity for reconstruction of the entire plant of a primitive conifer, normally difficult to discriminate solely on foliage characters; b) gives support to the Gondwana floral affinities with the record also in Brazil to these gimnosperms, yet well known from southern South America, Antarctica and India; c) suggest the presence of late Upper Triassic beds in Rio Grande do Sul and maintenance of good conditions for plant growth (the upper unit of the Botucatu Formation represents development of widespread desert conditions); d) it is an additional element indicating the end of the Triassic for appearance of modern-type conifers and of the form genus Pagiophyllum; e) gives support to the proposition of distinct climatic conditions (super-"hot house" interval?) at the end of Triassic that affected the Dicroidium Flora. MORPHOTYPES RELATED TO ELAEOCARPACEAE IN WESTERN ANTARCTIC PENINSULA: FURTHER EVIDENCE OF MESOTHERMIC AND WET CONDITIONS AT HIGH LATITUDES IN THE END OF CRETACEOUS. Tania L. DUTRA Universidade do Vale do Rio dos Sinos - UNISINOS, Av. Unisinos, 950- 93022-0000, Sao Leopoldo, RS, Brazil; [tania@euler. unisinos. br] Pinnate craspedodromous leaves with regularly spaced and upward curved secondaries (eucamptododrompus - cladodromous from Hickey, 1974 or cornophyllic morphotype from Crabtree, 1987) and sharp percurrent tertiaries were registered at high latitudes of Northern Hemisphere in the Upper Cretaceous. Their identification between fossil assemblages of similar age and distributed between 50-60°S are of great palaeoclimatic significance. Those morphotypes was attributed to representatives of primitive Magnoliidae and to the lineage that originated the modern Flacourtiaceae and Elaeocarpaceae, the last one a member of the modern tropical rainforests. In Brazil, Sloanea is found in the modern coastal rainforest (Atlantic rainforest or "Mata Atlantica" ) and species of Elaeocarpus are common members of the fossil record from Australia, New Zealand and South America since the end of Cretaceous and during the Tertiary and are alive in some of those land masses. The leaves here presented compound near 2% of the angiosperm leaf assemblages of the Upper Campanian levels from King George Island (northwestern Antarctic Peninsula) and exhibit many similarities with Elaeocarpus mulleri Ett. from Australian Cretaceous. They were found in tuffaceous levels from the middle part of Zamek Formation, exposed in Zamek Hill, at Admiralty Bay. The K-Ar age between 66-77 Ma obtained from previous works make this record the oldest and the best calibrated to these morphology in the West Gondwana. Their find, mostly associated with Nothofagus related leaves, but also accompanied by other primitive magnoliidae (abundant laurophyllic morphotypes and those with disorganized vein patterns), podocarpaceous conifers and Araliaceae, indicates a relatively dense wood formation and an altitudinal gradient of taxa distribution. The overlain tick lava succession indicates the forest elimination by the volcanic events that mark the end of Cretaceous and the beginning of Paleocene in the area. The more young strata in the island testify the regeneration of the biomas in the end of Paleocene and the maintenance of the elements that bear leaves with this morphology until the Lower Eocene in the periantarctic areas, always like a minor part of the communities. EARLY CAMBRIAN CALCIMICROBES FROM GERMANY Olaf ELICKI Freiberg University, Geological Institute, D-09596 Freiberg, Germany, [elicki@geo.tu-freiberg.de]. Early Cambrian calcimicrobes are known in Germany nearly exclusively from subsurface deposits in the vicinity of Leipzig (Zwethau Fm., middle Early Cambrian/Ovetian, Doberlug Syncline, E-Germany). Only few findings (.Epiphyton sp., Endoconchia angusta, Obruchevella delicata) came from the only other fossiliferous Early Cambrian (surface) outcrops near the German-Polish boundary (Charlottenhof Fm., higher Early Cambrian/Marianian-Bilbilian, Goerlitz Syncline, E-Germany). The calcimicrobial communities from the Gondwana-related Lower Cambrian Zwethau Fm. has been studied with focus on their palecological position.

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IPC2002 Poster Presentations The preserved succession started with sediments of a deep subtidal siliciclastic or siliciclastic-carbonate shelf which turned to a (1) deep subtidal carbonate ramp, later to a (2) shallow subtidal carbonate ramp and finally to a (3) shallow subtidal to intertidal mixed siliciclastic-carbonate ramp with migrating oolitic shoals. The diversity and regional distribution of the calcimicrobes within this succession show some remarkable aspects. So, in the deep subtidal stage (1) only (redeposited) Proaulopora and some oncoids ('1 Girvanella) occur; other biota are absent. The shallow subtidal stage (2) is characterized by much more different biota: skeletal fossils, many colonies of Epiphyton and Kordephyton, but also Botomaella, Renalcis, Subtifloria and (rare) Girvanella occur. Within this environment some calcimicrobial-archaeocyathan reef mounds were formed. The distinct most frequent calcimicrobe within such mounds is Epiphyton. Some colonies of Epiphyton were overgrown by clusters of Renalcis, but also Epiphyton was able to overgrow archaeocyaths, Botomaella, and Kordephyton. Furthermore, Epiphyton occurs in central cavities of redeposited regular archaeocyaths. These growth features indicate the importance of calcimicrobes in the processes of stabilizing and binding the sediment. They prepared the substrate for the subsequent colonialization by other biota (e.g. archaeocyaths). During the transition to the highly agitated oolitic shoal environment (3) a drastic change in the character of the biotic community can be observed. Now, calcimicrobes are rather rare; they occur mostly as redeposited colonies or as overgrowths on organisms and allochems. The increasing number of (partly very large) oncoids is distinctive. Generally, the biodiversity in calcimicrobes is relatively low in the deep subtidal ramp environment of the German Early Cambrian. The following shallow subtidal ramp environment offered much better conditions for the photosynthetic primary producers. Therefore the significant feature of this stage is the widespread occurrence of calcimicrobial meadows and gardens. The habitats are clearly dominated by Epiphyton. But, Renalcis is also frequent, except in pure bindstones. Only locally some other calcimicrobes occur. So, either Epiphyton had the highest ecological tolerance of all calcimicrobes or this form was especially successful (?very quickly) during colonialization of potential habitats. Such a high colonialization velocity could be a very important factor for the later distribution of the biota. This is also supported by the biotic diversity within the reef mounds: Here Epiphyton is distinctly dominant and only few species of archaeocyaths occur. Irregular archaeocyaths are much more frequent than the regular ones (which occur at the periphery of mounds and in the inter-mound areas). But, they were represented by three species only (Dictyocyathus stipatus, Protopharetra gemmata, Protopharetra dissuta). Because there is no indication for a significant ecological stress on the shallow ramp, so, a fast colonialization of the habitats may more likely the main controlling factor for the distribution of the calcimicrobes than any abiotic environmental conditions. The shallow mixed ramp environment (subtidal, parly intertidal) was not very favourable both for calcimicrobes and archaeocyaths. Most of the biota show distinct signs of redeposition. The occurrence of large Girvanella-oncoids (up to 5 cm in diameter) seems to be characteristic for these special shallow and highly agitated conditions. So, each ramp stage of the Early Cambrian Zwethau Fm. is characterized by typical calcimicrobial communities. Because of the significance of the occurrence of these communities within special environments, it is well possible to estimate the ramp geometry, the velocity and the type of ramp construction and evolution. This is of large interest for the reconstruction of sedimentary realms and processes and for correlation, especially when younger tectonic movements (as in Germany) have severly disturbed, transected, relocated and fragmented the profiles.

PARATETHYAN AFFINITY AND ENDEMISM OF LATEST MESSINIAN "LAGO-MARE" MOLLUSC FAUNAS FROM ITALY Daniela ESU Dipartimento di Scienze della Terra, Universita "La SapienzaP.le [daniela. esu@uniromal. it]

A. Moro, 5, 00185, Roma, Italy

Latest Messinian deposits yielding "lago-mare" mollusc assemblages are widespread throughout the Italian peninsula and in Sicily. These were sediments of freshwater-brackish environments laid down at the top of the Messinian evaporitic regime ("salinity crisis") within the Mediterranean basin. The best known fossiliferous outcrops occur in Piedmont (Alba), Tuscany (Sterza di Laiatico and Morra Valleys, Cava Serredi, Livorno), Romagna and Marche Apennines (Colombacci Fm.), Abruzzo (Le Vicenne, L'Aquila) and Sicily (NW margin of Hyblean Plateau and central Sicily) (Esu, 1997; Cipollari, 1999 cum refs. and studies in progr.). The Italian mollusc assemblages of the "lago-mare" biofacies consist of oligo-mesohaline gastropods and bivalves. The gastropods are represented by aquatic ipo- and oligohaline prosobranchs among which Theodoxus, Melanopsis, Melanoides, Hydrobia and Saccoia dominate. The bivalves are represented by significant oligo-mesohaline elements of the subfamily Limnocardiinae (Fam. Cardiidae) with Cerastoderma,

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IPC2002 Poster Presentations Limnocardium (Euxinicardium), Pseudocatillus, Paradacna, Eupatorina, Prosodacna (Prosodacna), Plagiodacna, Pontalmyra. Mactridae and Dreissenidae are also present. Significant palaeobiogeographic evidence can be drawn from the "lago-mare" mollusc assemblages. The recorded gastropod species are mainly endemic—related to their ecology tied to continental water systems. Most of them existed in Italian non-marine basins since the early Messinian, such as Theodoxus mutinensis, Melanopsis fusulatina and Saccoia fontannesi. By contrast, the bivalves both at genus and species level, such as Limnocardium (E.) subodessae, Pseudocatillus pseudocatillus, Paradacna abichi, Eupatorina littoralis, Prosodacna (P.) semisulcata, Plagiodacna carinata and Pontalmyra aff. spinosa show close relation with the early Pontian (Odessian) fauna of the Aegean area (Di Geronimo et al., 1989; Popov & Nevesskaya, 2000) and have strong Paratethyan affinities (with Dacian and Euxinian basins) where many of these taxa were distributed during early and late Pontian time (Nevesskaja et al., 2001). Their ecology is mainly tied to brackish water so that spreading of suitable habitats at the top of "salinity crisis" favoured their dispersal into the Mediterranean area. These taxa are not recorded in the Lower Messinian lacustrine/brackish deposits of Italy (Ghetti et al., 2000), the fauna of which contrasts palaeobiogeographically with latest Messinian ones: the oldest central-western European and Mediterranean ones are partly endemic and the youngest with clear Eastern Paratethyan and/or Aegean affinities. The palaeobiogeographic data suggest that the Aegean basin could be an intermediate basin from whence the Paratethyan type fauna migrated into the Mediterranean area in late Messinian time. The "lago-mare" mollusc assemblages disappear abruptly at the end of the Messinian interval when the sharp environmental change from Mediterranean brackish environments towards true marine conditions occurred at the beginning of Pliocene. CLPOLLARI, P., COSENTINO, D., ESU, D., GLROTTL, O., GLIOZZI, E. and PRATURLON, A., 1999. Thrust top lacustrine-lagoonal basin

development in accretionary wedges: late Messinian (Lago-Mare) episode in the central Apennines (Italy). Palaeogeography, Palaeoclimatology, Palaeoecology 151, 149-166. Di GERONIMO, I., Esu, D. and GRASSO, M., 1989. Gli strati a "Congerie" del Messiniano superiore del margine nord-occidentale ibleo. Atti Accademia Peloritana dei Pericolanti, Classed 67, 129-150. ESU, D., 1997. First data on Messinian oligohaline molluscs from Racalmuto and Alimena (central Sicily). Abstract Interim Coll. R.C.M.N.S. "Neogene basins of the Mediterranean region 55-56, Catania. GHETTI, P., ANADON, P., BERTINI, A., Esu, D., GLIOZZI, E., ROOK, L. & SOULIE-MARSCHE, I., 2000. The Early Messinian Velona basin (Siena, central Italy): palaeoenvironmental and palaeobiogeographical implications. AbstractXIR.C.M.N.S. Congress, 27, Fes. NEVESSKAYA, L.A., PARAMONOVA, N.P. & POPOV, S.V., 2001. History of Lymnocardiinae (Bivalvia, Cardiidae). Paleontological Journal 35, 3, 147-217. POPOV, A.V. & NEVESSKAYA, L.A., 2000. Late Miocene brackish-water mollusks and the history of the Aegean basin. Stratigraphy and Geological Correlation 8, 2, 195-205.

TIMING AND POSSIBLE CAUSES OF THE PERMIAN-TRIASSIC MASS EXTINCTION IN TETHYS Enzo FARABEGOLI & Maria Cristina PERRI Dipartimento di Scienze della Terra e Geologico-Ambientali, University of Bologna, Via Zamboni 67, 40126 Bologna, Italy. [fara@geomin. unibo. it; perri@geomin. unibo. it] The evidence of an unconformable surface (B-W US) in the Southern Alps dividing the Tesero Horizon (transgressive oolitic grainstones) of the Werfen Fmn from the underlying Bellerophon Fmn (dark-grey fossiliferous packstones, rich in fusulinids, green and red calcareous algae and gastropods) has been shown by Assereto et al. (1973). They considered the B-W US to correspond either to the P-T mass extinction event and, roughly, to the P-T boundary. In recent years, most of geologists failed to detect the B-W US in the field (Broglio Loriga et al. 1986; Magaritz et al. 1988; Noe & Buggisch 1994; Hallam & Wignall 1999; Scholger et al. 2000); therefore they ignored the subaerial regression phase and considered the B-W transition as transgressive and continuous. Moreover, they located the chronostratigraphic P-T boundary at different levels into the Werfen Fmn (Neri & Posenatol999). Farabegoli and Perri (1998) and Perri and Farabegoli (2002) have shown evidence in the Southern Alps of: 1) The B-W US lies about 130 cm below the FAD of Hindeodus parvus. 2) From the topmost of the Bellerophon Fmn to the base of the Werfen Fmn seven conodont biozones have been discriminated: Lower and Upper praeparvus, parvus, lobata, staeschei, isarcica and aequabilis zones. 3) In the first 2 m of the Werfen Fmn the Upper praeparvus and parvus zones, characterised by a relatively abundant conodont fauna, have been identified. Hi. praeparvus has been considered the ancestor of Hi. parvus, last representative of the genus Hindeodus in the Southern Alps, and of Isarcicella prisca from which the entire Isarcicella lineage could have originated. The evolutionary trend is Is. prisca, Is. turgida, Is. lobata, Is. staeschei and Is. isarcica. 4) The lowermost part of the Tesero Mbr is made of hummoky bedded "transitional beds": darkgrey packstone-grainstones, rich in litho- and bioclasts exhumed from the uppermost Bellerophon Fmn and

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IPC2002 Poster Presentations containing some survivors ("Permian" forams, Comelicania ex gr. ladina, Janiceps, lAraxathyris, Orthothetina, Ombonia) (Posenato 1988) and oolites. These beds lack conodonts. 5) Most of the authors were deceived by the dark colour of the "transitional beds", and looked fruitlessly for the B-W US at 10-30 cm above its actual location. 6) The uppermost Bellerophon Fmn is represented by a transgressive finingupwards sequence a few metres thick, containing rare Hi. typicalis and Hi. praeparvus identifying the L. praeparvus Zone. 7) Two sea level changes (shallowing-deepening) around the B-W US; each shallowing was in the order of 10-20 m. 8) The time-lag of the transgressive-regressive cycle antedating the B-W US range from 25 ka to 100 ka, recalling fourth- (100 k.y. period) and fifth- (10-25 k.yr.) order cycles driven by short-term sea-level (glacioeustatic?) fluctuations. An important result has been accepted globally: the first appearance of Hindeodus parvus specifies the P-T boundary at the GSSP at Meishan D (China, low-latitude in Eastern Palaeotethys). Most of the stratigraphic sections in the world spanning the P-T boundary have problems related to presence or absence of hiatuses and/or unconformities. In our opinion: 1) Two short regressive-transgressive sequences predating the FAD of H. parvus are commonly recorded in the P-T sections. 2) Many hypotheses about the cause of the P-T mass extinction derive mainly from uncertainty and inaccuracy of lithostratigraphic data. ASSERETO, R., BOSELLINI, A., FANTINI SESTINI, N. & SWEET, W.C., 1973. The Permian-Triassic boundary in the Southern Alps (Italy).

In Logan, A. & Hills, L.V. (eds), The Permian and Triassic Systems and their Mutual Boundary; Alberta Soc. Petrol. Geol. Mem., 2, 176-199.

BROGLIO LORIGA, C., NERI, C., PASINI, M., & POSENATO, R., 1986. The Upper Bellerophon FM. and the P - T boundary in the Sass de

Putia Mt. (Dolomites). In Broglio Loriga, C. et al. (eds), Permian and Permian-Triassic boundary in the South-Alpine segment of the Western Tethys. S.G.I., IGCP 203, Excursion Guidebook, 4-12 July 1986, 82-88, Pavia. FARABEGOLI, E. & PERRI, M.C., 1998. Permian-Triassic boundary and Early Triassic of the Bulla section (Southern Alps, Italy): lithostratigraphy, facies and conodont biostratigraphy. Giornale di Geologia, 3a ser., 60 (Spec. Issue), 292-310, Bologna. HALLAM, A. & WIGNALL, P.B., 1999. Mass extinctions and sea-lavel changes. Earth Sc. Rev., 48, 217-250. MAGARITZ, M., BAR, R., BAUD, A. and HOLSER, W., 1988. The carbon-isotope shift at the Permian-Triassic boundary in the Southern Alps is gradual. Nature, 331, 337-339. NERI, C. & POSENATO, R., 1999. Sedimentary and bio-chronostratigraphical aspects of the P/T boundary in the eastern Southern Alps. In Stratigraphy and facies of the Permian deposits between Eastern Lombardy and the Western Dolomites. Field Guidebook, 35-42, Pavia University. NOE, S. & BUGGISCH, W., 1994. Sequence stratigraphy in late Permian and lowest Triassic of the Southern Alps (Dolomites, Northern Italy) with special regard to the Permian-Triassic boundary. Jahrb. Geol. Bundensanst., 137, 297-318. PERRI, M.C. & FARABEGOLI, E., 2002. Conodonts across the Permian-Triassic boundary in the Southern Alps. AUSCOS 2 Proceedings, Courier Forschungsinstitut Senckenberg (in press). POSENATO, R., 1988. The Permian/Triassic boundary in the western Dolomites, Italy. Review and proposal. Annali dell'Universita di Ferrara. N.S., 1 (3), 31-45, Ferrara. SCHOLGER, R., MAURITSCH, H.J. & BRANDNER, R., 2000. Permian-Triassic boundary magnetostratigraphy from the Southern Alps (Italy). Earth and Planetary Sciences Letters, 176, 495-508.

LATE ORDOVICIAN LIMESTONES EMPLACED IN SILURIAN BARNBY HILLS SHALE, CENTRAL NEW SOUTH WALES John FARRELL1, Ian G. PERCIVAL2*and Yong-yi ZHEN3* 1 School of Education, Australian Centre for Educational Studies, Macquarie University, N.S.W. 2109 [jfarrell@ted.educ.mq.edu.au]; 2Specialist Services Section, Geological Survey of New South Wales, P.O. Box 76, Lidcombe, N.S. W. 2141 [percivai@minerals.nsw.gov.aul;3Division of Earth and Environmental Sciences, The Australian Museum, 6 College Street, Darlinghurst, N.S. W. 2010 [yongyi@austmus.gov.au]; * Honorary Research Associate, Centre for Ecostratigraphy & Paleobiology, Macquarie University, N.S. W. Allochthonous limestone blocks exposed in the Eurimbla area, west of the Mitchell Highway between Molong and Wellington in central New South Wales, are substantially older than the enclosing Barnby Hills Shale of Late Silurian age. Nine of the blocks yielded a diverse Late Ordovician conodont fauna, dominated by Panderodus gracilis, Belodina confluens, Periodon grandis, Paroistodusl nowlani and Yaoxianognathusl tunguskaensis. Occurrence of Taoqupognathus blandus in seven sampled blocks indicates a middle Eastonian (Ea2) age, although rare Taoqupognathus tumidus in one suggests an extension into the late Eastonian (Ea3). These age determinations are confirmed by the presence of a silicified brachiopod fauna dominated by Mabella halis and Doleroides mixticius, and also including Rhynchotrema oepiki, Australispira disticha, Sowerbyella billabongensis, with rare Sowerbyites isotes, Zygospira carinata, Protozyga definitiva, Skenidioides quondongensisl and Chaganella speciosa. All are typical elements of the previously defined fauna B of Eastonian 2 age. The conodont and articulate brachiopod faunas from the Eurimbla blocks are comparable with those described from autochthonous limestones of Eastonian age elsewhere in the Molong Volcanic Belt, except for occurrence of the conodont Webbygnathus munusculum and brachiopod Sowerbyella billabongensis which, in the Lachlan Orogen, are otherwise known only from the JuneeNarromine Volcanic Belt to the west. The nearest known in situ carbonate of Late Ordovician age, which

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IPC2002 Poster Presentations might have provided a potential source area for the Eurimbla blocks, is the Reedy Creek Limestone, exposed near Molong about 20 kms to the south. However, analysis of the affinities of the Eurimbla conodont faunas reveal greater similarities with those from carbonates of the Bowan Park Group on the western flank of the Molong Volcanic Belt, contrary to what might have been expected. Clumping of the limestone blocks in three separate groups, two to three kilometres apart, may reflect the presence of discrete channels or submarine valleys. The blocks are also emplaced at various stratigraphic levels within the Barnby Hills Shale, indicating that erosion and redeposition of material was not confined to a single episode. In one possible scenario, erosion of the Silurian Molong High succession, concurrent with deposition of the Barnby Hills Shale in late Wenlock to mid Ludlow time, would have led to emplacement of allochthonous blocks in the deeper water sediments flanking that tectonic feature. This model pre-supposes that only Eastonian limestone was available at the source site and that any carbonate material aged between Eastonian and the onset of deposition of the Barnby Hills Shale was either not present or had previously been eroded away. An alternative model involves tectonic uplift with multiple episodes of redeposition. In this interpretation, the Eurimbla blocks were derived from equivalents of the Quondong Limestone (Bowan Park Group), and were initially emplaced in the deeper water Oakdale Formation flanking the volcanic belt during late Eastonian time. Subsequent tectonic uplift of this unit would lead to a second erosional episode in which only the more competent limestones were redeposited as recognisable clasts into the Barnby Hills Shale. This may explain removal of associated finer-grained carbonate debris to leave only the larger blocks in the final depositional episode. Large-scale thrust faulting on the Curra Creek Fault (forming the present-day boundary of the western belt of Barnby Hills Shale outcrop) and related structures to the west provides a possible mechanism to bring Late Ordovician sediments to sufficiently shallow depths, exposing them directly to subaerial or submarine erosion without having to wear through Early Silurian cover. I.G. Percival publishes with permission of the Director General, N.S.W. Department of Mineral Resources. MID-GIVETIAN TRILOBITE EXTINCTION IN NORTH GONDWANA Raimund FEIST Institut des Sciences de I'Evolution, Universite de Montpellier II, 34095 Montpellier, France Global eustatic deepening related to the mid-Givetian Taghanic onlap (T-R cycle Ila of Johnson et al. 1985) brought about a series of extinctions and decrease in biodiversity. In particular, benthic biotas such as trilobites living in a great variety of shallow water and perireefal habitats on near shore epicontinental platforms were most severely affected by the sudden extension of off-shore domains (Feist, 1991). During the Taghanic Event one order and 5 trilobite families vanished. The drop in lower rank diversity was even more drastic when more then 30 genera each with numerous species disappeared apparently spontaneously. New data from trilobite faunas from mid-Givetian localities in North Gondwana (Tafilalet/Morocco, Montagne Noire/southern France, eastern Urals/Kazakhstania and the Broken River region pf NE Australia (Feist and Orth 2000, Feist and Clarkson 1989, Feist et al 1997, Feist and Talent 2000) are compared with long known, contemporaneous sites on the Avalonian margin of Euramerica. All these sites have a Middle varcus Zone age and from the 23 so far recorded genera in North Gondwana sensu stricto (i.e. Armorican plate excluded) occurring on both sides of the Rheic ocean, 14 disappear simultaneously in all sites at the Middle/Upper varcus boundary. Conversely, contemporaneous North American faunas both in the E and in the Mid-continent are composed of distinct taxa that experienced a series of stepwise extinctions extending until the end of the Givetian (Hickerson, 1992). The Taghanic Event affected trilobite communities, especially those of the European/North African Realm earlier than other benthic biotas such as corals/stromatoporoids (within the Late varcus Subzone) and brachiopods (between Early and Late hermanni-cristatus Subzones). A few lines, such as the cornuproetine Richteraspis lineage, and the tropidocoryphine Longicoryphe lineage survived the Taghanic Event both in North Gondwana and Avalonia, and gave rise to post-event radiations in deeper outer shelf habitats. The high degree of taxonomic affinity, the contemporaneity of both a sudden drop in diversity and high rate of extinctions at the end of the Middle varcus Zone, and the simultaneous post-event radiation of the same surviving lines characterise mid-Givetian trilobite communities on both sides of the remnant oceanic tract between N Gondwana and Euramerica. This situation supports a palaeogeographic model with continental masses and intervening microplates in close proximity at that time. FEIST, R. & ORTH, B. (2000): Trilobites de la limite Eifelien/Givetien de la region stratotypique (Tafilalet, Maider, Maroc). Proceedings

of the Subcommission on Devonian Stratigraphy (SDS) - IGCP 421 Morocco Meeting A. Tahiri & A. El Hassani (Eds), Trav. Inst. Sci. Rabat, Serie Geol. & Geogr. Phys, N°20-2000: 78-91, 2 pi.

FEIST, R. (1991): The Late Devonian trilobite crises. Historical Biology, 5: 197-214.

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IPC2002 Poster Presentations FEIST, R. and CLARKSON, E.N.K. (1989): Environmentally controlled phyletic evolution, blindness and extinction in late Devonian tropidocoryphine trilobites. Lethaia, 22: 359-373. FEIST, R., IVANOV, S. N . , SAPELNIKOV, V . P., ANCIGIN, N . Y . Y . , IVANOV, S. N . , MIZENS, L. I., BIKBAYEV, A . Z., & LUBOV, L. V .

(1997): Correlations between the evolution of benthic faunal communities and convergent movements of lithospheric blocks from the Silurian to the Late Devonian in the mid-Paleozoic Uralian basin. Tectonophysics, 276: 301-311. FEIST, R. and TALENT, J. A. (2000): Devonian trilobites from the Broken River Province N-Queensland, Australia. Memoirs of the Western Australian Museum, Supplement 58: 65-80.. HLCKERSON, W.J. (1992): Trilobites from the late Givetian Solon Member, Little Cedar Formation of eastern Iowa and northwestern Illinois. In: J.Day and B.J. Bunker (eds.), The stratigraphy, paleontology, depositional and diagenetic history of the Middle-Upper Devonian Cedar Valley Group of central and eastern Iowa. Iowa Dept. of Natural Resources, Guidebook 16: 123-139. JOHNSON, J.G., KLAPPER, G. and SANDBERG, C.A. (1985): Devonian eustatic fluctuations in Euramerica. Geoloical Society of America Bulletin, 96: 567-587.

PHYTOPLANKTON DIVERSITY AND DISTRIBUTION PATTERNS IN THE TRIASSIC: THE DINOFLAGELLATE CYSTS OF THE UPPER RHAETIAN KOESSEN BEDS (NORTHERN CALCAREOUS ALPS, AUSTRIA) Susanne FEIST-BURKHARDT1. Bjorn HOLSTEIN2 & Annette E. GOTZ3 department of Palaeontology, The Natural History Museum, Cromwell Road, London, SW7 5BD, England, UK, [s.feist-burkhardt@nhm.ac.uk]; Institute of Geology and Palaeontology, University of Frankfurt, Senckenberganlage 32-34, D-60325 Frankfurt, Germany, [bholstei@stud.uni-frankfurt.de]; institute of Applied Geosciences, Darmstadt University of Technology, Schnittspahnstrasse 9, D-64287 Darmstadt, Germany, [agoetz@geo. tu-darmstadt. de] The first unequivocal dinoflagellate cysts are known from the Upper Triassic, but the first relatively diverse assemblages in Europe occur in the uppermost Triassic, the Rhaetian. These assemblages are characterised by only a few species and genera belonging to many different families. The dinoflagellate cyst assemblages of the Koessen Beds from a key section in the Calcareous Alps (Eiberg section near Kufstein, Austria) are presented. Most samples are rich in well-preserved dinoflagellate cysts. For the first time, the species Wanneria listeri (STOVER & HELBY 1987) BELOW 1987, which was so far known only from the Norian of Australia and Indonesia, is recorded from European sediments. The dinoflagellate cyst assemblages change significantly in their quantitative and qualitative composition depending on the lithology of the samples and the position of samples in a sedimentary sequence. The observed distribution patterns are discussed in context with the cyclic sedimentation of the limestones and marls of the Koessen Beds. Moreover, we try to decipher the palecological factors that are responsible for the distribution patterns recognised in the Rhaetian of the Northern Calcareous Alps.

TAPHONOMY OF CONIPOLLENITES ARABICUS CAMERON 1974 FROM THE MIDDLE-LATE TRIASSIC OF WESTERN AUSTRALIA Clinton FOSTER 1 , Robin HELBY2 and Gordon WOOD3 ! Geoscience Australia, GPO Box 378, Canberra Australia 2601; 237 Primrose Terrace, Rosslyn Park, SA 5072; 3 23222 Willow Pond Place, Katy Texas, USA 77494 Morphologically distinctive, large (70-135 jim), trilete spores, with two exinal layers and a bizarre admixture and arrangement of apiculate sculptural elements (up to 40 jam in length), from spore-pollen floras of the Samaropollenites speciosus and Minutosaccus crenulatus Oppel Zones, are assigned to Conipollenites arabicus. As illustrated in this work, specimens we attribute to C. arabicus, from the Challis Formation of Western Australia's North West Shelf, display a continuum of diverse morphologies effected by preservation. Specimens that most resemble the type species, known only from two illustrations (Cameron 1974, pi. 1, figs 3-4) show evidence of corrosion, when compared with other examples within the same sample. Cameron noted that while the occurrence of C. arabicus was widespread: 'the preservation of most forms is poor. Complete specimens are rare and in most samples only fragments are observed.' We concur that the fragments are so distinct that the species can be recognised readily from small fragments. Within the morphologic continuum, and representative of our better-preserved material, there is also a striking similarity with taxa assigned to Jerseyiaspora punctispinosa Kar, Kieser & Jain 1972. Described initially from the Middle Triassic of Libya (Kar et al. 1972), J. punctispinosa is a key elements of Late Anisian palynofloras from the Barents Sea (Hochuli et al. 1989). Further detailed work is required to determine if J. punctispinosa is conspecific with Australian examples. Cameron's (1974) records of C. arabicus are from the Jilh Formation, shown in the original work to be of upper Scythian to Ladinian age: this has been revised to span

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IPC2002 Poster Presentations only the Anisian to Carnian. The Samaropollenites speciosus and Minutosaccus crenulatus Oppel Zones range in age from Ladinian? to Norian, with associated conodonts confirming that both Oppel zones are at least of Norian age (Nicoll & Foster 1994). The Middle-Late Triassic age of all these taxa is significant in that the Western Australian assemblages belong to the Onslow Microflora characterised by an admixture of European and Gondwana taxa (Dolby & Balme 1976) resulting from floral migration. CAMERON, D.K., 1974. New Triassic palynomorphs from the Arabian Peninsula. Grana, 14, 4-10. DOLBY J.H. & BALME, B.E., 1976. Triassic palynology of the Carnarvon Basin, western Australia. Review Paleobotany and Palynology, 22, 105-168. HOCHULI, P.A., COLIN, J.P. & VIGRAN, J.O., 1989. Triassic biostratigraphy of the Barents Sea area. In: J. D. Collinson, Editor, Correlation in hydrocarbon exploration. Chapman & Trotter, London, pp. 131-153. KAR, R.K., KLESER, G. & JAIN, K.P., 1972. Permo-Triassic subsurface palynology from Libya. Pollen et Spores, 14, 389-453. NICOLL, R.S. & FOSTER, C.B., 1994. Late Triassic conodont and palynomorph biostratigraphy and conodont thermal alteration, North

West Shelf, Australia. AGSO Journal of Australian Geology & Geophysics, 15, 101-118.

ORDOVICIAN AND SILURIAN CONODONT FAUNAS FROM THE SOUTHERN NEW ENGLAND FOLD BELT Terry FUREY-GREIG Centre for Ecostratigraphy and Palaeobiology, Macquarie University, NSW, 2109, Australia The Southern New England Fold Belt is a well preserved ancient convergent plate margin that was active along the eastern margin of Gondwana for much of the Palaeozoic and is dominated by tholeiitic and calcalkaline igneous rocks and associated sediments and subduction-accreted oceanic rocks. It comprises a number of structural blocks of differing stratigraphy, metamorphic grade and intensity of deformation. Analyses of the relationships between the blocks have seen differing scenarios advanced that include recent speculation that some represent discrete, fault-bounded "terranes" (eg., Flood & Aitchison 1988), in contrast with earlier work that indicated a less complex model of an eastern oceanic magmatic arc, flanking basin, forearc basin and subduction complex (eg., Cawood & Leitch, 1985). A fauna from the Haedon Formation east of Woolomin includes Ansella jemtlandica, Oistodus lanceolatus and Periodon aculeatus, an assemblage that ranges in eastern Australia from late Arenig to early Llanvirn and is the oldest Ordovician fauna in New England. Faunas from limestone blocks at a dozen localities in the olistostromal Wisemans Arm Formation between Attunga and Warialda are dominantly Eastonian (EA3) (Furey-Greig 1999, 2000a,), including Taoqupognathus tumidus, Panderodus nodus, Yaoxianognathus ani and Webbygnathus munusculum. An Early Silurian (late Llandovery- early Wenlock) fauna from the Wisemans Arm Formation at Uralba includes Apsidognathus tuberculatus and Distomodus sp. The Emsian Drik Drik Formation between Tamworth and Nundle contains olistoliths of Late Ordovician limestone at several localities (Cawood, 1980). A fauna of 1000+ conodonts from Dalveen east of Woolomin (Furey-Greig, 2001) includes Webbygnathus munusculum, Phragmodus undatus and Belodina confluens, an assemblage that, in the absence of the EA3 markers T. tumidus & Y. ani, may span the known range of W. munusculum, i.e., EA2-EA3 (Pickett & Furey-Greig, 2000). The Late Ordovician and Early Silurian faunas from New England compare closely with others reported from the eastern Lachlan Fold Belt. Further, Webbygnathus munusculum (Pickett & Furey-Greig) occurs in two structural blocks on either side of the Peel Fault System, evidence that those blocks are coeval, and not exotic "terranes". Geochemical analysis of ankaramitic basalt from the Wisemans Arm Formation associated with EA3 limestone in an olistostrome at Uralba indicated a calk-alkaline, island arc affinity (Furey-Greig 2000b), indicating that earlier suggestion that such Ordovician limestones were part of the remains of offscraped guyot-cappings are incorrect. CAWOOD, P.A., 1980. The Geological development of the New England Fold Belt in the Woolomin-Nemingha and Wiseman's Arm

regions: the evolution of a Palaeozoic forearc terrain. Unpub. PhD thesis, 429p. University of Sydney.

CAWOOD, P.A. & LEITCH, E.C., 1985. Accretion and dispersal tectonics of the southern New England Fold Belt, eastern Australia. In,

Howell, D.G., (ed) "tectonostratigraphic Terranes of the Circum-Pacific region, Circum-Pacific Council for Energy and Mineral Resources Houston, 481-492.

FLOOD, P.G. & AITCHISON, J.C., 1988. Tectonostratigraphic terranes of the southern part of the New England orogen. In. Kleeman, J.D.

(ed) New England Orogen: Tectonics and Metallogenesis. Department of Geology and Geophysics, University of New England Armidale, 7-10.

FUREY-GREIG, T.M., 1995. The "Nemingha" and "Loomberah" limestones (Early Devonian; Emsian) of the Nemingha-Nundle area, northern New South Wales: conodont data and inferred environments. Courier Forschungsinstitut Senckenberg, 182, 217-234,

Frankfurt.

FUREY-GREIG, T.M. 1999. Late Ordovician conodonts from the Wisemans Arm Formation, New England Region, Australia.

Geologisches Bundesanstalt Wien, Abhandlungen 54, "North Gondwana: Terranes, Stratigraphy and Biota" (IGCP 421), 303-321.

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IPC2002 Poster Presentations FUREY-GREIG, T.M., 2000a. Late Ordovician and Early Silurian conodonts from the "Uralba Beds", east of Manilla, northern New South Wales. Alcheringa, 24: 83-97. PICKETT, J.W. & FUREY-GREIG, T.M., 2000. Webbygnathus, a new Late Ordovician conodont genus from New South Wales. Alcheringa 24, 83-96.

CHITINOZOAN BIOSTRATIGRAPHY AND PALAEOGEOGRAPHY OF LOWER SILURIAN STRATA (SARCHAHAN FORMATION) IN THE ZAGROS BASIN OF SOUTHERN IRAN Mohammad GHAVIDEL-SYOOKI and Theresa WINCHESTER-SEETO Exploration Directorate ofNational Iranian Oil Company. PO Box 1065, Tehran, Iran; Centre for Ecostratigraphy and Paleobiology, Department ofEarth and Planetary Sciences, Macquarie University, 2109, Australia. 1

Palynological investigations were undertaken on sixty samples from the Sarchahan Formation. All samples contain abundant, well-preserved chitinozoans. A total of nine genera, and 28 species were recognized in this study, with eight described as new. Several chitinozoan species from the Sarchahan Formation are common in contemporaneous chitinozoan assemblages from Saudi Arabia, Algeria and Libya, with some also occurring in northwestern Spain, Estonia, Florida and Paraguay. These include : Pterochitina deichia, Conochitina algarada, Spinachitina fragilis, Angochitina macclurei, Ancyrochitina udayanensis, Plectochitina paraguayensis Plectochitina pseudoagglutinans, Plectochitina saharica, Plectochitina nodifera, Plectochitina ralphi, Clathrochitina aff clathrata, Ancyrochitina convexa, and Ancyrochitina vikiensis. Most of the chitinozoan taxa from the Sarchahan Formation have previously been recorded from the Qusaiba and Sharawra members of Qalibah Formation in Saudi Arabia, and there is a great deal of similarity in much of the lithological and palaeontological data. This similarity suggests that the same environmental conditions prevailed in northern and southern Persian Gulf throughout the Early Silurian. Based on chitinozoan data, the Sarchahan Formation ranges from earliest Rhuddanian (fragilis global biozone) to early Sheinwoodian (equivalent to margaritana global biozone). Thus, there is a hiatus between the Sarchahan (Early Silurian) and Zakeen (Early-Late Devonian) formations. This hiatus encompasses most of the Middle and Late Silurian strata, possibly corresponding to the Caledonian Orogeny. PRELIMINARY STUDY OF TRANSGERSSION-REGRESSION PATTERNS AND THE RELATIONSHIPS WITH CHANGES OF BIOTA NEAR TO F/F BOUNDARY IN CENTRAL IRAN Hossein GHOLAMALIAN & Mehdi YAZDI Department of Geology, University of Esfahan, Iran; h_gholam@yahoo.com; m.yazdi@sci.ui.ac.ir New studies on sedimentary and biostratigraphical data in calcareous and terrigenous sediments near to the Frasnian/Famennian Boundary in central Iran show a large regression at the end of Frasnian and begining of Early Famennian. The observations in Frasnian sediments prove shallow water facies in all sections in Central Iran. In some sections, such as Howz-e-Dorah and Ghale-Kalaghu (Shotori Range, Tabas area), depth of water is very shallow water or is represented by a total lack of marine sediments at the end of Late Frasnian and Early Famennian. These sequences become slightly deeper toward the end of Famennian. Middle Frasnian deposits in all sections (Central Iran) consist of reefal limestone beds with several species of corals, stromatoporids and brachiopods, but they are poor in conodonts. These fauna (corals and stromatopoirds) show the stability of marine environmental conditions in the Middle Frasnian in all of Central Iran sections. Late Frasnian sediments contain shallow water conodonts mostly related to pelekysgnathid-polygnathid and icriodid-polygnathid biofacies. There are differences between Late Frasnian sediments of Howz-e-Dorah, Kal-e-Sardar and Chahriseh sections. Kellwasser beds are observed at the top of Frasnian deposits in Kal-eSardar section and contain a lot of Latest Frasnian (linguiformis Zone) index conodonts. Some of these conodonts are: Ancyrodella curvata, Ancyrodella nodosa, Ancyrodella gigas, Ancyrognathus triangularis, Palmatolepis subrecta, Polygnathus evidens and P. planarius. One of the most interesting features of Late Devonian sedimentation in Central Iran can be seen in Ghale-Kalghu section near the F/F boundary. Big reworked limestone blocks are scattered in the beds of Late Frasnian and Early Famennian. Early Famennian sediments in all sections in central Iran begin with shallow water dark shale or black paper sandstone beds. As the matter of fact, sea level fluctuation and changes of sedimentological features in studied sections are different in intensity and their effects on the formation of sedimentary environment.

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IPC2002 Poster Presentations BARSKOV, I. S., VORONTSOVA, T. N., KONONOVA, L. I. and KUZ'MIN, A. V., 1991. Operdelitel' konodontov devona I nizhnego karbona (Index conodonts of the Devonian and Lower Carboniferous), pp. 1-183. Moskovskty gosudarstvennyy Universitet; Moscow. GHOLAMLAIAN, H., 1998. Biostratigraphy of Late Devonian sediments in Chahriseh area north-east of Esfahan based on conodont species. In: R. Mawson, J. A. Talent, G. Wilson.(eds), UNESCO-IGCP Project 421, North Gonwanan mid-Palaeozoic bioevent/biogeography patterns in relation to crastal dynamics. Esfahan meeting, Iran. Abstract book, p. 13. Esfahan. GHOLAMALIAN, H., TURNER, S., BURROW, C. J. and YAZDI, M., 2000. Recovery of Late Devonian (Frasnian) microvertebrates and conodonts from the Chahriseh area, north east of Esfahan, Iran. In: P. Cockle, G. Wilson, G. A. Brock, M. J. Engelbretsen, A. Simpson, & T. Winchester-Seeto (eds), Palaeontology Down Under 2000. Geological Society of Australia Abstracts, 61, p. 159. Orange. Jl, Q. and ZLEGLER, W., 1993. The Lalli section: An excellent reference section for Upper Devonian in south China. Courier Forschungsinstitut Senckenberg, 157, 1-183. MATYJA, H., 1993. Upper Devonian of western Pomerania. Acta Geologica polonica, 43 (1-2), 27-94.

TRANSITIONAL UFIMIAN-KAZANIAN MARINE DEPOSITS IN THE SOUTH-EASTERN SEABOARD OF THE KANIN PENINSULA T. GRUNT1, O. MALYSHEVA2, & G. KANEV2 1 Palaeontological Institute, Russian Academy of Sciences, Profsouznaya, 123, Moscow 117997, Russia; [1247.g23@g23.relcom.ru]; 2Institute of Geology, Komi Science Centre, Uralian Branche, Russian Academy of Science, Pervomaiskaja 54, Syktyvkar 167610, Russia; [malysheva@geo.komisc.ru] The Ufimian-Kazanian (Late Permian), exposed (up to 4 m) on the SW shore of Cheshskaya Bay between the Nadtei River estuary and Cape Jarneissale in the Kanin Peninsula, consists of shallow marine facies biogeographically part of the Barents Shelf Area. The Ufimian/Kazanian boundary, identified by D. Stepanov (Stepanov et al., 1975) based on change in brachiopod assemblages in the Sowerbina-Licharewia interval, was later suggested to occur between the local zones of Sowerbina granulifera and Licharewia stuckenbergi (Molin et al., 1983). In 2002 the authors undertook redescription of the section and made new palaeontological collections. Bbrachiopod and bivalve distributions enable a five-fold subdivision of the section: Sowerbina granulifera-Oriocrassatella komiorum layers (lowest) are exposed near Cape Nadtei. They consist of up to 2 m of interbedded greenish-gray sandstones, fine- or medium-grained polymict weakly laminated sandstones and massive coquinas. Abundant S. granulifera (Toula) and O. komiorum (Kanev) sometimes form minor banks. This interval could be assigned to the Solikamsk horizon of the Ufimian. This stratigraphic level corresponds to the Kozhim Rudnik Formation within in the Kozhim River section (Biota, 1998) and the Voringen Member of the Kapp Starostin Formation of Central Sptisbergen. Cancrinella cancrini-Schizodus rossicus layers (up to 10m) of diverse lithologies differ from overlying and underlying intervals. The latter consist of peculiar detrital bryozoan-crinoid limestones with gravel structure, micritic limestones with admixed clastics, oolites and polymict sandstones with abundant tracks of Taonurus, and detrital, dolomitic or calcareous micritic marly limestones with abundant fragments of Microcodium. Brachiopods include numerous Cancrinella cancrini and occasional Svalbardia capitolina, Sowerbina granulifera, bivalves and ostracods. Fine-grained laminated sandstones with abundant calcareous detritus occur in the uppermost part. Licharewia schrencki-Schizodus sp.nov aff. rossicus layers are represented by up to 3 m of interbedded sandy-calcareous rocks and detrital and oolitic limestones with fragments of quartz and quartzite, with numerous brachiopods Licharewia schrenckii, L. stuckenbergi, L. kaninensis Kulikov, bivalves, bryozoans and crinoids. On the basis of abundant Licharewiinae, this interval is Lower Kazanian. Kaninospirifer borealis-Parallelodon licharewi occur in 20-22 m of interbedded terrigeneous-carbonate rocks, detrital limestones and coqinites with brachiopods including Aulosteges wangenheimi, Craspedalosia pulchella, Kaninospirifer borealis, Purdonella soderberghi, bivalves, bryozoans, gastropods and nautiloids. Pinegathyris alata-Schizodus subobscurus characterize up to 6 m of calcareous sandstones with numerous subvertical worm tracks, abundant Pinegathyris alata, rare P. royssiana, bivalves, bryozoans, paleoniscids and plant detritus exposed near Cape Jarneisaale; this ends the marine part of the section. The interval was previously identified as Upper Kazanian Pinegathyris royssiana Zone (Molin et al, 1983). Investigations were supported by All-Russian Basic Scientific Foundation (RFFI) projects 01-05-64113 and 01-05-79187. MOLIN, A.V., KALASHNIKOV N.V., KOLODA, N.A. & MELNIKOVA, S.O., 1983. New data on palaeontologic characteristic of the Late Permian of the Kanin Peninsula. Trans, of the Inst of geology of Komi branch of the Acad. Sci of USSR. 43, 7-25 (Rus.). STEPANOV, D.L., KULIKOV, M.V. & SULTANAEV, A. A., 1975 Stratigraphy and Brachiopoda of the Late Permian of the Kanin Peninsula. Mess. Leningrad State University, 6, 51-65 (Rus.).

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IPC2002 Poster Presentations ON THE DEVELOPMENT OF THALASSOID SHELL FORMS IN LONG-LIVED LAKES : INTRASPECIFIC VARIATION OF "GYRAULUS (GYRAULUS) VARIANS VARIANS (FUCHS)" FROM FOSSIL LAKE PANNON Sandor GULYAS University of Szeged Department of Geology and Paleontology, H-6722 Szeged, Egyetem u. 2-6 [gubanc@yahoo. com, sanyi@geo. u-szeged. hu] In case of the species Gyraulus (Gyraulus) varians varians (FUCHS), originally described from Radmanest, a large-scale variation in the shell form and ornamentation can be observed. Shells are highly thalassoid with a lower and upper keel and a highly deflected ultimate whorl and a deeply inset umbilicus. However, the rate of whorl deflection, umbilicus inset and ornamentation tends to display a large-scale variance with age and environment. Older specimens from the littoral sands of Radmanest (9.5 MA) display a gently deepset spire running almost parallel with the upper strong keel. The umbilicus is bordered with a lower strong keel and is deeply indented turret-like. On the other hand in case of the younger specimens from the more protected, lagoonal sands and silts of Tihany (9 MA) the spire is gradually indented and the rim of the upper keel on the apertural surface is slightly uplifted. Meanwhile a gradual shallowing of the umbilicus can be observed accompanied with a less deflected aperture and ultimate whorl. This large-scale variance of forms suggested the presence of several taxa. Brusina (1902) in his work separated a small, less decorated form as Planorbis lendli BRUSINA - possibly juvenile forms- on the bases of a single specimen within such a highly varying group. Variance in form is quantified via outline analysis (EFA) of the forms in 2D from two localities (Radmanest and Tihany). Size was determined with traditional morphometric measurements (H/W). Other variants quantifying keel and striation numbers, angle of aperture deflection and inset of apex and umbilicus have been utilized as well. Total morphological variance was analyzed with the help of relevant multivariate methods - PCA, DA. Results of discriminant analysis and PCA underlie our hypotheses, that despite the large-scale variation specimens seem to constitute a single species with a gradual morphological transformation of the older Radmanest forms to the younger Tihany forms as part of some sort of adaptation. The separation of small less decorated forms by Brusina, as separate species within this group is not justified. To shed more light onto the ecological factors provoking this variation, analysis of shell ultra-structures have been carried out with SEM. According to our findigs there is a strong correlation between the shell ultrastructure and "thalassoidicity" of the above mentioned forms indicating the major role of abiotic (environmental) factors in creating this high variance, i.e adaptation to higher energy environments. Our work is supported by OTKA Grant T029342 and NSF Grant EAR9706230.

THE APPLICATION OF MODIFIED RAUPIAN PARAMETERS TO THE MODELLING OF SHELLS AND INVESTIGATING POSSIBLE HETEROCHRONY ON THE EXAMPLE OF ENDEMIC LACUSTRINE GASTROPODS Sandor GULYAS University of Szeged Department of Geology and Paleontology, H-6722 Szeged, Egyetem u. 2-6 [gubanc@yahoo. com, sanyi@geo. u-szeged. hu] Changes in size and shape are well traceable on the axial cross sections of gastropod shells.The application of the previously published method for cross sectional shell analysis via dental x-ray (Gulyas et al 2001) provides an excellent way for studying the inner structures of the shells. Furthermore, certain growth parameters can also be determined for the modelling of shell growth even on minute, fragile gastropod specimens as well. Application of the traditional Raupian parameters for the exact documentation of shell form and size changes through ontogeny is not eligible in all the cases. In such cases the development of new, modified shell growth parameters is required. Similar investigations have previously been carried out on larger endemic Lake Pannon Melanopsids.(Geary 1990) The apllicability of this old method was tested in case of endemic lacustrine Planorbids. The axial cross sections of 70 specimens of Gyraulus varians varians (FUCHS) has been prepared via application of dental x-ray. The developed dental films were digitized for easier quantification and data collection. In order to document shell growth changes (translation or expansion) the angle bw. the major coiling axis and a line drawn through the point of contact of the individual whorls (R) has been determined. These inner angles were taken as the function of shell growth through coiling (quantified as the length of the whorl on the coiling axis) in order to represent changes in size and shape through ontogeny. Since large inner angles refer to the major role of the expansional component while small inner angles indicate the dominance

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IPC2002 Poster Presentations of the translational component in shell growth through ontogeny via the comparison of the received diagrams the presence of heterochrony in the given lineages is well traceable. This work is supported by OTKA Grant T029342 and NSF Grant EAR9706230. GEARY, D.,H. 1990: Evaulating intrinsic and extrinsic factors in the evolution of Melanopsis in the Pannonian Basin. In R.M, Ross and

W. D. Almon (eds): Causes of Evolution: a paleontological perspective, Chicago, University of Chicago Press

GULYAS, S.B, SIVOK, M, SZONOKY 2001: Axial cross-sectional shell analysis with the help of dental X-ray on the example of Lake

Pannon Planorbidae, SOOSIANA Hungarian Malacological Newsletter, Vol.22:73-80

THE MIDDLE-UPPER DEVONIAN BOUNDARY IN THE ALTAY-SAYAN FOLDED AREA Ya.M. GUTAK . S.A. RODYGIN , & N.I. SAVINA Western-Siberian Trial Center, Novokuznetsk, Kemerovo region, Russia; Tomsk State University, Tomsk, Russia Kuzbass. The Middle-Upper Devonian boundary lies between the Izylinsky and Vassinsky horizons. The former, greenish-gray sandstones and calcareous siltstones, has produced the brachiopods Mucrospirifer vassinensis, Anathyris sibirica, An. helmerseni, Athyris is ilens is, and the conodonts Icriodus brevis, I. difficilis, I. expansus, Polygnathus aff. xylus, Po. cf. webbi, Po. cf. decorosus and Po. dubius. It is Lowermost asymmetricus Zone, latest Givetian. The Vassinsky interval consists of sandstones with the brachiopods Cyrtospirifer achmet, C. schelonicus, Mucrospirifer ales, Anathyris phalaena and the conodonts Polygnathus webbi, Po. alatus, Po. decorosus, Ancyrodella lobata, Icriodus expansus and I. brevis angustulus indicating Middle and Upper asymmetricus Subzones. Rudny Altay. The Middle-Upper Devonian boundary lies within arenite-siltstone sections of the Kamenevskaya Subformation characterized by the brachiopods Cryptonella piriformis, Emanuella cicer, Septalaria postascendes, Dalejina hanusi, the conodonts Klapperina disparilis, Polygnathus ovatinodosus, Po. ex. gr. varcus, Belodella devonica, the ammonoids Pharciceras cf. lunulicosta, Neopharciceras kurbatovi, Namarites subitus, Trianoceras cf. gerassimovi, the ostracods Costatiella aff. abundans, Praepilatina aff. adamczaki, Bairdiocypris aff. vactus, Libumella circulata, Parabairdiacypris holuschurmensis angulata, Bairdia aff. crebra, aff. plicatila, aperta, corals and radiolarians. This interval is followed by dark gray and black flints beyond which there are minor bioherms of limestone with the brachiopods Adolfia ziczack, Pugnax acuminatus ,Aulacella eifeliensis, Schizophoria tulliensis, Cyrtospirifer sp., the conodonts Mesotaxis falsiovalis, A.ncyrodella binodosa, A. soluta, A. pristina, A rotundiloba Belodella devonica Polygnathus dengleri, Po. decorosus, Po. pennatus, Po. lodinensis, Po. normalis, Icriodus symmetricus and the ostracods Acanthoscapha aff. kahlleitensis , Zaborovia aff. obscura, Healdianella aff. budensis, Coeloenellina parva, Ampuloides verrucosta, Amphhissites pulcher, Monocerratina sublimis spinosa, Jenningsina cavernosa, and the ammonoids Probeloceras (?) orientale and Tamarites subitus. The norrisi conodont zone occurs between these two intervals. The boundary interval is 30 m in thickness. Altay Mountains. Corresponding to the Middle and Upper Devonian in the SW part of the region are the Belgebashskaya (gray and black laminated organic limestone), the Uzuntalskaya (multi-coloured siltstones, argillites and sandstone) and the Akkainskaya (green calcareous siltstones and argillites) formations. The first is characterized by the brachiopods Euryspirifer cheehiel, Spinocyrtia martianovi, Mucrospirifer vassinensis, Athyris is Hens is, Anathyris helmerseni and the conodont Icriodus brevis. The Uzuntalskaya Formation has the brachiopods Euryspirifer cheehiel, Spinocyrtia martianovi and kisilschinika n its lower part, and in its upper part has plants including the genus Archaeopteris. The Akkainskaya Formation has the brachiopods Cyrtospirifer schelonicus, Anathyris phalaena, the conodonts Polygnathus webbi, Po. normalis, Po. lodinensis, Po. aequalis, Icriodus aff. symmetricus, and the ostracods Indivisia indistincta, Pribylites aff. domanicus, Aparchites calculus, Bythocypris nalivkini and Amphissites klarae. It is Frasnian. The Middle and Upper Devonian boundary lies within the upper part of the Uzuntalskaya Formation near the beds with Archaeopteris. 1

FROM SOURCE TO SINK - LINKING SHELF AND SLOPE BIOCLASTIC DEPOSITS IN THE LATE MIOCENE-EARLY PLIOCENE RECORD OF WANGANUI BASIN, NEW ZEALAND Austin HENDY. Adam VONK, Peter J.J. KAMP Department ofEarth Sciences, University ofWaikato, New Zealand

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IPC2002 Poster Presentations Shellbeds are conspicuous components of shelf-slope sedimentary successions in the late Miocene to early Pliocene Whangamomona Group (Matemateaonga, Kiore, and Urenui Formations) of Wanganui Basin, North Island, New Zealand. The Matemateaonga Formation (1000 m thick) is a cyclothemic unit, and represents shelf sediments or topsets of a prograding continental margin. It is characterized by the occurrence of thick (2-6 m thick) and continuous shellbeds, which represent the transgressive systems tracts (TSTs) of 6th-order depositional sequences. The shellbeds comprise predominantly disarticulated and fragmented molluscan and brachiopod elements. Several types of shellbed are identified within the TSTs of the Matemateaonga Formation: a basal onlap shellbed of locally transported bioclastic material, which is formed during sediment bypassing associated with shoreline trangression; a backlap shellbed of predominantly epifaunal taxa, which is formed through sediment starvation offshore from the shore-connected sand prism; and a compound shellbed, which comprises amalgamated onlap and backlap shellbeds in offshore locations. The Kiore and Urenui Formations represent slope deposits (slope-sets), and occur geographically and stratigraphically adjacent to the Matemateaonga Formation. The Kiore Formation (500 m thick) is inferred to have formed in outer shelf and upper slope palaeoenvironments and is characterized by a thick succession of laminated siltstone (sandstone interbeds), punctuated by small, laterally discontinuous channels infilled by silstone, sandstone, bioclastic material and conglomerates. The Urenui Formation accumulated in an uppermid slope palaeoenvironment and comprises an approximately 500 m thick succession of massive to laminated siltstone. Several large channels or canyons can be observed in the formation, which contain bioclast-rich conglomerates and breccias. In both formations, channels commonly comprise a bioclast-rich (lower) and siliciclastic-dominated (upper) sediment fill, which are further overlain by fine-grained siliciclastic background sediments. The skeletal material is typically of inner-mid shelf origin, is variably disarticulated, fragmented and abraded, and may be orientated in either chaotic or hydrodynamically stable positions. This suggests transportation into slope environments by both debris flow and traction current mechanisms. The Matemateaonga-Kiore-Urenui succession represents a progradational continental shelf-slope system. While the outcrops examined within the succession are of different age, they are representative of contemporaneous facies that accumulated on a prograding continental margin. A palaeoenvironmental linkage can therefore be inferred between the condensed skeletal assemblages observed in each of the stratigraphically adjacent formations. The source of the concentrated skeletal material observed in channels of the Kiore and Urenui Formation must have originated from the same inner shelf fauna that contributed to the contemporary shelfal TST shellbeds (Matemateaonga Formation). Wind/wave-driven currents probably transported shell material into existing channels on the slope where continued transport would have been achieved by sediment gravity flows. Further down-slope transportation of skeletal material in established canyon complexes would amalgamate material to form bioclast-rich conglomerates. Erosion of existing channelised deposits may have contributed towards the reworking of previously cemented coquina. As the supply of concentrated skeletal material on the shelf is determined by the state of sea level, the sequence stratigraphic framework established for the shelfal Matemateaonga Formation can be extended off the shelf and down the slope. During periods of sea-level lowstand, some of the shelf would have been exposed, channels may have incised the mid-outer shelf, and more established canyon systems would continue to develop on the slope. Skeletal material is concentrated into shellbeds on the shelf during transgressive phases of sea-level change. A supply of bioclastic material is therefore available to be redeposited off the shelf edge. The increased sedimentation rate experience on the shelf during highstand sealevel conditions is recorded by the stratigraphic truncation of TST shellbeds. This change in sea level is also expressed in slope channel deposits by a rapid transition from bioclast and conglomerate-rich facies to finegrained siliciclastic facies. Inevitably rapid sedimentation during this phase of sea level change, associated with progradation of the shelf and slope, buries the channels.

AN EXCEPTIONALLY WELL-PRESERVED SEEP COMMUNITY FROM THE CRETACEOUS YEZO FOREARC BASIN IN HOKKAIDO, NORTHERN JAPAN Yoshinori HIKIDA1, Seiichi SUZUKI2, Yoshihiro TOGO3 and Akira IJIRI4 ] Nakagawa Museum of Natural History, 28-9, Yasukawa, Nakagawa Town, Hokkaido 098-2626, Japan; 2 Dep. of Earth Sci. and Astron., Fukuoka Univ. of Edu, Munakata, Fukuoka 811-4146, Japan; 3 Dep. of Earth Sci., Iwamizawa Col., Hokkaido Univ. of Edu, Iwamizawa, Hokkaido 068-0835, Japan; 4 Graduate school of Science, Hokkaido University, Sapporo, 060-0810, Japan. A well-preserved Cretaceous seep community was recovered from a carbonate lens (142.2.25E, 44.39.26N) in the Omagari Formation, Upper Yezo Group, in the Nakagawa region. The Upper Yezo Group belongs to the Yezo Supergroup, and palaeogeographic setting of the supergroup is an early to late Cretaceous forearc basin. The Omagari Formation, throughout which slump structures are developed, is composed of muddy to

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IPC2002 Poster Presentations sandy turbidites intercalated with conglomerate and thick sandstone layers. Ammonoid and inoceramid fossils refer the Omagari Formation to the Coniacian to Santonian age. The carbonate lens is roughly ellipsoidal in plan view with diameters of about 10 m x 6 m, and it was composed mainly of various morphologies of high Mg-calcite containing several to 10mol% magnesium with poor iron and manganese. The carbonate lens was divided into upper tube worm-dominant boundstone and lower carbonate breccia facies. In boundstone facies concentric growth of precipitates observed in vestimentiferan tube walls (chimney) indicates that these worm tubes likely provide the conduits for seeping, and layered to vein-like precipitations of high-Mg calcite (bacterial stromatolite) are recognized. The carbonate breccia consists mainly of limestone breccia with sideritic, silty and tuffaceous matrices. The chemosynthetic bivalves occur in the upper to uppermost part of the limestone breccia. The most predominant bivalve is the lucinid Miltha sp. The lucinid Thyasira sp. and thraciid Nipponothracia cf. ponbetsensis are also found. Only one specimen of the vesicomid Calyptogena occurred from slightly upper part than the part contains other chemosynthetic bivalves. All of the bivalves are articulated and randomly oriented, indicating in situ burying. Many small molluscan fossils occurred in matrices of the breccia, in which the most predominant are archeogastropods of less than 1cm in diameter; others are limpets, mesogastropods and nuculacean bivalves. Many brachiopod shells of about 5 mm in height also occurred. Compared with recent bathyal gastropods living within or near the Calyptogena community of the Hatsushima Islet, Sagami Bay, central Honshu Japan, these Cretaceous archeogastropods are similar to the trochid Margarites in the recent Calyptogena-community. Two limpets are similar to Serradonta vestimentifericola and Bathyacmea nipponica respectively. In the recent community the former limpet attaches to the tube of Vestimentifera, and the latter to the shell of Calyptogena. The carbonate lens containing abundant chemosynthetic bivalves and vestimentiferan worm tubes may have been formed by bacterial sulfate reduction and methane oxidation in the chemosynthetic community, because of an extreme 13C-depletion (513C = - 4 1 to - 4 5 % o ) . Oxygen isotope (5 18 0 = - 0 . 7 to - 1 0 % o ) suggest temperatures of precipitation close to or slightly below ambient marine temperatures of seeping site. Compared with modern seep communities, the molluscan fauna from the Cretaceous carbonate rock in the Nakagawa region has high diversity, and Calyptogena is not predominant species in the community. This community may be similar to the modern cold seep community along the landward slop of the subductionzone complex off the Pacific coast of Japan.

ANCIENT DNA: POSSIBILITIES AND LIMITATIONS OF ANCIENT DNA STUDIES, GENETIC ANALYSES OF NEANDERTALS Michael HOFREITER1, David SERRE1, Doris NAGEL2 & Gemot RABEDER2 1 Max Planck Institute for evolutionary Anthropology, Inselstr. 22, D-04103 Leipzig, Germany, [hofreite@eva.mpg.de]; 2Institute of Palaeontology, Althanstrasse 14, A-1090 Vienna, Austria, [doris. nagel@univie. ac. at]. By studying the DNA from archeological and palaeontological remains it is possible to investigate the genetic relationship of extinct species and populations to their extant relatives. Investigations of ancient DNA sequences which are derived from samples ranging in age from some decade old museum specimens to more than 50,000 year old Pleistocene mammals have yielded new insights about the evolutionary history of both extinct and extant species. Recently it even became possible to analyse ancient DNA from up to 30,000 year old coprolites which makes it possible to gain information about the diet and therefore the habitat and behaviour of extinct species. Genetic analyses of Neandertals (David Serre): 350bp of the mitochondrial hypervariable region have been successfully amplified from Neandertal individuals from Germany, Croatia and Russia. All the sequences group together in a clade different to that of modern humans. These results do not exclude that interbreeding between Neandertals and modern humans may have taken place, but they show that even if it occurred, Neandertals did not end up contributing mtDNA to the contemporary human gene pool. Despite the fact that more extensive sampling of Neandertals is obviously desirable, the current sequences indicate that: a) the diversity of Neandertals is so restricted that it is highly unlikely that a Neandertal mtDNA lineage is divergent enough to form an ancestral lineage to some modern Europeans, and b) Neandertal may have been similar to modern humans in having a low species-wide mtDNA diversity. Ananlyses of further Neandertal specimens will reveal if a population history similar to that seen in modern humans underlies the reduced diversity in Neandertals. The evolution of cave bears from a molecular point of view (Michael Hofreiter): Due to the existence of many well preserved tooth and bone remains as well as large morphological differences between populations, the extinct European cave bear (Ursus spelaeus) is one of the most interesting Pleistocene species for ancient

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IPC2002 Poster Presentations DNA studies. In a study on mitochondrial DNA sequences from more than 50 remains it was found that the genetic diversity of cave bears was remarkably high when compared to their geographical range. Conversely, the genetic diversity within single populations was low and seems to have remained stable for up to 100,000 years, although in one case we found evidence for replacement of one population by a different one. Furthermore it was found that neither small sized high-alpine cave bears, nor large sized cave bears are monophyletic with respect to mtDNA. While small sized population probably retained this character as an ancestral state, large sized cave bears most likely evolved at least two times independently. Finally we found evidence that small and large sized cave bears could have been reproductively isolated from each other. The evolution of cave bears from the palaeontological point of view (Doris Nagel, Gemot Rabeder): There is a remarkable difference in the evolutionary level between two cave bear faunas in Austria. The cave bears of the Ramesch bone cave were smaller and the dentition was more primitive than the ones from the Gamssulzen cave. These results are not influenced by a different sex-ratio (female/male). Furthermore, the mean values of size and indices decrease in the Ramesch cave from the lower part of the profile the upper part. Therefore the possibility of two cave bear species living side by side was discussed and is now confirmed by genetic data.

TAPHONOMY OF PREDATION: PREY REMAINS OF THE EXTINCT EYLES'S HARRIER (CIRCUS EYLESI) Richard N. HOLD A WAY Palaecol Research, P.O. Box 16 569, Hornby, Christchurch, New Zealand Several late Quaternary deposits in New Zealand have yielded bones of small to medium-sized birds with patterns of element occurrence and damage that suggest an origin as food remains of an avian predator. The deposits are often on slopes, under overhanging rocks, sheltered from severe weather, typical feeding and nest sites for raptorial birds. The fossil accumulations are characterised by the presence of undamaged bones of the peripheral skeleton, and moderately to severely damaged bones of the wing and leg, but few of the trunk. Few or none of the bones show signs of digestion. Bone with greater muscle mass are more likely to be damaged, and humeri, ulnae, femora, and tibiotarsi often exhibit characteristic punctures at or near the articulations. In larger species, such as the New Zealand pigeon (Hemiphaga novaeseelandiae), the sternum is usually reduced to the pila carina, with jagged edges where the remaining bone has been stripped away. The pattern of representation of bones and the lack of evidence for digestion eliminates owls and falcons as the predators responsible for the prey accumulations. Deposits attributed to both the extinct laughing owl (Sceloglaux albifacies) and the New Zealand falcon (Falco novaeseelandiae) contain bones which have been slightly to heavily digested, and bones of the outer wing and foot are rare. Average prey size is also less, being below 200 g for both taxa. The only other predator in the late Holocene of New Zealand that is likely to have taken birds of 500-1000 g was the large extinct Eyles's harrier, Circus eylesi, which had body estimated at up to 2.5 kg, significantly greater than for living harriers, including the Australasian harrier (Circus approximans) which has colonised New Zealand in the past 1000 years. Identification of the deposits as prey remains of Eyles's harrier has led to a greater understanding of the habitat and diet of the species. In addition, recognition of the damage to bones characteristic of butchering of a carcase by the harrier has allowed a re-examination of the taphonomy of other sites where the mode of deposition was thought to be serendipitous incorporation in suitable sediments. In particular, many of the pigeon bones recovered from the swamp or lake deposit of Pyramid Valley in the north-eastern South Island show evidence of predation by Eyles's harrier. Deposits of bird bones in beach sands on Norfolk Island are also likely to have developed at or beneath feeding sites of accipitrid hawks, as many of the larger bones show similar damage to that on bones from harrier sites in New Zealand. Recognition of avian predation as a common mode of fossil deposition has consequences for analysis of species composition of assemblages of small fossil vertebrates in the Cenozoic.

LONG-TERM EFFECTS OF THE CRETACEOUS/TERTIARY BOUNDARY IMPACT ON SOUTHWEST PACIFIC CLIMATE AND OCEANIC PRODUCTIVITY C.J. HOLLIS1, J.I. RAINE1, J.S. CRAMPTON1, B.D. FIELD1, K.A. RODGERS2, K.M ROGERS1, C.P. STRONG1 & V. VAJDA3 institute of Geological and Nuclear Sciences, PO Box 30368, Lower Hutt, New Zealand [c.hollis@gns.cri.nz]; 2PO Box 67-092, Mt Eden, Auckland; department of Geology, Lund University, Sweden [v.vajda@geol.lu.se].

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IPC2002 Poster Presentations

Detailed micropalaeontological, palynological, geochemical and sedimentological studies of six New Zealand Cretaceous/Tertiary (K/T) boundary sections, representing a continental margin transect from terrestrial swamp to ocean basin, play a pivotal role in understanding how the K/T asteroid impact influenced high-latitude biocomplexity, biogeochemical processes and climate. Major changes in lithofacies across the K/T boundary are not evident in terrestrial (Moody Creek Mine, West Coast) and marginal marine (Waipara River, North Canterbury) sections but the pollen record (Vajda et al 2001) reveals that catastrophic disruption of terrestrial ecosystems at the boundary was followed by a prolonged recovery succession including (1) a well-developed fern-spike, dominated by the ground fern Gleicheniidites, with an estimated duration of 5-10 kyrs, (2) a tree fern-dominated interval of similar duration, (3) a conifer-dominated interval of 0.5-1 Myrs (4) recovery of angiosperms and other elements of the Cretaceous-type mixed forest community. Abundant cool-temperate elements within the coniferdominated interval suggest that initial recovery was followed by a prolonged period of cool climatic conditions. In four marine sections in southeast Marlborough, representing a shelf-to-mid-slope transect, an abrupt switch from carbonate to biosiliceous lithofacies at the K/T boundary (Hollis et al., 1995) reflects mass extinction of calcareous plankton and subsequent expansion of relatively few species of diatoms and radiolarians. Limited recovery of calcareous plankton is short-lived in the earliest Paleocene (c. 50 kyrs) prior to a progressive increase in diatoms and radiolarians. Trends in diatom/radiolarian ratio, biogenic Si, biogenic Ba, carbon isotopes, Ti/Al and the chemical index of alteration (CIA) indicate that biosiliceous productivity increases as total biological production and wind strength increase and chemical weathering decreases. Geochemical and gamma-ray data show that terrigenous input increases across the K/T boundary and fluctuates through the biosiliceous episode before sediment composition returns to average Cretaceous values at c. 63.5 Ma. Milankovitch-scale cycles in sediment composition increase in amplitude and thickness across the K/T boundary implying enhanced sensitivity to climate drivers and either an increase in sedimentation rate or in the dominant orbital period. When related to Atlantic and Pacific deep sea records, these trends indicate that mass extinction and disruption to marine and terrestrial food webs at the K/T boundary led to southern high-latitude climatic deterioration and amplification of climate cycles through 1-2 Myrs of the earliest Paleocene. HOLLIS, C.J., RODGERS, K.A. & PARKER, R.J., 1995. Siliceous Plankton Bloom in the Earliest Tertiary of Marlborough, New Zealand.

Geology 23, 835-838. VAJDA, V., RAINE, J.I. & HOLLIS, C.J., 2001. Indication of Global Deforestation at the Cretaceous-Tertiary Boundary by New Zealand Fern Spike. Science 294, 1700-1702.

FIRST REPORT OF CARBONIFEROUS LYCOPODS FROM CENTRAL IRAN (ESFAHAN, SOH AREA) Mehri HOSSEINI & Mehdi YAZDI Department of Geology - Faculty of Science - University of Esfahan - Esfahan - Iran; [mehr_geo@yahoo. com; m.yazdi@sci. ui. ac. ir] Well presered Late Carboniferous lycopods remains were recoverd from Central Iran, Soh area (Isfahan). This is the first time these plants remains, have been reported from Central Iran. These remains can be classified into Lepidodandral and Sigillariaceas. According to Stewart & Rothwell (1993) the presence of Lepidodandral in association with Sigillariaceas indicates a Late Carboniferous (Westphalian) age. Morphological features associated with the design on the lycopods trunks suugest these forms can be assigned to the Carboniferous - Permain time interval (White 1990, p. 65). The design on the trunk has different ornamentation than Devonian lepidodandral. The presence of these plant in Westphalian (Late Carboniferous) sediments from Iran can be used for international correlation. WHITE, M. E., 1990, The Greening of Gondwana, Reed Books Pty Ltd (Australia), 255p. STEWART, W. N., and G. ROTHWELL, W., 1993, Paleobotany and the Evolution of Plants: Cambridge University press, p. 512.

LATEST CRETACEOUS (LATE CAMPANIAN - MAASTRICHTIAN) CALCAREOUS NANNOFOSSIL AND FORAMINIFERAL BIOSTRATIGRAPHY OF THE AUSTRALIAN NORTHWESTERN MARGIN R.W. HOWE1'2, R.J. CAMPBELL1 & J.P. REXILIUS3

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IPC2002 Poster Presentations department of Geology & Geophysics, The University of Western Australia, 35 Stirling Hwy, Crawley, WA 6009, Australia [rhowe@geol.uwa.edu.au, rcampbel@geol.uwa.edu.au]; 2Present address: Energy & Geoscience Institute, The University of Utah, 423 Wakara Way, Suite 300, Salt Lake City, UT 84108, USA. [rhowe@egi.utah.edu]; 3International Stratigraphic Consultants Pty. Ltd., 73 Rule St., North Fremantle, WA 6159, Australia, [jrex@iscbiostrat.com] Latest Campanian - Maastrichtian calcareous nannofossil and planktonic foraminiferal assemblages of the southern hemisphere were biogeographically differentiated into the high latitude Austral Province (with cool surface water masses), low latitude Tethyan Province (with warm surface waters), and the mid latitude Transitional Province. The application of Tethyan biostratigraphic zonal schemes to the Transitional assemblages of the northwestern Australian margin is awkward due to the absence or difference in ranges of many Tethyan marker species. As a result previous studies on the northwestern Australian margin have avoided Tethyan zonations. Local schemes such as the KCN (nannofossils), KPF (planktonic foraminifera), KBF (benthonic foraminifera), and KCCM (composite calcareous microfossil) zonations have been developed (Fig. 1). Revision and refinement of these locally developed zonations led to the recognition of: (i) additional nannofossil events such as the lower Upper Maastrichtian highest occurrences of Ahmuellerella octoradiata, Petrarhabdus vietus, and Stoverius sp. 1 (S. coangustatus)\ (ii) discrepancies in the ranges of the planktonic foraminiferal species Abathomphalus mayaroensis, Contusotruncana contusa, and Racemiguembelina fructicosa; and (iii) a hiatal event which extends from the late Early Maastrichtian - latest Campanian on the Exmouth Plateau. CALCAREOUS NANNOFOSSIL STAGE Haq etal. (1987)

STAGE BIOSTRATIGRAPHY Gradstein etal. Calcareous (1994) Rexilius This [unpubl.) study Nannofossil

66.5 Ma

>5.0±0.1 Ma

Events W Ureteceous j ^ planktonic forams. M. prinsii A

C. kamptneri

^^^

M. murus

PLANKTONIC FORAMINIFERAL BIOSTRATIGRAPHY Rexilius unpubl.)

This study

Planktonic Foraminiferal Events

BENTHONIC FORAMINIFERAL BIOSTRATIGRAPHY Rexilius unpubl.)

This study

Benthonic Foraminiferal Events

COMPOSITE CALCAREOUS MICROFOSSIL BIOSTRATIGRAPHY Rexilius (unpubl.)

This study

Calcareous Microfossil Events W Cretaceous i l planktonic forams. M. prinsii

Cretaceous planktonic forams.

A. mayaroensis ^(Tethys)

L quadratus . A C. contusa

R. levis

A C. contusa ^^ R. fructicosa A L praequadratus, C. gallica »Stoverius sp. 1 n R. powelli m. P. intermedia A- mayaroensis Z. bicrescenticus R. levis

r Q. trifidum. T phacelosus

Q. trifidum, T. phacelosus

A. octoradiata L. praequadratus, C. gallica P. vietus •

Si Z. bicrescenticus

R- fructicosa

k R. powelli . P. intermedia ^ A. mayaroensis (This study)

A. parous f constrictus

s *

r<3

~KC(

i G. cuvillieri

V (Rexilius, unpubl.) 74 M a . U CAMP

E. eximius. R. anthophorus

H. semicostata

semicostata

Figure 1. Maastrichtian - latest Campanian calcareous nannofossil (KCN), planktonic foraminiferal (KPF), benthonic foraminiferal (KBF), and composite calcareous microfossil (KCCM) zonations of this study compared to the previous schemes.

PRE-GLACIAL, WARM-TEMPERATE FLORAL BELT IN GONDWANA DURING THE EARLY CARBONIFEROUS Roberto IANNUZZI1, Hermann W. PFEFFERKORN2 1 Departamento de Paleontologia e Estratigrafia, Instituto de Geociencias, Universidade Federal do Rio Grande do Sul, Cx. P. 15.001, Porto Alegre, RS, 91.501-970, Brazil; department of Earth and Environmental Science, University of Pennsylvania, Philadelphia, PA 19104-6316, U.S.A. Specific fossil floras from South America (Peru, Bolivia, Brazil), Africa (Niger), India, and Australia are distinctly different from both earlier and later Carboniferous floras of Gondwana. Stratigraphic, palynologic,

219

IPC2002 Poster Presentations and isotope data allow assignment of these floras as "middle" Carboniferous age (late Visean-earliest Serpukhovian). These floras are dominated by pteridosperm foliage (Nothorhacopteris, Triphyllopteris, Sphenopteridium, Diplothmema) and characterized by occurrence of tree-lycopsids (Tomiodendron) and primitive shrubby sphenopsids (Archaeocalamites). The tree lycopsids are a growth form that cannot survive periods of frost. These floras thus represent a warm temperate, frost-free,floralbelt in Gondwana extending to 30° to 60° S that existed immediately prior to the onset of the major episode of the Carboniferous glaciation. The plants lived during an interval of very warm climate on Earth, indicated by the width and extent of the floral belt. The term Paraca Floral Belt, previously restricted to north-central South American floras, is redefined and extended to include all such floras throughout Gondwana. An important palaeofloristic implication is discrimination of the stratigraphic and compositional difference between floras of the Paracas Floral Belt and the well-know Nothorhacopteris-Botrychiopsis-Ginkgophyllum Flora found in the Upper Carboniferous deposits of Argentina. PERMIAN INSECT FOLIVORY ON GLOSSOPTERIS-DOMmXTED GRANDE DO SUL, SOUTHERN BRAZIL

FLORAS FROM RIO

Roberto IANNUZZL Karen ADAMI-RODRIGUES, Iraja Damiani PINTO Departamento de Paleontologia e Estratigrafia, Instituto de Geociencias, Universidade Federal do Rio Grande do Sul, Cx. P. 15.001, Porto Alegre, RS, 91.501-970, Brazil Among the kinds of interactions between plants and arthropods, feeding traces are the ones most easily preserved in the fossil record. Damage found in leaf adpressions is the only direct evidence of plantarthropod interaction encountered in the Upper Palaeozoic sequence of the Parana Basin. This evidence is recorded in leaf assemblages from strata of Rio Bonito and Irati formations considered to be, respectively, Early (Artinskian-Kungurian interval) and Middle (Kungurian-early Kazanian interval) Permian in age based on palynological studies. The leaf assemblages of the Rio Bonito Formation contain small arborescent lycophytes, marattialean and other ferns, glossopterids and codaiteans as abundant elements, shrubby sphenophytes, ginkgoaleans and conifers as complementary elements. No insect remains have been preserved in these Lower Permian flora-bearing horizons. The assemblage of the Irati Formation include glossopterids, marattialean ferns, ginkgoaleans and cordaiteans. Insect remains (blattoids, hemipteroids, coleopterans, mecopterans and neuropterans) have been documented in association with this Middle Permian leaf assemblage. This contribution involves the identification of leaf specimens and qualitative assessment of the damage types. Several categories of traces are recognized among the palaeobotanical material analyzed: marginfeeding (tip feeding and continuos and interrupted marginal traces), hole-feeding, skeletonization and possible leaf mine (blotch and linear traces). All seven types of traces recognized occur on glossopterid leaves, suggesting a preferential host specificity for glossopterids by phytophagous insects. The cordaitean specimens exhibited significantly lower levels of herbivory with only one type of feeding traces on these leaves (i. e., interrupted marginal trace). No damage has been observed in the other co-occurring taxa. Among the glossopterids the following species show the presence of feeding traces: Gangamopteris obovata (Carruthers) White, Glossopteris angustifolia Brongniart, G. communis Feistmantel, G. cf. indica Schimper and G. occidentalis White. The cordaitean specimens correspond to only one species Cordaites hislopii (Bunbury) Seward (= Rufloria gondwanensis Guerra-Sommer). Notably, pteridosperm groups (i. e., medullosan seed ferns, glossopterid and gigantopterid) are associated with elevated levels of insect herbivory during the Late Palaeozoic, being apparently the prefered host of insects. The broad-leaved foliar features of the pteridosperms pre-date similar features in anthophytes. Thus, the co-evolution of insect folivory and pteridosperms starting in the Late Palaeozoic set the stage for the later interactions of insects and anthophytes. LATE DEVONIAN OMALODONTID-LIKE SHARK FROM THE KUZNETSK BASIN, WESTERN SIBERIA A. IVANOV & O. RODINA department of Palaeontology, St. Petersburg University, St. Petersburg, Russia. Institute of Petroleum Geology, Novosibirsk, Russia. 1

Omalodontid-like teeth belonging to a new genus were found in the Famennian Cheibekkel Formation, Middle triangularis-Early rhomboidea conodont zones, and in the Podonino Formation, trachytera-expansa

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IPC2002 Poster Presentations zones, of the Kuznetsk Basin, W Siberia. The teeth have an asymmetrical crown with three to five cusps and a base with labial extension. The lateral cusps are higher than central and intermediate ones but one of them is considerably larger. The cusps are separated from each other, curved linguad, rounded in cross-section, completely ornamented by striae. They are composed of orthodentine with short dentine tubules and thin enameloid layer. The lingual part of the base is reduced; the basal surface is flat. A vascularization system consists of numerous narrow canals forming a complicated network filling up the whole base. The vascular canals open on the lingual rim and in different places on the labial side of the base. Turner (1997) erected the order Omalodontida including the genera Omalodus, Doliodus and some Antarctic taxa, e.g. Aztecodus, Portalodus and Anareodus characterised by the labial extension and reduced lingual part of the base, irregular cusps in the crown and lacking elements for tooth-to-tooth articulation in the row. The cusps of Omalodus teeth form a well-developed phoebodont-like crown and are composed of an orthodentine; the vascular canals run across the base from the labial to lingual sides. The crown of Aztecodus consists of the pleuromin without enameloid; the base has the same arrangement of two vascular canals as in Omalodus teeth (Hampe & Long, 1999). The teeth of Portalodus have an enameloid, orthodentine and trabecular dentine in the crown and the base without canal openings in the labial side (Hampe & Long, 1999). Thus, the teeth of those taxa including a new genus show the labial direction of the base and asymmetry of the crown, except for Omalodus, but they differ in external and histological structures of the crown and the type of vascularization system. The base directed labiad with reduced lingual part could occur probably in the several shark groups. HAMPE, O. & LONG, J.A., 1999. The histology of Middle Devonian chondrichthyan teeth from southern Victoria Land, Antarctica. Records of the Western Australian Museum Supplement 57, 23-36. TURNER, S., 1997 "Dittodus" species of Eastman 1899 and Hussakof and Bryant 1918 (Mid to Late Devonian). Modern Geology 21, 87119.

MIDDLE DEVONIAN (GIVETIAN) PLACODERMS OF SOUTH SIBERIA AND KAZAKHSTAN A. IVANOV Department of Palaeontology, St. Petersburg University, St. Petersburg, Russia. Antiarchs have been described from among the Middle Devonian placoderms of the Altai-Sayan Foldbelt and Kazakhstan (e.g. Malinovskaya, 1977). The almost complete skull roofs and some trunk shield plates of a peculiar new placoderm have been collected in the Lower Givetian Saragash Formation of the North Minusa Depression, southern Siberia. This placoderm shows the features of various groups. Young (1993) believed this taxon to be a "primitive quasipetalichthyid like placoderm", but it more resembles early actinolepids by the skull roof pattern. The presence of contact between the praeorbital plates behind the pineal plate, the lack of a second paranuchal plate, the short supraorbital sensory line running only on the praeorbitals, and the well-developed sensory line canals on the central plate are characteristic of actinolepid placoderms. However, some features such as the small pineal plate deeply notching the anterior margin of the praeorbitals, the unusual shape and position of postorbital plate, as well as the unclear position of marginal plates, do not allow reference to the Actionolepidae. A new petalichthyid placoderm occurs in the Givetian Taldysai Formation of the Sarysu-Teniz watershed, western part of Central Kazakhstan, where three antiarch genera, Asperaspis, Stegolepis and Tenizolepis, were previously recorded (Malinovskaya, 1977; Panteleev, 1993). The petalichthyid is represented by skull roofs and trunk-shield plates of a new species of Eurycaraspis (family Quasipetalichthyidae) and there is a new genus of macropetalichthyids. The first differs from Chinese species in the larger nuchal plate, the smaller posterior paranuchal plates, the shorter postorbitals, the direction of the infraorbital process, and the shorter spinal plates. The macropetalichthyid is similar to some Early Devonian macropetalichthyids such as Notopetalichys and Shearsbyaspis from Australia and Sinopetalichthys from China but differs in the position of orbits, the larger rostral and pineal plates, the longer praeorbitals, the smaller centrals, and the longer anterior ventro-lateral plates. Quasipelichthyids were found previously in the Eifelian of North and South China (e.g. Zhu et al. 2000) and considered as endemic to China. The new finds of a quasipelichthyid in Kazakhstan shows wider distribution of that placoderm group. The occurrence of the quasipelichthyid and macropetalichyid resembling Chinese and Australian taxa allows inference of relations between Kazakhstan and North and South China at least by Middle Devonian time. The palaeogeographic interpretation of Kazakhstan as separate block is uncertain and controversial. MALINOVSKAYA, S.P., 1977. Systematic position of antiarchs of Central Kazakhstan, pp. 29-35 In Menner, V.V. (ed.), Ocherki po Filogenii i Sistematike Iskopemykh Ryb i Beschelyustnykh, Nauka, Moscow, [in Russian]. PANTELEEV, N.V., 1993. New antiarchs (Placodermi) from the Middle Devonian of Central Kazakhstan. Paleontologicheskiy Zhurnal 2, 62-71.

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IPC2002 Poster Presentations YOUNG, G.C., 1993. Vertebrate faunal provinces in the Middle Palaeozoic, pp. 293-323. In Long, J.A (ed.), Palaeozoic Vertebrate

Biostratigraphy and Biogeography, Johns Hopkins University Press, Baltimore.

ZHU, M., WANG, N.-Z. & WANG, J.-Q., 2000. Devonian macro- and microvertebrate assemblages of China. Courier Forschungsinstitut Senckenberg 223, 361-372.

BIOLOGICAL MARKERS (FATTY ACIDS) CHARACTERIZING THE CHEMOSYNTHETIC COMMUNITY IN THE JAPAN TRENCH Robert Gwvn JENKINS , Shigenori OGIHARA , Kazuyoshi ENDO , Kantaro FUJIOKA and Kazushige TANABE Department ofEarth and Planetary Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo, 113-003, Japan [robert@gbs.eps.s.u-tokyo.ac.jp]; DEEPSTAR, Japan Marine Science and Technology Center (JAMSTEC), Natsushima-cho 2-15, Yokosuka city, Kanagawa, 237-0061, Japan A chemosynthetic community consisting of molluscs, vestimentiferans ("tube worms"), etc. has been found at various sites on the ocean floor, mid-oceanic ridge, trench and continental slope in the world ocean, where the water supplied from hydrothermal vents, cold seeps, ground water seeps and whale skeletal remains is rich in sulfite and methane. Faunal structure of chemosynthetic communities can be classified into several types on the base of differences of various ecological and environmental factors such as modes of reproduction, larval ecology, substrate type, water pressure, dissolved oxygen level and amounts of sulfides or methane of the habitats. Previous reports have suggested that the distribution pattern of each faunal element in the chemosynthetic communities appears to be strongly constrained by special chemical conditions provided by activity of microorganisms (e.g. Jannasch and Taylor, 1984). Combined analysis of DNA and fatty acids is one of the useful approaches to determine taxonomic diversity and biomass of microbiota associated with chemosynthetic communities from hydrothermal vents and cold seeps, but this approach has little been used in the previous works except for Li et al. (1999). In this study, we have analyzed DNA and fatty acid compositions in the sediment cores recovered from the two sites within and neighbor of the Calyptogena colony in the Japan Trench to distinguish biological markers characterizing chemosynthetic bacteria. DNA analysis revealed existence of sulfur-reducing and sulfur-oxidizing microbes included in 8 proteobacteria and y proteobacteria respectively. The obtained phylogenetic tree shows that the identified bacteria include typical taxa which have been reported from the chemosynthetic communities in the world ocean. Fatty acids in the sediment cores taken from the inside and outside of the Calyptogena colony show a bimodal distribution in the chromatograms, with an anterior peak of CI6:0 and a posterior peak of C26.0. The branched and monounsaturated fatty acids included in the anterior thread indicate a bacterial origin. The most characteristic fatty acids in the sediments within the colony is C16:ln7c, that occurs abundantly in the sediments above 4cm depth. This fatty acid is presumably originated in sulfur-oxidizing bacteria and regarded as a characteristic fatty acid biomarker in the Calyptogena colony. 1

JANNASCH, H.W., and TAYLOR, C.D., 1984, Deep-sea microbiology: Annu. Rev. Microbiol., v. 38, p. 487-514. LI, L., GUENZENNEC, J., NICHOLS, P., HENRY, P., YANAGIBAYASHI, M., and KATO, C., 1999, Microbial Diversity in Nankai Trough

Sediments at a Depth of 3843m: Journal of Oceanography, v. 55, p. 635-642.

THE LAU GLOBAL EXTINCTION EVENT (LATE SILURIAN): LITHOLOGIC, CONODONT AND ISOTOPE DATA AND IMPLICATIONS L. JEPPSSON , R. MAWSON , A. J. SIMPSON , J.A. TALENT . A. ANDREW , D.J. WHITFORD , and C. CORRADINI Department of Geology, Solvegatan 13, SE 223 62 Lund, Sweden [lennart.jeppsson@geol.lu.se]; Macquarie University Centre for Ecostratigraphy and Paleobiology, Department ofEarth and Planetary Sciences, Macquarie University 2109. Australia; CSIRO Exploration & Mining, PO Box 136 North Ryde 1670, Australia; CSIRO Petroleum Resources, PO Box 136 North Ryde 1670, Australia; Dipartimento di Scienze della Terra (Paleontologia), Universita di Modena e Reggio Emilia, via Universita 4,1-41100 Modena, Italy 1

The Lau Global Extinction Event has already been identified on Baltica (Gotland, Skane, Latvia, Poland), Gondwana (E Australia, Sardinia, Carnic Alps) and Laurentia (Missouri). The Silurian sequences of Gotland (Sweden), the Broken River region of NE Australia, and Sardinia (the three foci of this investigation) were located on different palaeocontinents, the first on Baltica, the others on the Gondwana margin. Though faunal

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IPC2002 Poster Presentations differences are evident, conodonts enable high precision correlation of the stratigraphies and identification of the Lau Global Extinction Event (mid-Late Silurian) in the three regions. The event affected, inter alia, acritarchs, corals, polychaetes, brachiopods, chitinozoans, ostracods, trilobites, tentaculites, graptolites, conodonts and fish. Imprecise knowledge of range-ends hampers quantitative evaluation of extinctions but, based on the review of the above groups, a loss of at least 30 to 50 % of the species seems probable. Among higher taxa, the event caused extinction of a suborder of tabulate corals and, among brachiopods, a profound decrease in diversity of the order Pentamerida. Among conodonts, no platform-equipped taxon survived but 70% of species known to have persisted until the beginning of the event survived. Persisting taxa include both those that are found just before the event and those with known range extending through the beginning of the event. Since Walliser (1964), leading specialists on Silurian conodonts have based their taxonomies on large collections, and have been able to use a biologic species-concept that, incidentally, makes the taxa useful for biostratigraphic alignments. The community structure changed through the Lau Event; low diversity faunas, dominated by a single taxon, developed during the most severe part of the event. Unexpected, was correspondence in the sequence of lithologies and, where independent means of correlation are available, even appreciable synchronicity in lithologic change: A. argillaceous strata before the event; B. more weathering-resistant limestones during the early part of the event; C. oncoids and crinoids (oncolitic crinoid limestone or oncolite with crinoids) during the middle part of the event: D. argillaceous oncolite during the late part of the event, and then E. terrigenous clastics followed by F. oolite before G. return in each area to normal sediments. Isotopic changes are very similar in the Gotland and the Broken River sequences indicating globality of changes in ocean chemistry. Coupled positive excursions in a C . and a C (amplitude up to 8 to 9 %<,) started at the beginning, increased through and culminated near the end of the event. The detailed record from the COG section in North Queensland C (carbonate, organic C), Sr and O isotope records indicate changes in ocean chemistry leading up to the event and in its aftermath and allows the relative timing of isotopic changes to be related to lithological and faunal change. A higher CAI (Colour Alteration Index) of 5.5 for the Silius section in Sardinia has resulted in degraded signals for the Lau Event, but this can nevertheless be detected. During other events studied in detail, extinctions occurred step-wise, but in the case of the Lau Global Extinction Event, the number of datum points and their exact position have not been identified with the very high precision we would have liked. The many changes during the event nevertheless permit high resolution correlations. 13

carb

org

OCCURRENCE OF EARLY ORDOVICIAN GRAPTOLITES IN THE MUNGOK FORMATION, YEONGWOL, KOREA Young-Pil JIN and Jeong Yul KIM Department ofEarth Science, Korea National University ofEducation, Cheongwon, Chungbuk, 363-791, Korea; [jhnyp@hanmail.net, kimjy@cc.knue.ac.kr] Nineteen species belonging to six genera of graptolites are described from the upper part of the Mungok Formtion, Yeongwol, Korea. They are Dendrograptus lotololatzensis Mu 1955, Dendrograptus suni Mu 1955, Dendrograptus sp. A, Callograptus curvithecalis Mu 1955, Callograptus sp. A, Callograptus sp. B, Dictyonema uniforme Mu 1953, Dictyonema sp. A, Dictyonema sp. B, Dictyonema sp. C, Anisograptus richardsoni Bulman 1941, Adelograptus callavei Elles and Wood 1902, Adelograptus sp. A, Adelograptus sp. B, Adelograptus sp. C, Adelograptus sp. D, Adelograptus sp. E and Psigraptus arcticus. Most of are reported for the first time from Korea; the report of Psigraptus is only the sixth occurrence globally, following the Yukon of Canada, Victoria and Tasmania of Australia, and Jilin and Hebei of China. Based on the graptolite fauna three biozones are recognized in the upper part of the Mungok Formation: Anisograptus richardisoni, Adelograptus, and Callograptus curvithecalis-Dendrograptus zones in ascending order. These graptolite zones are correlated with those of the Lancefield Formation, Lancefield, Australia, the Yehli Formation, Jilin, China, and the Road River Formation, Yukon, Canada. According to the graptolites and their biozones, the age of the upper part of the Mungok Formation is assigned to the late Early to early Late Tremadoc. THE MOST PRIMITIVE EARWIGS (INSECTA: DERMAPTERA: ARCHIDERMAPTERA) FROM JURASSIC OF NEIMONGGOL REGION, NORTHEASTERN CHINA JUN Fengzhang

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IPC2002 Poster Presentations Nanjing Institute of Geolgy & Palaeontology, Chinese Academy of Sciences, Nanjing 210008, Jiangsu, China; [jfzhang@nigpas.ac.cn] The most primitive earwigs (Insecta: Dermaptera: Archidermaptera) were discovered from the Upper Jurassic of China. They are defined as the undoubted earwigs by the typical earwig-like venation of the hindwing, a character first illustrated in these fossils. This feature is wanting in all other fossils reported to be earliest earwigs. Three thoracic sterna show the special pattern and structures which are first described in this work and, are unknown in other sister-groups of Archidermaptera. The tegmina locking device and spiny crests are strongly developed. Tarsi of all three pairs of legs are clearly five-segmented. Hindleg coxae are distinctly elongated. The posterior margins of the tegmina are produced into a point. Neck is divided into anterior and posterior two proportions. These five diagnoses are considered as unique, plesiomorphic properties appearing in these fossils and are the earliest known earwigs. The following basic characters also are present in other early dermapterans: a compressed body; body vestiture of hairs; lateral margins of abdomen nearly parallel; antennae elongated, filiform and multi-segmented; two well developed ocelli and eyes; denticulate mandibles; scutellum much enlarged; tegmina relatively long and armed with obvious veins; Femora armed with keels; claws and arolia fully developed; abdominal tergites apparently not overlying the edges of sternites; soft and multi-segmented cerci; and prominent ovipositor. A new family, Sinopalaeodermatidae, and two new genera and two new species, Sinopalaeodermata neimonggolensis and Jurassimedeola orientalis are described to accommodate these fossils. The origin of earwigs was probably in Asia. BIOTURBATION OF PERMIAN TO JURASSIC RADIOLARIAN CHERT SEQUENCES, SOUTHWEST JAPAN Yoshitaka KAKUWA Department ofEarth Science and Astronomy, Graduate School of Tokyo University, 3-8-1 Komaba, Meguro, Tokyo 153, Japan; [kakuwa@chianti.c.u-tokyo.ac.jp] Trace fossils reported from deep basin's are frequently from siliciclastic rocks, such as turbidites, deposited close to continents. Data from truly pelagic oceanic environments come from deep-sea-drilling cores from the Pacific, Atlantic and Indian oceans. The oldest sedimentary rocks recovered by drilling are late Middle Jurassic from the western Pacific Ocean; trace fossils indicating pelagic oceanic bottom are still not known from more ancient times. Radiolarian cherts in 'orogenic belts' are the only source of information on the preLate Jurassic pelagic realm. Here I report various bioturbation and trace fossils found in Permian to Jurassic radiolarian chert sequences. Permian to Jurassic radiolarian chert sequences of the Panthalassa Ocean are widely distributed in the SW Japan accretionary complex. These sequences are faulted and segmented, but the original sedimentary succession, reconstructed by radiolarians and conodonts, is as follows: Late Carboniferous to Late Permian radiolarian chert overlying basic volcanic rocks; Early Triassic carbonaceous and siliceous claystones; Middle Triassic to Middle Jurassic radiolarian chert; Middle Jurassic to Late Jurassic hemipelagic radiolarian mudstone and sandy mudstone; and Late Jurassic to Cretaceous terrigenous sandstone. Upward increase in terrigenous materials indicates approach of the oceanic plate to the continent. Trace fossils in cherts are almost invisible to the naked eye in the field and even on polished surfaces, so hydrofluoric acid-etched surfaces are served for observation. Also efficacious is to process images of a digital camera by software for image analysis. Some small questionable textures are easier to identify by observing the decompacted images using this method. Chondrites, Planolites and various unknown groups are well developed in Early Triassic siliceous claystones and radiolarian cherts, and also in Middle to Late Jurassic radiolarian-bearing hemipelagic rocks. Zoophycos, common in deep-sea cores, has not been found yet. Based on ichnofabric indices, change in palaeo-oxygenation of the deep oceanic bottom across the Permo-Triassic boundary is apparent (Kakuwa, 2000). Trace fossils are, however, rarely encountered in Permian to Jurassic radiolarian cherts, generally as a consequence of intense cementation and recrystallization. Low availability of food is considered to be another reason for lack of bioturbation of the cherts. For example, trace fossils are abundant in Middle to Late Jurassic radiolarian-bearing hemipelagic rocks, but are very small and few in radiolarian cherts of the same age. Evolutionary history of benthic organisms and environmental change in the pelagic deep oceanic bottom during the Phanerozoic can be established from study of trace fossils of radiolarian cherts

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IPC2002 Poster Presentations DISTRIBUTION OF SILURIAN - EARLY DEVONIAN MONDOLEPIDS (VERTEBRATA, CHONDRICHTHYES?). V. KARATAJUTE-TALIMAA \ O. RODINA2 & A. IVANOV3 Institute of Geology, Vilnius, Lithuania; institute of Petroleum Geology, Novosibirsk, Russia; of Palaeontology, St. Petersburg University, St. Petersburg, Russia.

department

Mongolepids are known from the Lower Silurian, Lower and Middle Llandovery of Irkutsk Amphitheatre, South Yakutia, Russia (Karatajute-Talimaa & Predtechenskiy, 1995); Upper Llandovery of Western Mongolia (Karatajute-Talimaa et al, 1990; Karatajute-Talimaa & Novitskaya, 1992, 1997), of the Tarim Basin (Wang et al., 1998), South China (Sansom et al, 2000) and Tuva (Karatajute-Talimaa, 1995), and probably from the Lower Devonian (Lochkovian?) of Eastern Mongolia (Wrona & Nyamsuren, 1998). Three well described taxa, Mongolepis, Sodolepis, Teslepis, were reported from joint from the Khutsynbulak Beds, Upper Llandovery of Western Mongolia. An undescribed new genus (Udalepis by Karatajute-Talimaa, 1995) was recorded from the Lower and Middle Llandovery of South Yakutia. The well preserved mongolepid scales are found in the Uste Sadra Beds, Maliy Bachat Regional Stage, Lower Emsian, Lower Devonian of the Lebed' River Basin, Gorniy Altai, Siberia. They are few in numbers of specimens but represented by three taxa: Teslepis, cf. Mongolepis and a new genus Udalepis. It is a first occurrence of mongolepids in the Altai - Sayany Folded Area and youngest in the world. On the basis of the new material, mongolepids were more distributed than is considered before. The similar taxonomic composition shows the relations between the Altai and Mongolia during the Silurian - Early Devonian time. The stratigraphic ranges of mentioned taxa are almost all the Silurian and Lower Devonian: from the Llandovery to Emsian. KARATAJUTE-TALIMAA, V.N., 1995. The Mongolepidida: scale structure and systematic position. In: Premiers Vertebres et Vertebres inferieurs, Eds. Lelievre, H., Wenz, S., Blieck, A. and Cloutier, R., Geobios, Memoire Special 19, 35-37. KARATAJUTE-TALIMAA, V . N . , NOVITSKAYA, L.I., ROZMAN, K h . S . and SODOV Zh., 1990. Mongolepis

- a new elasmobranch genus

from the Lower Silurian of Mongolia. Paleontologicheskiy Zhurnal 1, 76-86 [in Russian]. KARATAJUTE-TALIMAA, V.N. and NOVITSKAYA, L.I., 1992. Teslepis - a new representative of mongolepid elasmobranchs from the Lower Silurian of Mongolia. Paleontologicheskiy Zhurnal 4, 36-46 [in Russian]. KARATAJUTE-TALIMAA, V.N. and NOVITSKAYA, L.I., 1997. Sodolepis - a new representative of mongolepids (Chondrichthyes?) from the Lower Silurian of Mongolia. Paleontologicheskiy Zhurnal 5, 96-103 [in Russian]. KARATAJUTE-TALIMAA, V.N. and PREDTECHENSKIY, N.N. 1995. The distribution of the vertebrates in the Late Ordovician and Early Silurian paleobasins of the Siberian Platform. Bulletin de Museum national d'Histoire naturelle, 4e ser., 17, section C, 39-55. SANSOM, I.J., ALDRIDGE, R.J. and SMITH, M.M., 2000. A microvertebrate fauna from the Llandovery of South China. Transactions of the Royal Society of Edinburgh: Earth Sciences 90, 255-272. WANG, N.Z., ZHANG, S., WANG, J.Q. and ZHU, M., 1998. Early Silurian chondrichthyan microfossils from Bachu County, Xinjang, China. Vertebrata PalAsiatica 10, 257-267. WRONA, R. & NYAMSUREN, G. 1998. New Early Devonian chondrichthyan scales (Chondrichthyes) from Eastern Mongolia. Mongolian Geoscientist, 10, p.79.

LATE DEVONIAN BRACHIOPODS AND CONODONTS BIOSTRATIGRAPHY IN THE KALESARDAR OF TABAS) Mohammad R. KEBRIA-EE & Mehdi YAZDI Department of Geology, Faculty of Sciences, Isfahan University, Isfahan, Iran [Mkebria_ee@Hotmail.com; M. Yazdi@sc. ui. ac. ir]. Kale-Sardar area is located 22 km east of Tabas. The lower boundary of the Shishtu Formation in this area is faulted on the oolitic and fossilferous limestone of Famennian age, and the upper boundary is comforable. In the study area the thickness of Shishtu Formation is 14 metres. Lithology of the section consists of biostrome, nodular limestone and muddy limestone with abundant fossils (specially brachiopods). Brachiopods of the section were collected and identified as follows: Schizophoria striatula (Schlotheim 1813), Aulacella cf eifeliensis (Schnur 1853), Caucasiproductus sardarensis Legrand-Blain 1999, Productella cf. belanskii Stainbrook 1943, Spinulicosta sp. Nalivkin 1937, Coeloterorhynchus tabasensis Sartenaer 1966, Spinatrypina bodini (Mansuy 1912), Spinatrypina chitralensis (Reed 1922), Spinatrypina cf. robusta Copper 1967, Desquamatia sp. Alekseeva 1960, Athyris chitralensis Reed 1922, Athyris cf. communis (Gosselet), Athyris sp. M'coy 1844, Anathyris sp. Von Peetz 1901, Crurithyris cf. inflata (Schnur 1853), Cyrtospirifer cf. verneuili (Murchison 1840), Cyrtospirifer cf. minor (Gurich 1903), Indospirifer sp. Grabau 1931, Warrenella sp. Crickmay 1953. Frequency precentages of the above mentioned brachiopods are: Spiriferida 39%, Strophomenida 37%, Rhynchonellida 23%, Orthida 1%.

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IPC2002 Poster Presentations Conodont specimens were collected out of beds that have brachiopods as well. Conodonts are associated with brachiopods are as follows: Ancyrodella curvata, Ancyrodella nodosa, Icriodus alternatus alternates, Icriodus expansus, Polygnathus webbi, Polygnathus capolloci, Polygnathus evidence. As a result, the accurate age for the studied section can be propose as: Frasnian (linguiformis Zone). LEGRAND- BLAIN, M. 1999. A Frasnian productid brachiopod fauna from Kale- Sardar, Tabas region, Eastern Iran, Ann. Soc. Geol. du Nord, T 7, 13-19. SARTENAER, S. 1966b. Frasnian Rhynchonellida from the Ozbak- kuh and Tabas regions (East Iran), Geological Survey of Iran, Report No. 6, 25- 53. STOCKLIN, J. et al. 1965. Geology of Shotori Range (Tabas area, East Iran), Geological Survey of Iran, Report No. 3, 69. YAZDI, M. 1996. Late Devonian- Carboniferous conodont biostratigraphy of the Tabas area, Eastern Iran, Sydney: Macquarie University, Ph.D. thesis, 200.

ECOLOGY OF AN EARLY EOCENE RAINFOREST AT BRANDY CREEK, VICTORIAN HIGH PLAINS, SOUTH-EASTERN AUSTRALIA R.L. KEEFE & D.R. GREENWOOD School of Life Sciences and Technology (S008), Victoria University of Technology, PO Box 14428, Melbourne City MC, VIC 8001, Australia, [Rachael.Keefe@research.vu.edu.au] The Early Eocene is recognised as the warmest interval of the Cenozoic, with palaeontological evidence from around the world showing extensive forests at high latitudes and tropical-like biota. Southeastern Australia in the Early Eocene lay at high southern latitudes (~60°S). Microfloras (spore-pollen) has indicated the presence in southeastern Australia in the Early Eocene of diverse mesothermal (? megathermal) multistratal dicotdominated rainforests with emergent Araucariaceae. Nothofagus was present, but likely was a minor component of regional vegetation. Until recently, little was known of Australian Early Eocene macrofloras. Macrofloras and microfloras provide complimentary information on past environments, as some plant taxa are absent or undetected in the microflora, yet preserve well as macrofossils (eg. Lauraceae) and the reverse is also true. The Early Eocene (55 to 50 million years ago) microflora and leaf macrofossils from Brandy Creek Mine offer insight into the climate and vegetation during the Early Eocene of southeastern Australia. Brandy Creek Mine is located 7.8 km east-southeast of Mount Hotham, Victoria (37° 01' S, 147° 13 ' E), at a present-day elevation of approximately 1500m. Brandy Creek fossils are preserved as mummified leaves in fluvial sediments approximately 1.4 metres deep reflecting local vegetation. The microflora is diverse but is dominated by treefern spores (Cyathidities paleospora cf. Cyathea 66%, Ischyosporites irregularis 2.5%, and Matonisporites ornamentalis aff. Dicksonia trace). Conifers (2.5%) and angiosperms (8.5%) were minor fractions of the spore-pollen sum. Araucaricites spp. and Dilwynites granulatus were present in trace amounts. Nothofagus pollen was present in low numbers (<5%). The Brandy Creek macroflora is highly diverse with 54 morphotypes, and is dominated by Lauraceae with 21 morphotypes, with some of these taxa dominating the dispersed cuticle in successive samples. Lauraceae and a number of other taxa have affinities with extant genera found today in tropical rainforest of northeastern Queensland. These include; Endiandra, Cryptocarya, Litsea and Beilschmiedia (Lauraceae), Cunoniaceae and Elaeocarpaceae. The diversity of Lauraceae and mix of taxa also matches the floristic character of present-day northeastern Queensland tropical rainforests. Sampling of macrofossils in contiguous layers of the outcrop indicates changes in composition and frequency of fossil leaf morphotaxa over a hundred to thousand year period. This reflects changes in floristic composition of the adjacent species-rich forest community over that interval. Data from this research provide insight into forest dynamics and can assist in predicting responses of vegetation to physical forces such as climate change. Palaeoenvironment estimates MAT 18-19°C and MAP c.2500 mm/yr. reflect a mesothermal wet climate and mild winters, which is consistent with tropical northeastern Queensland rainforests today.

CRETACEOUS CHONDRICHTHYAN BIODIVERSITY IN EARLY CRETACEOUS SEAWAYS OF QUEENSLAND Noel R. KEMP1 and Susan TURNER2 l Tasmanian Museum, GPO BOX 1164, Hobart, TAS 7001; 2Queensland Museum, P.O. Box 3300, South Brisbane, QLD 4101 Gottfried (2001) claimed a Cretaceous pan-"Gondwanan" elasmobranch fauna as in modern oceans with few endemics. Such cosmopolitan taxa he regarded as useful for assessing palaeogeography and geophysical

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IPC2002 Poster Presentations models. His hypothesis of parallel pattern in neoselachian lineages will be checked by comparison with the Cretaceous of Australasia, in particular the Aptian-Cenomanian faunas of Queensland e.g., orectoloboids, odontaspidids, and cretoxyrhinids and rays (e.g. Kemp 1996). Even rarer forms such as deepwater echinorhinids and chimaeroids (Edaphodon, endemic Ptyktoptychion) are represented by widespread taxa. Sharks also have an important role in biostratigraphy with great potential of the use for mega-lamniform and other pelagic shark remains (teeth and vertebrae) in intercontinental correlation of mid-Cretaceous marine deposits and we can use them to examine Meso-tethyan geography. Preliminary work on shark vertebrae (Turner & Rozefelds 1996) predicted 5 m-plus lamniforms, which has recently been confirmed by the find of articulated Cardabiodon dicki Siverson 1999, in the Cenomanian of West Australia. Such vertebrae can provide evidence of growth and age of the shark and of cold and warm seasonal cycles by checking 5 0 and 8 0 isotopic variation. Cretaceous fish microvertebrate work in Australia is in its infancy. Kemp & Ward (e.g., 1997) listed some two dozen taxa obtained from 600 kg from 15 localities in the Eromanga Basin of Queensland. The Queensland Museum bulk-sampling programme in the Rolling Downs Group to recover dinosaurs etc., has brought to light microremains and provided many kilograms of rock to search. The late Aptian to earliest Cenomanian Wallumbilla and Toolebuc Formations, the Allaru Mudstone, and Mackunda and Winton Formations have diverse assemblages of both pelagic and demersal species. Pelagic taxa in the Coreena Mb., Toolebuc and Mackunda Formations include an early dogfish, Squalus, lamniformes including some megaforms such as Archaeolamna, " Cretolamna", Johnlonga, Leptostyrax, Otodus and Carcharias, Protolamna, Paraisurus and Pseudoisurus. Dermersal taxa are similarly widespread and include Heterodontus, orectolobiforms such as early Wobbegongs e.g., Orectoloboides and a new orectolobid, several new parascylliid taxa, Acanthoscyllium, Chiloscyllium, a triakid (Squatigaleus) as well as a number of Rajiformes with several batoids such as ?Sechmetia and a schlerorynchid. The assemblages in the Coreena Mb. and Mackunda Fm suggested to Kemp and Ward (1997) normal, well-oxygenated, marine conditions. However, the Toolebuc Fm has a relatively low representation of bottom dwelling taxa, suggesting a normal water column but hypersaline bottom conditions and an oxicanoxic interface at, or very near, the water-sedimentary boundary. Gottfried's (op. cit.) contention that species' level taxonomy is always suspect because of ontogenetic variation, heterodonty and convergence is rejected. Detailed character analysis in shark teeth has helped overcome this problem in most cases (e.g. Shimada 1999) and we see no reason to doubt the efficacy of that approach in the Cretaceous. Shark macro- and microfossils can provide as good if not more precise zonation than molluscan megafossil chronozones. 18

GOTTFRIED, M.D. 2001. Cosmopolitanism in Cretaceous Gondwana elasmobranchs. Journal of Vertebrate Paleontology 21(3S), 56A. KEMP, N.R., 1996. Chondrichthyans in the Cretaceous and Tertiary of Australia. In, Vertebrate Palaeontology of Australasia, P. VickersRich, Monagahan, J.N., Baird, R.F. & Rich, T.H. eds, Pioneer Design Studios with Monash University Publications Committee, Clayton, 1494-1495.

KEMP, N.R. & WARD, D.J., 1997. Cretaceous sharks and palaeoenvironments of the Eromanga Basin in Queensland, p. 36, Abstracts, 6th CAVEPS, Perth, Western Australia, July 7-11, 1997. SHIMADA, K. 1999. Contribution of dental characters to elucidate the phylogeny of lamniform sharks. Journal of Vertebrate Paleontology 19 (3S), 75A-76A. TURNER, S. & ROZEFELDS, A., 1992. Tip of the pyramid?: Cretaceous megasharks from Australia. The Beagle 9 (1), 262-263.

VERTEBRATE AND INVERTEBRATE TRACE FOSSILS FROM THE LATE CENOZOIC HAMORI FORMATION OF JEJU ISLAND, KOREA Jeong Yul KIM and Kyung-Soo KIM Department of Earth Science, Korea National University of Education, Cheongwon, Chungbuk, 363-791, Korea [kimjy@cc.knue.ac.kr, ksmsone@chol.com]. Very abundant and diverse vertebrate and invertebrate trace fossils have been discovered in the Late Cenozoic (Quaternary) Hamori Formation of Jeju Island, Korea. The fossil-bearing strata consist of volcaniclastic deposits probably formed in tidal flat or the lagoon environments. The vertebrate trace fossils consist of several thousand mammalian footprints made by Artiodactyla and Perissodactyla, more than one hundred avian footprints and fossil fish trails. The invertebrate trace fossils are Cochlichnus anguineus, Palaeophycus tubularis, Skolithos isp., Spongeliomorpha isp., Taenidium barretti, Thalassinoides horizontalis, T. Paradoxicus, T. suevicus and three types of arthropod trackways including trackways of crabss. Mammalian footprints have not previously been reported from Korea, and the fossil fish trails, Undichna isp., are the first record from Caenozoic strata globally. The Artiodactyla and Perissodactyla footprints provide an important clue to the origin of Jeju Jorangmal (the native horse of Jeju Island), deers and roes living on Jeju Island. The mammalian and avian footprints can be used in correlation of the Late 1

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IPC2002 Poster Presentations Cenozoic strata of Korea, China, and Japan because these trace fossils could be distributed widely in all three countries. The abundance and diversity of trace fossils and palaeocommunities can be recognized by analysing vertebrate and invertebrate trace fossils. Furthermore, the palaeoenvironment and palaeoecology of the formation can be reconstructed by analysing sedimentary facies, mammalian and avian footprints, and invertebrate trace fossils.

MOLLUSCAN RESPONSE TO EARLY PLEISTOCENE WARMING IN THE SEA OF JAPAN Akihisa KITAMURA Institute of Geosciences, Shizuoka University, Shizuoka 422-8529, Japan fseakita&ipc. shizuoka.ac.jp]. Organisms that live for longer than one year have behavioral and/or physiological mechanisms that allow them to live through seasonal cycles. As a consequence, the responses of such relatively long-lived organisms to future climate changes will be much more complex than those of organisms with short life spans. Knowledge of past biotic responses to Quaternary climate change may prove instructive for assessing fUture climate change. This study has addressed the effects of climatic change on benthic molluscan faunas in the NW Pacific middle-latitude shelf from the fossil record of the lower Pleistocene Omma Formation. The latter is exposed around Kanazawa on the coast of the Sea of Japan, central Japan. Its middle part is composed of sixth-order (41-k.y.) depositional sequences accumulated in inner- to outer-shelf environments during oxygen isotope stages 50 to 28. Within each sequence, major changes occurred in molluscan faunas during the transition from glacial to interglacial stages due to rapid warming associated with inflow of the warm Tsushima Current (a branch of the Kuroshio Current). The alkenone-based sea-surface temperature measured in sediment cores from the SW Sea of Japan shows a sharp increase from 14°C at 11.6 ka to 19°C at 11.1 ka, as the current began to flow into the sea. The warming rate was less than that predicted for future warming, but is very high for the Quaternary of Japan. Molluscan fossil records indicate that there were two patterns of faunal change. The first was when warmwater species migrated into the Sea of Japan and co-occurred with cold-water species, accompanied by a northward shift in species ranges. The second pattern involved migration of warm-water molluscs and local extinction of cold-water species. In the latter, it is possible that benthic molluscan communities with very low diversity and density extended a few km laterally and a few tens of meters vertically on the southern Sea of Japan inner- to outer-shelf. Such a community has no modern analogue, but may have resulted from a marine climate with a higher seasonality than occurs today. It is estimated—based on data from present-day molluscan species—that winter temperatures were lower than 6°C and summer temperatures higher than 20°C. Such environments may have temporarily prevailed at least three times (stage transitions 48 to 47, 44 to 43 and 32 to 31) during early Pleistocene deglaciation intervals. These deglaciations corresponded to the three highest peaks of July solar insolation at 65°N during oxygen isotope stages 50 to 28. This anomalously high seasonality, caused by orbital insolation cycles, is likely to have played an important role in establishing non-analogous benthic mollusk communities with very low density and diversity in the early Pleistocene Sea of Japan. If this is correct, such communities will not be established again for the next 150,000 yr, i.e. as long as the present global and/or regional climate systems prevail.

TRIASSIC CONODONT DATUM LEVELS IN SIBERIA AS A POSSIBILITY OF BOREALTETHYAN CORRELATION Tatyana V. KLETS Novosibirsk State University In the past two decades in Siberia as a leading proving ground for development of Triassic boreal standard there were achieved much success in the study of major components of marine ecosystems and in correlation of Triassic deposits. In stratigraphic investigations of the region, the data on some groups of microfauna (foraminifers and conodonts) were first used. Further progress in Triassic correlation is related not only to detailed zonal scales but to application of diverse methodological approaches also. One of such methods is the determination of datum levels of correlation which are treated as stratigraphic intervals corresponding to the stages of levelling of biota taxonomic composition (fig.). The study of conodont assemblages found recently in northern Siberia at different startigraphic levels and their comparison with Tethyan conodont standard will provide more reliable Boreal-Tethyan correlation. The Olenekian Age (the time of maximum transgression in the Triassic) is the first datum stage. In the Early Olenek deposits in Siberia along with endemics (Neogondolella buurensis, N. composits and others)

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IPC2002 Poster Presentations there were wide distributed cosmopolitan species dominated by Neospathodus waageni, Neogondolella mosheri, N. milleri and in Late Olenekian by N.jubata. In the Late Anizian time the quantity and diversity of conodonts greatly reduced. Boreal basins were inhabited only by cosmopolitan Neogondolella cornuta and N. aff. longa. These species have rather precise stratigraphic confinement in European and Asian sections, that allows host rocks to be compared with Neogondolella cornuta Zone the top conodont zone of the Anizian Stage established on the Balkan Peninsula. Neogondolella aff. haslachensis, N. aff. constricta and N. cf. balkanica have penetrated to the Siberian basin in the Early Ladinian. The Early Carnian cosmopolitan Paragondolella foliata was wide spread in high latitudes, that allows host rocks to be compared with diebeli - tethydis conodont zones of the European conodont standard. The Norian time is characterized by penetration of species Norigondolella navicula and N. steinbergensis from low latitudes. Norigondolella navicula is index-species of the lowest subzone of the Norian Stage in conodont European standard for the Tethyan and Norigondolella steinbergensis is known from Middle and Late Norian of Austria and other regions. The study was financially supported by grant E00-9.0-8 from Ministry for Education of the Russian Federation.

CENTIMETER-SCALE CHARACTERIZATION OF SMALL-SCALE CYCLES IN THE KOPE FORMATION (UPPER ORDOVICIAN), CINCINNATI, OHIO USA REGION: IMPLICATIONS FOR STRATIGRAPHIC RESOLUTION AND CORRELATION. Russell H. KOHRS, Brian T.KIRCHNER, Carlton E. BRETT, Department of Geology, Univ of Cincinnati, H.N. Fisk Laboratory of Sedimentology, 500 Geology Physics Building, Cincinnati, OH 45221 The Kope Formation is an Upper Ordovician (Cincinnatian Series) mudrock-carbonate unit deposited in a storm-dominated, mixed siliciclastic-carbonate ramp setting. Lack of a regional fine-scale stratigraphy has obscured evidence of Kope depositional processes; previous stratigraphic analyses have characterized the

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IPC2002 Poster Presentations Kope as a mosaic of localized microfacies. However, recent detailed studies demonstrate that these rocks are commonly correlatable at meter- and even decimeter-scale over large areas. The unit contains more than 40 meter-scale mudrock-siltstone successions capped by prominent thin skeletal packstone/ grainstone bed bundles; these parasequences stack into 5-10 meter intervals (submembers) showing general thinning upward of mudstones. Preliminary centimeter-scale analysis of the 5-6 m Alexandria submember (middle Kope Fm.) probes the limits of high resolution event stratigraphy and provides insights into depositional processes. Each of the six component meter-scale shale-limestone parasequences displays unique attributes that permit unambiguous identification. In addition to characteristic spacing, each of the 5-20 cm capping limestone bundles displays stratinomic, faunal, and taphonomic attributes (e.g., re d-weathering dalmanellid brachiopods in bed 29; reworked concretions in bed 30a). Moreover, intervening mudstones also contain numerous thin (mm to cm), highly distinctive marker beds; these include a) single depositional events (e.g. graded siltstones; obrution beds with distinctive trilobite/crinoid faunas), b) time-averaged lag horizons (e.g. fragmentary graptolite beds; trilobite hash beds), and c) diagenetic beds (e.g. concretion horizons). Most of these horizons (~20) have been found at all Alexandria submember exposures over an area of several hundred square kilometers in southwest Ohio and northern Kentucky. These results have several implications. They (1) indicate the efficacy of very high resolution correlation at regional scale, (2) imply widespread, spatially uniform, but temporally fluctuating environmental conditions and episodic sediment accumulation of regional scale, and (3) suggest that very high resolution correlation may be a necessary tool for palaeoenvironmental interpretation of other siliciclastic-carbonate ramp units. MICROBORINGS IN CONODONT ELEMENTS P. KONIGSHOF & I. GLAUB Forschungs ins titut und Naturmuseum Senckenberg, Senckenberganlage 25, D-60325 Frankfurt am Main, Germany; [pkoenigs@sng.uni-franlrfurt.de]; Geologisch-Palaontologisches Institut, Senckenberganlage 3234, D-60325 Frankfurt am Main, Germany; [I.Glaub@em.uni-franlrfurt.de] In numerous conodont samples small cavities in conodont elements are observed. The first evidence of microborings in conodonts was given by Rohon & Zittel (1886), the first detailed analysis by Mtiller & Nogami (1972). It is assumed that some of them are microborings produced by microendoliths, e.g. endolithic algae or fungi. Fossil microboring communities in carbonate substrates are important as a palaeobathymetric tool (e.g. Glaub 1994, Vogel et al. 1995). Conodonts are a non-carbonate substrate of special interest. A special technique of preparation (cast-embedding technique) together with SEM photography was used to record and document microborings in conodonts. Investigations, based on approximately 300 conodont elements from America, Germany and China show that four microcavity types can be discriminated. In contrast to the few studies on microborings in conodont elements, studies on microendoliths in calcareous substrates are numerous. Three of the microcavity types described by Glaub & Konigshof (1997) can be compared with cavities in fossil and modern molluscan shells. Though they display morphological similarities in some points, there are still some open questions: Do we have specific boring organisms in conodonts? Are the microcavities described in conodont elements typical for the apatitic-substrate or do identical cavities occur in other substrates, especially in calcareous material? Two of the analogues found for microborings in conodonts are rarely observed in calcareous substrates. Thus, does the morphological similarity between such "conodont trace fossils" and borings of modern endoliths allow interpretations converning the biofacies of conodonts? Is it possible to use microborings in conodonts as a potential tool in determining palaeodepth? 1

GLAUB, I., 1994. Mikrobohrspuren in ausgewahlten Ablagerungsbereichen des europaischen Jura und der Unterkreide (Klassifikation

und Palokologie). Courier Forschungsinstitut Senckenberg 174, 1-324. GLAUB, I. & KONIGSHOF, P., 1997. Microboring in conodonts. Courier Forschungsinstitut Senckenberg, 2 0 , 1 3 7 - 1 4 3 . MULLER, K.J. & NOGAMI, Y., 1972. Entoken und Bohrspuren bei Conodontophorida. Palaontologische Zeitschrifit, 46, 68-86. ROHON, J.V. & ZITTEL, K.A.V.,1886. Uber Conodonten. Sitzungsbericht der Koniglich-bayerischen Akademie der Wissenschaften., Mathematisch-Physikalische Classe., 1886, 108-136. VOGEL, K., BUNDSCHUH, M., GLAUB, I., HOFMANN, K., RADTKE, G. & SCHMIDT, H., 1995. Hard substrate ichnocoenoses and their relations to light intensity and marine bathymetry. Neues Jahrbuch fur Geologie und Palaontologie, Abhandlungen, 193,49-61.

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IPC2002 Poster Presentations CONODONT ALTERATION INDEX (CAI) AND DEFORMATION OF CONODONTS IN LOW GRADE METAMORPHOSED SEDIMENTS (MONTAGNE NOIRE, S-FRANCE) P. KONIGSHOF . U. WIEDERER & W. FRANKE Forschungsinstitut und Naturmuseum Senckenberg, Senckenberganlage 25, D-60325 Frankfurt am Main, Germany [pkoenigs@sng.uni-frankfurt.de]; Institutfur Geowissenschaften, Universitat Giessen, Senckenbergstrafie 3, D-35390 Giessen, Germany; [wolfgang.franke@geolo.uni-giessen.de] 1

The Montagne Noire, situated on the S flank of the Variscan Belt in South France, is a classical example of a "mantled gneiss dome". The ENE-trending dome structure ("Zone Axial") is cored by HT/LP gneisses and anatectic granites, encased by dextral shear zones, and flanked by low- to very low-grade Palaeozoic metasediments (Franke et al. 2000). In most of the area, Late Ordovician and Silurian deposits are missing and Devonian sediments cover Early Palaeozoic sequences. Apart from the basal clastic member, the Devonian sequence is composed entirely of carbonates. Most of the analysed samples are hemipelagic, nodular carbonate mudstones of Late Devonian to Early Carboniferous age. Based on about 300 conodont samples, CAI values have been analysed. These data show that in all sampled areas metamorphism decreases away from the Axial Zone. The same trend had already been observed in a study of illite crystalinity by Engel et al (1981). There are, moreover, irregularities in distribution of CAI values in some areas (parts of the Faugeres Nappe and Mt. Peyroux Nappe)—probably related to hydrothermal alteration. In the southern part of the Minervois (CAI values of 3-7) conodont elements show characteristic features due to contact metamorphism and /or hydrothermal alteration. The conodont elements from carbonate rocks in the above areas show correlation between the grade of deformation of carbonates and the conodonts. Generally, in low-grade areas the deformation of conodont elements is brittle, leading to fragmentation during processing. A large number of conodont elements show ductile deformation. This pattern occurs in samples with CAI 5 and CAI 5.5-6. We conclude that the temperature level attained at CAI 5 defines the brittle-ductile boundary of fine-grained apatite for the (unknown) lithostatic pressures and strain rates prevailing (Wiederer et al.). ENGEL, W., FEIST, R. & FRANKE,W., 1982. Le Carbonifere ante-Stefanien de la Montagne Noire: rapports entre mise en place des nappes et sedimentation. Bulletin du B.R.G.M., deuxieme serie, Section I, 4, 1980-1981, 341-389. FRANKE,W., DOUBLIER, M., KONIGSHOF, P. & WIEDERER, U., 2000. Exhumation of an anatectic gneiss dome: news from the Montagne Noire (S-France). Terra Nostra. 2000/1; p. 42. WIEDERER, U., KONIGSHOF, P. & FRANKE, W. [submitted]: Low grade metamorphism in the Montagne Noire (S-France): Conodont Alteration Index (CAI) in Palaeozoic carbonates and implications for the exhumation of a hot metamorphic core complex.

RUGOSE CORAL CYSTOPHRENTIS IN HEPU, GUANGXI, AND ITS DISTRIBUTION KUANG Guodun Guangxi Institute of Geology and Mineral Resources, Nanning 530023, Guangxi, China The biogeographically significant rugose coral Cystophrentis is mainly Asian in distribution, is commonly found in South China, and is mainly latest Devonian in age. It has, however, some typical Carboniferous rugose coral characters such as a clearly cardinal fossula and cardinal septal stereozone. Its geographic distribution is similar to that of Carboniferous rugose corals. Cystophrentis has the same distribution as the Kuichouphyllum-Yuanophyllum fauna in South China. Neither Cystophrentis nor Yuanophyllum have yet been found in the western areas along the You Jiang Fault Zone, nor has this fauna been found in the northern areas of Viet Nam adjacent to Guangxi. Most species of Cystophrentis are small, but some species of Cystophrentis in Hepu are very large; these were wrongly assigned to Pseudouralinia and the two genera were always thought to have lived together. Upper Devonian in Hepu, Guangxi is composed of three units. The lower unit consists of clastic rocks with interbedded argillaceous limestones. The middle and upper units consist of clastics, but the uppermost part consists of argillaceous limestones. The sediments in Hepu are very different to those from northern Guangxi. A recent comparative study (Kuang et al., 1999) has demonstrated that the sedimentary sequences and rugose coral assemblages are very similar to those in the Haiphong area of central Viet Nam, but differ considerably from Upper Devonian sequences in areas of northern Viet Nam. These data and the contrasts associated with them will be useful in considering Devonian and Carboniferous biogeography. KUANG, G. D., LI, J. X., ZHONG, K., SU, Y. B., & TAO, Y. B., 1999. Carboniferous of Guangxi. Stratigraphy of Guangxi, China, Part 2:

258 pp.. Compiled by the Bureau of Geology and Mineral Recources of Guangxi Zhuang autonomous region, China.

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IPC2002 Poster Presentations MIDDLE PALAEOZOIC RADIOLARIAN BIOSTRATIGRAPHY OF THE FUKUJI AREA OF THE HIDA-GAIEN TERRANE, JAPAN Toshiyuki KURIHARA JSPS Research Fellow. Institute of Geoscience, University ofTsukuba, Ibaraki 305-8571, Japan Silurian to Devonian shallow marine carbonates and arc-related felsic tuffaceous sequences are well developed in the Hida-gaien Terrane in the Inner Zone of SW Japan, the Kurosegawa Terrane in the Outer Zone of SW Japan, and the South Kitakami Terrane of NE Japan. The Fukuji area of the Hida-gaien Terrane consists mainly of unmetamorphosed Ordovician to Permian rocks. It has produced several diverse Silurian to Devonian radiolarian assemblages with high biostratigraphic potential from a tuffaceous and clastic sequence (Furutani, 1990), but structural complexity of the examined section, poor chronostratigraphic control, and sparse radiolarian data in the early 1990's hampered age-assignment and understanding of stratigraphic relationships between the assemblages. The Silurian-Devonian strata in this area are subdivided into the Silurian Osobudani Formation, the Silurian to Devonian Yoshiki Formation, and the Silurian to Devonian Fukuji Formation. The two former units consisting of tuffaceous turbidite contain rich radiolarians. Eight radiolarian assemblages ranging from Early Silurian through Early Devonian have been discriminated from several localities in the Osobudani and Yoshiki Formations. The oldest assemblage is the Early Silurian Oriundogutta sp. B -Palaeoscenidium sp. A Assemblage occurring in calcareous mudstone of the Osobudani Formation. Four Late Silurian assemblages have been identified in the lower part of the Yoshiki Formation: the Fusalfanus osobudaniensis-Rotasphaera itoigawai Assemblage, the Zadrappolus spinosus-Praespongocoelia parva Assemblage, the Stylosphaera(l) magnaspina Assemblage, and the Pseudo-spongoprunum{l) tauversi Assemblage. These four assemblages can be correlated with assemblages of the Palaeoactinosphaera{l) asymmetrica Lowest Occurrence Zone, the Praespongocoelia Taxon Range Zone, the S.(?) magnaspina Taxon Range Zone, and the Devoniglansus unicus-P.{l) tauversi Interval Zone of West Texas (Noble, 1994). Three Early Devonian assemblages have been recognized within the upper part of the Yoshiki Formation: the Futobari solidus-Z. tenuis Assemblage, P. ishigai-Deflantrica furutanii Assemblage, and the Pactarentinia intermedia-P. igoi Assemblage. The F. solidus-Z. tenuis Assemblage correlates with the F. solidus Zone of Umeda (1998) in the Kurosegawa Terrane; the P. ishigai-D. furutanii and P. intermedia-P. igoi Assemblages also correlate with the Trilonche(?) sp. A Zone of Umeda (1998). These new faunal data reveal that the Silurian radiolarian zonal scheme, especially Upper Silurian, is a reliable tool for age-assignment for radiolarian-bearing rocks. Further biostratigraphic work is needed to discriminate distinctive radiolarian biohorizons for the Lower Devonian and to improve calibration of these intervals. SPECIES RELATIONSHIPS IN THE PTYCHAGNOSTIDAE John R. LAURIE Geoscience Australia, Canberra, ACT The Ptychagnostidae have received a considerable amount of attention over the last 30 or so years, with disparate views on the arrangement of species being presented by several authors. Opik (1979) recognised as many as 15 genus group names while Robison (1984) recognised only 5. More recently, Westrop et al. (1996) undertook a cladistic analysis of 42 species from the family using Agnostus pisiformis and Peronopsis brighamensis as the outgroup species. The result was recognition of monophyletic groups such as Aotagnostus and Goniagnostus, both of which were subsumed in a large, confused group of species which Westrop et al. (1996) referred to as Ptychagnostus sensu lato. Outside this, only Lejopyge and Pseudophalacroma were recognised as monophyletic groups. Consequently, Westrop et al. (1996) stated that their analysis did not support the finer classification of Opik (1979) and Laurie (1988, 1989), but was consistent with Robison's (1984) more conservative approach. A close examination of the character states used by Westrop et al. (1996) demonstrates many problems with their coding. These include: choice of arbitrary boundaries within continua (Characters 4, 23, 27); oversimplification of complex variation (Characters 2, 8, 13, 15, 17, 19, 25, 26); tendency to not include intraspecific variation when coding for a species (Characters 1, 3, 5, 9, 14, 15, 24); and use of simple length ratios (Characters 12, 20). The use of quantitative characters is recommended against in cladistic analysis (Pimentel & Riggins, 1987), yet many of the characters used in the analysis of Westrop et al. (1996) are just that, although they may not be stated mathematically. For example, characters such as: basal lobe shape (short, slightly elongate, strongly elongate); pygidial F1 shape (subtransverse, moderately curved, strongly

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IPC2002 Poster Presentations curved); and tubercle on pygidial M2 lobe (small, large, spinose), are simply quantitative characters in another guise. Westrop et al are not alone in this. This is the case with most morphological characters other than real, rather than massaged nominal variables. Although cladistic analysis is popular in palaeontology, and morphology is all we have to play with, it is wise to realise that morphology is a poor proxy for the genetic code of an organism and can rarely, if ever, provide an unequivocal solution to a phylogenetic problem. Despite this, several approaches were tried in attempting to reconcile the varying ptychagnostid taxonomic schemes derived from the various papers mentioned above. Firstly, the characters and character states used by Westrop et al (1996) were revised to minimise the problems and inconsistencies listed above; secondly a new set of characters were developed to take into account as much of the range of morphological variation as possible; and thirdly a restricted set of more complex characters on a restricted set of species designed to decrease the impact of polymorphisms as well as that of effacement. Each of these approaches yielded a consensus cladogram more closely aligned to the 'less conservative' taxonomic approach of Laurie (1988, 1989) LAURIE, J.R., 1988. Revision of some Australian Ptychagnostinae (Agnostida, Cambrian). Alcheringa 12, 169-205. LAURIE, J.R., 1989. Revision of species of Goniagnostus Howell and Lejopyge Corda from Australia (Agnostida, Cambrian). Alcheringa 13, 175-191 OPIK, A.A., 1 9 7 9 . Middle Cambrian agnostoids: systematics and biostratigraphy. Bureau of Mineral Resources, Geology and Geophysics, Bulletin 172, vol. 1, 188p., vol. 2, 67 pis. PlMENTEL, R.A. and RlGGlNS, R., 1987. The nature of cladistic data. Cladistics 3(3), 201-209. ROBISON, R.A., 1984. Cambrian Agnostida of North America and Greenland, Part 1: Ptychagnostidae. University of Kansas Paleontological Contributions, Paper 109, 59p. WESTROP, S.R., LUDVIGSEN, R. and KINDLE, C.H., 1996. Marjuman (Cambrian) agnostoid trilobites of the Cow Head Group, western Newfoundland. Journal of Paleontology 70(5), 804-829.

FUSULINID BIOSTRATIGRAPHY OF THE CARBONIFEROUS-PERMIAN STRATA, SOUTH KOREA Chang Zin LEE Department of Science Education, Chungbuk National University, Cheong/u 361-763, South Korea [leecz@cbu. ac. kr] One hunderd and four species belonging to 21 genera of fusulinids are described and identified from the Carboniferous-Permian strata of the Danyang, Jeongseon, and Yeongweol coalfields, South Korea, and five fusulinid biostratigraphic zones are established, viz, the Eostaffella-Pseudostaffella, Profusulinella, Beedeina, Hanostaffella-Fusulina, and Pesudoschwagerina-Pseudofusulina Zones in ascending order. These fusulinid zones are arranged from the two fusulinid zones in the Danyang coalfield, two fusulinid zones in the Jeongseon coalfield, and five fusulinid zones in the Yeongweol coalfield. Especially the Bamchi equivalent formation is found from the Hoedongri area of the Jeongseon coalfield. Five fusulinid zones in the study area are correlated with those of Russia, China, Japan, and North America and with the chronostratigraphic units of the standard Eurasian stratotype as follow, viz, the Eostaffella-Pseudostaffella Zone is correlated with the Bashkirian Series, the Profusulinella and Beedeina Zones with the early Moscovian Series, Hanostafella-Fusulina Zone with the late Moscovian Series, and the Pseudoschwagenia-Pseudofusulina Zone with the Sakmarian Series. Triticites, Upper Carboniferous index fusulinid, has never been found so far in the study areas. It is suggested to have been a considerable time break representing as paraconformity between the Hanostaffella-Fusulina Zone and the PseudoschwagerinaPseudofusulina Zone. PALAEOZOIC RADIOLARIAN FAUNA STUDY AND TECTONIC SIGNIFICANCE IN THE SOUTHERN TIANSHAN, XINJIANG, NORTHWESTERN CHINA Yu LIU School ofEarth and Space Sciences, Peking University, Beijing 100871, P. R. China Abundant and well-preserved fossil Radiolaria have been found from siliceous rock located on the top of ophiolite from southern Tianshan, Xinjiang Uygur Autonomous Region. There have long been different opinions regarding the age of the ophiolite. The lithology of the section dominated by siliceous rock is interbedded with sandstone and shale. The section, the top of the ophiolite, was deposited at the same time with ophiolite suit. Therefore, the age of the section could represent the age of the ophiolite. As in the past years, well-preserved radiolarians could not be separated from siliceous rocks. The age of the siliceous rocks

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IPC2002 Poster Presentations is identified by the fossils from limestone. Some people think the ophiolite suite belongs to MiddleDevonian. Some people believed that the ophiolite suite is of Upper Silurian-Lower Devonian, however, we think that the ophiolite suite is Early Carboniferous in age, namely, Tournaisian-Visean. In the meantime, four Radiolarian assemblages have been divided, namely, the Triaenosphaera palimbola, Entactinia vulgaris, Belowea cf. variabilis and Archocyrtium sp. assemblages. The fauna may be correlated with that from the Early Carboniferous of Germany and North America. Because there is the lack of genus of Allbaillella, the name of assemblage is different. Based on these analyses, the sequence of Radiolarian-bearing is compared with that established by Mr. Andreas Braun from Germany. The elements of assemblage zone and appearance sequences of these elements in the section are quite similar, even though those two assemblage zones are named by the different Radiolarian. Therefore the age of the assemblage zone is the Early Carboniferous. In addition, these elements widely dispread in Lower Carboniferous in the North America and the Southern China. The wall rock of the four radiolarian assemblages is red purple and thin-bed siliceous rock. It is concentrated in ferric iron. Eu-hedral form and ana-hedral form grand magnetite can be seen. They represent a kind of environment of hydra-thermal cascade. The fossils of Radiolarian fauna are of small and fine thin shell decoration as well as symbiotic life of Spongespine and Conodonts. The conodont assemblages belong to Nandan type. Based on these analyses, the environment is suggested to be of low latitude, warm water and normal sanity. According to the sediments, Radiolarian, symbiotics and petrochemistry, we think that the ophiolite reflects low-speed expanding original ocean on the basis of the land-shell with region scale. The above researches provide the basic information for further study of the evolution history of South Tianshan.

THE RECORD OF DINOSAUR EXTINCTION IN THE SOUTH-CENTRAL PYRENEES N. LOPEZ-MARTINEZ1, L. ARDEVOL2, M.E. ARRIBAS1, J.I. CANUDO3, A. LACASA4, X. PEREDASUBERBIOLA5, R. SOLER-GIJON1, A. TORICES1, and E. VICENS6 1 Universidad Complutense de Madrid; 2GeoPlay, Tremp; 3Universidad de Zaragoza; 4Institut d'Estudis Ilerdencs, Lleida; 5Universidad del Pais Vasco - EHU; 6Universitat Autdnoma de Barcelona The south-central Pyrenees (Spain) provide one of the most complete fossil records of the last 8.5 Ma of the dinosaur succession. Dinosaur remains such as bones, teeth, footprints, eggs and eggshell fragments are common in the Upper Cretaceous Aren and lower part of Tremp formations. The Aren Fm consists of shales, sandstones, and calcarenites deposited in a deltaic and shoreface environment. The laterally equivalent lower part of the Tremp Fm consists of red beds deposited in a coastal plain environment. These rocks have a maximum thickness of some 2,500 m and are divided into five depositional sequences that have been mainly correlated by means of rudist-bearing horizons and chemostratigraphy, and dated by means of planktonic foraminifera and magnetostratigraphy from late Campanian to Maastrichtian (Ardevol et al., 2000; Vicens et al., in press). Some 147 dinosaur sites have been recognized in these formations: 100 sites contain mainly eggs or eggshell fragments, 36 contain bones and teeth, and 11 show footprints (Lopez-Martinez, in press). 117 of these sites belong to the sequence 2 of latest Campanian age, 15 sites are located in the sequence 3 of earlylate Maastrichtian age, and 11 in the latest Maastrichtian sequence 4. Four dinosaur sites are located in the sequence 5 that contains the K/T boundary is situated below a low delta 13C anomaly at the upper part of chron c29r, in a 1-3 m interval without fossils (Lopez-Martinez et al., 1998). The study of the fossil content and distribution of the sites have led to the following conclusions: (1) There is a sudden decrease in dinosaur fossil localities around the Campanian/Maastrichtian boundary (according Gradstein et al., 1995). In the sequence 2 there is a frequency of 50 sites/Ma, while the sequences 3-4 show only five sites/Ma. This uneven distribution is highly significant (the Chi-square probability is as low as 2.48"15). No depositional or taphonomic changes seem to be related to this rapid decrease. (2) There is a gradual change in the taxonomic composition from lower to upper Maastrichtian. Sauropod-rich assemblages in sequence 2 are replaced by hadrosaur-dominated assemblages in sequence 4. Titanosaurs, hadrosaurs and theropods are present in the entire succession, however ankylosaurs and the ornithopod Rhabdodon have not yet been found in sequences 4-5. (3) Each sequence shows about 8-10 dinosaur taxa, hence dinosaur diversity does apparently not change in the succession until their sudden demise at or close to the K/T boundary.

TABULATE CORALS OF CENTRAL TIMAN (NORTH-EAST EUROPEAN RUSSIA) Vladimir Yu. LUKIN

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IPC2002 Poster Presentations Institute of Geology, Komi Science Centre, Ural Division ofRAS, Syktyvkar, Russia Devonian deposits in the Pechorskaya Pizhma River basin (central Timan) were first investigated by F.N. Tchernychev in the late 1800s. In 1940-1948 A.A. Malakhov and S.V. Tikhomirov investigated the stratigraphy in detail, making correlations with synchronous deposits of S Timan, the Main Devonian Field and elsewhere. Further study by, inter alia, M.I. Osadchuk, G.V. Matveeva, G.I. Khanzeina, A.E. Tsaplin and V.S. Sorokin have produced results that are basic for establishing correlations at regional and subregional scale with the stratigraphic scales for the Devonian of the Russian Platform. Unfortunately until now organic remains from Devonian deposits of central Timan remained virtually unknown. Some tabulate and rugose corals were described by N.I. Lebedev (1902), but the taxonomy of these forms needed revision and there was uncertainty regarding the Frasnian biostratigraphy based on tabulate corals and other groups. In 1997 Devonian deposits of the Pechorskaya Pizhma River basin were investigated by V.S. Tsyganko and the author. Representative collections of tabulate corals and other organisms were obtained from Frasnian sedimentary sequences, with tavulate corals specifically from Sargaevo, Domanik, Vetlosyan, Sirachoy and Evlanovo -I- Livny horizons. According to V.S.Tsyganko (1999), the Sargaevo horizon comprises the Ust'yarega and the lower part of the Kraypol suites. The latter produced, inter alia, Thamnopora trachyporoides Dubat., Crassialveolites domrachevi (Sok.), C. evidens Dubat. and Mastopora compacta (Tchern.). The Domanik horison (middle part Kraypol suite) is represented by clays, limestones, siltstones and sandstones with the tabulates C. evidens Dubat., Aulopora sp. and Mastopora compacta (Tchern.). The upper part of the Kraypol suite (= Vetlosyan and Sirachoy horizons) lacks tabulate corals in the clays and marls of the Vetlosyan horizon, but the uppermost part of the Kraypol suite (bottom Sirachoy horizon) has coral biostromes with numerous colonies of only two species: Crassialveolites domrachevi (Sok.), and Alveolitella sp. Fossils from the siltstones and sandstones of the Kamennyj Ruchej suite (Evlanovo + Livny horizons) are poorly preserved but include the tabulate Thecostegites sp. Analysis of tabulate coral faunas shows similar associations to those of Frasnian sequences of the Russian Platform, Western Urals and NE Russia (S Verkhoyanye). Thus study of tabulate corals and other fossils allows elucidation of the Frasnian stratigraphy of central Timan and correlation with sequences elsewhere. LEBEDEV, N.I., 1902. A role corals in Devonian deposits of Russia. Works of Geology Commitee, 17 (2): 180. TSYGANKO, V.S., 1999 The Pechora Plate in Late Devonian: biotic events and their correlation potential. Geology and Mineral Resources of Northeast European Russia: New Results and New Prospects. Syktyvkar, 2: 237-239.

THE LIFTING AND CONSERVATION OF MEGAFAUNA BONES FROM THE PLEISTOCENE SITE OF CUDDIE SPRINGS, EASTERN AUSTRALIA Colin MACGREGOR Acting Head, Materials Conservation Dept., Australian Museum,[colinm@austmus.gov.au] The site at Cuddie Springs is a dried up lake bed in an arid area of central New South Wales. The site has been known to be rich in bones of extinct fauna for over one hundred years. In recent years systematic excavation has revealed stone tools in the same levels as the bones of large extinct marsupials. As a site that may provide clues to the interaction between megafauna and humans, the conservation of the fragile bones is an important part of this work. The semi-mineralised bones are often in a crushed condition held together by damp clay. The lifting, transport and subsequent consolidation must be appropriate to ensure that maximum data is obtained from the material. Lifting has been achieved using a combination of facing up and plaster or polyurethane lifting jackets. Consolidation in the laboratory is carried out with an acrylic resin dissolved in an organic solvent. BIVALVIA FROM THE MAECURU FORMATION, MIDDLE DEVONIAN OF THE AMAZON BASIN, NORTHERN BRAZIL Deusana Maria Da Costa MACHADO & Vera Maria Medina Da FONSECA Laboratorio de Estudos de Comunidades Paleozoicas, Departamento de Ciencias Naturais, ECB, CCBS, UNI-RIO, Rua Voluntarios daPatria 107, Botafogo, 22.270-000, Rio de Janeiro, RJ, Brasil [fsr@centroin.com.br]; Departamento de Geologia e Paleontologia, Museu Nacional/UFRJ; Quinta da Boa Vista, s/n, 20 940-040, Rio de Janeiro, RJ, Brasil; [vmedina@acd.ufrj.br]. 1

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IPC2002 Poster Presentations The Devonian Bivalvia from the Amazon Basin, northern Brazil, are found in two lithostratigraphic units, the Maecuru and Erere formations. They were firstly studied by the Canadian and North American naturalists C.F Hartt, R. Rathbun and J. M. Clarke. After those monographs a few studies have been done by Katzer (1903), Costa (1982) and Machado (1990a; 1990b). The Maecuru Formation is divided into two Members: Jatapu and Lontra. The material studied was collected from the uppermost part of Lontra Member, represented by fine to coarse-grained sandstones. They are considered shallow marine tempestites of Eifelian age. The fossiliferous outcrops occur in six localities in the Maecuru River and in the Lontra Falls, at the Curua River, both situated in center-northwest of Para state, northern of Brazil. It were identified at least two distinct brachiopod-bivalve dominated associations. The Mucrospirifer katzeri-Ptychopteria (Actinopteria) eschwegei association is found in the fine-grained sandstones and the "Schuchertella" agassizi-P. (A.) eschwegei one in the medium to coarse-grained sandstones (Machado, Fonseca & Moraes Rego, 1996) Twenty-three bivalve species are known from the Maecuru Formation. Besides bivalves there are brachiopods, tentaculitoids, trilobites, crinoids, gastropods, bryozoans, rugose corals and connulariids. The most abundant bivalve species are Ptychopteria (Actinopteria) eschwegei (Clarke, 1899), P. (A.) humboldti (Clarke, 1899), "Modiomorpha" sellowi Clarke, 1899 and Toechomya(?) rathbuni (Clarke, 1899). The bivalves occur in associations: Ptychopteria (Actinopteria) eschwegei; Aviculopecten coelhoanus Katzer, 1903; "Modiomorpha" sellowi; Sanguinolites kasteni (Clarke, 1899), Toechomya (?) rathbuni in one association, and P. (A.) eschwegei; Cypricardella hartti Clarke, 1899; "C." pohli Clarke, 1899, Glossites helmreicheni (Clarke, 1899); "Grammysia" burmeisteri Clarke, 1899; Grammysioidea gardneri (Clarke, 1899); G. lundi (Clarke, 1899), G.(?)pississi (Clarke, 1899); G. sp. A; G.? sp. B; Limoptera browni (Clarke, 1899); "Leioptera" sawkinsi Clarke, 1899, 'Modiomorpha" sellowi Clarke, 1899, Nuculoidea? bellistriata parvula Clarke, 1899, Nuculites (Trilobonuculites) smithi Clarke, 1899, Nyassa ortoni Clarke, 1899; Palaeoneilo orbignyi Clarke, 1899, Ptychopteria (Actinopteria) humboldti (Clarke, 1899), Sanguinolites kasteni (Clarke, 1899), Sedwickia(?) pondeana (Clarke, 1899); Sphenotomorpha bodenbenderi (Clarke, 1899) and Toechomya (?) rathbuni in the other association. Trophic habits identified in the Maecuru bivalves are epibyssate, endobyssate, semi-infaunal byssate, infaunal filter feeders, and infaunal deposit feeders. The infaunal types are almost absent from the Mucrospirifer katzeri-Ptychopteria (Actinopteria) eschwegei association, but well represented in the "Schuchertella" agassizi-Ptychopteria (Actinopteria) eschwegei association. CLARKE, J.M. (1899). Moluscos Devonianos do Estado do Para, Brazil. Arch. Mus. Nac., 10: 49-174, est.3-8; Rio de Janeiro

COSTA, D.M (1982). O genero Pthcopteria (Mollusca-Bivalvia) no Devoniano da Amazonia. An. Acad. Bras. Cien., 54 (1): 253-254; Rio

de Janeiro.

HARTT, C.F. & RATHBUN, R. (1875). Morgan Expeditions, 1870-71; On Devonian trilobites and mollusks of Erere, Province of Para,

Brazil. Ann. Lyceum. Nat. Hist., 11 (13): 110-127; New York. KATZER, F. (1903). Grundziige der Geologie des unteren Amazonasgebeites (des Staates Para in Brasilien), 298 p., est. 1-16, map; Leipzig, Max Weg,. MACHADO, F. (1990a). Bivalvios Devonianos da Bacia do Amazonas (forma9oes Maecuru e Erere): Considera9oes sistematicas e paleoautecologicas. Disserta9ao de Mestrado Universidade Federal do Rio de Janeiro, Rio de Janeiro, 283p., 20 ests., unpublished) MACHADO, F. (1990b). Algumas Considera9oes Estartigraficas e Biogeograficas acerca do Bivalvios Devonianos da Bacia do Amazonas. In: Congr. Bras. Geol., 36, Natal, 1990. Anais, v.l: 425-35.). MACHADO, F. & MORAES, R., (1996). Estudos Preliminares sobre a distribui9ao dos macrofosseis na Forma^o Maecuru do Devoniano Medio da Bacia do Amazonas, Para. In: Simposio Latino-Americano do Siluro-Devoniano, Ponta Grossa. Anais: 237-245.

SHALLOW MARINE FORAMINIFERA OF THE LORD HOWE ISLAND SHELF. A. MACKINTOSH School of Geosciences, University of Wollongong. Northfield Ave, Wollongong NSW 2500, Australia [amackintosh@iprimus. com. auJ Lord Howe Island is situated to the NE of Sydney in the southwest Pacific Ocean. The island is best known for having the southernmost coral reef in the world. The shelf surrounding Lord Howe Island represents an open ocean transition zone between tropical and temperate carbonate sedimentation. This provides a unique opportunity for tropical marine organisms to live at their southern limit and for subtropical organisms, which do not occur in the tropics, to coexist. The aim of this study was to discover if foraminifera from the shelf are representative of this transition. Lord Howe Island lies in the warm Tasman water mass, which has a mean winter temperature of 19.8 degrees and a mean summer temperature of 24.4 degrees. In summer the Tasman front is located around Lord Howe Island bringing warm water form the Coral Sea to the island contributing to the small seasonal variation to sea surface temperatures.

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IPC2002 Poster Presentations Surrounding Lord Howe Island is a large planated shelf, a feature derived from the weathering of the volcanic edifices. The shelf is relatively shallow being approx 40-50m deep with a steep drop at the shelf edge around 70m. The main feature on the shelf is a discontinuous fossil reef, which occurs mid way between the island, and the shelf edge. It is mostly 30m deep with isolated patches of Holocene give up reef rising to 25m The dominance of the fossil reef has influenced population assemblages with foraminifera living either attached to the reef or to algae growing on the firm substrate. Samples were collected from the shelf using a Smith-Mclntyre grab sampler and sealed for later analysis. Foraminifera were identified according to the classification used by Loeblich and Tappen (1988). The preliminary results of benthic and larger foraminifera indicate a mixed distribution with Cibicides and Amphistegina species dominating the samples. The presence of larger foraminifera, including Amphisorus, Marginopora, Sorites and Peneroplis indicates warm conditions with good light availability and sediment compatibility. Baculogypsina species are restricted to the upper portion of the shelf. A large proportion of tests are weathered indicating post mortem transportation, abrasion and possibly a contribution from the aeolianite dune deposits of the Island. Strong currents also contribute to the mechanical abrasion of tests and the mixing of assemblages. The currents also ensure stratification associated with seasonal water temperatures does not occur and maintains the equitable water climate.

FLORISTIC PROVINCIALISM IN ANCESTRAL PALAEOZOIC CONIFERS Gene MAPES & Gar W. ROTHWELL Environmental and Plant Biology, Ohio University, Athens, Ohio, USA The most ancient ancestral conifers are described from Upper Carboniferous and Permian deposits of Euramerica, whereas conifer remains from Angara, Cathaysia, and Gondwana appear first in the Permian. Although concepts of these plants were developed largely from Euramerican species, the most widely accepted evidence for conifer origins is based on the Gondwanan species Buriadia heterophylla (Feistmantel) Seward and Sahni. Incompletely preserved and minimally studied specimens from Gondwana, Angara and Cathaysia traditionally have been assigned to Euramerican genera, giving the impression that such taxa were globally ubiquitous, but the most completely understood plants from each province are clearly systematically distinct. The earliest and most extensively studied fossils from Euramerica come from Upper Carboniferous and Lower Permian strata, and are commonly known as walchian conifers. Plant concepts of these conifers were originally synthesized and segregated by Florin as species of Lebachia and Ernestiodendron, though more recent studies have revised their nomenclature and clarified their systematic boundaries. Walchian species can now be reliably assigned to the families Emporiaceae, Utrechtiaceae, or Thucydiaceae, or left in open nomenclature. Walchian species typically display an orthotopic stem with two orders of plagiotropic lateral branches. Though simple leaves are the most common, many species display leaf dimorphism with forked leaves on penultimate branches. Ovulate structures comprise compound cones, or fertile zones, in which there are flattened ovuliferous dwarf shoots in the axils of helically arranged bracts. Sterile scales typically occur on all sides of the ovuliferous dwarf shoots, and sporophylls with inverted ovules are either interspersed among the sterile scales or are terminal. The most well known walchian pollen cones bear adaxial pollen sacs on leafy sporophylls in simple cones, except in Thucydia. Thucydia has compound pollen cones with bracts, axillary dwarf shoots and sporophylls with terminal pollen sacs. Monosaccate, eusaccate prepollen appears to characterize walchian species. The Late Permian conifers of Euramerica are assignable to the Voltziaceae, Ullmanniaceae and Majonicaceae. These plants have simple leaves and terminal ovulate cones with flattened ovuliferous dwarf shoots in which the parts are reduced and fused. Their individual sporophylls are difficult to recognize without internal anatomy. Structure of the pollen cones is also less completely understood in the Late Permian species. Conifer remains occur throughout the Permian of Angara. Angaran species have simple leaves and compound ovulate cones or fertile zones, in which nearly radial, axillary ovuliferous dwarf shoots bear several sporophylls interspersed among a large number of sterile scales. Pollen cones are apparently simple and bear monosaccate, protosaccate prepollen. The best known Angaran conifers are assigned to Concholepis, Kungarodendron, and Timanostrobus. Although most conifer fossils from Permian Cathaysia have been ascribed to walchian or voltzian taxa, the best preserved and most thoroughly characterized are unique to Cathaysia. These include Szecladia and Batenburgia. Szecladia is irregularly branched with multiveined simple leaves and typical conifer internal anatomy. Batenburgia consists of compound ovulate cones with lanceolate bracts that partially sheath axillary ovuliferous dwarf shoots, each of which bears several sterile scales and a single ovule. Permian conifers from South American Gondwana are characterized by compound ovulate cones with helically arranged bracts and axillary ovuliferous dwarf shoots, each consisting of an axis with a single,

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IPC2002 Poster Presentations terminal ovule. Pollen cones appear to be simple with adaxial pollen sacs and saccate pollen. Species are assigned to the Ferugliocladaceae and the conifer-like genus Genoites. Other than vegetative remains ascribed to the morphotaxon Brachyphyllum, the most common species from Permian deposits of Australian Gondwana is Walkomiella australis. Species of both genera have small, triangular, appressed leaves, and almost all of the material is vegetative. However, some specimens of W. australis have swollen, bud-like tips that have been interpreted to be seed cones and pollen cones. Although the structure of these organs is unclear, they are not similar to conifer cones from other Late Permian sources. While most Palaeozoic conifers are characterized by compound ovulate cones sensu Florin, a small number has been described as having ovules borne individually on otherwise vegetative branches. The best known of the latter is Buriadia heterophylla from the Gondwana of India. Buriadia has bifid and multifid, as well as, simple leaves, and the inverted seeds have been described as occuring on sporophylls inserted in the normal phyllotactic helix. Based on that interpretation, Buriadia has been widely regarded as a model for ancestral conifer morphology in a transformational series leading to the compound seed cone. Such characters have also been offered as evidence for a close relationship between conifers and taxads. Recent reinvestigation of Buriadia reveals that no fertile attachments can be documented. Therefore, the fertile organs of Buriadia are still unknown, and the origins of conifers and taxads remain elusive. The recent dramatic increase in knowledge about Palaeozoic conifers reveals that the Permian species from Angara, Cathaysia, South American Gondwana, Australian Gondwana, and Indian Gondwana are all systematically distinct from one another and are distinct from the Permo-Carboniferous Euramerican conifers. Palaeogeographic reconstructions suggest that the conifer floras were geographically isolated during the Pennsylvanian and Permian, and lend support to the recognition of several late Palaeozoic floristic provinces. Serious questions now emerge about the presumed monophylly of conifers, because of (1) the absence of synapomorphies for a putative conifer clade and (2) the lack of resolution for a conifer clade in cladistic trees of coniferophytes. With the currently incomplete understanding of sister group relationships for conifers as a whole, and of relationships among the various fossil and modern conifer families, we must now question whether conifers represent a single clade with a common ancestor that was a conifer, or whether similar adaptations to water stress and wind pollination led to the parallel evolution of a conifer syndrome of characters in several ancestral clades.

IMPLICATIONS OF THE MOSASAURS (REPTILIA: SQUAMATA) FROM THE LATE CRETACEOUS OF AUSTRALIA James E. MARTIN1 & John A. LONG2, Museum of Geology, SD School of Mines and Technology, Rapid City, South Dakota 57701 USA; 2 Western Australian Museum, Perth, Western Australia 6000 Mosasaurs are extremely rare in Australia, but at least two types have been collected in the Late Cretaceous Molecap Greensand and Miria Formation in the Perth Basin of Western Australia. The Miria Fm. is Maastrichtian in age based upon ammonite correlations, and the poorly preserved mosasaurs provide no evidence for dissention. Overall, the invertebrates and vertebrates are most similar to those of the upper Lopez de Bertodano Formation of the Antarctic Peninnsula, suggesting that western Australia may have been part of the Weddellian Biogeographic Province during the Late Cretaceous. On the other hand, the age of the Molecap Greensand is less known, but does contain an unusual assemblage. The occurrence of both mosasaurs and ichthyosaurs is the only such occurrence in the world and has caused some authors to suggest that the ichthyosaur occurrence is the latest appearance of this group of Mesozoic reptiles. However, the mosasaur specimens occur higher in the section than the ichthyosaur, which occurs in a basal phosphatic lag. The mosasaurs indicate at least a Santonian age, but the ichthyosaur may be reworked or the conglomerate is a separate depositional package, separated in time and space from the upper portion of the formation.

LATE MIOCENE MOLLUSCS FROM SOUTHWESTERN ATLANTIC OCEAN: A BIOGEOGRAPHIC ANALYSIS S. MARTINEZ1 and C. J. DEL RIO2 1 Facultad de Ciencias. Igua 4225. (11400) Montevideo, Uruguay. 2Museo Argentine de Ciencias Naturales B. Rivadavia. Seccion Paleoinvertebrados. A. Gallardo 470 (1405) Buenos Aires, Argentina

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IPC2002 Poster Presentations Distribution and diversity patterns of genera and species of marine molluscs along the southwestern Atlantic littoral point to the existence of the Late Miocene Valdesian and Paranaian Provinces. The geographic range of these units is roughly equivalent to that of the Recent Argentinean Province, and both are characterized by the development of mainly paratropical warm-water faunas. The Valdesian Province includes assemblages recovered from the Puerto Madryn Formation and its southern limit is placed at 42°S, while the northern boundary with the Paranaian Province is situated approximately between 37°S and 39°S. The Paranaian Province includes assemblages contained into the Parana and Camacho Formations, and extends along the Uruguayan and Southern Brazilian littorals. Its northern boundary still remains unknown because coeval fossiliferous horizons are lacking to the north of Rio Grande do Sul. An incipient thermal gradient is recognized, being the temperature values for the Paranaian Province rather slightly higher than those for the Valdesian Province. Anyway -taking into account that in the latter one water temperature was in fact warm - it is concluded that the cold Malvinas (Falkland) Current was not completely developed or had only an incipient effect in the area by the Late Miocene. Geological data are consistent with those provided by molluscan faunas, indicating some impediment to the free circulation of the Antarctic Circumpolar Current. It is also suggested the presence of upwelling phenomena based on of the presence of widely distributed turitellids beds. Once it was developed after Late Miocene, the Recent Argentinean Province arose, being controlled by the confluence of the cold Malvinas (Falkland) Current with the warm Brazilian Current. This Recent unit is characterized by a typical "mixed" fauna and a extremely low persistence of typical "entrerriense" molluscs, leading to the conclusion that the former Valdesian and/or the Paranaian Provinces can not be considered immediate ancestors of the Argentinean Province, as it has been recently suggested by some authors. 60°

52°

BRAZIL lURUGUAY

Valdesian Province

EARLY CRETACEOUS SHESTAKOVO ASSEMBLAGE OF MAMMALIAN FOSSILS FROM WESTERN SIBERIA E.N. MASCHENKO1. A.V. VORONKEVICH2, S.V. LESHCHINSKIY2, A.V. FAYNGERTS2 1 Paleontological Institute Russian Academy of Sciences, Profsouyznaya Str. 123 Moscow, 117 995 Russia, [Evmash@paleo.ru]; 2Tomsk State University, Lenin Ave. 36 Tomsk, 634050 Russia The Shestakovo sites of the Early Cretaceous fossils of continental vertebrates, situated in the vicinity of the village of Shestakovo in the south-east of the West-Siberian plain (the Kiya river basin, Kemerovo Region), are among the most prominent Mesozoic localities in Russia. By now five sites with the vertebrate fauna assigned to the Ilek Formation (Valanginian-Aptian?) have been explored in the Kiya river basin, mammalian remains being discovered in two of them (Shestakovo-1 and Shestakovo-3). The major part of the palaeontological finds have been confined to weakly calcareous, loose, obliquely laminated, coarse-grained sands. They appear to be deltaic or, probably, channel deposits of river downstreams. Representatives of six

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IPC2002 Poster Presentations have been discovered and identified from The Shestakovo assemblage includes six vertebrate classes (about 20 genera and 26 species): palaeonisciform and sinamiid fishes, amphibians, "macrobaenid" turtles, lizards, protosuchian and shartegosuchid crocodiles, dinosaurs, pterosaurs, birds, trythilodontid and mammals. The earliest data on the mammals from the Shestakovo assemblage were obtained in 1995. Their remains are mostly represented by jaw fragments, isolated teeth, vertebrae and scarce fragments of limb bones. The Shestakovo mammalian assemblage includes 3 groups of Mesozoic mammals. The remains of amphilestid "triconodonts" (Gobiconodon and Amphilestinae gen. et sp. indet) are the most abundant (about 50 specimens). The remains of gobiconodonts have been discovered at the sites Shestakovo-1 and Shestakovo-3. The relative abundance of their remains suggests that these were the most numerous group of the Early Cretaceous mammals of the Shestakovo assemblage. Of the greatest interest are Gobiconodon hoburensis Trofimov, G. borissiaki Trofimov, Gobiconodon trofimovi sp. nov. and one form of Amphilestinae gen. et sp. indet. The latter ranks next to Gobiconodon in the number of finds. The presence of Amphilestidae in the Early Cretaceous of Siberia is not beyond the scope of the concept on the stratigraphical distribution of the group, i.e. Hauterivian-Barremian to Aptian-Albian of Eurasia and North America. The Shestakovo Amphilestidae are represented by different forms which are apt to occupy diverse ecological niches. They differ in their molars' dimensions, number and morphology, and represent a group of non-specialized carnivores. The dimension class of each Amphilestidae species were evidently determined by the dimensions of their potential prey. The finds of the second and third groups are represented by scarce fossils discovered at the Shestakovo-1 site (only a single fossil has so far been found at Shestakovo-3). The second group includes the finds of Peramura and Kiyatherium cardiodens Maschenko, Lopatin et Voronkevich, gen. st sp. nov. Previously the finds of the representatives of this group have only been reported from the Jurassic and Lower Cretaceous deposits of Europe and Africa. Peramura is the largest form of the Shestakovo mammals. It is characterized by the mosaic morphology of the upper molars and is a more primitive form than the most part of Peramuridae known so far by reason of the absence of a genuine metacone (which is replaced by cusp C). Kiyatherium cardiodens is supposed to be a more specialized carnivore than Gobiconodon; its dimensions suggest an ecological niche other than in all other mammals from the Shestakovo assemblage. The specialization of Kiyatherium cardiodens is supposed to have been determined not only by the size of a prey. The third mammalian group of the Shestakovo assemblage is represented by Docodonta possessing the specularly inverted "tribosphenic" structure of lower molars (pseudo-talonid is in front of "trigonid"). The remains of Docodonta have been found only within a single layer of the section of the Shestakovo escarpment (Shestakovo-1 site). This form bears a resemblance to the Late Jurassic Simpsonodon (England) and especially to Tegotherium from Mongolia. The Shestakovo Docodonta does not differ from Tegotherium in the structure of the last molar. The Shestakovo Docodonta, Tegotherium and Docodonta found recently from the Late Jurassic of Central Asia constitute a peculiar group of Asian Docodontae. The molars of the Shestakovo Docodonta have well-developed crests, a long pseudo-talonid, well-differentiated trigonid cusps and a well-expressed talonid analogue. Docodontida from the Shestakovo assemblage is comparable with the Late Jurassic Shuotherium (China) in the number of cheek teeth (three pre-molars and four molars). But it differs from the latter in some peculiarities of the molar morphology: well developed crests, better expressed pseudo-talonid, the considerable differentiation of main cusps and the presence of a small talonid analogue. The Shestakovo assemblage of mammals is dated by different authors from Berriasian to Aptian-Albian. The mammalian fauna of the Khoboor Locality (Mongolia) dated to Aptian-Albian, may be considered the most similar by the presence of analogous forms. Common to both localities are Amphilestids (Gobiconodon borissiaki, G. hoburensis) and Peramuridae (related to different groups). But there are some differences: one Amphilestinae form and Docodonta have been found in the Kiya basin that have not been established from the Late Cretaceous of Mongolia. Besides, Docodontidae (Tegotherium) is known from the Late Jurassic of Mongolia (Shar Teeg), but Multituberculata and Metatheria (Asioryctitheria) typical for Khoboor have not yet been established in the Shestakovo assemblage. The presence of Docodonta with pseudo-tribosphenic molars and of a trithilodontid Xenocretosuchus sibiricus is possibly indicative of a somewhat greater age of the Shestakovo mammalian assemblage in comparison with the Khoboor one, which fact is in agreement with the presence of crocodiles of the Late Jurassic aspect in Shestakovo-3. There are also some fauna elements in common with the Sheramine (Kuwaijima Formation) of Japan (?valanginian-hauterivian), where a tritilodont similar to Xenocretosuchus and Amphilestinae has been found. All these peculiarities may be accounted for by zoogeographical factors. One of such factors may be the presence of a refugium in the south of Western Siberia for the Jurassic relicts that had been extinct by the Early Cretaceous in other areas. The geological peculiarities of the Shestakovo region eliminate the possibility of the significant redeposition of the Jurassic sediments within the Ilek formation. It is very likely that to reliably, The presence of advanced vertebrate forms will most likely be the governing factor in estimating the age range of the Shestakovo assemblage. Along with Gobiconodon, Symmetrodonta has been recovered from coeval faunas of North America and Mongolia, the latter being missing in the Shestakovo assemblage. However, it is not improbable that further investigations will establish them. Most mammals of the Shestakovo assemblage are small-sized (even for the Mesozoic mammals). Data on the diversity of mammals in the Shestakovo assemblage prove the high rate

240

IPC2002 Poster Presentations of sructurization of the community and the peculiar environment within this palaeogeographical realm through the Early Cretaceous. The diversity of ecological niches occupied by Amphilestidae on the one hand, and Docodonta and Peramuridae, on the other, still leaves disputable the problem of the carnivorism rate in different mammalian forms. Since the potential ecological niches have not all been marked off by palaeontological finds (so far no small herbivore forms have been discovered), the future investigations in the Kiya river basin have much potential in contributing essentially to the diversity of the Shestakovo assemblage of the Mesozoic mammals which is the first of its kind in Russia. The work was supported by the Russian Foundation for Basic Research, projects 00-15-97754 and 010449548.

EARLY DEVONIAN (AND ?LATEST SILURIAN) CONODONT BIOSTRATIGRAPHY AND PALAEOECOLOGY, EASTERN FLANK OF THE DARLING BASIN, WESTERN NSW, AUSTRALIA David MATHIESON Centre for Ecostratigraphy and Paleobiology, Department of Earth and Planetary Science, Macquarie University, NSW2109, Australia The Cobar Supergroup is an elongate band of Silurian and Devonian rocks trending approximately NW-SE from Bourke in the north to Lake Cargelligo in the south consisting of a thickness of 5-10 km of deepwater marine sediments overlain by approximately 1 km of shallow marine sediments. Cobar Supergroup limestones are scattered and have been hypothesised as having been variously fringing reefs and carbonate shelf deposited on topographic highs (MacRae 1986). The only previous published work on conodonts from the region is from the Rookery and Mountain Tank limestones (both members of the Meryula Formation) and from the Boomerang Tank Limestone Member of the Baledmund Formation (Pickett, 1980) SE and E respectively of Cobar. Limestones from the Stoney Tank Formation (Sharp, 1992), in the Gunderbooka National Park, 70 km SW of Bourke, from the Booth Limestone Member of the Winduck Group on 'Manuka' station, 100 km south of Cobar, from the Mountain Dam Limestone on 'Marabee' station, 50 km SE of Nymagee, and from "Bluff' station, 50 km SW of Cobar, have all produced conodonts indicating a Lochkovian-early Pragian (Early Devonian) age. The colour alteration index (CAI) of the conodonts, like those from bores in the nearby Darling Basin (R. Mawson and J. Talent, pers. comm.), is considerably lower than conodonts of a similar age from the coeval limestones farther east, such as the Garra and Camelford limestones of the Molong High, indicating less thermal alteration. MACRAE,G.P.,

1986. Geology of the Lachlan Downs 100,000 sheet 8033. New South Wales Geological Survey, Sydney.

PICKETT, J.W., 1980. Conodont assemblages from the Cobar Supergroup (Early Devonian), New South Wales. Alcheringa, 4: 67-88.

T., 1992. Mapping of the Devonian sequence at Mt Gunderbooka north of Cobar with emphasis on stratigraphy and sedimentology, 81 pp. B. App. Sci. dissertation. University of Technology Sydney.

SHARP,

MIDDLE PALAEOZOIC CONODONT FAUNAL ANALYSIS OF THE NORTH GONDWANA AND ADJACENT CONTINENTAL MARGINS: INITIAL RESULTS Ruth MAWSON1, Andrew SIMPSON2, John TALENT1 & Terry FUREY-GREIG Macquarie University Centre for Ecostratigraphy and Paleobiology, Department of Earth and Planetary Sciences, Macquarie University 2109, Australia; 2Division of Environmental and Life Sciences, Macquarie University 2109, Australia Quantitative evaluation of conodont data documented from the broad region covered by IGCP Project 421 North Gondwana mid-Palaeozoic bioevent/biogeography patterns in relation to crustal dynamics is being undertaken as essential background for biogeographic analysis. The area of focus is the North Gondwana mid-Palaeozoic continental shelf and supposed former North Gondwana crustal blocks—extending from northern South America/Central America and northern Africa through southern Europe (Spain to Turkey), Armenia and Azerbaijan, south and south-central Asia (including the crustal blocks of the South Tyan' Shan and Pamir), south-eastern Asia (including South China and various crustal blocks in Xinjiang and Xizang), to New Zealand. The region includes the rump continental blocks from which the above crustal blocks were (or may have been) calved, namely Australia, India, Africa and South America. The time interval for the initial focus of the project is End-Ordovician to Middle Devonian.

241

IPC2002 Poster Presentations The basis of any serious biogeographic analyses is the accuracy of the age of faunas being compared. For the time interval under consideration, conodont ages are globally accepted as the standard for dating. All published conodont faunas from Late Ordovician through to the Middle Devonian (a 60 million year timeslice) will be evaluated in the same way that brachiopod data from the Asia-Australia hemisphere are been analysed (Yolkin et al., 2000; Talent et al., 2001). Initial comparisons of Silurian faunas from mid-western New South Wales and the Guizhou Province in China during compilation of the database indicate the existence of a Sino-Australian biogeographic province during the Early Silurian. This is undoubtedly a temporal extension of the Late Ordovician biogeographic province previously recognised by Nowlan et al. (1997). Distribution of Early Devonian conodonts indicates either former close juxtaposition of terranes in Australia, Tajikistan, Uzbekistan and Arctic North America, or of circulation patterns facilitating migration between these blocks (Mawson et al., 2002). By the late Emsian, ties further developed extending from E Australia and Tajikistan through other regions on or close to the northern margin of Gondwana including Spain and South China as well as central Nevada, the Klamath Mountains, western North America and Baltica, and in the Frankenwald of Germany. Later in the Emsian, conodont faunas from La Grange, NW France, are extremely close to those from eastern Australia; this accords with the view, based on macrofaunas (predominantly brachiopods) that this region was indeed part of the northern margin of Gondwana during Emsian times. MAWSON, R., TALENT, J. A. & SIMPSON, A. J., 2002. Conodonts. In: The Geology of Victoria, 3

Society of Australia (in press).

edition. Victorian Division, Geological

NOWLAN, G.S., MCCRACKEN, A.D. & MCLEOD, M.J. 1997. Tectonic and paleogeographic significance of Late Ordovician conodonts in the Canadian Appalachians. Canadian Journal of Earth Sciences 34: 1521-1537. TALENT, J.A., GRATSIANOVA, R.T. & YOLKIN, E.A., 2001. Latest Silurian (Pridoli) to Middle Devonian of the Asia-Australia

hemisphere: rationalization of brachiopod taxa and faunal lists; correlation charts. Courier Forschungsinstitut Senckenberg, 236: 221 pp.

YOLKIN, E.A., YOLKINA, V.N., TALENT, J.A., GRATSIANOVA, R.T., KIPRIYANOVA, T.P., & KIPRIYANOV, A.A., 2000. Brachiopod

biogeography of the Asia-Australia hemisphere during Pragian (Early Devonian) times. Records of the Western Australian Museum Supplement 58: 349-384.

CORRELATION OF THE LOWER-MIDDLE CAMBRIAN BOUNDARY INTERVAL IN THE CIRCUM-PACIFIC REGION BASED ON ORYCTOCEPHALID TRILOBITES Linda B. MCCOLLUM, and Frederick A. SUNDBERG, Geology Department, Eastern Washington University, Cheney, WA 99004 USA; [lmccollum@mail.ewu.edu]; and Las Animas High School, 300 Grove Ave., Las Animas, Colorado, 81054 USA; [fred.sundberg@lasanimas. kl 2. co. us]. Oryctocephalid trilobites first appear in the Lower Cambrian and become extinct just prior to the Middle Cambrian Ptychagnostus atavus Zone. They appear to have evolved rapidly, and are found in many of the open marine lithofacies globally. A study of the oryctocephalids within the Lower-Middle Cambrian boundary interval in the circum-Pacific region has identified cosmopolitan species; however, a comprehensive study of this trilobite group will be needed to assess their utility for international correlation. One oryctocephalid species which had originally been described in India, Oryctocephalus indicus (Reed, 1910), was recognized by Jell and Hughes (1997) as also occurring in China and Korea, and by Sundberg and McCollum (1997) as occurring in collections from the western United States. This led to a detailed correlation by Sundberg, Yuan, McCollum, and Zhao (1999) of the Lower-Middle Cambrian boundary interval of South China and the western United States, and to a suggestion by Peng and Robison (2000) that the FAD of O. indicus might serve as an international series boundary. Zhao, Yuan, McCollum, Sundberg, Yang, Guo, Zhu, and Yang (2001) proposed two candidate GSSP sections, one in Guizhou Province, South China and the other in Esmeralda County, Nevada, USA. The problem is that O. indicus does not have a worldwide distribution, and therefore, international correlation depends on associated trilobite species. We (Sundberg and McCollum, in review) have recognized Oryctocephalites runcinatus Shergold, 1969, an Australian species, and Oryctocephalus orientalis Saito, 1934, a Korean species, immediately below the FAD of O. indicus in the western United States. The next step is to reevaluate the oryctocephalid faunas from Russia, to see if there are any species in common with the circum-Pacific region. JELL, P.A. and HUGHES, N.C., 1997. Himalayan Cambrian trilobites. Special Papers in Palaeontology, 58, 113 p. PENG, S. and ROBISON, R.A., 2000. Agnostid biostratigraphy across the Middle-Upper Cambrian boundary in Hunan, China.

Paleontological Society Memoir 53, 103 p.

242

IPC2002 Poster Presentations SUNDBERG, F.A. and MCCOLLUM, L.B., 1997. Oryctocephalids from the Lower-Middle Cambrian boundary interval from California

and Nevada. Journal of Paleontology, 71, 1065-1090.

SUNDBERG, F.A. and MCCOLLUM, L.B., in review. Early and Middle Cambrian trilobites from the outer shelf deposits in Nevada and

California, USA. Submitted to Palaeontology.

SUNDBERG, F.A., MCCOLLUM, L.B., YUAN, J., and ZHAO, Y., 1999. Correlation of the Lower-Middle Cambrian boundary of South

China and western United States of America. Acta Palaeontologica Sinica,. 38, 102-107.

ZHAO, Y.L., YUAN, J.L., MCCOLLUM, L.B., SUNDBERG, F.A., YANG, R.D., Gui, Q. J., ZHU, L. J., and YANG, X.L., 2001. A potential

GSSP for the Lower and Middle Cambrian boundary near Balang village, Taijiang County, Guizhou province, China. Acta Palaeontological Sinica, 40, supp., pp. 130-142.

ORDOVICIAN FOSSILS OF MONGOLIA Ch. MINJIN & J. UNDARYA Mongolian University of Science and Technology [minjin@mtu.edu.mn] During the last 30 to 40 years, geological mapping and biostratigraphic investigations have resulted in many discoveries of Ordivician fossiliferous sections and localities in Mongolia. Stratigraphic positions and distributions of the fossil occurrences are shown in the table and locality map below. Ordovician correlation table for main fossil groups -o= $2f <3 -C £ 03

Hovd zone

Gobi altai-Sukhbaatar zone West East

South (3.4.5.6)

North (1.2)

Cyrtophyllids Tabulates HelioUtids Rugosans Brachiopods Bryozoans Stromatoporoids Trilobites Ostracods Gastropods

Bryozoans Brachiopods Stromatoporoids Sponges Rugosans Gastropods Graptolites

Cyrtophyllids,Tabulates Heliolitids, Rugosans, Brachiopods,Bryozoans, Trilobites,Bivalves, Crinoids

Brachiopods Bryozoans Trilobites Rugosans Gastropods

Bivalves Brachiopods Crinoids

Tabulates Crinoids Rugosans

Brachiopods Bryozoans Rugosans

East (15)

Tabulates Heliolitids Rugosans Brachiopods Bryozoans Gastropods Trilobites Conodonts Ostracods Cephalopods Tabulates Tabulates Bryozoans Heliolitids Brachiopods Brachiopods Crinoids Stromatoporoids Crinoids

Bryozoans Brachiopods Trilobites Crinoids

L o c a l i t i e s a n d s t c t i o n s of O r d o v i c i a n f o s s i l s i n M o n g o l i a

_ _J * T I n \

Bracliiopods

(Arenigian) (Upper)

Bayanhongor zone (16)

Gobitaynshan zone West (14)

(7.8.9.10) (11.12.13)

Graptolites Graptolites

Central Mongolia

Sourth Mongolia

(Ashgillian)

Mongolian Altai

(Caradocian)

Darriwilian

vazone

soon

Y\A • ^

\ G

M o n

S o > " an •

y s i r

- ^ r ^ S/ s •to! O l^J-^iL y

Localites and sections: 1 Uureg nuur 2. Achit nuur 3 Khoit Tsenher

4. BocJgon 7. Gichgen® 10.Mushgai 13 ShovdolOvoo 5. KhaShinga 8. UlaanKhan 11. Under Shil 14. BaruunTsohoo 6. Tonhol 9 ShineJinst 12. Altan Shirw 15.Tavan Khar 16.Tsagaandel

243

IPC2002 Poster Presentations SILURIAN SEDIMENTARY ROCKS AND FOSSILS OF MONGOLIA Ch. MINJIN Mongolian University of Science and Technology [minjin@mtu.edu.mnj Fossiliferous Silurian successions are distributed across a number of fold zones in Mongolia, including the Altai, Hovd, Lake-Northgovi, Kharkhira, Govialtai-Sukhbaatar, and Bayankhongor-Northeastern Mongolian zones. The sedimentary rocks of these folded zones may be subdivided into four main representative types. The first type occurs in the Altai and Lake-Northgovi zone, where the successions are represented by red and white conglomerate, quartzose sandstone, variegated shale, with associated faunas including brachiopods, bryozoans, crinoid stems, rare gastropods, bivalves, cephalopods, and fish-teeth. In some sections argillaceous limestones are also developed which contain rich upper Llandoverian tabulate and rugose corals, stromatoporoids, brachiopods, crinoid stems, rare trilobites, cephalopods, and gastropods. The succession in the Lake zone includes some andesitic and basaltic volcanics. The second type is represented in the Hovd zone, within an island-arc setting. They include very thick black and green shales, sandstones, white reef-limestones, and basaltic pillow lavas. The black shale contains Llandoverian, Wenlockian and Ludlovian graptolites and rare lingulides. The reef-limestone has yielded poorly preserved fossils, mostly crinoid stems and very rare Llandoverian corals; and also a few Ludlovian brachiopods. The third type is developed in the Kharkhira, and the Govialtai-Sukhbaatar zones. Here Silurian sequences include very thick terrigenous and terrigenous-carbonate sediments which formed within Pacifictype continental margins and back-arc basins. In the Kharkhira zone these sediments comprise thick green, gray sandstone and shale, which contains very rare fossils, such as bryozoans and crinoids, which indicate a Llandovery-Wenlockian age. In Southern Mongolia, the Govialtai-Sukhbaatar zone exhibits more continuous Silurian sections, from mid-Llandoverian to Pridolian age. In this zone, thick terrigenous sediments are dominant, with green shale, sandstone, in places turbidites and carbonate sediments. These latter are interbedded mudstones with biohermal limestones, reefs and open-shelf facies. In the terrigenous rocks fossils are rare, only poorly preserved brachiopods and crinoids. Carbonate facies in this area contains a diverse shallow-water fauna dominated by Llandoverian-Wenlockian corals (tabulates, heliolitids, rugosans), stromatoporoids, brachiopods, crinoids, rare trilobites, gastropods, bivalves and conodonts. In the reef facies there are many, poorly preserved crinoid stems and other debris. These reefs only exhibit abundant and well preserved Llandoverian-Wenlockian corals in a few places. The fourth characteristic type is exhibited in the Bayankhongor zone and North-eastern Mongolia. In this region, Silurian sequences are represented by thick green and gray shales and sandstones with brachiopods (the Tuvaella fauna), bryozoans, crinoids, rare gastropods, bivalves, and trilobites. Here the carbonate facies is poorly developed. Near the town of Bayankhongor Llandoverian-Wenlockian graptolites have also been discovered. Studies of Silurian fossils of Mongolia are presently limited to some brachiopods, tabulates, bryozoans, rugoses, and stromatoporoids. In the brachiopods assemblages of Mongolia the Tuvaella fauna has been established, which is very specific to the Central Asian region. BRACHIOPOD FAUNA AND REDEPOSITION OF SHELF LIMESTONES AMONG DEEP-SEA FACIES OF THE EASTERN SLOPE OF THE SOUTH URALS A.G. MIZENS & G.A. MIZENS Institute of Geology and Geochemistry UrB RAS, Pochtovyi pereulok, 7, Ekaterinburg, 620151, Russia; [mizens@igg. uran. ru/. In the southern Urals, Upper Devonian flysch and cherty-argillaceous intervals are widespread. On the eastern slope these deposits are represented by the volcano-sedimentary Ulutau Formation (D g-D f), the Mukasovo Formation consisting of cherty turbidite interbeds (D f _ ) and flyschoid Zilair Formation (D fm). The Ulutau formation is about 2000 m in thickness, the Mukasovo from 30-50 m in the south to 700 m in the north and the Zilair more than 2000 m. The lower part of Zilair Formation has thick rudaceous complexes: olistostromes and debris-flow deposits. Among these deposits, the Koltuban Formation is most distinct south of the Magnitogorsk Megazone. Its calcareous conglomerates contain reef limestone blocks about a hundred metres in length; these usually contain upper Frasnian brachiopods. Many geologists suggest they are in situ reefs, but this is contradicted by the deep-water nature of the enclosing deposits. The relationship of these limestone bodies to the underlying Mukasovo Cherts testifies to displacement of the blocks. Large limestone bodies are always associated with conglomerates, the pebbles of which are limestones, volcanic rocks, and outliers of Mukasovo Cherts, sometimes 10-20 m thick. 2

3 2

244

IPC2002 Poster Presentations Brachiopods and conodonts were studied in order to obtain information about the nature of limestones. We have chosen sections where relationship of the limestone bodies to the cherts is most varied. Typical of these is the basin of the Malaya Urtazymka River, a right tributary of the Ural river. In this area the conglomerate thickness reaches 100 m, and limestone bodies may be up to 70 m or more. Conglomerates cut down into the cherty formation to different depths. In some the cherts (to 30 m thick and more) have been completely removed. The brachiopod study has demonstrated at least two age-intervals. One limestone group (large blocks and boulders situated in sections both below and over the cherts) contain Aulacellal sp., Schizophoria sp., Gypidula ex gr. biplicata (Schnur), G. cf. biplicatiformis Mark., G. ex gr. brevirostris (Phill.), Devonogypa! ex gr. globa (Bronn), Productellal sp., Hypothyridina crassicostata Nal., H. cf. cuboides (Sow.), H. cf. incisiva (Roem.), Pseudoatrypa posturalica (Mark.), Desquamatia sp., Spinatrypina bifurcata (Mark.), Iowatrypa ex gr. kadzielniae (Gur.), Iowatrypa? sp., Carinatina! biohermica Yud., Adolfia zickzack (Roem.), Warrenella cf. koltubanica (Nal.), Emanuella subumbona (Hall), Conispiriferl cf. conoideus (Roem.), Cyrtospirifer sp., and Pyramidalia simplex (Phill.). This association is typical of the Askyn horizon of the upper Frasnian. The second group contains Schizophoria sp., Praewaagenoconcha! sp., Spinulicostal sp., Hypothyridina cf. crassicostata Nal., Parapugnaxl sp., Pugnoides triaequalis Mark., Eoparaphorhynchus? lentiformis (Nal.), Phlogoiderhynchus ex gr.formosa (Schnur), Spinatrypina? sp., Gibberosatrypa gibberosa (Mark.), Adolfia zickzack (Roem.), Undispiriferl sp., Cyrtospirifer tschernyshewi Khalf., Cyrtospirifer sp., Athyris angelica Hall, Ath. bayeti Rig., Ath. concentrica Buch, and Ath. ex gr. globularis Phill., which are characteristic of the Barma Beds of the western slope of the Urals (Frasnian/Famennian boundary deposits). All associations represent shallow reef communities. The age of the Mukasovo cherty rocks in the Malaya Urtazymka river basin and adjacent regions corresponds to the Domanik, Mendym, and most of the Askyn horizons (punctata, hassi, jamieae, rhenana conodont zones according to O. Artyushkova and V. Maslov). The data obtained shows that the calcareous block conglomerates are younger than the Mukasovo deposits despite their relationship to the chert sequence. Facial and palaeontological research indicates that the limestones of the Koltuban Formation have been re-worked. They are blocks and olistostromes of shallow reef limestone moved into the deep-sea zone of sedimentation. Among them are limestones of the different ages. Askyn limestones are predominant. It is apparent that during Askyn times the South Urals region was very favorable for reef development. However at the beginning of Famennian these were destroyed and redeposited downslope, possibly connected with a global lowering in level of the World Ocean. This work was funded by a young scientist grant of the UrB RAS and by grant 02-05-64479 from the Russian Foundation for Basic Research.

MORPHOLOGICAL VARIATION IN THE PA ELEMENT OF PTEROSPATHODUS FROM THE EARLY SILURIAN OF BOREE CREEK, NSW Peter MOLLOY & Andrew SIMPSON Macquarie University Centre for Ecostratigraphy and Paleobiology, Sciences, Macquarie University 2109.

Department of Earth and Planetary

Pa elements of the Silurian conodont genus Pterospathodus have been recovered from the Boree Creek Formation in mid-western New South Wales, Australia. Species of this genus define Early Silurian conodont zones, so detailed scrutiny, particularly of Pa elements is required. Three distinct lineages can be recognised. A small percentage of these elements show development of elaborate structures on the platform that have not been documented from contemporaneous collections of the genus elsewhere, although a small number of similar structures have been previously illustrated. Three forms have also been documented recently from a subsurface sample in the Cadia region (Rickards et al, 2001), but numbers are small and no unconventional morphologies were recorded. For the purposes of this study the three forms are considered separate species: Pterospathodus procerus is typically characterised by a relatively straight blade, relatively narrow, flat platform and a single outer lateral process. Variations on this morphology include development of an extended platform on the inner side adjacent to the cusp, development of a short inner lateral process and an occasional bifurcation in the anterior process or the outer lateral process. Pterospathodus amorphognathoides (sensu nov.) is characterised by a relatively straight blade and a relatively broad, flat platform. Variations on this morphology include development of an extended platform lobe along the inner posterior margin, development of an inner postero-lateral process and bifurcating outer postero-lateral process. Pterospathodus rhodesi is characterised by a strongly curved anterior process and a broad platform with enrolled margins, ariations on this morphology include a pennate or bifurcated outer lateral process (noted by

245

IPC2002 Poster Presentations Mannik & Aldridge 1989), development of a short inner lateral process and reversal in the direction of curvature in the anterior process. All the above variations effectively increase surface area of the platform. Corradini et al (1995) speculated that a greater number of pathological morphologies would develop during Secundo episodes of high planktic productivity. Because of the similar nature of these variations across species, we are disinclined to support this interpretation. They may represent ecophenotypic variation, or expression of a range of possible morphologies that are not expressed under normal conditions. Larger collections, study of ultrastructure, and greater understanding of functional morphology and their distribution through time are needed to allow conclusive interpretations. CORRADINI, C., OLIVIERI, R. & SERPAGLI, E. 1995. Possible relationships between anomalous conodonts and Silurian oceanic episodes. Neues Jahrbuch fur Geologie und Palaontologie Mh. H 12: 737-746. MANNIK, P. & ALDRIDGE, R.J., 1989. Evolution, taxonomy and relationships of the Silurian conodont Pterospathodus. Palaeontology 32: 8 9 3 - 9 0 6 .

RICKARDS, R.B., PERCIVAL, I.G., SIMPSON, A.J., & WRIGHT, A.J. 2001. Silurian biostratigraphy of the Cadia area, south of Orange, New South Wales. Proceedings of the Linnean Society of New South Wales 123: 173-191.

PALYNOLOGICAL ATLAS FOR THE SADC REGION OF SOUTHERN AFRICA Emma MSAKY Tanzania Petroleum Development Corporation, P.O.Box 5233, Dar Es Salaam, Tanzania Outcrops and exploration well samples from Karoo through Tertiary were collected from six Southern African Development Community (SADC) countries. These include Malawi, Lesotho, Swaziland, Tanzania, Zimbabwe and Mozambique. The samples were palynologically analyzed using standard palynological techniques. The main objectives of the analysis were to study the palynomorphs, determine the age of the sediments and use the well preserved specimens to prepare a palynological Atlas for the region. Materials from Tanzania, Zimbabwe and Mozambique have been presented in Volume 2, (part I) of the Atlas. In this Volume, some biostratigraphically significant sporomorphs and dinocyst species found in the sedimentary rocks of the SADC region ranging in age from late Permian to Tertiary are illustrated. Materials from Malawi, Lesotho, and Swaziland are still under study; and will be presented in Volume 2, (part II) of the Palynological Atlas for the region when the study is complete. Volume I of the Atlas presents the study of microfauna in the region. Karoo sediment samples from Tanzania were dated as late Permian to early Jurassic and those from Zimbabwe as late Permian to early Triassic. Comparison was not possible for the Jurassic system as available samples were from Tanzania only. Cretaceous sediment samples were collected from both Tanzania and Mozambique. This study revealed that the Cretaceous sedimentary sequence of Tanzania bears a remarkable resemblance to that of Mozambique. A slight difference was documented in in the Neocomian where Cribroperidinium cornutum, Phoberocysta neocomica and Cribroperidinium asarotum were recorded from Mozambique sediments only. Furthermore , in the Tertiary, palynomorphs documented from the Tanzania samples differ to those of Mozambique except for the early Eocene. The early Eocene sequence for both countries is marked by the presence of the dinocyst species Apectodinium homomorphum and Cordosphaeridium fibrospinosum. This work will be useful for the region on persisting the growth of knowledge in biostratigraphy as applied to hydrocarbon exploration. It will also be used as a practical guide for geologists, academicians, commercial micropalaeontologists and palynologists who work in the region.

THE LUNDGRENI(WENLOCK, SILURIAN) GRAPTOLOID EXTINCTION EVENT IN THE WELSH BORDERLAND, UK Lucy MUIR Department of Geology and Geophysics, University of Edinburgh, Grant Institute, West Mains Road, Edinburgh, EH9 3JW, UK [Lucy.Muir@glg.ed.ac.uk] The extinction event at the end of the lundgreni biozone was one of the most severe that affected graptoloids during the Silurian. One hypothesis for the cause of the event is the spread of anoxia in the oceans. If this was the cause, at least some sections across the event should show a change from an oxic to an anoxic environment at the time of the extinction.

246

IPC2002 Poster Presentations The section along Trewern Brook (Long Mountain Inlier, Welsh Borderland) shows a change from an anoxic to an oxic environment at the time of the extinction, based upon the appearance of burrows and a benthic fauna. This finding does not support the hypothesis that the spread of anoxia was responsible for the extinction. Comparison with other sections across the extinction event will reveal whether or not this pattern is seen globally. STABLE ISOTOPE VARIATION IN THE JURASSIC ALGA SOLENOPORELLA JURASSICA FROM ENGLAND Xinan MU & Robert RIDING laboratory ofPaleobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy ofSciences, Nanjing, China; Earth Sciences Department, Cardiff University, Cardiff, U.K. 1

Solenoporaceans are an extinct group ranging Early Palaeozoic to Mid-Cenozoic. They reached their maximum distribution and diversity in the Mesozoic and were of particular importance in the Jurassic, occurring abundantly in many regions and being locally important reef builders. The group is heterogeneous, but includes forms that appear related to coralline algae, an important extant group of rhodophytes (red algae). Well-preserved Solenoporella jurassica from the Jurassic of Europe shows a distinct banded stucture of alternate wide pink bands and narrow white bands. These have been interpreted as seasonal growth banding, the pink bands forming in summer and the white bands in winter (Wright, 1985). A well-preserved specimen of Solenoporella jurassica with distinct growth bands from the Jurassic of England was examined for oxygen and carbon stable isotope variation. The results reveal distinct cyclic patterns for both 5 0 and 8 C values transecting the growth bands. The 5 0 values range 3.14 - 2.15 %o and those of 8 C range 1.38 - 2.01 %o. These variations are well-correlated. However, the variation in 5 0 contrasts with predicted values: the 5 0 minima, which should represent higher temperatures in summer, occur in white 'winter' bands and the maxima representing lower temperatures are from pink 'summer' bands. This unexpected pattern of 5 0 is tentatively interpreted as a result of combined vital effect and diagenesis in the algal skeleton. 18

WRIGHT, V.P., 1985, Seasonal banding in the algae Solenopora jurassica from the Middle Jurassic of Gloucestershire, England. Journal

of Palaeontology 59, 721 -732.

LATE WENLOCK GRAPTOLITES FROM NEAR ORANGE, NEW SOUTH WALES Lucy MUIR Department of Geology and Geophysics, University ofEdinburgh, Grant Institute, West Mains Road, Edinburgh, EH9 3JW, UK[Lucy.Muir@glg.ed.ac.uk] The extinction event at the end of the lundgreni biozone (Wenlock, Silurian) was extremely severe for graptoloids. Australia appears to have been a refugium for some graptoloids; certain taxa, for example Monograptus testis, persist after the lundgreni event in Australia but went extinct elsewhere (Rickards & Wright 2001). Therefore studies of Australian graptolites are useful for elucidating the anatomy of this event. Assemblages of graptolites from sections at One Tree Hill and Wallace Creek are described. The Wallace Creek specimens come from the lundgreni zone. A possible faecal pellet made up of individuals of Monograptus testis was found at one locality. Most of the One Tree Hill specimens come from the praedeubeli-deubeli zone, following the lundgrenitestis zone. They include large retiolitids (four millimetres rhabdosome width) and Monograptus insperatus. This is the first record of Monograptus insperatus from New South Wales and the second outside central Asia. This has implications for graptoloid biogeography after the lundgreni event, implying a faunal connection between central Asia and Australia at this time. RICKARDS, R.B. & WRIGHT, A.J., 2001. Lazarus taxa, refugia and relic faunas: evidence from graptolites. Journal of the Geological

Society, London, 159, 1-4.

247

IPC2002 Poster Presentations ACRITARCH AND PRASINOPHYTE ALGAL BIOSTRATIGRAPHY OF THE TYPE LUDLOW SERIES, SILURIAN Gary L. MULLINS, Ruth E. RICHARDS, Richard J. ALDRIDGE and David J. SIVETER Department of Geology, University of Leicester, University Road, Leicester LEI 7RH, United Kingdom The type area for the Ludlow Series (Silurian) is located near the town of Ludlow, England. High resolution sampling at 1 m intervals, with closer spacing across formation and series boundaries, has been undertaken. Two biostratigraphical schemes, based on the acritarchs and prasinophyte algae (microphytoplankton), have been defined. Seven biozones have been recognized. Four biozones are based on the first appearance of the acritarchs Ammonidium ludloviense, Gorgonisphaeridiuml listeri listeria Leoniella vilis and Triangulina sanpetrensis. Three biozones are based on the first appearance of prasinophyte algae Glyptosphaera helterskelter, Cymatiosphaera mortimerensis and a taxon yet to be named. Work in progress on samples from the middle and upper parts of the Ludlow Series of the type area will further enhance these biostratigraphical schemes. Our high resolution study provides a firm basis for accurate comparison of sections elsewhere with the Ludlow type area. Our data also enable palaeoenvironmental fluctuations to be determined at a much finer scale than previously possible and allow the testing of evolutionary and climatic models.

PALAEOGEOGRAPHIC SIGNIFICANCE OF THE LATE CENOZOIC BIVALVE FORTIPECTEN TAKAHASHII (YOKOY KMX) IN THE NORTHWESTERN PACIFIC Rei NAKASHIMA JSPS Research Fellow, Geological Survey of Japan, 1-1-1 Higashi, Tsukuba, 305-8567, Japan The molluscan genus Fortipecten Yabe and Hatai (1940) is one of the best-known extinct Cenozoic fossils of the northern Pacific because of its heavy and peculiar bowl-like right valve. The type species, F. takahashii (Yokoyama, 1930), was first described from the Pliocene Maruyama Formation in southern Sakhalin; it has been reported from northern Japan, Sakhalin, and Kamchatka. I have collected Fortipecten species from the uppermost Miocene to lower Pleistocene strata in Hokkaido, and estimated the geological age of Fortipectenbearing horizons using diatom biostratigraphy. I have also re-examined the distribution of F. takahashii, F. kenyoshiensis and F. hallae, and the geological ages of Fortipecten-bearing strata in the northwestern Pacific. Fossil occurrences indicate that Fortipecten species lived in Hokkaido from about 7.0 to 1.2 Ma. The geologic occurrences and age of Fortipecten in the NW Pacific imply that the geographic history of the species was strongly influenced by climatic fluctuations. The latest Miocene (6-5 Ma) migration from central Hokkaido southward to N Hoshu was associated with global cooling. In contrast, the early Pliocene (4 Ma) climate was warmer than today's climate, so the northward expansion of Fortipecten to Kamchatka was evidently related to a highstand and warm-water extending into this region. Contraction of the distribution during the latest Pliocene (3-2 Ma) was associated with frequent cooling induced by glacial events. Frequent climatic fluctuations in the latest Pliocene to early Pleistocene made the distribution of Fortipecten increasingly restricted. Fortipecten takahashii ultimately became extinct at about 1.2 Ma during extreme cooling characterized by inflows of abundant Subarctic taxa around Hokkaido. The origins of Pliocene Fortipecten have not yet been determined, but the ancestral form of the Pliocene Fortipecten is thought to have originated in the Boreal north Pacific and to have migrated southward to around Hokkaido in the latest Miocene. Four species of Astarte occur with F. takahashii in three horizons on Hokkaido. The lowest horizon (about 6-5 Ma) in the Atsuga Formation is considered to correlate with Astarte-bearing horizon (5.5-5.4 Ma) in the Milky River Formation in SW Alaska; the latter are temporally connected the initial opening of Bering Strait.

CORALLINE BIOSTRATIGRAPHY OF THE LOWER CARBONIFEROUS MOBARAK FORMATION IN SHAHAMIRZAD, NORTH IRAN Isao NIIKAWA Department of Geology, Faculty of Science, Niigata University, 8050 Igarashi Ninocho, Niigata, 950-2181, Japan

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IPC2002 Poster Presentations The Palaeozoic deposits of Shahamirzad in northern Semnan, SE Elburz Mountains, northern Iran, consist of the Cambro-Ordovician Mila Formation, the Devonian-Carboniferous Geirud and Mobarak Formations—the latter disconformably overlying the Geirud Formation, and being overlain unconformably with a basal conglomerate by the Permian Dorud Formation. Numerous coral occurrences occur within the Mobarak Formation. This unit has been subdivided into ten intervals (locally referred to as "beds") numbered A to J in ascending order. Carboniferous corals previously described from the Elburz (Flugel, 1963, 1993) were regarded as upper Visean because of the presence of Kueichouphyllum. However, the geological context and stratigraphy were not probed in detail, the fauna produced the Tournaisian corals Shiphonophyllia and Kyseringophyllum and, moreover, Kueichouphyllum have been documented from the upper Tournaisian in nearby Armenia by Papojan(1969) and reported from the upper Tournaisian elsewhere (Niikawa, 1994). Rugose corals from the Mobarak Formation consist of 8 genera and 12 species: Zaphrentites sp. A, Zaphrentites sp. B, Kueichouphyllum laosense Fontaine, K sinense Yu, Shiphonophyllia cylindrica Scouler in Griffith, S. sp. A, S. sp., Cyathoclisia sp., Amygdalophyllum n.sp., Uralinia sp., Caninia cornucopiae Michelin in Gervais, Campophyllum n. sp and one unknown genus and species. Tabulates consist of two genera: Cleistopora sp. and Syringopora sp. On the basis of these corals, "Beds" A and B are regarded as lowest Tournaisian, Tnlb to Tn2c. "Beds" C to H Beds are equated with Tn3a, and "beds" I and J are regarded as correlating with Tn3b to probably earliest Visean, Via. The entire Mobarak Formation is accordingly regarded as Tournasian or, in other words, Courceyan to Chadian in the Dinantian.

THE KOPPA'S POOL LOCAL FAUNA, AN EARLY PLIOCENE FOSSIL VERTEBRATE ASSEMBLAGE FROM THE WELLINGTON CAVES COMPLEX, AUSTRALIA David A. NIPPERESS Department of Biological Sciences, Macquarie University, NSW, 2109 [dnippere@rna.bio.mq.edu.au] The graded-bedded unit of the Phosphate Mine Beds, Wellington Caves, NSW, is a well-cemented, graded osseous sandstone interbedded with thin mud horizons. The 'sand' fraction of this unit is primarily composed of small (< 2 mm) bone fragments. Current stratigraphic interpretations of the Wellington Caves complex indicate the graded-bedded unit is the oldest fossil-bearing sediment from the system (Osborne, 1997). Stratigraphic mapping of a c. 1.4 m thick exposure of this deposit has revealed at least 16 depositional events, each delineated by a thin mud horizon. Bone fragments have been recovered by acetic acid dissolution from several of these subunits. The fauna includes murids, burramyids and peramelids and is interpreted as an early Pliocene assemblage based on biocorrelation. U/Th/He dating of an enamel fragment from a murid rodent indicated an age of ~ 0.3 Ma. The discrepancy between the radiometric and biochronological dates is attributed to diagenetic alteration of the tooth. The strongly size-sorted and fragmentary fossil material of the graded-bedded unit is considered to have been accumulated by a combination of predator activity and water transport. It seems likely that the deposit has been at least partially accumulated by a species of Ghost Bat {Macroderma: Megadermatidae). Evidence for reworking of the bone fragments within the deposit, and the close similarity of the 'faunules' of the subunits to one another, indicates that the fauna should be treated as a single palaeoecological and biochronological unit. As this fauna is stratigraphically distinct from the otherwise very similar Big Sink Local Fauna, it should be regarded with the status of a 'local fauna' (Tedford, 1970), herein dubbed "Koppa's Pool Local Fauna". O S B O R N E , R. A . L . , 1 9 9 7 . Rehabilitation of the Wellington Caves Phosphate Mine: Implications for Cainozoic Stratigraphy. Proceedings

of the Linnean Society of New South Wales 117, 175-180. TEDFORD, R. H. 1970. Principles and practices of mammalian geochronology in North America, pp. 666-703. In Yochelson, E. L. (ed.),

Proceedings of the North American Paleontological Convention, Field Museum of Natural History, Chicago, 5-7 Sept 1969; Allen Press, Chicago.

PLIOCENE CHEMOSYNTHETIC CARBONATE MOUNDS COMPOSED OF CALYPTOGENA KA WAMURAI (BIVALVIA:VESICOMYIDAE) FROM THE UPPER TO MIDDLE SLOPE DEPOSITS IN THE SAGARA-KAKEGAWA AREA, CENTRAL JAPAN Takami NOBUHARA Science Education (Geology), Faculty of Education, Shizuoka University, 836 Ohya, Shizuoka 422-8529, Japan [etnobuh@ipc.shizuoka.ac.jp]

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IPC2002 Poster Presentations The living vesicomyid clam, Calyptogena kawamurai (Kuroda), has been obtained from shelf to slope depths (around 200-400m deep) off the Pacific coast of central and southwest Japan by longlines for demersal fish and by trawlers, and the habitat depths are shallower than those of any other Japanese Calyptogena species. However, its ecology is little known because any alive communities have not yet been confirmed by submersible surveys. Fossil chemosynthetic carbonate mounds composed of dense communities of Calyptogena kawamurai occur from the Pliocene massive siltstone of the Tamari and Hijikata Formations, the Sagara-Kakegawa area, central Japan. The siltstone was deposited on the upper to middle slope of the Plio-Pleistocene fore-arc basin lying in an arc-trench gap between the subducting Philippine Sea Plate and the overriding Honshu Arc. The tectono-sedimentary setting is nearly the same with that of the present fore-arc basin off the Pacific coast of central and southwest Japan. The carbonate mounds mainly consist of siltstone rubbles and shells, which were cemented by dolomite. The dolomicritic matrix shows flow structure under microscopic observation. The carbonate mounds often contain abundant Calyptogena conjoined valves with their life orientation preserved. Moreover small lucinid bivalves irregularly form shell-clusters and paterogastropods frequently attach to the Calyptogena shells. The carbonate mounds are also characterized by network of irregular veins and various-sized void spaces, both of which were fringed or filled by authigenic dolosparites. Burrow cavities in the carbonate blocks are fringed by splayed fibrous aragonite, which yields remarkably negative513C values: - 43.59%o to -48.01%o. These indicate that the Calyptogena kawamurai communities on the slope muddy sediments depended on methaneseepage system associated with gas eruption, which may have been triggered by a decomposition of subbottom methane-hydrate. Biological architectures such as burrows and cavities in large dead valves acted as efficient conduits for the seepage and made a contribution to sustain the habitat condition of the chemosynthetic communities during plural bivalve generations.

MIDDLE TO LATE PERMIAN IN THE SUBSURFACE OF ISRAEL: LITHOSTRATIGRAPHY AND FORAMINIFERA Olga ORLOV-LABKOVSKY1 & Francis HIRSCH2 National Museum of Natural History, Tel-Aviv University, Israel, [olgaorl@post.tau.ac.il]; 2Naruto University of Education, Tokushima Prefecture, Japan [francis-hirsch@mrj.biglobe.ne.jp]. Permian rocks are not exposed in Israel, and all available information comes from boreholes penetrated in the northern Negev and the southern Coastal Plain of South Israel. The lithological composition consists of alternating sandstones, shales and carbonates what appears to be continuous sedimentation in shallow marine and continental environments and reaches a maximum thickness of approximately 450-m in the Coastal Plain. These Permian deposits were assigned to the Sa'ad and Ar'qov Formations (Weissbrod, 1969). Unconformable overlying the Precambrian Zenifim Formation, the Sa'ad Formation and the lower part of the Ar'qov Formation belong according to palynomorphs to the Early Permian Potoniesporites noviscus zone, whereas the middle and upper parts of the Ar'qov Formation belong to the Late Permian Lueckisporites virkkiae zone (Eshet, 1990). A Late Permian age was assigned to the Ar'qov Formation based on foraminifers and algae (Garfunkel et Derin, 1984) and ostracodes (Gerry & al., 1987). Permian foraminifera from a continuous sequence in two boreholes - Gevim-1 and Pleshet-1 of the southern Coastal Plain in Israel are analyzed. As a result, three foraminiferal species - associations are defined. None of the boundaries of the lithostratigraphic subdivisions of the Sa'ad and Ar'qov formations coincide with the foraminiferal associations and palynological zones. A lower association of foraminifers ranges from the Sa'ad Formation into the lower part of the Ar'qov Formation. The second and third associations correspond to the middle and the upper parts of the Ar'qov Formation The Sa'ad Formation consist mostly of sandstone with a few interlayers of limestone and its thickness is of 75 to 100 m. The limestone varies from algal, foraminiferal-algal to algal-detrital. The first assemblage of foraminifers that occurs in the Sa'ad Fm consist the following species: Globivalvulina sp., Hemigordius irregulariformis, Multidiscus padangensis, Angellina alpinotaurica, Baisalina pulchra, Geinitzina sp., Pseudodunbarula ex gr. arpaensis, Codonofusiella sp., Frondina permica, Staffella sp., Nankinella sp. and algae: Pseudovermiporella sp., Gymnocodium bellerophonites, Mizzia sp., Permocalculus sp. This assemblage of foraminifers has an age - range from Midian (Middle Permian) to Djulfian (Late Permian), according to the Tethyan scheme. The age of the Sa'ad Formation is probably Midian (Middle Permian). The Ar'qov Formation consists of alternating sandstone, shale and limestone-units of over 200 m thick. The base of this unit consists of alternating layers of sandstone and shale with few layers of limestone. The number of limestone layers increases toward the upper part of this formation. The limestone is algal, foraminiferal-algal, algal-detrital, granular, clayey and oolitic. The assemblage of the foraminifers in the basal part of the Ar'qov Formation is analogous to that found in the underlying limestone layers of the Sa'ad

250

IPC2002 Poster Presentations Formation, but the following species are also found: Baisalina globosa, Dagmarita sp., Ichthyolaria primitiva, Geinitzina postcarbonica, G. caucasica, Globivalvulina graeca, G. vonderschmitti, Sichotenella sutchanica, Schubertella rara, Codonofusiella sp., Ogbinella ogbinensis, Pseudodunbarula arpaensis, P. minima, Yangchienia cf hainanica. This association is still distinguishable the First Association. The middle and upper parts of the Ar'qov Formation contain the Second and Third Associations. The assemblage of the Second Association includes 77 species, among them Paraglobivalvulina mira, Geinitzina gloria, Ichthyolaria permotaurica, Pachyphloides cf. oberhauseri, Nodosaria piricamerata, N. mirabilis caucasica, Pseudolangella globifrondina, Schubertella rara, Codonofusiella kwangsiana, C. nana, Pseudodunbarula arpaensis, Ogbinella ardaglensis, Abadehella sp. This assemblage correlates with the zone of Codonofusiella kwangsia that corresponds to the lowermost Djulfian Stage (Upper Permian of the Tethyan Scale). The assemblage of foraminifers of the Third Association includes 67 species, among them: Paraglobivalvulina mira, Robuloides acutus, Pseudotristix ? sp. (P. solida Reitlinger), Geinitzina ichnousa, Pachyophloia schwageri, Nodosaria doraschamensis, N. tranncaucausica, Protonodosaria globifrondina, Lingulonodosaria kamaensis, Pseudolangella doraschamensis, Reichelina media, Codonofusiella sp Colaniella cf. minima, C. minuta, Abadehella conoformis. This association correlates with the Djulfian Stage, possibly ranging into the lowermost Dorashamian Stage (Upper Permian of the Tethyan Scale).

GROWTH-PERIODICITY IN PALAEOZOIC CORALS Narima K. OSPANOVA Institute of Geology, Academy of Sciences of Tajikistan, 267 ul. Ainy, 734063 Dushanbe, Tajikistan. [ospanova@ac. tajik, net] The growth-periodicity (the alternation of dark and light zones in skeletal materials) of Palaeozoic corals is strongly expressed. It is related with the periodicity of the climatic changes (Ma 1933; Sokolov 1955 et.al.) and with phases of sexual reproduction (Bassler 1950; Preobrazhensky 1967 et. al.). The growth-periodicity in Tabulata and Heliolitida consists of the following: 1 - Variation in frequency of tabula, 2 - Thickening of corallite walls, 3 - Variation in length of septal spines (Sokolov 1955), 4 -Thickening of septal elements or appearance in their arrangement of distinct vertical orientation, 5 - Appearance of septal building or increase in their quantity, 6 - Periodic variation of the shape of tabula, 7 - Thickening of the tabula and development of spines on their surface, 8 - Sharp increase of the number and sizes of walls pores, 9 - Change of colour and microstructure of skeletal formation, 10 - Development of a layer of stereoplasma on the walls and spines (Preobrazhensky 1967), 11 Increase in number of connective tubes in Syringoporida (Chudinova 1971, 1986), 12 - Appearance of axial structures in corallites (Bondarenko 1978), 13 - Substitution of septal spines for septal plates (Bondarenko 1978, Ospanova 1980); 14 - Appearance of tubes in vesicular coenenchyme of Heliolitida (Leleshus and Ospanova 1979); 15 - Contraction and expansion of corallite cavities (Sokolov 1955). Zonation of growth is demonstrated in Rugosa in the following: 1 - Contraction and discharge of wrinkled integument of the epitheca, 2 - Variation of frequency of tabulae, 3 - Decrease and increase of the size of dissepiments, 4 - Thickening of corallite walls, septa, tabulae and dissepiments, 5 - Emerging of additional layers of stereoplasma up to complete filling of the visceral space (confluence of the septa with each other, and appearance of stereoplasmatic covers), 6 - Appearance, complication or clearer expression of axial structure, 7 - Periodical contraction ("zones of rejuvenation") and broadening of corallite" s cavities, 8 - Intensification of the gemmation process, 9 - Variation in the angle of inclination of fibres and trabeculae in the walls and septa of corallites, 10 - Variation in other microstructural features (for example, variation of carbonate solidity). Study of growth-periodicity is important for sclerochronology (Douglas 1988), climatology and palaeoclimatology (Ma 1933, 1934, 1937; Leleshus 1970), biostratigraphy (Sokolov 1955), cosmogony (Wells 1963; Scrutton 1978; Semenoff-Tian-Chansky and Guillaume 1991), and for systematics and evolutionary concepts.

NEW SYSTEMATIZATION OF BIVALVIA CLASS Yu. S. PAPIN State Oil and Gas University, Tyumen, Russia,[yuripapin@mail.ru]. Modern systematizations of the Bivalvia class on the highest hierarchical levels are based on peculiarities of a shell structure, a musculature, a gill apparatus, a stomach, larval development and a hinge. On the first level, according to the existing schemes, the Bivalvia class is divided into three subclasses or superorders.

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IPC2002 Poster Presentations But on this level of classification the researchers do not pay attention to the important feature of shell morphology - to the character of the hinge line. At the same time the hinge line undoubtedly corresponds to the highest hierarchic rank among other diagnostic features, because the Bivalvia class is divided by this feature into the fewest (two) number of groups, which sharply differ from each other like a plus and a minus. The hinge line of the first group consists of one posterior branch whereas the hinge line of the second group of two branches, posterior and anterior. In both cases shells are developed by quite different ways. On the one hand the concentric lines of growth focus in the apex without constructing an anterior branch of the hinge line and it is presented by the only posterior branch. On the other hand the shells grow with constructing both branches of the hinge line - anterior and posterior. So, the type of ontogenesis of the Bivalvia shells is brightly displayed in the type of the hinge line and according to these types the whole Bivalvia class is separated into two groups. It is proposed to give them the rank of subclasses and to denominate them as the Monodorsa and Bidorsa. Shells with one posterior branch belong to the Monodorsa subclass and with posterior and anterior branches - to the Bidorsa one. Roughly speaking, both subclasses are equal by quantity. As for the morphological diversity, they are homologous and have uniform changeability. In particular, in both subclasses there are groups of shells with the same type of the hinge, groups of isometric forms with the subcentral position of apexes and groups of shells developed by length or diagonal with apexes greatly removed forward. There is a certain correlation between the morphology of shells and the length of the hinge line. The latter is short in the group with isometric shells and it is long in the group of shells which are developed by diagonal or length. So, on the following level it is favourable to divide each subclass into two groups according to the general morphology of shells and the length of the hinge line. The category of superorder is given to these groups (fig.). The shells of the Bidorsa subclass with the isometric form and a short hinge line (0.3-0.4 of valve length) are united into the Birotunda superorder but the shells developed by length or diagonal with a long hinge line (0.5-0.6 of valve length) - into the Bilonga superorder. There are homologous groups in the composition of the Monodorsa subclass. They are denominated as the Monorotunda and Monolonga superorders. Isometric shells with a short hinge line (0.2- 0.3 of valve length) belong to the Monorotunda superorder. The shells of Monolonga superorder are characterized by length or diagonal developing and they have a long hinge line. Class

Bivalvia

Subclass

Monodorsa

Bidorsa

Superorder Monorotunda Monolonga Birotunda Bilonga Fig. 1. Bivalvia systematization on the highest hierarchical levels

On the lower hierarchical levels (order-family) it is proposed to classify the Bivalvia by type of the hinge. Ya.I. Starobogatov combined all types of hinges into ctenodont, praeheterodont and heterodont groups. Peculiarities of a gill apparatus, a stomach and larval development is well conformed with these three groups of the hinges. Among the groups of hinges given above the ctenodont type is of the least distribution and its structure is intermediate between the praeheterodont and heterodont types. Exactly with regard to the latter types of hinges each superorder is divided into two orders. Further according to Ya.I. Starobogatov's scheme the orders are separated into infraorders, superfamilies and families by the concrete type of the hinge, some features of the shell morphology and the structure of inside organs. The morphology of shells and the position of apexes on them allow to single out genera and species in the composition of families. The main regularity of the Bivalvia classification proposed above is its binial structure, when each time any taxon is divided only into two units on the lower hierarchical level (latin bini means england pair). This regularity is observed through the whole animate and inanimate world. It especially brightly and evidentially takes place on the highest hierarchical levels, in the structure of a living cell and other cases. Precisely speaking together with bini-taxons there is the third component of the whole. But it is suppressed in quantity and has intermediate features between bini-taxons.

PALAEOGEOGRAPHIC AND STRATIGRAPHIC INTERPETATION OF THE GREAT DIVERSITY OF BIOTA IN ORDOVICIAN Yu. S. PAPIN State Oil and Gas University, Tyumen, Russia, [yuripapin@mail.ru]. The alteration of the fossil quantity, their taxonomical diversity and general characteristic (size of shells) take simultaneously place and stipulate first of all by changing of palaeogeographic situations in accordance with

252

IPC2002 Poster Presentations rotation of transgressions and regressions of different orders. The most quantity, diversity and size of marine (aquatic) fauna is connected with the transgressive facies hereby the stratigraphic interval with such fauna has petty thickness and situates in the base of new sedimentation cycle. On the other hand underlying sediments are presented in the same extent by the most regressive (continental) rocks which crown the previous cycle of the sedimentation. The boundary between two contiguous rhythms is associated with the interruption in deposition or with the most continental sediments. For example such palaeogeographic and stratigraphic interpretation was substantiated for the great diversity of fauna on the boundary between Lower and Upper Permian in the Kuznetskian basin, Jurassic and Cretaceous systems of West Siberian. In the first case the boundary between Lower and Upper Permian (between balakhonskian and kolchuginskian series) in the Kuznetskian basin conforms to the level which situates in some meters upper of the top balakhonskian coal bed. The sharp change of regressive facies into transgressive ones occurs here. By the lithologic and palaeontologic features maximum of the transgression is connected with the basal packet of claystone. Firstly, this packet is characterized by thin rhythmicity and their mainly argillaceous composition and, secondly, by accumulation of biggest Bivalvia shells. So the size of shells reaches 90 millimeters whereas in underlying and overlying deposits a maximal length of shells doesn't exceed 15-25 mm. But the size of some samples reaches 40-47 mm. Further this interval is distinguished by great diversity of Bivalvia. There are 17 genera and 27 species in the Bivalvia composition. Such great taxonomic diversity is not observed on any stratigraphic interval of Permian deposits. It is predictable that the basal packet of argillaceous rocks underlies by the continental deposits, coal-bearing formation. The presence of basal kolchuginskian conglomerate, washout of the upper part of balakhonskian series with relative amplitude up to 140-540 m, maximal expression of oxidative processes, which are taking place immediately above upper balakhonskian coal bed, justify about continental discontinuity in sedimentation. There is no another stratigraphic level in Permian section of Kuznetskian basin on which features of discontinuity would so brightly be expressed. It is proved that maximum of transgression and regression are conjugated and stratigraphic converged. It allow to enunciate new principle of stratigraphy - principle of conjugation of two opposite maximum or principle of the most sharp change of facies. In the section of Kuznetskian basin the same conjugation of continentality and flooding maximum is observed on the boundaries between free coal and coal-bearing parts of kolchuginskian series and other levels. Hereby there is one regularity - the less rank of stratigraphic units the less extent of the expression of continentality and flooding maximum. In Mesozoic deposits of West Siberian the highest rank has the boundary between Oxfordian and Kimmeridgian stages of the Upper Jurassic. On this level there is the conjugation of the most expressive maximum of continentality and flooding through the whole Mesozoic section. In particular maximum continentality of Oxfordian stage underlines by presence of coal beds in its composition, whereas overlying deposits of Kimmeridgian and Volgskian (Tithonian) stages are presented by the argillaceous rocks with frequent accumulation of marine fauna - Belemnitida and Ammonitida. Fossils of Belemnitida are only in the Kimmeridgian stage and they absent in any stratigraphic interval of Mesozoic section of West Siberian. This peculiarity indicates a maximum of transgression inside Mesozoic section. As for fossils of Ammonitida they appropriate to Kimmeridgian and Volgskian stages by frequent accumulation of the biggest through JurassicCretaceous section shells. It underlines a maximum transgression on the level of Kimmeridgian and Volgskian stages. So the boundary between Oxfordian and Kimmeridgian stages can and must be accepted as a boundary between Jurassic and Cretaceous systems, between Lower and Upper Mesozoic. The Ordovician great diversity of fauna is connected with transgressive facies as well, with the most transgression inside Lower Palaeozoic, which incorporates Cambrian, Ordovician and Silurian. It substantiates to divide the Lower Palaeozoic cycle into two cycles of subsequent hierarchical level and to determine the boundary between these cycles in the middle Ordovician. According to the principle of conjugation of two opposite maximum transgressive facies must be immediately underlain by rocks with brightly expressed features of continentality, i.e. regressive facies. By the way on Ural there is the thick packet of conglomerate in the Middle Ordovician. The highest for Lower Palaeozoic hierarchical rank of the boundary between regressive and transgressive facies in the Middle Ordovician confirms by peculiarities of development of Pentamerida (Sapelnikov's data), Stromatoporoidea (Bogoyavlenskaya's data) and some others researches.

ICHNOFOSSILS FROM THE CAMBRIAN SUCCESSION OF THE PIN VALLEY, SPITI HIMALAYA, INDIA: PALAEOECOLOGICAL SIGNIFICANCE AND PALAEOENVIRONMENTAL IMPLICATIONS S.K. PARCHA and B.P SINGH Wadia Institute of Himalayan Geology, 33 GMS Road, Dehradun, India [bswihg@sancharnet.in]

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IPC2002 Poster Presentations Well preserved ichnofossils are known from the Tethyan as well as Lesser Himalayan regions of the Indian subcontinent. In the present studies, cubichinal, hypichinal and epichincal to fodochinal ichnofossils are reported from the basal part of the Kunzum La Formation (Cambrian) of the Pin valley (Spiti valley, Himachal Pradesh). Most are trails and tracks on bedding surfaces. They include species of Diplichnites, Dimorphichnus, Rusophycus, Gordia, Monomorphichnus, Chondrites, Bergaueris, Planolites, Grychorte, Skolithos, Phycodes and trilobite scratch marks as well as lo various burrows. So far no trilobites have been reported from immediately overlying and underlying strata or in association with the ichnofossil assemblages. The only Cambrian trilobite reported from the Pin valley is Redlichia noetlingi collected from float by Hayden (1904) and subsequently collected by one of the authors during earlier fieldwork. It seems that the Oryctocephalusbearing horizon, occurring well above the ichnofossil-bearing horizons in this section, may be higher than the beds with Redlichia noetlingi. Hence, the ichnofossil assemblages may be late Early and/or early Middle Cambrian in age. Ichnofossils provide compelling evidence regarding environments. The Pin valley ichnofaunas are diverse and occur in fine to medium grained carbonaceous sediments consistent with a low energy environment of deposition. The epifaunal assemblages of Rusophycus and Diplichnites dominate the ichnofauna in both abundance and range of behavior indicating palaeoenvironments with low current velocities with welloxygenated water columns and without strong current activity. Though Cruziana itself has not been identified, the ichnofossils belong mostly to the Cruziana facies (Crimes, 1970b), but it is mostly dominated by species of Diplichnites. The former is mostly found in high-energy sediments in which Diplichnites is absent. Since the Pin valley assemblages of ichnofossils suggest low energy not high-energy deposition, it is presumed this is the reason for absence of Cruziana. Representing intermediate ichnofacies are Planolites and Phycodes.

AUSTRALIAN LOWER CARBONIFEROUS TETRAPOD SITE: TAPHONOMY AND GEOLOGY K.E. PARKER1, A.A. WARREN1, J.A. WEBB2, & S. TURNER3 department of Zoology, La Trobe University, Melbourne 3086, Australia; 2Department of Earth Science, La Trobe University, Melbourne 3086, Australia;3Queensland Museum, St Lucia, Brisbane 4067, Australia. Middle Paddock, in the mid Visean Ducabrook Formation, Queensland, hosts the first recorded tetrapod remains from the Visean in Gondwana (Thulborn et al. 1996). Isolated, disarticulated and size-sorted elements of Chondrichthyes, Gyracanthides, Actinopterygii, Rhizodontiformes, Dipnoi, and Tetrapoda, are preserved in the single Tetrapod Unit. The fossils present varying degrees of post-mortem alteration, such as fragmentation, weathering and abrasion. Predation, subaerial exposure and transport by strong river currents had a substantial impact upon the remains prior to and during deposition. Thus although the taxa may have co-existed, the individuals represented in the assemblage were sampled from temporally disparate communities. The Tetrapod Unit consists of three closely spaced horizons with abundant vertebrate fossils; the high energy sedimentary structures present and the coarse grain size indicate that it was deposited by a twinpeaked high-magnitude storm-induced flood event. This unit marks the transition between two environments. Below the Tetrapod Unit are alternating siltstone and wave-rippled sandstone/oolitic limestone, deposited by episodic shallowing and deepening of a hostile saline lagoon. Above the Tetrapod Unit are interbedded calcrete-bearing siltstone and current- and tide-influenced sediments, including sandstone with plane lamination and unidirectional tabular and trough cross bedding. These strata represent cyclic channel fill/floodplain and tidal deposition. The overall coarsening-up sequence and the transition from lagoonal to fluvial/supratidal environments indicate progradation of a delta. The Middle Paddock site is but one of a few early tetrapod sites (eg: Elliot & Taber 1981) that were affected by estuarine influences during deposition. ELLIOTT, D.K., & TABER, A. C., 1981. Mississippian vertebrates from Greer, West Virginia. Proceedings of the West Virginia Academy of Science 53, 73-80. THULBORN, T., WARREN, A.A., TURNER, S., & HAMLEY, T., 1996. Early Carboniferous tetrapods in Australia. Nature 381,777-780.

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IPC2002 Poster Presentations FUSED SCHMALESEEIA (TRILOBITA, CAMBRIAN) FROM THE HUAQIAO FORMATION IN WESTERN HUNAN, SOUTH CHINA Shanchi PENG1 & Loren BABCOCK2 Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing China 210008, [speng@pub.jlonline.com]; 2The Ohio State University, Columbus, USA 43210; [bacock.5@osu.edu] Schmalensseia is one of small-sized, widespread polymeroid trilobites, know from Europe, Siberia, Australia, and South China (Moberg, 1903; Westergard, 1922; Larzarenko, 1960; Jago, 1972, Yang, 1978). An ontogenic series from a single bed of 2.5 cm of the Huaqiao Formation at Paibi, western Hunan Province, South China, represents apparently a new, unnamed species of the Cambrian burlingiidaen trilobite Schmaleseeia, The material is from the uppermost of Proagnostus bulbus zone (Peng and Robison, 2000) and shows that, unlike all other trilobites so far as known, the exoskeleton of the new species has not been tripartitely separated during its any of its ontogenetic stages, but remained with the cephalon, thorax and pygidium fused. The cephalon is readily recognizable by a transverse ridge, joining at the posterior border and the occipital ring bearing a node, but the thorax and the pygidium cannot be be differentiated in all observed ontogenetic stages. The ontogeny shows the size of the thoracopygon increases almost to twice as large as the cephalon during the growth. The unsegmented tergite obscures differentiation of the protaspid and meraspid stages but the holaspid stage, as suggested by large specimens, begins when the thoracopygon reaches a maximum of 13 somites. The presence of facial sutures, and the absence of librigenae in all available specimens suggest the species may have a normal process of exuviation with sutures opening and separating librigenae for freeing the molted body. MOBERG, J.C. ,1903. Schmalenseeia amphionura, en ny trilobite-type. Geologiska Foreningens i Stockholm Forhandlingar 25, 93-102. LAZARENKO, N.P.,1960. Nekotorye verkhnekembriskie trilobity severo-zapada Sibirskoi Platformy [Some Upper Cambrian trilobites from the northwestern Siberian Platform]. Sborniks Statei po Paleontologii i Biostratigrafii (NIIGA) 20, 12-44. PENG, S. and ROBISON, R. A., 2000. Agnostoid biostratigraphy across the Middle-Upper Cambrian boundary in China. Paleontological Society Memoir 53, (Journal of Paleontology, 74, supp. to n .4), 104 p. YANG, JlALU, 1978. Middle and Upper Cambrian trilobites of western Hunan and eastern Guizhou. Chinese Academy of Geological Sciences, Professional Papers of Stratigraphy and Palaeontology 4:1-83, pi. 1-13. WESTERGARD, A. H., 1922. Sveriges olenidskiffer. Sveriges Geologiska Undersokning. Afhandlingar och Uppsatser Ser. C 18, 1-205.

THE PTERASPIDIFORMES OF THE WOOD BAY FORMATION (SPITSBERGEN, LOWER DEVONIAN) AND THEIR RELATIONSHIP WITH THE OTHER CIRCUM-ARCTIC FAUNAS Vincent PERNEGRE Laboratoire de Paleontologie, Museum National d'Histoire Naturelle - UMR 8569 Museum-CNRS, 8 Rue Bujfon, 75005 PARIS, France; [Pernegre@hotmail.com] The Heterostracan (Vertebrata) fauna of the Wood Bay Formation (Spitsbergen, Lower Devonian) is presently studied on the basis of new original material collected in 1969 by the CNRS-MNHN expedition in Svalbard. This study, more than the revision of the already described forms (Heintz, 1962; Heintz, 1967, Blieck and Goujet, 1983), has revealed the presence of several new species and genera, which allow us to enlarge our knowledge of the Devonian pteraspidiform diversity. It gives new clues for comparison between the Circum-arctic faunas and new schemes of phylogenetic relationships into the Pteraspidiformes families. HEINTZ, N., 1962. Gigantaspis - a new genus of fam. Pteraspidae from Spitsbergen (a preliminary note). The Downtonian and Devonian vertebrates of Spitsbergen XI. Reprint from Norsk Polarinstitutt - Arbok, 22-27. HEINTZ, N., 1967. The pteraspid Lyktaspis ng. from the Devonian of Vestspitsbergen,. In 0rvig, T. (ed), Current Problems of lower Vertebrates Phylogeny; Nobel Symposium IV, Stockholm., pp. 73-80 BLIECK, A. and GOUJET D., 1983. Zascinaspis laticephala nov. sp. (Agnatha, Heterostraci) du Devonien inferieur du Spitsberg. Annales de Paleontologie 69,43-56.

TAXONOMIC AND BIOSTRATIGRAPHIC REVIEW OF FAMENNIAN CONODONTS FROM THE CANNING BASIN, NORTHWEST AUSTRALIA Maria Cristina P E R R I ^ Robert S. NICOLL2 1 Dipartimento di Scienze della Terra e Geologico-Ambientali, University of Bologna, Via Zamboni 67, 40126 Bologna, Italy. Fax: +39 051 2094522 [perri@geomin.unibo.it]; 2 Department of Geology, Australian National University, Canberra 0200, ACT, Australia; [bnicoll@goldweb.com.au].

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The northern margin of the Canning Basin of NW Australia has excellent sequences of Upper Devonian carbonates extending for 350 km along strike and displaying a broad spectrum of sedimentary facies, among them exhumed reef complexes and associated lithofacies (Playford & Lowry, 1966). Conodont faunas from those areas have been previously described (Glenister & Klapper, 1966; Druce, 1969, 1976; Nicoll & Druce, 1979; Nicoll, 1980, 1984; Nicoll & Playford, 1993; Metzger, 1994). A taxonomic and biostratigraphic review of the Canning Basin Famennian conodonts has been done not only for stratigraphic alignments, but as the necessary basis for an exercise in palaeobiogeographic analysis globally—the ultimate aim of the investigation. A taxonomically consistent database is imperative before meaningful computer biogeographic analysis can be broached. Without a taxonomically consistent database any computer-based analysis is likely to reflect more the divergences in taxonomic style between authors than real faunal differences. The collections forming the basis of the study were derived from sampling undertaken by one of us (RN) in the 1970s when employed by the Australian Bureau of Mineral Resources; the collections are now housed in its successor organization, Geoscience Australia, in Canberra. The Canning Basin conodont faunas are oligospecific, elegantly preserved, and have a CAI (Color Alteration Index) of 1. The faunas consist mainly of polygnathids, icriodids and subordinate palmatolepids implying predominantly shallow water environments. Even though abundances vary greatly from sample to sample, polygnathids seem to predominate. Remarks on some species of Polygnathus and extensions of ranges have been reported. Fourteen biozones of the standard Famennian biozonation (Sandberg & Ziegler, 1990) have been identified: M. and U. triangularis, L., U. and Umst. crepida, U. rhomboidea, L., U. and Umst marginifera, L and U. trachytera, U. postera, and M. and U. expansa. Viewed qualitatively, the Upper Devonian conodont faunas display significant levels of endemism— not appreciated by previous workers who focused primarily on establishing best-possible correlations from sequence to sequence and region to region, tending to focus, in the first instance (understandably), on palmatolepids for making intercontinental stratigraphic alignments. Some biogeographic patterns are emerging from the study. That such patterns can be discerned is in large measure due to the greatly increased number of data points for Famennian conodonts now available compared with a decade or two ago. Some of this improvement in global coverage stems from important contributions on shallow marine Late Devonian conodont faunas of eastern Australia (Mawson & Talent, 1997), the Russian Platform and China published since the major monographs on Canning Basin Devonian conodont faunas by Druce and Nicoll mainly 20 years and more ago. It is hoped that patterns of provinciality eventually discriminated globally may provide illumination regarding patterns of oceanic circulation and longitudinal positioning of some of the crustal blocks for which palaeomagnetic data have been lacking or not compelling. DRUCE, E.C., 1969. Devonian and Carboniferous conodonts from the Bonaparte Gulf Basin, northern Australia. Bull. Bur. Miner. Resour.Geol. Geophys. Austr., 98, 242 pp. DRUCE, E.C., 1976. Conodont biostratigraphy of the Upper Devonian reef complexes of the Canning Basin, Western Australia. Bur. Miner. Resour. Aust. Bull., 158, 303 pp. GLENISTER, B.F. & KLAPPER, G., 1966. Upper Devonian conodonts from the Canning Basin, Western Australia. J. Paleont., 40, 777842.

MAWSON, R., & TALENT, J.A., 1997. Famennian-Tournaisian conodonts and Devonian-Early Carboniferous transgressions and regressions in north-eastern Australia. Geol. Soc. America Spec. Pap. 321: 189-233. METZGER, R.A., 1994. Multielement reconstructions of Palmatolepis and Polygnathus (Upper Devonian, Famennian) from the Canning Basin, Australia, and Bactrian Mountain, Nevada. J. Paleont., 68: 617-647. NICOLL, R.S., 1980. The multielement genus Apathognathus from the Late Devonian of the Canning Basin, Western Australia. Alcheringa, 4:133-152. NICOLL, R.S., 1984. Conodont distribution in the marginal-slope facies of the Upper Devonian reef complex, Canning Basin, Western Australila. Geol. Soc. Am. Spec. Pap., 196: 127-141 NICOLL, R.S. & DRUCE E.C., 1979. Conodonts from the Fairfield Group, Canning Basin, Western Australia. Bull. Bur. Miner. Resour.Geol. Geophys. Austr., 190: 134 pp. NICOLL, R.S. & PLAYFORD, P.E., 1993. Upper Devonian iridium anomalies, conodont zonation and the Frasnian-Famennian boundary in the Canning Basin, Western Australia. Palaeogeog., Palaeoclimatol., Palaeoecol., 104: 104-113. PLAYFORD, P.E., & LOWRY, D.C., 1966. Devonian reef conplexes of the Canning Basin, Western Australia, Geol. Surv. Western Aust. Bull., 118: 150 pp. SANDBURG, C.A. & ZIEGLER, W., 1990. The Late Devonian standard conodont zonation. Cour. Forsch.-Inst. Senckenberg, 121: 115 pp.

CONCEPTIONS ABOUT MORPHOTYPES OF FOSSIL HEXACTINELLIDS E.M. PERVUSHOV Historical Geology and Palaeontology, Saratov State University, Ul. Astrakhanskaya 83, 410026 Saratov, Russia The original morphotypes of the skeletal forms are certain initial skeletal hexactinellid forms that allow visualising and describing the whole of known sponge diversity. Six principal original morphotypes of

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IPC2002 Poster Presentations hexactinellids have been recognized; these morphotypes reflect, to some extent, trends in skeletal hexactinellid morphogenesis. These trends (pariform - pliciform - gemmiform) are established reliably enough. A pariform skeleton has the simplest structure consisting of a rhizoid system, a rod and a goblet made of a skeleton-forming wall. Outlines of a paragastral cavity reflect the form of the original conical or cylindrical goblet (Ventriculitidae, Craticularia and Leptophragma). The parameters of the irrigation system and sculpture change within a wide range; elements of attachment to the substrate are often developed. Leaflike skeletons are known (Schizorabdus). Rods may dominate the structure of some skeletons, while a skeleton-forming wall is hardly decipherable. Pliciform skeletons are thin-walled; the presence of the subosculum is characteristic in the bend of wall. The appearance of forms with mobile wall is characteristic of the latest stages in morphogenesis of skeletal hexactinellids (Napaeana-Lychniscosz, LeptophragmaHexactinosa). Primary and secondary gemmiform skeletons are recognized reflecting the roles of the primary or the secondary paragastral cavity in the sponge structure. The primary paragastral cavity is always narrow, slit-like, situated within the walls, making a lobe. Radial multi-lobe (from three to five) skeleton structure is most characteristic. A prolonged distal lobe is recognized in some skeletons, with shorter lobes developing from it in turns. In the structure of the secondary gemmiform skeletons, the conditional cavity is clearly manifested, appearing from the lobe bends (primary cavity), and it is called the secondary paragastral cavity. It is situated between the primary slit-like osculum, making its base and the upper margin of the skeletons. At least five principal lobes are known in the mushroom-like and the umbel-like skeleton structure (Coeloptychiidae); these dichotomize at the bends and are traced from the rod-like part. Formation of gemmiform skeletons is associated with isolation of the subosculum-bearing satellites in morphogenesis of the pliciform sponges. The process is traced on the example of representatives of the family Leptophragmidae (Hexactinosa): Leptophragma-Guettardiscyphia-Balantionella-Lobatiscyphia. Increase of the satellite volumes, lengths and diameters was accompanied by the obvious volume reduction of the primary paragastral cavity, becoming progressively less important in skeleton structure. Primary and secondary pliciform skeletons have been recognized. They are known for the appearance of bridges in the structure of secondary skeletons and areas of interlabyrinth space. Gemmiform sponges are regarded as transitional in their level of organization; they are known within both suborders of skeletal hexactinellids {Plocoscyphia-Lychniscosa; Labyrintholites-Hexactinosa). The interlabyrinth skeletons are peculiar for their half-spherical outlines; they are pierced by intercommunicating areas of interlabyrinth space; a central secondary osculum is present, and the shape of paragastral cavity is complicated, labyrinth-like (Etheridgea, Camerospongia). The skeleton-forming wall is thin, the sculpture elements unknown. In their organization, these sponges may be regarded as colonial, with a single paragastral cavity clearly recognized in their structure; the rounded slit-like oscula open into the secondary cavity. The interlabyrinth openings serve to promote water flow through the sponge skeletons along the interlabyrinth space. This flow was most probably little regulated by the skeleton architecture and the volume of the incoming water was controlled by size and number of openings, as well as by availability of a membrane. A favosiform skeleton is formed with large, often high folds or branches that bend to open several (up to three, five and more) oscula in the upper parts of each one. Multiple, rounded-polygonal oscula compose the upper surface of the skeleton or the base of the secondary cavity. The skeleton-forming wall is very thin. The number of primary lobes is generally more than five; sculpture is missing (Cavifavosa, Becksiidae) or, in other cases, round prosopores are densely placed (Euretidae). Forms with primary paragastral cavity are peculiar for their small sizes. Numerous bridges occur among the primary branches in transitory sponges (Tremabolites); they are covered with elongate, spiniform outgrowths of satellites. In forms with secondary paragastral cavity, the lower, rod-like part of the skeleton is poorly developed. Colonial (Cavafavosa, Becksiidae) and transitory forms are recognized (Petrosifavosum, Euretidae). Ramosiform skeletons are ramose and bushy; the shapes and the sizes of the single paragastral cavity are similar to the skeleton outlines. Several equivalent oscula make a peculiar feature; the oscula are situated at the same level in bushy forms, or in various areas of ramose forms. The skeleton-forming wall is generally thin; the sculpture elements are not characteristic (Aphrocallistes), or densely distributed (Adramosiscyphia and Paracraticularia). Many sponges with ramose skeletons are regarded as colonial forms. The subcylindric sponges with two equivalent and oppositely-oriented oscula (known from many genera of Dictyonina) may be regarded as the original forms that gave rise to ramosiform skeletons.

MODULAR ORGANIZATION OF LATE CRETACEOUS SPONGES E.M. PERVUSHOV Historical Geology and Palaeontology, Saratov State University, Ul. Astrakhanskaya 83, 410026 Saratov, Russia

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IPC2002 Poster Presentations A variant of organization of the levels of "module" organization for the skeletal hexactinellids is presented, based on study of fossil sponges. Some of the organization levels thus revealed (transitional forms) may pertain exclusively to sponges. Only in rare cases (Craticularia and Paracraticularia; Pleurostoma and Guettardiscyphia), has the importance of obvious features of mono-oscule and polyoscule skeletons been regarded as meaningful genus-species characteristic. The sponge organization level is the principal characteristic of a subfamily or tribe in skeletal hexactinellids. A skeleton in solitary hexactinellids is formed by a skeleton-forming wall with one paragastral cavity and a corresponding osculum. A circulation system is developed, similar to the sculpture elements. Solitary forms are supposed to be predecessors of large phylogenetic branches; they are known from practically all families, being most common among fossil hexactinellids. Familiate forms have been recognized only among pariform sponges, and such sponges, in their turn, possess a bearing skeleton; one of the wall or rod surfaces hosts small, conical, bud-shaped structures, the subsatellite (submoduli) shallow central cavities do not communicate with the paragastral cavity. In one case, the submoduli are relatively regularly positioned on the paragastral of the broad wall bend (Contubernium). The parameters of the submodule cavities are substantially smaller than those of the central paragastral cavity; the submoduli are likewise vertically oriented. Examples are known of chaotic distribution of submoduli on the dermal surface of the bearing skeleton or rod (Columelloculus); the small cavities of the submoduli are perpendicular to the central cavity. The formation of familiate forms may be an example of aborted budding. The autonomous level of organization is the lowest organization-level in polyoscule sponges; the skeleton formation is determined by polymerization of the original module. The paragaster of every module is always morphologically manifest; outlines of every osculum are clear. Polymeric and similiate sublevels of autonomous sponges have been recognized. A polymeric skeleton is formed on the basis of several pariform modules of conical or cylindrical outlines, without additional skeleton-forming elements. Trioscule forms are rare. Skeletons of similiate forms are peculiar for additional elements among the modules: a common wall above a bend (Communitectum\ Marinifavosus) or a common base (Rhizopoterionopsis) with modules on it. The modules of a single skeleton are equivalent; their number varies from two-three to seven-eight. Familiar notions were used to describe the relative positions of the modules: tectorial, catenular, stolonal skeleton, etc. The transitional level of organization is defined on the example of skeletal hexactinellids, with several suboscula recognized alongside the principal osculum; the suboscula are situated in the lobe bends or in apical areas of the satellites distant from the central part of the paragastral cavity. The suboscula used to function as additional oscula. Transitional forms are recognized among pliciform (Coeloptychiidae - Lychniscosa; Guettardiscyphia - Hexactinosa), gemmiform (Plocoscyphia - Lychniscosa), and favosiform (Tremabolites - Lychniscosa) sponges. Complicated structures are characteristic of transitory sponges with bridges, areas of interlabyrinth space and the cortical membrane of the upper margin. There are three, conditionally determined, sublevels among transitory forms. The first sublevel consists of original pliciform and gemmiform forms with one central osculum (Guettardiscyphia, Balantionella - Hexactinosa), and with barely isolated suboscula. Skeletons of sponges of the second sublevel are polymeric forms, peculiar for more complicated character resulting from polymerization of the original pliciform (Ceniplaniscyphia) or gemmiform {Balantionella) forms; the morphology of two or three skeletonforming modules can still be traced. Outlines of the original modules are hard to determine in the structures of polyoscule skeletons in the third sublevel: this is due, especially, to development of bridges, areas of interlabyrinth space and outgrowths of the spicule lattice. Such forms are regarded as similiate because the oscula (areas of the paragastral cavity) are equivalent, though sometimes distributed chaotically within the skeleton structure. Formation of some transitory forms may be traced in phylogenesis of pliciform sponges. The colonial level of organization is determined in skeletons of hexactinellids with a single, often complicatedly structured paragastral cavity opening outwards by means of several oscula, equivalent in sizes and outlines. The oscula lie at one height level - bushy forms: Becksia - Lychniscosa; Paracraticularia Hexactinosa, or at various levels - branching forms: Cavafavosa - Lychniscosa; Aphrocallistes - Hexactinosa. Formation of colonial forms within many phylogenetic branches of hexactinellids is regarded as a "polyphyletic" phenomenon associated with late stages of Late Mesozoic eustasy. Gradually they became dominant within the sponge settlements, and migrated to deep-sea zones far more successfully. Some of them are currently known as inhabitants of the oceans (Aphrocallistidae, Craticulariidae).

RHYTHMOSTRATONS AND UPPER CRETACEOUS FORAMINIFERA FROM WESTERN SIBERIA V.M. PODOBINA Tomsk State University, 36 Lenin Ave., Tomsk, 634050, Russia; [podobina@ggf.tsu.ru] In biostratigraphic investigations we applied palaeogeographic and palaeobiogeographic approaches as well as the rhythmostratigraphic method for determining and specifying positions of local stratigraphic

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IPC2002 Poster Presentations subdivisions (stratons) through the Late Cretaceous of western Siberia. The rhythmostraton method is based on determining relative quantitative and qualitative distributions of foraminifera—which depend on transgressive and regressive cycles in a basin. Regularities of transgression-regression (T-R) alternations, governed by tectonic activity, resulted in changes in foraminiferal ratios and taxa within the Upper Cretaceous of the West Siberian Basin. In this region, siliceous agglutinated foraminifera predominated in the Cenomanian to Santonian, with calcareous agglutinated and secreted forms in the Campanian to Maastrichtian. The fauna responded sensitively to slightest changes in physicogeographic and biotic conditions of the habitat, and hence they are useful indicators for such changes. Rhythmic T-R cycles in the Late Cretaceous basin development were evident from alternations in lithology and accompanying changes in composition of foraminiferal faunas. This provided a possibility for establishing local biostratigraphic (foraminiferal) zones. Based on variations in the averaged quantitative distribution of foraminifera in the area, a generalized faunal curve (GFC) has been constructed. The established foraminiferal zonal stratigraphy of the Upper Cretaceous has been superimposed on the GFC diagram based on relative distribution of foraminifera. Three distinct rhythms stand out in the GFC, corresponding to great rhythmostratons. Each rhythm associated with the respective rhythmostraton is separated on the GFC by a borderline between two greatest changes in curve directions corresponding to maximum transgressions. Each of the three GFC subdivisions, corresponding to one or two horizons, we have termed a 'rhythmothem Qualitative characterization of foraminifers through the Upper Cretaceous section demonstrates changes in taxa present at the level of orders and families; these are usually similar in composition within separate rhythmothems. Horizons (or portions thereof, subordinate to rhythmothems) diverge lithologically and are characterized by definite generic composition. In the hierarchy of rhythmostratons, they may be given equivalent status with such rhythmostratigraphic subdivisions as rhythmotherms [from the Latin termus-a cut-off portion of a branch]. Local biostratigraphic (foraminiferal) zones, distinguished by peculiar species assemblages, have been called rhythmolithes. These are subordinate to rhythmotherms, and the latter to rhythmothems. We have established three transgressive (TJ-T 3 ) and three regressive (R1-R3) cycles in the basin. The boundaries of the rhythmotherms are plotted in the mid-points of the GFC, i.e. between two maximal transgressions. The fauna of these rhythmotherms are distinct at the generic level and, to a less extent, at family level. They are confined to separate horizons (or portions thereof) and are separated by the base of the maximum transgression curve on one side and by the middle point in the GFC (the boundary between maximum transgressions) on the other one. Successive rhythmolithes are zones of moderate thickness containing distinct foraminiferal assemblages. They are marked by the mid-points between maximum and intermediate GFC values, i.e. by the boundaries between separate T-R cycles in the basin. The distribution of foraminifera by rhythms involves isolation of successive rhythmostratons within sections based on T-R cycles of the basin brought about by tectonic changes in the region. We consider that rhythmostratons, characterized by micropalaeontologic data, as evidenced in the Upper Cretaceous, could be applied to the stratigraphy of the Phanerozoic elsewhere.

EARLY CRETACEOUS DINOSAURS FROM WESTERN SIBERIA V.M. PODOBINA. G.M. TATYANIN, S.V. LESHCHINSKIY, A.V. VORONKEVICH, and A.V. FAYNGERTS, Tomsk State University, Lenin Ave. 36, Tomsk 634050, Russia, [podobina@ggf.tsu.ru] Early Cretaceous dinosaurs were first discovered on the Kiya River (village Shestakovo, Kemerovo region, SW Siberia) by A.A. Mossakovskiy and I.V. Lebedev of Tomsk State University (TSU) in 1953. Two fragmentary dinosaur skeletons were found in the Ilekskaja suite deposits - on the steep bank of the Kiya (site Shestakovo-1). Later, in 1960, they were assigned to Psittacosaurus mongoliensis Osborn. Early in the 1960s bones of a larger dinosaur were discovered in Shestakovo-1. No description of the first dinosaur remains has been published. The next discovery of Early Cretaceous vertebrates (including two dinosaurs) did not take place until 1994. A cheek tooth of a therapsid (tritillodont) and a phalanx of a sauropod were discovered by TSU scientists in debris on the high bank of the Shestakovo ravine. It was the first find of tritillodontids in the Cretaceous; they were thought to have become extinct in the Middle to Late Jurassic. In 1995 workers from the TSU Chair of Palaeontology and Historical Geology found sauropod bones and located two new sites of Early Cretaceous reptiles and other vertebrates in the same area: Shestakovo-2 and Shestakovo-3. Since 1998, work at the Shestakovo sites has been coordinated by workers of the Siberian palaeontological Scientific centre of Tomsk State University (SPSC TSU). The main permanent excavations

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IPC2002 Poster Presentations is now taking place at Shestakovo-3. At Shestakovo-1 and Shestakovo-2, washing of coarse-grained sands and gravels is being carried out to recover small vertebrate remains. During 1998-1999, large-scale washing of the bone-bearing deposits (about 4 tonnes of sands and gravels) at Shestakovo-1 resulted in important new finds of mammals, tritillodontids, lizards, turtles and other vertebrates. Every year SPSC TSU workers, as well as scientists from the Moscow Palaeontological and St.-Petersburg Zoological Institutes take part in field work at the Shestakovo sites. During a five-year period of study, new data have been obtained on morphology and systematics of fish, reptiles and other vertebrates. At the Palaeontological Museum of the SPSC TSU, work is underway on a new exhibit of two Psittacosaurus skeletons found in 1999. At SPSC TSU the Shestakovo complex vertebrate fossils are being curated and studied. Up to date, remains of sauropods, therapods (dromeosaurids) and ceratops (psittakosaurs) have been found at the Shestakovo sites. In Shestakovo-3, the existence of a fragmentary skeleton of a small carnivorous dinosaur (family Troodontidae) has been reported. In the SPSC TSU collection, sauropods are represented by a juvenile tooth, as well as by a vertebra and an incomplete foot of Sauropoda indet. with no less than three ungual phalanges. The Ceratopsia group is represented by the abundant bone material (including two skeletons) belonging to a small ornithischian dinosaur, Psittacosaurus sibiricus Voronkevich & Averianov, 2000. This species differs from other known psittacosaurs; it is considered the largest and most advanced of the Psittacosaurae. Further work will provide more details on the morphology and taxonomy of the fossils, Early Cretaceous palaeogeography, and on the genesis and age of the deposits. Continued investigation of the Shestakovo Early Cretaceous vertebrate assemblage will bring about amendments to the regional stratigraphic chart and palaeogeographic definitions. In 2000-2001 the palaeontologic team of SPSC TSU undertook an extensive search for new locations of Early Cretaceous terrestrial vertebrates in the basin of the Chulym River (a right tributary of the Ob River). The exploration, carried out in the SW of the Krasnoyarsk region, resulted in discovery of a new "dinosaur" area (because dinosaur remains dominated the palaeocoenoses) in Siberia. This area of Western Siberia will doubtless produce other accumulations of fossil vertebrate remains. Investigation of these will help to solve many problems in Cretaceous biological history. LATE QUATERNARY HISTORY OF THERIOFAUNA IN THE NORTH-EAST OF EUROPEAN RUSSIA D. PONOMAREV Institute of Geology Komi Science Center Ural Division RAS, Pervomayskaya St., 54, Syktyvkar, 167982, Russia, [kainos@geo. kom isc. ru] Recent analysis of history of theriofauna has shown more complicated picture of spatial and temporal dynamics of fauna than it has been considered before. Six phases of theriofauna development during last 40 000 years are revealed. In Late Pleistocene there were three phases of: Middle Valdai (Weichselian) Interglacial, Late Glacial Maximum and Late Glacial. During Postglacial there were phases of Early, Middle and Late Holocene. These phases differ from each other in species composition and ecological structure and they are closely connected to environmental changes in the region. Phases of Middle Valdai and Postglacial are similar in the presence of brown bear and nearly equal proportions of remains in the two pairs of ecologically distinct species musk ox - primitive bison and polar fox - wolf. These peculiarities are probably caused by the relatively milder climate of Middle Valdai and Postglacial intervals. In the contrast theriofauna of Glacial Maximum hasn't included brown bear. Species adapted to coldest climate - polar fox and musk ox dominated in this phase. Micromammalian assemblages demonstrate very similar distinctions in species composition and ecological structure between these phases. Thus during Glacial Maximum one species adapted to cold and dry climate - collared lemming dominated in this phase. At the Pleistocene - Holocene boundary "mammoth's complex" disappeared and Early Holocene theriofauna has become forest fauna. Peculiarities of Middle Holocene theriofauna are best demonstrated at the north of the region occupied now by tundra and forest-tundra zones. This fauna, in contrast with modern one, contained forest species that was caused by Subboreal warming. During the next (Late Holocene) phase faunas of both modern tundra and forest zones has become modern-like. Forest and grassland species prevail among micromammalian communities in the south of the area. Northwards forest and tundra species becomes dominant. Distinctions in composition and structure of theriofauna allows to stratify Upper Quaternary deposits. Most important signatures of micromammalian dynamics are: changing proportions of species belonging to different biotops (tundra, forest, grassland) and ratio between tundra species. On the basis of studying not numerous findings of bones it is suggested that Late Pleistocene brown bears were larger than modern ones and Late Pleistocene polar fox is closer to Late Pleistocene subspecies Alopex

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IPC2002 Poster Presentations lagopus rossicus by proportions of M/l. Late Holocene martens were smaller than Holocene martens of Baltic region. Morphometric study of series of bones has allowed to reveal geographical variability of Late Holocene hares. The largest hares occupied the Polar Urals. Late Holocene of the Polar Urals is not different from modern tundra reindeer in sizes of postcranial bones.

ABBERATIONS IN PALAEOBOTANIC STUDIES IN MOUNTAINS, EXEMPLIFIED BY THE ALTAY MOUNTAINS OF RUSSIA E.A. PONOMAREVA1. A.S. TRESVYATSKAYA2, V.V. BUTVILOVSKY1 Western-Siberian Trial Centre, Novokuznetsk, Kemerovo region, Russia; 2Dresden University, Germany. Palaeocarpological and palynological studies of Quaternary deposits have long been accepted as of prime importance in reconstructing palaeogeographic environments and their change through time. We need nevertheless to solve some paradoxical contradictions appearing when interpreting palaeobotanic data. Such contradictions appear mostly in mountains where geobotanic environments are compressed and have a mosaic structure. The above mentioned studies, as well as specific pecularities of seeds, foeta, spores and pollen burial were evaluated on a high-altitude profile of Tuzhu-Teletskoye Lake in the NE Altay Mountains. Specimens characteristic of all landscape zones of this region (steppe, mixed taiga and mountain tundra) were collected. The material obtained was used in evaluation of taphocoenosis-forming conditions. Palynological analysis reflected domination of mixed taiga elements in all biotas of the Tuzhu-Teletskoye Lake profile (from steppe to mountain tundra) and significant distortion of the composition of modern vegetation of the vertical belt of the NE Altay. It was clear that in most cases this was due to domination, especially regionally, of the most productive plants (according to pollen groups) such as the conifers of the mountain mixed taiga (Abies, Picea, rarely Larix, Pinus). Domination of conifer pollen was connected with its typical feature - ability to flow and fly over wide areas. This has resulted in dominance of conifers in pollen spectra in oryctocoenosis of biotopes at different altitudes in the mountains of the NE Altay. Experiments were made with specimens from plains and foothills and, often, spore-pollen spectra were different qualitatively and quantitatively from the modern vegetation composition of the studied areas (A.A. Kizyar, 1985, inter alia). Palaeocarpological studies of high-altitude profile samples reflected more precisely correlation of thanatocoenosis plants—the first stage of the taphocoenosis process, a term coined by I.A. Efremov (1950, 1954) and modern plants of the mountain landscape. But in this case also, species-composition of seeds and foeta would not be complete. Firstly, objects without solid covers (Populus, Geranium, representatives of the Fabaceae, etc.) are destroyed, as are germinated or damaged seeds. The composition of the future seed flora disappeared from the spectrum of species typical of the modern vegetation of the region. Joint use of palaeocarpological and palynological analysis in study of the same samples enabled us to succeed in obtaining regional as well as local inferences about compositions of taphocoenosis, and to make more precise interpretations of palaeobotanic data and palaeogeographic restorations in mountains. Multi-pronged use of palaeobotanic data enables us to solve some paradoxical contradictions in interpretation of data on the Early and Later Holocene deposits of the Altay and its foothills—which could not be solved by using a single approach.

A HISTORY OF ELEPHANT FISHES OF THE GENUS CALLORHINCHUS LACEPEDE, 1798 (HOLOCEPHALI, CHIMAEROIDEI) Evgenii V. POPOV Scientific Research Geological Institute of the Saratov State University (SRGISSU), 120 Bol'shaya Kazach'ya Str., Saratov, 410026, Russia. [PopovEV@info.sgu.ru, niig@sgu.ssu.runnet.ru]. Elephant fishes of the genus Callorhinchus Lacepede, 1798 (ex Gronovius, 1763) are primitive group of chondrichthyan chimaeroid fishes (Chimaeriformes, Callorhinchidae). They are inhabit in the oceans of South Hemisphere and so are met near coasts of Australia and New Zealand. In the modern fauna this genus is considered as monotypic for superfamily Callorhinchoidea (Didier, 1995). It is represented by three recent species: Callorhinchus callorhynchus Linnaeus, 1758, G. milii Bory de St. Vincent, 1904 and C. capensis Dumeril, 1865 (Didier, 1995). Externally, callorhinchids are characterized by an elongate snout with a fleshy plow-shaped flap, closed lateral line canal, small eyes, a heterocercal tail, and an anal fin. Dentition consists of three pairs of crushing dental plates, which are comparatively thick and with well developed basally

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IPC2002 Poster Presentations descending laminae. Tritors on the dental plates are not numerous, mainly massive and consist of vascular pleromin (sensu 0rvig, 1985). Based on particularities of primitive anatomy, geographical destribution, systematic composition and position in the suborder the genus can be considered as "living fossil" (sensu Gilyarov, 1985). In the fossil record remains of representatives of the genus are very rare and known on findings of isolated dental plates. Also several imprints of egg cases: Callorhinchus germanicus (Brown, 1946) from the Middle Jurassic (Bajocian) of Wurttemberg, Germany, ?C newmexicana (Brown, 1946) from the Upper Cretaceous of New Mexico, USA (Stahl, 1999) and C. rossica Voronetz, 1952 from the Upper Jurassic of Yakutia, Siberia, Russia are assigned to the genus. Those associations of egg cases to the genus are not unquestionable, because of there are another Mesozoic genera (e g. Brachymylus, Pachymylus) attributed to the family Callorhinchidae Garman, 1901. An ancient history of the genus is connected to the North Hemisphere. The origin of the genus can be connected to Triassic (Norian) of Franz Josif Archipelago (North Ice Ocean), where several mandibular dental plates cf "Eomanodon" sp. were collected (material in the collection of SRGI SSU unpublished data). and is certainly traced back to the Cretaceous of European Russia. New, still unpublished material indicates a presence of the genus from the Upper Jurassic (Upper Tithonian substage; = Boreal Middle "Volgian" substage) deposits of Moscow Province, Russia. The oldest described Callorhinchus species is C. borealis Nessov et Averianov, 1996 from Lower Cretaceous (Albian) deposits of Belgorod Province, based on dozen dental plates. Also this species is known from the Upper Cretaceous (Cenomanian) of Saratov Province. A next Cretaceous record is "vomerine" dental plate of Callorhinchus sp. from the Upper Cretaceous (Santonian) of Penza Province, European Russia (Averianov, 1997). A right "palatine" dental plate of Callorhinchus hectori Newton, 1876 are known from the Upper Creteceous (?Senonian) of Amuri Bluff, South Island, New Zealand. Based on several "palatine" and mandibular plates, C. regulbiensis Gurr, 1963 (= C newtoni Ward, 1973) are known from the Palaeogene (Thanetian - Yprisean) of Kent, England. This species is last record of the genus in the North Hemisphere. Based on comparatively large mandibulare and several fragments of "palatine" dental plates from the Miocene Patagonian formation of Santa Cruz (Argentina), C. crassus Woodward & White, 1930 was described. And finally, there is an instruction (Stahl, 1999) on new findings of "palatine" and mandibular dental plates of Callorhinchus from the Pliocene (Waipippian = Early Piacenzian) of Taranaki, North Island, New Zealand, collected by Dr. Joseph McKee (NZ). Fossil species of Callorhinchus are characterized by single-type construction of a dentition and are comparatively difficult to diagnose by dental plates (especially by "vomerine" and "palatine" ones). Long existence of the genus could be connected with small food specialization of its representatives, as an result of universal dentition. Discoveries of the fossil remains from deposits of shallow epicontinental seas in the North Hemisphere correspond to comparatively shallow lifestyle of recent representatives of the genus in the South Hemisphere, which are, probably, driving back relics.

NEW FINDS OF CHELICERATE ARTHROPODS FROM THE SIEGENIAN (LOWER DEVONIAN) OF THE RHENISH SLATE MOUNTAINS (GERMANY) Markus POSCHMANN1 & Ulrich JANSEN2 1 Landesamtfur Denkmalpflege Rheinland-Pfalz, Referat Erdgeschichte, Grojie Langgasse 29, D-55116 Mainz, Germany; 2Forschungsinstitut Senckenberg, Senckenberganlage 25, D-60325 Frankfurt am Main, Germany Along the new ICE construction site from Cologne to the Rhein/Main area, temporary outcrops existed in the Westerwald Hills which exposed middle Lower Devonian (Siegenian) sedimentary rocks (Poschmann & Jansen, in prep.). One of the sections near Hombach village is characterized by the occurrence of several dark mud- and siltstone beds, rich in terrestrial plant material, which are intercalated into sandstones. In two of the fine-grained beds, well preserved land plants, articulate and inarticulate brachiopods, and a comparatively rich arthropod fauna have been found. The brachiopods ("LingulaRhenorensselaeria) indicate a marine influence. The sequence is assigned to a marginally marine environment, in which terrestrial and restrictedmarine animals were buried together. The arthropods are represented by eurypterids, terrestrial arachnids, chasmataspidids, and arthropleurids (Poschmann, Dunlop & Anderson, in prep.). The fauna contains the oldest occurrences of the eurypterids Parahughmilleria hefteri Stormer, 1973, Alkenopterus brevitelson St0rmer, 1974, and Moselopterus sp., of the chasmataspidid Diploaspis sp., and the arthropleurid ? Eoarthropleura in the Rhenish Slate Mountains. A similar arthropod association is only known from Lower Emsian strata of Aiken near Koblenz (Stormer, 1976). The Phalangiotarbida, an enigmatic order of terrestrial arachnids, have hitherto been known only from the Lower Carboniferous (Visean III) to the Lower Rotliegendes (boundary interval Carboniferous/Permian)

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IPC2002 Poster Presentations (RoBler & Schneider, 1997). The occurrence of fully developed representatives in the Siegenian section under consideration indicates an early separate development of this group. At last, trigonotarbid arachnids have been discovered which are the oldest evidence outside Great Britain where an Upper Silurian (Pridolian) form has been recorded (Jeram et al., 1990). Lithostratigraphically, the fossil-bearing sequence near Hombach village is assigned to the Lower Siegen beds. This is confirmed by the fact that it is overlain by a typical sequence of the Middle Siegen beds. In the latter, rich fully marine faunas, with echinoderms, bryozoans, tentaculites, bivalves, and brachiopods have been found. The presence of the brachiopod species "Orthotetes" ingens, Multispirifer solitarius, Fascistropheodonta sedgwicki, Boucotstrophea herculea, Acrospirifer primaevus etc., and the absence of Tropidoleptus carinatus rhenanus, Chonetes unkelensis, and Rhenorensselaeria demerathia, indicate a Middle Siegenian age of the succession. JERAM, A.J., SELDEN, P.A. and EDWARDS, D., 1990. Land animals in the Silurian: arachnids and myriapods from Shropshire, England. Science, 250: 658-661.

ROBLER, R. and Schneider, J.W., 1997. Eine bemerkenswerte Palaobiocoenose im Unterkarbon Mitteleuropas - Fossilfiihrung und Palaoenvironment der Hainichen-Subgruppe (Erzgebirge-Becken). Veroffentlichungen des Museums fur Naturkunde Chemnitz, 20: 5-44. ST0RMER, L., 1976. Arthropods from the Lower Devonian (Lower Emsian) of Aiken an der Mosel, Germany. Part 5: Myriapoda and additional forms, with general remarks on fauna and problems regarding invasion of land by arthropods. Senckenbergiana lethaea, 57(2/3): 87-183.

EVOLUTIONARY PATH OF THE FUSULINOIDA Svetlana T. REMIZOVA Institute of Geology Komi Science Centre RAN, Syktyvkar, Russia, [remizova@geo.komisc.ru] The superorder Fusulinoida was predominant component among the Late Palaeozoic invertebrate marine biota. Fusulinoida have taken place from Endothyroida in Early Carboniferous and during the existence have yielded 6 orders, more than 150 genera and almost 2500 specieses. Despite of variety and extreme evolutionary plasticity, Fusulinoida have extincted by the end of Permian epoch completely. Apparently, the causes of Fusulinoida extinction are not only in geologic cataclysms, but also in laws of evolutionary process. In the history of phylogenetic development of Fusulinoida can be distinguished the periods aromorphosis and idioadaptation. The phases of a becoming of large taxons (superorders, orders) are connected to the periods of aromorphosis. With the periods of idioadaptations are connected phases of adaptive irradiation and specialization. The originating of a new taxon was preceded with long process of its becoming. The evolutionary novelties arose as unstable aberrations, which one in further were stabilised under operating of natural selection. The gradual transferring consecutive genera each other are observed. The transforming of morphology of a shell pristinely encompassed final stages of an ontogenesis, being dislodged in process of evolutionary development on earlier stages. In rearrangements of constructional features of a shell is observed the correlation dependence. The integrative systems provide conformity of shell structural features and its functions (Solovieva, 1978). Malfunction of correlations was the cause of elimination of some taxons (fig.). In the whole directivity of Fusulinoida evolution in augmentation of the dimensions and complication of organism's organization showed. During an evolution Fusulinoida developed more and more complex structures for supply of communication of an organism with environment. Any evolving unit is characterized by a store of evolutionary potential consisting in historically adding up epigenic system. As a result of limitation of potential opportunities of structural variations of communicative system Fusulinoida within the framework of their structural - spacing entities in conditions with sharply varying environment in Late Permian time their further evolution has appeared impossible. SOLOVIEVA M.N. (1978) - Foraminiferal integrative systems. Voprosy micropaleontologii, 21, 3-16 (in Russian).

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COMPARISON OF THE JURASSIC DINOFLAGELLATE CYST RECORD IN THE NORTHERN HEMISPHERE AND AUSTRALASIA; IMPLICATIONS FOR LONG RANGE CORRELATIONS James B. RIDING British Geological Survey, Keyworth, Nottingham NG12 5GG, UK; [jbri@bgs.ac.uk]. The Jurassic dinoflagellate cyst records in the Northern Hemisphere, which is largely based on European studies, and Australasia exhibit marked incoherence. The ranges of selected cosmopolitan species are apparently markedly different. For example, the range tops of Nannoceratopsis pellucida and Rigaudella aemula are significantly younger in Australasia than in Europe. Reworking appears not to be a rational explanation for these disparate ranges. It is likely that palaeogeographical and/or palaeolatitudinal factors may explain some of the disparities. Between the hemispheres, macrofaunal correlations are significantly more problematical than palynological ones because molluscs exhibit much more endemism than palynomorphs and other microfossils. Approaches other than standard species range analysis may prove useful to long distance palynological correlation. These include generic ranges and statistical methods of assemblage characterisation. Strontium isotope stratigraphy will also be useful in providing independent age dates for key biozones. The principal areas of similarity and disparity are analysed in this assessment of the existing literature. The basic units analysed are the constituent biozones in the four Mid Triassic to Valanginian Superzones of Helby, Morgan and Partridge (1987), the standard Australian palynological zonation. The Shublikodinium Superzone (Anisian-Pliensbachian) is characterised by low diversity dinoflagellate cyst associations. Despite the presence of endemic Australasian forms, several key bioevents allow a good correlation with Europe. For example, the Rhaetogonyaulax rhaetica Interval Zone in Australia is deemed to be of late Rhaetian age due to the abundance of the index species. In the early Bajocian to late Callovian Pareodinia ceratophora Superzone of Australia, several of the constituent zones appear to be considerably older than the ages originally suggested by Helby et al. (1987) based on European dinoflagellate cyst datums. Similar patterns have been observed for the Oxfordian to Tithonian to Berriasian/Valanginian Pyxidiella and Fromea cylindrica superzones. Revised age interpretations are given for the Anisian to Berriasian/Valanginian dinoflagellate cyst zonation of Australia with supporting evidence from Europe. DISTRIBUTION OF SILURIAN-EARLY DEVONIAN MONGOLEPIDS (VERTEBRATA, CHONDRICHTHYES?). O. RODINA , V. KARATAJUTE-TALIMAA & A. IVANOV institute ofPetroleum Geology, Novosibirsk, Russia. Institute of Geology, Vilnius, Lithuania. Department ofPalaeontology, St. Petersburg University, St. Petersburg, Russia. 1

Mongolepids are known from the Lower Silurian, middle Llandovery of the Irkutsk Amphitheatre, Russia (Karatajute-Talimaa & Predtechenskiy, 1995); upper Llandovery of W Mongolia (Karatajute-Talimaa, 1995), the Tarim Basin (Wang et al., 1998), South China (Sansom et al, 2000) and Tuva (Karatajute-Talimaa,

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IPC2002 Poster Presentations 1995), and probably from the Lower Devonian (Lochkovian?) of E Mongolia (Wrona & Nyamsuren, 1998). Three well described taxa, Mongolepis, Sodolepis, Teslepis, were reported together rom the Khutsynbulak Beds, upper Llandovery of W Mongolia. An undescribed new genus (Udalepis according to KaratajuteTalimaa, 1995) was recorded from the upper Llandovery and Wenlock of Staroe Balturino in the Irkutsk Amphitheatre. Well preserved mongolepid scales are found in the Uste Sadra Beds, Maliy Bachat regional stage, Lower Emsian (Lower Devonian) of the Lebed' River Basin, Gorniy Altai, Siberia. They consist of few specimens but represent three taxa: Teslepis, cf. Mongolepis and a new genus Udalepis. It is the first report of mongolepids in the Altai-Sayan Foldbelt and youngest in the world. New material shows that mongolepids were more widely distributed than previously believed. The similar taxonomic composition shows the relations between the Altai and Mongolia during Silurian-Early Devonian time. The stratigraphic ranges of the mentioned taxa are almost all Silurian to Lower Devonian: from the Llandovery to Emsian. KARATAJUTE-TALIMAA, V.N., 1995. The Mongolepidida: scale structure and systematic position. In: Premiers Vertebres et Vertebres inferieurs, Eds. Lelievre, H., Wenz, S., Blieck, A. & Cloutier, R., Geobios, Memoire Special 19, 35-37. KARATAJUTE-TALIMAA, V.N. & PREDTECHENSKIY, N.N. 1995. The distribution of the vertebrates in the Late Ordovician and Early Silurian paleobasins of the Siberian Platform. Bulletin du Museum national d'Histoire naturelle, 4e ser., 17, section C, 39-55. SANSOM, I. J., ALDRIDGE, R.J. & SMITH, M.M., 2000. A microvertebrate fauna from the Llandovery of South China. Transactions of the Royal Society of Edinburgh: Earth Sciences 90, 255-272. WANG, N.Z., ZHANG, S., WANG, J.Q. & ZHU, M., 1998. Early Silurian chondrichthyan microfossils from Bachu County, Xinjiang, China. Vertebrata PalAsiatica 10, 257-267. WRONA, R. & NYAMSUREN, G. 1998. New Early Devonian chondrichthyan scales (Chondrichthyes) from eastern Mongolia. Mongolian Geoscientist, 10, p.79.

CONODONTS OF MIDDLE/UPPER DEVONIAN BOUNDARY BEDS IN THE RUDNYI ALTAI (RUSSIA) S.A. RODYGIN Tomsk State University, Tomsk, Russia In 1987 the International Subcommission on the Devonian stratigraphy (SDS) established, by voting, the Middle/Upper Devonian boundary (GSSP) in the base of the Lower asymmetricus Zone, where the conodont species Ancyrodella rotundiloba (Early form) was first recovered (Klapper et al.9 1987). Sandberg, Ziegler and Bultynck (1989) refined definition of this boundary. In the opinion of these authors, the GSSP for the D2/D3 boundary coincides with the level of combined occurrence of the Ancyrodella binodosa and A. pristina. In the new standard scale, developed with regard to evolution of pelagic conodonts, the GSSP for the D2/D3 boundary occurs within the Early falsiovalis Zone. Currently this boundary is placed at the top of the norrisi Zone (Ziegler and Sandberg, 1990; Johnson, 1990). Study of boundary levels in various regions and sequences ranks among the essential problems of conodont biostratigraphy. The Rudnyi Altai is a region where the Middle/Upper Devonian boundary level has been precisely defined by conodonts. In the Goryunovo region, horizons of the Lower Kamenevskaya Subsuite occur. These siliceous-terrigenous rocks with nodular limestones have produced the conodonts Klapperina disparilis, Polygnathus ovatinodosus Ziegler and Belodella devonica. Co-occurrence of first two species is characteristic for the top of the Givetian and the bottom of the Frasnian . In the Titovsko-Razdolninsky section in the Zolotukha Rriver basin (grey detrital limestone of the Upper Kamenevskaya Subsuite; sample 9744208-69) has association of the conodonts Mesotaxis falsiovalis, Ancyrodella binodosa, A. pristina, Polygnathus dengleri, P. decorosus, P. pennatus, P. lodinensis, P. normalis and Icriodus symmetricus. This assemblage belongs to the Lower falsiovalis Zone. Co-occurrence of Ancyrodella binodosa and A. pristina is characteristic for the beginning of the Frasnian Stage. This is the level of the Global Stratotype Section and Point (GSSP) for the base of the Frasnian Stage and for the Middle/Upper Devonian boundary. Consequently, these boundaries occur within the section studied, possibly in sample 9744208-69. The lower part of the reef facies of the Upper Kamenevskaya Subsuite is exposed in the Neverov limestone quarry. The following conodonts have been obtained from this exposure: Ancyrodella lobata, Polygnathus normalis, Belodella triangularis, Hindeodella aculeata, H. subtilis and Ozarkodina elegans. Corals, brachiopods, trilobites and other fossils, as well as the conodonts listed, indicate an early Frasnian age aligning with the falsiovalis-punctata zones. JOHNSON, J.G., 1990. Lower and Middle Devonian brachiopod-dominated communities of Nevada, and their position in a biofaciesprovince-realm model, with a section on Revision of Middle Devonian conodont Zones, by G. Klapper and J.G. Johnson. Journal of Paleontology 64, 902-941. KLAPPER, G., FEIST, R., and HOUSE, M.R., 1987. Decision on the Boundary Stratotype for the Middle/Upper Devonian Series Boundary. Episodes 10, No. 2,97-101.

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IPC2002 Poster Presentations SANDBERG, C.A., ZLEGLER, W., and BULTYNCK, P., 1989. New Standard Conodont Zones and Early Ancyrodella Phylogeny across Middle-Upper Devonian Boundary. Courier Forschungs-Institut Senckenberg 110, 195-230. ZlEGLER, W., and SANDBERG, C. A., 1990. The Late Devonian Standard Conodont Zonation. Courier Forschungs-Institut Senckenberg 121,1-115.

MARINE HOLOCENE OF URUGUAY: TEMPERATURE AND SALINITY INFERRED FROM MOLLUSCAN PALAEOECOLOGY Alejandra ROJAS & Sergio MARTINEZ Departamento de Paleontologia, Facultadde Ciencias, Igua 4225. CP 11400, Montevideo, Uruguay. E-mail: alejandra@fcien. edu. uy The taphonomic and palaeoecological study of mollusc assemblages from deposits of the Villa Soriano Formation of Uruguay allowed to determine globally the temperature and salinity that prevailed during part of the Holocene. This lithostratigraphic unit comprises great granulometric variability, from claystone to conglomerates, and is characteristic its mollusc richness. Chronologically, it has been situated in the Late Pleistocene-Holocene. The samples studied were taken from eleven localities situated along the coastline of Uruguay. The radiocarbonic dating of selected molluscs from all the localities considered, yielded ages from ca. 6000 yr AP to ca. 2400 yr AP. The analysis involved the taxonomic identification of the species found in each sample, all of which are extant, and its classification in relation to their thermic and salinity requirements. The relative proportions of the categories in each locality were compared with the information on temperature and salinity requirements of the present Uruguayan molluscan fauna. Related to palaeotemperature and considering the localities globally, we found a greater proportion of calid water species, and a lower of cold water species than nowadays. In addition, it was verified the presence of four calid water species that do not live in the Uruguayan coast today, and with a southern distributional limit situated northwards from Uruguay. In relation to palaeosalinity, limnic species were not registered, and a great proportion of marine species was found even in the subenvironments that today are occupied by brackish and fresh water. The mollusc assemblages show that temperature for the times considered was higher than nowadays, probably due to a stronger influence to the south of the Brazilian Calid Current. The presence of a higher proportion of marine species along the entire coast of the present Rio de la Plata estuary during the Holocene, shows that the marine influence was greater westwards than the stated by previous authors. THREE-DIMENSIONAL RECONSTRUCTIONS OF COMPOUND WALLS IN SOME ARCHAEOCYATHA S.V. ROZHNOV Palaeontological Institute, Russian Academy of Sciences,[sergey_r@paleo.ru] Archaeocyaths are Cambrian sponge-like animals which are very important for understanding early evolution of primitive metazoans, as well as for Lower Cambrian stratigraphy. An archaeocyath skeleton usually is cup-shaped and consists of two walls (outer and inner) connected by transverse or longitudinal plates. Walls are perforated either by pores or by canals that may bear various additional structures (e.g., spines, bracts, additional sheaths). Their morphology is commonly investigated in thin sections. Unfortunately, in some cases such a method obscures compound three-dimensional structures of the skeleton while the smallest but important details are unrecognizable. Thus, a number of unsupported speculations exists concerning some important skeletal structures which are influential for the basis systematic. SEM study of the threedimensionally preserved specimens etched naturally or with weak acids allows new and more correct reconstructions. In a longitudinal section so-called Ethmophyllum-XxkQ outer wall looks like a thin plate pierced by "A"shaped canals. Often by analogy with a common archaeocyathan wall structure (pore with bract), it is determined as a wall pierced by straight slightly inclined canals covered with downward curved extensions (bract), a curved spine grows vertically from the junction of canal and bract. As a result, archaeocyaths which wall structures are interpreted by such a way are classified together. North American Ethmophyllum, Aulocricus, Stephenicyathus, Cordilleracyathus, and Yukonocyathus possess Ethmophyllum-like outer walls. Geniculate (bent) canals are distinct structures in the limits of the wall. They lack bracts or any other extensions. There are two plates in the structure of each canal restricting the canal opening. The first plate grows upward at the bend of the canal, while the second plate grows downward at inner (exhalent) canal

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IPC2002 Poster Presentations opening. Thus, quite different structures that are geniculate canals and canals-plus-bracts are indistinguishable in thin sections now. The spine-like structure visible in thin sections of geniculate canals is in fact a short plate restricting the canal opening. This is also probably true for some Tuvinian species ascribed to Carinacyathus genus. Another Tuvinian genus Kordecyathus has a very complicated inner wall where each pore bears an upwardly curved extension (cupped bract) from the central cavity side. The distal margin of each bract joins with the base of the adjacent upper bract producing a vertical rib, which runs along the central cavity depth. Earlier such a structure was interpreted as an additional porous membrane completely covering the inner wall from inside. Canal covered with bract and geniculate canal differs by structure and possibly also by function. As a result, archaeocyaths differing so deeply in the outer wall structure have to be classified separately in the frames of current archaeocyathan taxonomy. On the other hand, archaeocyathan outer and inner walls probably have no compound structures in common.

TRACKING THE WORLD'S BIGGEST TRILOBITE SPECIES: TRACE FOSSILS FROM THE UPPER ORDOVICIAN OF NORTHERN MANITOBA, CANADA David M. RUDKIN1, Graham A. YOUNG2'3, Robert J. ELIAS3. and Edward P. DOBRZANSKI2 Department of Paleobiology, Royal Ontario Museum, Toronto, Ontario, Canada M5S 2C6; 2Manitoba Museum of Man and Nature, 190 Rupert Avenue, Winnipeg, Manitoba, Canada R3B 0N2; 3Department of Geological Sciences, University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2. One of the most spectacular examples of a Paaleozoic rocky shore succession is exposed along the coast of Hudson Bay near Churchill, Manitoba. Here, a thin sequence of transgressive carbonates of the Churchill River Group (Upper Ordovician, Richmondian) was deposited over a boulder-strewn platform adjacent to an elongate ridge of Precambrian Churchill Quartzite. This exhumed palaeoshore, which represents deposition in a tropical epeiric setting, is coincident with the modern subarctic coastline. It has yielded rare individuals of a very large new species of Isotelus (Trilobita: Asaphidae), including an impressive specimen (70 cm long) that is currently the world's largest known trilobite. This species occurs in an interval of the carbonate succession considered to have been deposited under nearshore, shallow subtidal conditions, with hydrodynamic energy decreasing as water depth increased. In addition, these strata bear a conspicuous ichnofauna including traces attributed to the activity of the giant trilobites on the basis of co-occurrence, similarity in size, and morphological correspondence. Our ongoing study of the large trilobite trace fossils, to date based on field observations and limited sampling, allows a preliminary description and interpretation. Individual traces are 5 to 40 centimetres wide (within the size range of co-occurring Isotelus specimens) and may exceed 1.5 metres in preserved length. The horizontal to slightly undulating traces may be straight, gently curved, exhibit sharp turns, or double back to run closely parallel in opposite directions. A typical trace consists of a shallow trough of roughly arcuate, nested bands with conspicuous relief, sometimes bounded laterally by low raised ridges. Interpretation of the mode of trace production must take into account several factors, including orientation of the arcuate bands with respect to direction of movement of the trilobite, and depth of formation within the substrate. The shape of the bands conforms roughly to the curvature of the anterior/posterior exoskeletal margins of Isotelus. Earlier workers assumed that these bands were oriented concave backwards and represented successive cephalic imprints. We tentatively suggest that the arcuate bands are concave forwards with respect to the trilobite's orientation and direction of movement, and that they are the surface expression of inclined, trough-shaped packages of sediment excavated by the appendages and packed behind the animal as it moved forwards. This is interpreted as systematic searching and feeding behaviour. Available evidence suggests that the traces were generated near or at the sediment-water interface. The apparently abrupt appearance and termination of individual traces may reflect slight adjustments in depth of penetration within the substrate. Unlike most forms typically associated with trilobite activity, these trace fossils are not obviously bilobate, nor do they clearly show evidence of paired appendages directly engaging the substrate. They are also unusual in being observed primarily on the upper bedding plane surfaces of shallow subtidal dolostone units. The Churchill River Group trilobite traces, as yet unnamed, bear a superficial resemblance to a number of other large Palaeozoic ichnotaxa such as Climactichnites, Beaconites, and Taenidium. The latter forms have been described mostly from siliciclastic units deposited in shallow subtidal to intertidal, fluvial, and coastal dune settings. The majority of these occurrences, however, postdate the end-Ordovician extinction of the Asaphidae and none of the traces has been convincingly attributed to a trilobite of any kind.

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PALAEOBIOSPHEROLOGY AS A NEW SCIENTIFIC METHOD IN BIOSTRATIGRAPHY AND BIOGEOCHRONOLOGY V.P. SAPEL'NIKOV, A.G. MIZENS, L.I. MIZENS Institute of geology and geochemistry UrB RAS, Pochtovyi pereulok, 7, Ekaterinburg, 620151, Russia Authors have offered palaeobiospherology as a new term (Sapel'nikov et al., 1999). It regards the research in one of the topical fields of historical geology - zonal biostratigraphy and evolutionary palaeontology. Therefore, palaeobiospherology represents a part of the doctrine on the biosphere of the Earth. It emerged from two scientific disciplines - palaeontology with its famous palaeontological (biological) method and stratigraphy. Being closely connected with each other, the aforementioned disciplines are of crucial importance in the system of the Earth Sciences. They determine development of both applied and scientific geology. It should be noted that in the beginning of the XIX century palaeontolgocial method, initially applied in mining and geological research, provided naturalists with such unique tools as the time scale and the geological map. This very method introduced and firmly established historicity and the idea of development in the geological and natural sciences. It also described the fundamental character of the palaeontological research as well as its general philosophical and heuristic significance. XX century, especially the beginning of its second half, marked an intensive development of the applied stratigraphical palaeontology. This was due to continually increasing demand for accuracy and validity of the standard chronostratigraphical scale, the subglobal correlation of sections, and various palaeogeological events. During that time period palaeontology was constantly improving its methodology and gradually drifting away from geology. It was transforming from a purely descriptive science into an independent theoretical one, enriched by general biological content, ideas of evolutionary and population genetics. These factors determined the development of palaeobiospherology as a new discipline in the sciences of the Earth and the Biosphere doctrine. Its main objective is to determine the pattern and specificity of the historical development of Earth palaeobiota and Earth stratisphere in their systematic unity and continuing geochronological sequence. The main geological goal is to develop the criteria for the objective high-quality subglobal correlation of various palaeoevents, basic (zonal) phylogenetically based stratons, and boundaries dividing them. The latter is of great importance because phylogenetical data mark in the most objective and accurate way the stages of evolutionary development of ancient fauna as well as various palaeobiological and geological events. To sum up, palaeobiospherology has two consequent connected stages of research: a) palaeobiologic study of ancient organisms, and b) based on it phylogenetic biozonal monotaxonomical stratification of the shelf formation. The former is characterized by the general historical and morfofunctional approach in the study of a specific fauna group evolution. The latter (stratigraphical method) provides highly guaranteed correlation and tracing of the specific phylogenetic zones that can be applied both as the local basic stratigraphical sections and as reliable regional biochronological equivalents of ISS. Principles and methods of this research can be found in two monographs on the system and phylogeny of pentamerids (Sapel'nikov, 1985a, b). In present time we are working on publishing a specialized book on the fundamentals of palaeobiospherology. It will also include a number of general and individual results obtained by means of palaeobiospherology. This work was funded by young scientist grant of UrB RAS. SAPEL'NIKOV V.P. 1985a. Morphological and Taxonomic evolution of brachiopods (order Pentamerida). Sverdlovsk, UNTs AN SSSR, 231 p. [In Russian] SAPEL'NIKOV V.P. 1985b. System and stratigraphical significance of brachiopod suborder Pentameridina. Moscow, Nauka, 206 p. [In Russian] SAPEL'NIKOV V.P., MIZENS L.I., MIZENS A.G. 1999. To the problem of the interrelation of the palaeobiospherology and the principle of binial'nost' in geology. Biniology - new natural science. Tyumen', TyumGNGU, p. 59-69. [In Russian]

DEVONIAN BRACHIOPOD COMMUNITIES FROM VOLCANIC-TERRIGENOUS DEPOSITS OF THE SOUTH URALS V.P. SAPEL'NIKOV. A.G. MIZENS, L.I. MIZENS Institute of geology and geochemistry UrB RAS, Pochtovyi pereulok, 7, Ekaterinburg, 620151, Russia The major part of Urals Middle Palaeozoic formations consists of volcanic deposits. Their stratification and definition of formation time is the most complicated problem of regional geology of Urals. Therefore the macrofauna found "in situ" in the volcanic strata is of especially important significance. In the middle of 90s of last century representative Community samples of those fauna were found in three different locations in the South Urals: in 1994 in the Ayat river, near Nikolaevka village (Zaural'skaya structure-facies zone), in

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IPC2002 Poster Presentations 1995 on the left bank of Bol'shoj Kizil river near Rysaevo village (western part of Magnitogorsk megazone), and in 1997 in the Sibai region within South-Fajzulino manganic field (the same megazone). In all three locations samples consist of corals, crinoids, rare mollusks, and different brachiopods. On the Ayat river Pragian age of unnamed strata of polymictic sandstones was determined on the base of the palaeontological data. Eight brachiopod species of Howellella and Hysterolites genera were found. They are characteristic for Konepruss limestones of Barrandian. They belong to brachiopod level bottom Community "Striispirifer" (Boucot, 1975). They are absent in the North reefal deposits of Urals and indirectly confirm the specificity of geological history of Devonian palaeobasin on the South Urals and its close connection with Palaeothetys of Europe. On the left bank of Bol'shoi Kizil river fauna was collected from tuff sandstones and tuff of pyroxeneplagioclase porphyrite of lower part of Irendyk formation. Brachiopod Community is represented here by one sample; it consists of 11 forms - Schizophoria sp., Fascizetina cf. evelina Havl., Iridiostrophial sp., Plebejochonetesl ex gr. plebejus (Schnur), Losvia cf. suboperosa (Khod.), Leiorhynchusl ex gr. strajeskiana (Vern.), Carinatina ex gr. arimaspa (Eichw.), Plesicarinatina cf. submala (Khod.), Karpinskia conjugula Tschern., Vagrania cf. osturalica Rzhon. et L.Miz., Multispirifer ex gr. sergaensis (Khod.), which permitted to determine their Emsian age. The latter gives convincing proof of correlation of the whole formation with Karpinsk and Tal'tiya horizons of the Urals, and one can refer it to Emsian and lowest part of Eifelian. This conclusion is of important significance for Urals Devonian biostratigraphy and its correlation with ISS. It gives evidence concerning indivisible time of forming volconogenous Irendyk formation and sea sediments of Karpinsk and Tal'tiya horizons. This time interval is of united integral stage in geological history of the whole Uralian region in Devonian period. However, fauna collected in South-Fajzulino manganic field is the most interest to us. It was discovered in the roof of hematite-quartzous lens on the contact with gray jaspers in the upper part of cherty Bugulygyr formation. Fauna is abundant and diverse. It is very leaching and replaced by manganese oxides. Fauna bedding is 40-50 cm thick. Brachiopods, tabulate corals, crinoids predominate; bryozoans and tetracorals are more rare, few pelecipods and gastropods. All fauna is notable for small sizes and general oppression. However its species composition is typical for benthos biota of the Urals. Brachiopods Schizophoria aff. schnuri Struve, Pentamerella ex gr. sosvaensis Khod., Gypidula cf. subbrevirostris Tjazh., Wyella! ex gr. suburalica Khod. et M.Breiv., Ivdelinia cf. multiplicata (Roem.), Kransia subcordiformis (Schnur), Beckmannia angularis (Phill.), Camerophorina cf. terpsichorae Sap. et L.Miz., Vagrania cf. ventosa (M. et I.Breiv.), Davidsonia verneuili Bouch.-Chant., Emanuella ex gr. pachyrincha Vern. and some others (more than 30 species) were determined. It is possible to establish Middle Eifelian age of this sample. But what makes of the fauna unique is that it belongs to palaeobiocenose of low-temperature near hydrothermal oasis of ancient organisms. This is the first discovery in the Urals, the study of which may result in obtaining principally new knowledge about life development on the Earth and palaeoecology of the life of ancient representatives. This work was funded by young scientist grant of UrB RAS. BOUCOT A.J. Evolution and extinction rate controls. Elsevier, Scientific Publishing Company. Amsterdam, Oxford, New York, 1975. 427 p.

FAUNAL RESPONSE OF BIVALVES AND GASTROPODS TO LARGE ENVIRONMENTAL DISTURBANCES CAUSED BY THE CONSTRUCTION OF A DYKE FOR RECLAMATION AND ITS PALAEOECOLOGIC IMPLICATIONS Shin'ichi SATO The Tohoku University Museum, Aoba, Aramaki, Aoba-ku, Sendai 980-8578, Japan Analysis of faunal response to large environmental disturbance can be a very instructive approach in ecology and palaeoecology. Recently, industrialization has resulted in large impacts on the natural environment. Such anthropogenic effects are especially noteworthy in tidal flat and estuarine environments around the Japanese coasts where many benthic animals are threatened with extinction. Descriptions of such artificial changes in the benthic community are useful in understanding the mechanisms of faunal response to large-scale environmental changes that occurred in the geologic past. On April 14, 1997, the inner part of Isahaya Bay was shut off from the Ariake Sea, western Kyushu, Japan with a dyke for reclamation. After construction of the dyke, aspects of water quality suddenly changed, and the fauna of bivalves and gastropods was drastically replaced. In March 1997, before the dyke was completed, 15 species of marine bivalves and gastropods were collected in large numbers. These species were still alive in May 1997, but most had died by August 1997. However, an introduced species, Potamocorbula sp. cf. P. laevis that was not found prior to the isolation of this bay, replaced the pre-isolation bivalve community. This species also increased in Saemangeum and Sihwa, western Korea, after dyke

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IPC2002 Poster Presentations construction. This species, therefore, can survive and multiply alone through large environmental changes such as isolation. Fossils of Potamocorbula sp. were also found from several horizons in Pleistocene and Holocene deposits in Japan and China. These fossils have common features: 1) most specimens are less than 10 mm in length, 2) only this species occurs densely in a shell bed, and 3) some marine bivalves occur in lower horizons of the shell bed. We observed that Potamocorbula sp. could survive and multiply alone after isolation, and we therefore suggest that aggregations of Potamocorbula shells in Pleistocene and Holocene deposits represent similar isolation events in the past. FIRST RECORD ON UPPER CARBONIFEROUS INSECTS AND PERMO-TRIASSIC TETRAPOD FOOTPRINTS FROM MOROCCO: BIOSTRATIGRAPHIC AND BIOGEOGRAPHIC IMPLICATIONS J. SCHNEIDER , D. HMICH , O.ELICKI ; F. KOERNER ; H. SABER ; M. EL WARTITI 1echnische Universitat Bergakademie Freiberg, Germany; Universite Mohammed V, Rabat, Morocco; Universite Chouaibid Doukkali, ElJadida, Morocco 1

Broutin et al (1989, 1998), El Wartiti et al (1990) and Saber et al (1995) have pointed out the close relationship of the C/P Macro- and Microfloras of Morocco and Europe, resulting from the immigration of Eurasian elements into North Gondwana. Recently (September 2001, March 2002), the first Moroccan Carboniferous/Permian (C/P) vertebrate remains (tetrapod bones, fish scales) and insects, besides other arthropods (conchostracans, ostracods) and bivalves, were sampled from three different localities of the Ida Ou Zal / Ida Ou Ziki sub-basins of the Souss basin of the High Atlas mountains West of Agadir. Additionally, in the overlaying Permian/Triassic (P/T) red beds of the Argana basin tetrapod footprints were discovered for the first time. Insects. The fossil bearing horizons of the Souss basin consist of dm-thick laminated black shales intercalated within fluvio-lacustrine plant bearing sequences. The entomofauna is dominated by blattoid insects of the families Opsiomylacridae, Spiloblattinidae and Phylloblattidae. Very frequent is the mesophile genus Opsiomylacris, which points together with common meso- to xerophile conifers on xeric conditions around the lake. Most important are the Spiloblattinidae. Because of their common occurrence in Europe and North America during the whole Stephanian and Autunian, an insect zonation has been established for this time interval (Schneider 1982, Schneider & Werneburg 1993). In phylomorphogenetic lineages, changing of colour patterns on their wings deliver useful chronospecies. Cross-checking with other zonations, likewise based on phylomorphogenetic lineages (e.g. amphibian zonation - Werneburg 1996 ff.; freshwater-shark teeth zonation - Schneider 1985, Schneider et al. 2001) and isotopic ages leads to relatively reliable ages. A first evaluation of the specimens of the Souss basin give a lower Gzhelian (300 - 303 Ma) age for the Moroccan entomofauna. Broutin et al. (1998) have discussed the occurrence of mixed Gondwanan/Euramerian and Gondwanan/Euramerian/Cathaysian floras in the Permian of North-West Gondwana (Morocco, Niger, Gabon), East Gondwana (Oman) and Spain. The Guadalcanal-Rio Viar locality in Southwestern Spain has delivered some insects besides the mixed flora. It can be assumed, that the entomofauna will contribute to the understanding of floral and faunal exchange between Gondwana and Laurasia and the evolution of Pangean C/P biota in general. Tetrapods. The Permotriassic Argana basin is well known for his Upper Triassic vertebrate assemblages (Dutuit 1976). Resulting from the discovery of Paraiasaurian skeletons (Jalil & Dutuit 1996), the formerly assumed lower Triassic part of the profil (T1 and T2) has been put in the Upper Permian. Just now (March 2002) first tetrapod footprints have been discovered in T2 or 7T2/T3 transition near the Paraiasaurian locality close to Irehri village. A first examination indicates the ichno-taxa Ichniotherium and Rhynchosauroides. Ichniotherium has his First Appearance Date (FAD) in the Val Gardena Formation of the Bletterbach Section in the Southern Alps (Italy). The famous ichnofauna of the Val Gardena Formation, displaying "clear Triassic affinity" is the youngest one in the Permian of Laurasia, based on palynomorphs of Upper Tatarian (Lopingian) age (Massari et al. 1994). Some of the trackways are ascribed to Gorgonopsids and Dicynodonts. A similar modern, but possibly somewhat older ichnofauna is known from the Southern French Lodeve basin (Gand et al. 2000). Excavations, just in progress, have delivered skeleton remains of Therapsidean affinity most possibly immigrants from Gondwana. Their FAD is linked to a sudden and drastic facies change from playa deposits via debris flows to fluvial channel and alluvial plain deposits. Biostratigraphic data based on insects, conchostracans and isotopic ages are in progress. First results point on climatically induced late Permian Pangea-wide faunal migrations (Schneider 1996, Schneider et al., in prep.).

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ORDOVICIAN GRAPTOLITE ZONATION FOR THE CENTRAL PART OF THE RUSSIAN PLATFORM Nikolay V. SENNIKOV Institute of Petroleum Geology of Siberian Branch of Russian Academy of Sciences, Novosibirsk, Russia Ordovician strata occur subsurface in the Moscow Syneclise, central Russian Platform. Mudstones and siltstones from 21 cores from 35 holes produced graptolites from depths between 600 and 2300 m. The ramosus, uralense Zone is established for the middle Tremadocian (Fig. 1); the association includes Rhabdinopora uralense (Obut), Bryograptus aff. kjerulfi Lapworth, Br. ramosus Brogger and Clonograptus tenellus (Linnarsson). The murrayi Zone is defined In the late Tremadocian; it is characterized by Adelograptus cf. hunnebergensis (Moberg), Araneograptus cf. murrayi (J.Hall), Temnograptus aff. multiplex (Nicholson) and Acrograptus geometricus (Tornquist). The graptolite association of the lowermost Arenigian phyllograptoides, approximatus Zone in the Moscow includes Tetragraptus phyllograptoides Linnarsson, Tetragraptus bigsbyi aff. divergens Monsen, Paratetragraptus approximatus (Nicholson). The succeeding balticus Zone is represented by Acrograptus balticus (Tullberg), Tetragraptus bigsbyi (Hall), T. serra (Brongniart), T. aff. phyllograptoides Linnarsson, Eotetragraptus quadribrachiatus (Hall), Expansograptus taimyrensis Obut & Sobolevskaya, Ex. ex gr. validus (Tornquist), Ex. ex gr. suecicus (Tullberg), Kinnegraptus aff. kinnekullensis Skoglund and Phyllograptus densus Tornquist. The graptolite association of the overlying densus Zone includes Phyllograptus densus Tornquist, Ph. anna Hall, Ph. ilicifolius glaber Monsen, Pseudophyllograptus angustifolius regularis (Monsen), Azygograptus aff. ellesae Monsen, Az. aff. suecicus Moberg, Acrograptus nicholsoni (Lapworth), Corymbograptus aff. deflexus (Elles et Wood) and Expansograptus aff. praenuntius (Tornquist). The next zone is the angustifolius elongatus Zone characterized by Pseudophyllograptus angustifolius elongatus (Bulman), Ps. angustifolius regularis (Monsen), Phyllograptus anna Hall, Ph. ilicifolius Hall, Ph. ex gr. densus Tornquist, Tetragraptus bigsbyi (Hall), T. ex gr. serra (Brongniart), Eotetragraptus crucifer (Hall), Eot. harti (T.S.Hall), Eot. headi (Hall), Eot. quadribrachiatus (J. Hall), Eot. harti (T.S. Hall), Expansograptus suecicus (Tullberg), Ex. extensus (Hall), Ex. slemmerstadi (Monsen), Acrograptus ex gr. nicholsoni (Lapworth), Corymbograptus cf. uniformis (Elles &Wood), Cor. cf. deflexus (Elles et Wood). The hirundo zone is discriminated in the upper part of the Arenigian; it includes Expansograptus hirundo (Salter), Ex. suecicus (Tullberg) and Tetragraptus aff. serra Brongniart. Three zones were established for Llanvirnian of the Moscow Syneclise. They are: 1) "artus", 2) murchisoni, geminus and 3) "teretiusculus". The first, previously referred to as the bifidu Zone, is provisionally distinguished as beds with graptolites lacking index-species. It is overlain by the Arenigian hirundo Zone and underlain by the Llanvirnian murchisoni, geminus Zone. Characteristic of the "artus" Zone are Expansograptus sp., Pseudoclimacograptus ex gr. scharenbergi (Lapworth) and Amplexograptus sp. The graptolite association of Didymograptus murchisoni (Beck), Did. geminus (Hisinger), Did. pakrianus Jaanusson, Expansograptus sp., Eoglyptograptus ex gr. dentatus (Brongniart) and Pseudoclimacograptus ex gr. scharenbergi (Lapworth) represent the murchisoni, geminus Zone. The "teretiusculus" beds can be discriminated in the upper part of the Llanvirnian in the Moscow palaeobasin. Though zonal index-species were not found, this interval is well correlated with beds with Amplexograptus perexcavatus (Lapworth), Oepikograptus bekkeri (Opik) and Gymnograptus linnarssoni Tullberg that have limited stratigraphic ranges. Probably the upper part of this subdivision coincides with the lower part of Caradocian. Beds with Amplexograptus fallax Bulman and Climacograptus brevis Elles & Wood are proposed for the middle part of the Caradocian of the Russian Platform. Beds with Orthograptus calcaratus basilicus Elles & Wood can be discriminated in the upper Caradocian and possibly lower Ashgillian of the Moscow palaeobasin. Graptolite associations obtained from Ordovician strata in the central part of the Russian Platform are widely distributed forms. Tremadocian and early Arenigian graptolite associations in the studied sequences include many taxa known only from the Baltica palaeobasin.

REVISION OF THE BIOSTRATIGRAPHICAL AND PALAEOBIOGEOGRAPHICAL DISTRIBUTION OF THE ORDOVICIAN ACRITARCH CORYPHIDIUM Thomas SERVAIS1 & Jun LI2 1 UP RES A 8014 DUCNRS, SN5, USTL, Cite Scientifique, F-59655 Villeneuve d'Ascq, France [Thomas.Servais@univ-lillel.fr]; 2Nanjing Institute of Geology and Palaeontology, Academia Sinica, Nanjing 210008, China [junli@nigpas.ac.cn]

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IPC2002 Poster Presentations The acritarch genus Coryphidium Vavrdova, 1972, and its type species C. bohemicum were first described from the "Arenigian" Klabava Shales of Bohemia. Additional species were subsequently described from the Tadla Basin in Morocco by Cramer and coworkers in the early 1970s (C. almohadillum, C. australe, C. barakum, C. elegans, C. miladae, C. minutum, C. ramiferum, C. tadlanum), and more recently from Iran (C. persicanum Ghavidel-syooki, 1990) and from southern China (C. longispinosum Gao Lianda, 1991). The attribution of the species C. sichuanense Wang Fuxing & Chen Qiao, 1987, described from the Lower Cambrian of China, to the genus Coryphidium is rejected. The revision of the literature shows that the genus has now been mentioned in over 100 publications. The data available in previously published papers, the reinvestigation of the material from the type-localities in Bohemia, Morocco and China, and additional studies of large populations of Coryphidium from other areas allow a revision of the biostratigraphy and of the palaeobiogeography of the genus. This revision indicates that Coryphidium shows a large intraspecific variability. In addition, the genus is strongly related to the genus Vavrdovella Loeblich Jr. & Tappan, 1976 (nom. subst. pro Tetradinium Vavrdova, 1972, non Tetradinium Klebs, 1912). Due to the very high variability it is difficult to establish clear biostratigraphical informations at the specific level. At the generic level, however, the genus Coryphidium is of great importance, both in biostratigraphical and palaeogeographical terms. In terms of biostratigraphy, the first species appear in the uppermost Tremadocian, indicating a First Appearance Datum (FAD) in the A. murrayi graptolite Biozone (Servais & Mette, 2000). The genus is very abundant in the "Arenigian" and "Llanvirnian", i.e. in the upper part of the Lower Ordovician and in the whole Middle Ordovician. Palaeogeographically, the genus is limited to peri-Gondwanan localities. Together with the the species Arbusculidium filamentosum (Vavrdova, 1965) Vavrdova, 1972, emend. Fatka & Brocke, 1999, and the genus Striatotheca Burmann, 1970, Coryphidium is an indicator of the "peri-Gondwanan acritarch province" that extends around the border of Gondwana in a zone reaching from Argentina through northern Africa and peri-Gondwana (Avalonia, Armorican Terrane Assemblage, Perunica, etc.) up to Iran, Pakistan and southern China (Li and Servais, 2002), i.e., from high latitudes around the South Pole to low latitudes at the equator. This is a contribution to the IGCP project nr. 410 "The Great Ordovician Biodiversification Event" and to the French-Chinese PICS project (CNRS-Academia Sinica). Li JUN and SERVAIS, T., 2002. Ordovician acritarchs from China and their utility for global palaeobiogeography. Bulletin de la Societe Geologique de France (in press).

SERVAIS, T. and METTE, W., 2000. The messaoudensis-trifidum

acritarch assemblage (Ordovician: late Tremadoc-early Arenig) of the Barriga Formation, Sierra Morena (SW-Spain). Review of Palaeobotany and Palynology 113: 145-163.

A REVIEW OF FOSSIL CONCHOSTRACANS FROM THE TACUAREMBO FORMATION, URUGUAY, WITH NOTES ON ITS GEOLOGICAL AGE SHEN Yanbin , Oscar GALLEGO , Sergio MARTINEZ Nanjing Institute of Geology and palaeontology, Chinese Academy of Sciences, 39 East Beijing Road, Nanjing 210008, P. R. China.[ybshen@jlonline.com]; Dpto. Biologia - Paleontologia (FACENA- UNNE) y Area Paleontologia (CECOAL-CONICET), Casilla de Correo 128, 3400 Corrientes. Argentina. [ofgallego@hotmail.com]; Depto. Paleontologia, INGEPA, Facultad de Ciencias, Igua 4225, 11400 Montevideo, Uruguay. [smart@fcien.edu.uy] 1

Fossil conchostracans are rare in Uruguay. There are only two records of it presence in, one from the Upper Permian (Yaguari Formation), and the other from the Lower Cretaceous (Castellanos Formation). In 1985, Cyzicus (Lioestheria) ferrandoi Herbst was the first described fossil conchostracan from the (informal) lower member of the Tacuarembo Formation, dated then as Late Triassic in age. We restudied these materials (from original localities), which come from two levels of the lower member of the Tacuarembo Formation. According to new taxonomic scheme of these fossils and correlation with Africa and China we placed them in the genus Migransia, and suggest that this formation seems to be probably of Late Jurassic in age, and might be possibly extended into Early Cretaceous. The Tacuarembo Formation crops out mainly in a discontinuous north-south trending belt in the Uruguayan Departments of Tacuarembo and Rivera. Two unnamed members can be distinguished within the formation. In the lower member subhorizontal stratifications are the predominant sedimentary structure. There is an alternation of different lithologies, mainly fine- and medium grained sandstones, shales, siltstones and mudstones. The lower member is an important fossiliferous bed and might be deposited in a subaquatic environment, but other authors proposed a depositional environment of braided rivers. The upper member is characterized by the presence of sandstones produced by the sedimentation of sand dunes in an arid environment. This member is non-fossiliferous.

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IPC2002 Poster Presentations The lower member of Tacuarembo Formation yields a variety of freshwater fossil groups, including unionoid bivalves (Tacuaremboia caorsii, Diplodon batoviensis, Diplodon dasilvai), gastropods, ostracods, conchostracans, ichnofossils, osteichthyes (Semionotidae, Ceratodus), crocodiles, fresh-water sharks, and dinosaurs, but most of these provide only questionable evidence about the age of the formation. They are poorly preserved, which makes precise identification of lower taxa very difficult, and those adequately classified have a long geological range. The age of the formation has been estimated on the basis of purely stratigraphic criteria. There is no agreement in the published literature. Different authors assigned to the Tacuarembo Formation an age interval from the Late Triassic or Early Jurassic to the Early Cretaceous. They pointed out a relative uncertainty about the limits of the age, especially if the Lower Member belongs to the Upper Jurassic or the Lower Cretaceous. Recently progress in the finding of vertebrate fossils (Perea et al., 2001. Palaeontology 44, 1227) provide a valuable evidence for the geological age of the formation, as the record of dinosaurs (theropod teeth) which is similar to certain Coelurosauria, and the first non African finding of the fresh water hybodontid shark Priohybodus arambourgi which is only previously known from the Upper Jurassic to Lower Cretaceous deposits of Saharan, Africa. The latter allowed the authors to propose an Upper Jurassic-Lower Cretaceous age for the formation. The overlying Arapey Formation has been radiometrically dated by K/Ar providing 126.8 ± 3.1 Ma for the younger volcanic events to 152.4 ± 8.2Ma for the older ones, which lies on, or is interbedded with, the upper section of Tacuarembo Formation. Taking into account the radiometric dates, the stratigraphic relationships, and the known fossil record of Priohybodus arambourgi (fresh-water shark), the Tacuarembo Formation would not be older than Kimmeridgian or younger than Hauterivian in age. The fossil conchostracans from the lower member of Tacuarembo Fm. are characterized by having small carapace, subcircular configuration, short dorsal margin, numerous growth lines that bears serration structure along its lower margin and interspaces ornamented with more regular radial striae which is not continue in the external mold at the middle and upper parts of the valve. Migransia ferrandoi (Herbst) is very closest to M biaroensis (Defretin-Lefranc) and M. caheni (DefretinLefranc) in its shell configuration, ornamentation and serration margin. Both latter were found from the Stanleyville Series, N Congo basin, which is considered to be of Late Jurassic (Kimmeridgian) in age. M. ferrandoi (Herbst) is also somewhat similar to M kasaiensis (Marliere) that was from Wealden sediments, N Congo basin in the ornamentation. In China Migransia first appears in Late Jurassic (Kimmeridgian) and developed in Early Cretaceous (Barriasian—Barremian). M ferrandoi (Herbst) is more similar to those of Late Jurassic than that of Early Cretaceous based on its discontinuous radial striae. Migransia sichuanensis (Shen et Chen) and Qinghaiestheria hungshuikouensis (Chang) were collected from the Upper Jurassic Penglaizhen Formation in Sichuan Province, SW China and the Upper Jurassic Hungshuikou Formation, Qinghai Province NW China respectively. Thus it can be seen that the conchostracans of the lower member of Tacuarembo Formation show more similarities to those of Late Jurassic in Congo Basin and China than that of Early Cretaceous. So we suggest this formation seems to be an age not older than Late Jurassic, possible of Late Jurassic (probably Kimmeridgian), but the possibility that it extended into Early Cretaceous can not be completely ruled out. This seems to be in favor of isotopic dating and fossil fresh-water sharks.

DATING THE MUNDOONEN SANDSTONE Lawrence SHERWIN1 & Desmond STRUSZ2 1 Geological Survey of New South Wales, 2 Geology Department, Australian National University The Mundoonen Sandstone (Sherrard 1939, Crook et al 1973) is a unit of problematic age and relationships. Recent mapping by the Geological Survey of NSW indicates that in the type section of the formation, and for many kilometres north and south, the Mundoonen Sandstone consists of several stacked fault slices. The true thickness is thus likely to be less than the 2800 m quoted by Pickett (1982), though still about 1000 m. Most of its western margin is faulted against the Hawkins Volcanics. However, in a short well exposed section in a railway cutting just west of the Mundoonen Range, the Hawkins Volcanics overlie the Mundoonen Sandstone with slight angular unconformity. The base of the Mundoonen Sandstone, where not faulted, is gradational with Late Ordovician black siliceous shales, conventionally assigned to the Warbisco Shale. Recent road works a few kilometres north of Murrumbateman show the onset of Mundoonen Sandstone type sedimentation as thin sandy bands within the underlying Warbisco Shale. Graptolites in the Warbisco Shale in this region, although poorly preserved, favour a Late Ordovician (Eastonian) age. The base of the Mundoonen Sandstone is thus of Ordovician age, but unlikely to be much older than the Eastonian-Bolindian boundary.

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IPC2002 Poster Presentations The fauna reported from the upper Mundoonen Sandstone (Crook et al 1973) is poorly preserved, with no remaining calcareous matter. However, it is sufficiently distinctive to indicate approximate age equivalence with that known from the Bango Limestone Member (Hawkins Volcanics), which passes laterally into silts and sands. The species listed dated the fauna as no older than Wenlock. The authors assigned a late Llandovery to early Wenlock age to the Mundoonen Sandstone. They also reported a specimen of Monograptus dubius from silty lenses within the Bango Limestone. This has a damaged proximal end, but the proximal curvature is typical of the late Wenlock meneghini group. This results in the paradox of (late) Wenlock Hawkins Volcanics, dated by the fauna within sedimentary members, resting with gentle unconformity on the Mundoonen Sandstone with a fauna of similar age in its upper part. One possible but unproven solution is that the repeated fault slices within the Mundoonen Sandstone could include slices of sedimentary parts of the Hawkins Volcanics, especially if these were more laterally extensive than the actual volcanic component. Two such sandy units separated only by a low-angle unconformity would be difficult to distinguish, a possibility admitted by Crook et al (1973). The same situation could exist farther south, almost along strike, between Canberra and Bredbo. In Canberra, if the thin, graptolitic State Circle Shale were locally eroded away in a late Llandovery - early Wenlock event, it could be difficult to separate Black Mountain Sandstone from more resistant sandstones within the Pittman Formation. Moreover, multiple faulting such as in the type area of the Mundoonen Sandstone is likely to result in loss of less competent units like the State Circle Shale. Based on these arguments, the Mundoonen Sandstone (sensu stricto) is currently regarded as having a gradational lower boundary of Eastonian - Bolindian age. The overall thickness of the unit suggests that it probably spans the remainder of the Ordovician. The age of the upper boundary is much less certain. It is clearly older than late Wenlock, given the unconformable relationship with the overlying Hawkins Volcanics. Given these uncertainties, the age of the upper boundary of the Mundoonen Sandstone is best considered to be post Bolindian but pre Wenlock - i.e. within the Llandovery. The contribution by L. Sherwin is published with the approval of the Director General, Department of Mineral Resources. PICKETT, J., 1982 (ed). The Silurian System in New South Wales. Geological Survey of New South Wales, Bulletin 29, 264 pp. CROOK, K.A.W., BEIN, J., HUGHES, R.J. & SCOTT, P.H., 1973. Ordovician and Silurian history of the southeastern part of the Lachlan

Geosyncline. Geological Society of Australia Journal 20, 113-138.

SHERRARD, K.M., 1939. The general geology of the district east of Yass, N.S.W. Proceedings of the Linnean Society of New South

Wales 61, 131-150.

CALCAREOUS NANNOFOSSILS FROM THE CRETACEOUS-PALEOGENE BOUNDARY S.I. SHUMENKO & A.V. MATVEYEV Kharkov National university, Ukraine The question about the position of Danian stage is extremely important for global stratigraphy because of the problem of a boundary of Mesozoic and Cenozoic. The nannofossils studying at this boundary was started in sixties of last century and goes on till now due to that apeared new data. Recently our attention was concentrated on the east part of Peritethys and first of all on the section, which were considered as continuum ones by many authors. The study of Farafra (Egypt) and Mangyshlek (Kazakhstan) sections has shown that there is a hiatus on the boundary of maastrichtian and danian stages it is minimal in Farafra and here the part of the upper maastrichtian zone M.prinsii has retained. As in many world regions on the boundary Maastrichtian - Danian here the majority of Mesozoic nannofossils species disappear and new Cenozoic ones appear. However it's necessary to note that in the North Africa the diminution of the nannofossils species though in much less degree is marked as on the boundary Campanian - Maastrichtian as in the type Maastrichtian. These facts testify against the hypothesis of cosmic catastrophe as the only one or the main factor resulting to nannoflora change. It is preferable a suggestion about the significant variations in the system of Tethys ocean connected with hydrohemical and thermal characteristics of all World ocean. The cosmic cataclysms may by only additional but not basic factor. THE SEDIMENTOLOGY, PALYNOLOGY, AND ENVIRONMENT OF DEPOSITION OF THE MID TO LATE TRIASSIC (LADINIAN TO NORIAN) OF THE CHALLIS OIL FIELD, NORTH WEST SHELF, AUSTRALIA Natalie SINCLAIR

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IPC2002 Poster Presentations Geoscience Australia; [Natalie.Sinclair@ga.gov.au] This project was the first attempt to integrate sedimentology, palynological analyses, and wireline log parameters to refine the environment of deposition at the Challis Oil Field, and to determine if relationships could be identified and used predictively, between palynological assemblages and wireline log signatures. This study has refined the interpretation of the depositional environment of the Triassic (Ladinian to Norian) Challis Formation sediments. The sediments and the associated organic matter are interpreted as being deposited in a broad macrotidal dominated estuary producing thin, laterally continuous tidal channel sands that grade into overlying finer grained sediments deposited in subtidal, intertidal to supratidal mudflat environments. This conclusion is supported by detailed analysis of sedimentary structures, palynological assemblages and revised wireline log correlations. The repetition of lithologies and palynological assemblages in vertical succession indicate this estuarine environment has been influenced by repeated minor transgressive events. These are represented as stacked, aggradational parasequences deposited in a Highstand Systems Tract. The parasequences are not seen to prograde or retrograde because sediment supply was equal to the accommodation space produced either by regional post rift thermal subsidence or sea level rise. Palynological assemblages were analysed to determine if the assemblages could be used for time correlation within the Challis Formation sequence. It is the conclusion of the present work that the repetition of plant microfossil assemblages is not always time significant, but reflect shifting environments, local influences and minor eustatic adjustments within the estuary. One Assemblage Group can be traced between wells and is informally named the Acritarch Horizon. This study has determined through sedimentary analysis that the units that contain this assemblage group are 0.2 to 1.5m thick and are lithologically variable. Routine palynological sampling in petroleum wells is rarely spaced closely enough to locate the thin units that contain this assemblage, and sampling from an adjacent unit containing a different lithology or palynological assemblage can confuse correlation. Likewise these units are too thin and lithologically variable to produce a characteristic wireline log signature. Well Completion Reports indicate the wireline logs have a resolution of approximately 2m, so these units are not able to be used for correlation using wireline logs. The correlation and timing of deposition of some units has been determined or refined in this study. Dolomitisation within the sequence is interpreted to be not just a diagenetic overprint but a primary feature in the Challis Formation sediments. 'Primary' dolomite may have formed as crusts in a supratidal environment, early cementation of the fine grained sediments may have occurred in the mixing zone between marine and meteoric water, or dolomite replacement occurred of a previously existing carbonate other than calcite or siderite. The 'sand stringers' in Challis 4 are determined to have been deposited synchronously with the CS 3.0 sand unit as a result of marine palynomorphs present in the palynological samples at the equivalent depth. Implications for this interpretation is that the sand stringers may be well connected to the main sandstone reservoir and may be less argillaceous than previously thought, allowing for better production from these stringers. Similarly the uppermost sand unit in Challis 14 is reinterpreted to correlate with the CS 3.1 unit in the neighbouring Challis 3 well. Detailed logging of the core and wireline log comparison revealed that the sand reservoir is thinner than previously interpreted, and the presence of a dolomitic horizon above the unit and an acritarch horizon below the unit that can be correlated to the Challis 3 well support this interpretation. The thinner interpretation of this unit has implications for the predicted petroleum reserves, however the probable increased lateral extent of the unit may compensate for the loss of thickness. This integrated study has added significantly to the delineation of the Challis reservoir and understanding of the environment of deposition of the Challis Formation. Further work is needed to confirm the hypothesis that it is possible to identify a unique log signature that is characteristic of a certain lithology and palynological assemblage for use in field wide correlation in petroleum fields.

IDENTIFICATION OF THE PRAGIAN/EMSIAN BOUNDARY IN THE BARRANDIAN AREA (CZECH REPUBLIC) Ladislav SLAVIK Institute of Geology, Academy of Sciences CR, Rozvojova 135, 165 02 Prague, Czech Republic The Pragian/Emsian boundary with possible GSSPs were subjects of many discussions until the SDS (in 1989) accepted a level of the base of Polygnathus dehiscens conodont Zone. However, applicability of this marker is not easy in the Barrandian area where other Lower Devonian stages were proposed. The Praha Formation (a typical representative of the Pragian stage in the Barrandian area) is overlain by the Zlichov Limestone of the Zlichovian stage (or lower Emsian substage). The original base of the Zlichovian was at the base of the Kaplicka breccias (cf. the Basal Zlichovian Event, Chlupac & Kukal (1986). This Zlichovian base lies significantly higher than any first occurrences of Polygnathus dehiscens Philip & Jackson (or Po.

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IPC2002 Poster Presentations kitabicus—a disputable concept of Yolkin et al, 1994), i.e., several metres into the Praha Formation. Besides, there are still persisting problems of dealing with differing viewpoints of workers as regards taxonomy and evolution of early polygnathids (e.g. Mawson, 1995). Scarcity and differences in first findings of Po. dehiscens seem to be the main problem in this region. Another lithological marker separates the latest portion of the Praha Formation, in practice among scattered pccurrences of Po. dehiscens. This is a graptolite-bearing interval with Monograptus atopus Boucek in the Stydle vody section. The detailed strata sequence at this horizon was described by Hladil et al. (1996); correlation with several other sections in the NW limb of the Barrandian brachysynform has been suggested. Unfortunately, several discoveries of Po. dehiscens are older than this black-shale event horizon (Kalvoda and Schoenlaub in Chlupac & Lukes, 1999), which precludes coupling of this event with the base of the range of this taxon. This GSSP-defining taxon embraces two subspecies, Polygnathus dehiscens dehiscens Philip & Jackson and Po. dehiscens excavatus (Carls & Gandl), representing indices for the lower and upper subzone, respectively. With regard to the disputable "kitabicus" r r sample concept of Yolkin et al. (1994), no Po. kitabicus has been found in the Barrandian sections. Here, repeated sampling in six Pragian-Emsian sections revealed that polygnathids are an extremely scarce and M stratigraphically unreliable component. In contrast to problems with polygnathids, Latericriodus sa , i bilatericrescens gracilis Bultynck seems to be a promising alternative for recognition of this boundary I (17 specimens from 5 sections). L. b. gracilis is the 5 * oldest of the Latericriodus bilatericrescens group, and M 0a IQ O II fI conodonts of this species provide better indications of S1 5£ i the earliest Emsian in the Barrandian than the above polygnathids. The lowest occurrences of scattered elements belonging to the "dehiscens group", I haphazardly obtained from the Barrandian sections, roughly correspond to the level of occurrences of L. b. gracilis. A regular presence of L. b. gracilis in several sections (such as Na Pozarech, Na Branzovech, Stydle vody and Mramorka) allows suggestion of a new "gracilis Zone". The first occurrences of this taxon in sections allows good correlation with Morocco (cf. An example of conodont distribution in Pragian/Emsian interval in the Stydie vody section Bultynck, 1985; Benfrika, 1994). BENFRIKA, M. 1994. Conodontes Siluriens et Devoniens (Wenlock-Givetien) du Nord-Ouest de la Meseta Marocaine: Systematique, Stratigraphie et Biofacies. MS Katholieke Universiteit Leuven, 261 p. BULTYNCK, P. 1985. Lower Devonian (Emsian) - Middle Devonian (Eifelian and lowermost Givetian) conodont successions from Ma'der and the Tafilalt, southern Morocco. Cour. Forsch. Inst. Senckenberg 75, 261-286. CHLUPAC, I. and KUKAL, Z. 1986. Reflection of possible global Devonian events in the Barrandian area, CSSR. In WALLISER, O.H. (ed) Global Bio-Events, 169-179. CHLUPAC, I. and LUKES, P. 1999. Pragian/ Zlichovian and Zlichovian/ Dalejan boundary sections in the Lower Devonian of the Barrandian area, Czech Republic. Newsl. Stratigr. 37, 75-100. HLADIL, J et al. 1996. Sedimentology and orientation of tentaculite shells in turbidite lime mudstone to packstone: Lower Devonian, Barrandian, Bohemia. J. Sedimentary Res. 66, 888-899. MAWSON, R. 1995. Early Devonian polygnathid conodont lineages with special reference to Australia. Cour. Forsch.-Inst. Senckenberg 182,389-398. YOLKIN, E.A., WEDDIGE, K., IZOKH, N.G. and ERINA, M.V. 1994. New Emsian conodont zonation (Lower Devonian). Cour. Forsch.Inst. Senckenberg 168, 139-157.

SPECIFICITY OF TEREBRATULIDS (BRACHIOPODA) FROM THE UPPER PERMIAN OF THE NORTHWESTERN RUSSIAN PLATFORM T.N. SMIRNOVA Moscow State University, Vorob'evy gory, Moscow, 119899 Russia; [tatsmirn@mtu.ru] The Kazanian terebratulids of the NW Russian Platform (Boreal Realm) were revised; ten species were found, the majority endemic to the Russian Platform; all forms are endemic to the Boreal Realm. Only Dielasma elongata is known in the German Zechstein, but some of the new Kazanian species from the Russian Platform may also occur in the German Zechstein—they are similar to many morphologic groups of terebratulids decribed by Brugge (1974) from the Zechstein.

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IPC2002 Poster Presentations / Transverse sections were made for recognition of genera. It was possible that besides Dielasma and Beecheria there are some new genera with unknown inner structure. All genera are absent from Tethys, though Dielasma occurs in Australia. A high level of species and genera endemism is characteristic of Upper Permian terebratulids of the Russian Platform. The presence of dental plates is a very important feature for discrimination of families. Terebratulids of Russian Platform have dental plates; terebratulids of Tethyan Realm are devoid of dental plates—both regions have different families. There are two big groups of Upper Permian terebratulids developed in parallel in the Tethyan and Boreal Realms. The family Dielasmatidae is absent in Tethys, but is widely distributed in the Boreal Realm and in Australia (Antiboreal Realm). A new family Beecheriidae is proposed with dental plates, a septalium in early growth stages, separation of crural bases from the hinge plate and their junction with the bottom of the shell in later growth stages. Beecheriidae includes the genera Beecheria Hall and Clarke, 1893 and Hoskingia Campbell, 1965, the last from Australia. The presence of the families Dielasmatidae and Beecheriidae in the Boreal and Antiboreal Realms demonstrates bipolar distribution of some Upper Permian terebratulids. These families are absent in Tethys. This research was made with support from the Russian Fund for Fundamental Investigation (RFFI) Jfs0204-48086. BRUGGE, N., 1974. Zur Kenntnis von Dielasma elongata (Schlotheim, 1816), einer Leitform (Brachiopoda, Terebratulida) aus dem Werra-Zyklus des Germanischen Zechsteins. Zeitschrift fur Geologische Wissenschaft. 2: 185-205

ACRITARCHS RETAINING THEIR VOLUME AND FEATURES DURING METAMORPHISM: PALAEOENVIRONMENTS, PALAEOBIOLOGY AND CLASSIFICATION A.M. STANEVICH Institute of the Earth's Crust SB RAS, 664033, Lermontov str., 128, Irkutsk, Russia Organic-walled Precambrian acritarchs (A) preserving their volume and features in metamorphic conditions up to low-grade greenschist facies (AV) have been known for a long time. The AV belong to the subgroup Implethomorphitae Jank. & Mikh. of the Acritarcha. The AV are often present in association with deformed and oblate A (AO, for example: Leiosphaeridia Eis., Podolina Herm., Pterospermopsimorpha Tim., etc.) within the same lamina. AV are small and less represented in shelf deposits than AO and are thus less well known. According to publications, AV are best known from the Folded Frame of the Siberian Platform (FFSP). Ecobiological interpretation of A associations from Meso- and Neoproterozoic sediments of the FFSP reflect shelf, slope and deep-sea floor conditions under different geodynamic basinal regimes. Morphological features of microfossils enable comparison with types of recent algae and bacteria whose metabolic properties correspond with the reconstructed biotopes. Four ecobiological groups of AV have been determined. Close relationship with the matrix of carbon-bearing silty claystones allowed us to speculate about attribution of most of these AV (e.g. Bavlinella Schep., Eomarginata Jank., Nucellosphaera Stan, and Rosella Stan.) to anaerobic, sulphate-reducing bacterial coenosis and about their dwelling and burial in varied settings up to aphotic bathyal zones. Coccolite structures such as Bavlinella, found in virtually all settings, seem to have represented colonial bacteria overlying remains of eukaryotic algae and prokaryotes in syngenesis or substituting for the forms they had during life. The star-like Floris Stan, are similar in their habitat and morphology to aerobic prosthecobacteria of recent water-bodies. The orthorhombic shape of Octoedrixium Rud is possibly determined by crystallization of trapped sulfur and its subsequent diffusion during diagenesis from cells of aerobic sulphur bacteria. Forms of the last two groups are found in shallow sediments of different types of basins. Some AV (Centrum and Tchuja Stan., Dictyodium minor Stan., Micrhystridium certum and M. insetum Trestsh., Retiforma Mikh., etc.) can be compared to the planktic forms of green algae in features of their reproductive organization and wide distribution in shelf deposits. Three group are found in Neoproterozoic sediments of the FFSP. The appearance of AV comparable with green algae coincides with formation of the foreland basin at the end of Late Riphean. The relatively synchronous appearance of forms belonging to this group is used for correlation in the FFSP. The last conclusion supports the axiom that evolutionary changes in Precambrian microbiotas can be revealed likely only in the limits of the biological cognate morphotypes. However, Acritarcha Evitt evidently includes dissipated remains of taxa up to kingdom-level. In addition, the principles and order of A classification are not direct for determining phylogenetic relationships of microfossils—biologically cognate forms can be attributed to different subgroups. Thus, with the purpose of obtaining a systematic perspective on the group Acritarcha, it is logical to modify this group so that subgroups can be distinguished according to

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IPC2002 Poster Presentations their biology and ecology. The ultimate objective is to discriminate probable natural communities. Division of the group based on different physical-chemical resistance of the forms to diagenetic and metamorphic factors was given earlier (Nemerov and Stanevich, 2001). It is proposed that the Acritarcha Evitt, 1963 be divided into subgroups: Oblisomorphi (Stanevich, 1999) subgr. nov., Impethomorphi (Jankauskas & Mikhailova, 1989) comb. nov. and Incertae sedis. The Oblisomorphi Stan (<oblisus, Lat., oblate) includes organic-walled forms observed only in oblatoid leaf-like state, i. e. which are not able to preserve the initial volume even in conditions of early diagenesis. The Implethomorphi (Jank. & Mikh.) Stan, includes morphologically diverse forms preserving the volume of the membrane and features under conditions of diagenesis and metamorphism. The Incertae sedis includes morphologically nonuniform microfossils whose features do not allow inclusion in either of the above two subgroups. The subgroups are divided into infragroups differing in morphology, ecology, etc. NEMEROV V.K. and STANEVICH A.M., 2001. Evolution of the Riphean-Vendian biolithogenesis settings in the Baikal Mountainous

Area. Geologiya i geofizika (Russian Geology and Geophysics) 42,456-470.

THE ORDOVICIAN OSTRACODS FROM THE SOUTHERN PART OF THE SIBERIAN PLATFORM Natalia I. STEPANOVA East-Siberian Sc. Res. Institute of Geology, Geophysics and Mineral Resources Decabrskih Sobitiy St., 29, Irkutsk, 664007, RUSSIA The Ordovician deposits are widely spread in the southern part of the Siberian platform. Rather often they have a rich palaeontological characteristic and they were studied by a lot of specialists. The stratotypes of some unified horizons of the regional stratigrafic scale of the Siberian platform are recovered here (Nikiforova, Andreeva, 1961; Problems of stratigrafy, 1977; Kanygin et al., 1989 et al.). The most imposing ostracods assemblages are known in karbonate and karbonate-terrigene rocs of the Krivolutskaya, Chertovskaya and Makarovskaya Formations of the Middle Ordovician of the Lena facial zone. In deposits of the Krivolutskaya and Chertovskaya Formations one can notice provincial ostracod zones, found in the Ordovician of the Siberian platform by A.V. Kanygin (Kanygin, 1985). In the Lower Krivolutskaya Subformation the assemblage of the zone Soanella maslovi (Volginskiy horizon) was represented, in the Upper Krivolutskaya Subformation - Quadrilobella recta (Kirensko-kudrinskiy horizon). The overlying Chertovskaya Formation is characterized by zone Bodenia aspera (Chertovskoy horizon). The assemblage is suplemented by new taxa, which stratigraphic range is limited by this zone. In the deposits of the Makarovskaya Formation there was discovered an assosiation, very much different from the provincial ostracod zone of the Baxanskiy horizon Parajonesites notabilis, spread on in the rest area of the Siberian platform. Together with the dominating ostracods Macronotella formosa, Schmidtella dorsicostata new taxa of the genera Glandites, Parenthatia, Tajurina and almost unknown on this stratigrafic level representatives of the family Quadrijugatoriidae Kesling et Hussey (relating to genera Soanella, Fidelitella, Fuscinites), were found. Their studying it still going on. he indicated complex is revealed in Lena facial zone on territory of the Makarovskaya Formation in the stratotypical area on r. Lena, r.r. Nepa, Tajura and others. This part of the section is the marginal part of the Siberian epicontinental basin of the Caradoc time. The significant difference from typical complex of the provincial ostracod zone Parajonesites notabilis may be explained by facials features of the sedimentary basin. Besides, in deposits of the Makarovskaya Formation there are cephalopods and conodonts of the Baxanskiy age.

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Stage

Sistem

Series

Table

Horizon

Macronotella formosa V.Ivan., Schmidtella dorsicostata V.Ivan., Glandites vigens sp.n., Fuscinites simmetricus sp.n., Soanella lenaica sp.n., S. proxima sp.n., Fidelitella insueta sp.n., Parenthatia distincta sp.n.

Chertovskoy

Bodenia aspera

Bodenia aspera V.Ivan., Coelochilina sp., Tajurina admiranda sp.n., T. parva sp.n., Bichilina sibirica sp.n.

Kirenskokudrinskiy

Quadrilobell a recta

Quadrilobella recta V.Ivan., Q. arpilobata V.Ivan., Primitia annae V.Ivan., Fidelitella simplex V.Ivan., F. unica V.Ivan., Schmidtella dorsicostata V.Ivan., Pribylina levis V.Ivan., Ginella primitiformis V.Ivan, et al.

Volginskiy

Soanella maslovi

Soanella maslovi V.Ivan., S. arpilobata V.Ivan., Sibiritella costata V.Ivan., S. rara V.Ivan., Egorovella defecta V.Ivan., E. cuneata Kan., Schmidtella spinosa Kan. et al.

Middle

Llandeillo

< u >

SIBERIAN PLATFORM Lena facial zone (characteristics species)

Parajonesite s notabilis

Baxanskiy

Caradoc

Ostracod zone

ORGANIC-WALLED FOSSILS AND ACRITARCHS FROM THE VENDIAN AND LOWER CAMBRIAN OF THE SIBERIAN PLATFORM Tatjana F. SUBITSKAYA East Siberian Scientific Institute of Geology, Geophysics and Mineral Resources, Dekabrskih Sobitiy St. 29, 664007 Irkutsk, Russia. Vendian deposits of the East Europe platform come from four horizons: Drevianian, Redkinian, Kotlinian and Rovenian. Across the boundaries of these divisions there are global changes in taxonomic structure of the microbiota. Within the limits of the Siberian platform, a large evolutionary change occurs in Vendian biota between the base of the Riphean and authentic Cambrian. This event can be subdivided into two biostratigraphic horizons: Talahsky and Ajansky. The first horizon contains an acritarch association with obvious similarity to Vendian microbiota—based on comparison with acritarchs of the East Europe platform. Together with numerous environments having Leiosphaeridia and elementary filamentous algae, which have little importance in correlation, the acritarchs Spumosina, Bavlinella, Podolina and Podoliella, typical for Vendian, are present. The association is limited in distribution. Above this assemblage, at the base of the upper Nepa subhorizon, there is a significant biological event. Against a background of development of simple Leiosphaeridia, there are three associations displaying a variety of acritarchs (complex III). Two of them, with index III-A and III-B, are endemic and are also dated as Late Vendian (Vendian-Cembrian). The first consists of fine concentric-layered acritarchs of genera Bailikania, Aducta, Sibiriella, Paracrassosphaera and others. In association III-B are oval and lengthened forms referred to the genera Leiovalia and Navifusa. Of special interest with association III-C are various acritarchs with needles/thorns belonging to the genera Comasphaeridium, Gonoisphaeridium, Baltisphaeridium and Skiagia. This association occurs in all zones of the Sugdjero-Nepa and PredpatomVilui structural-facial zones (the Ajansky biostratigraphy horizon) on the same stratigraphic level—occurring in the essentially terrigenous upper Nepa subhorizon and in the basal Danilovsky carbonate horizon (with terrigenous partings). Absence of Acanthomorphitae later in the Danilovsky is regarded as reflecting insalubrious conditions. In East European Platform deposits, the acritarch association of Skiagia, Comasphaeridium, Gonoisphaeridium and Baltisphaeridium was widely distributed during the Early Cambrian, based on the Lycatisky (Talsinsky) horizon. Therefore the highly developed late Danilovsky occurrences are ambiguously defined. Most acritarchologists investigating this association consider it to be Early Cambrian (Ajansky biostratigraphic horizon), though some workers believe this association to be Cambrian or VendianCambrian. Others consider the age of beds with these acritarchs to be Vendian because of similar finds in the

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IPC2002 Poster Presentations Pertatataka Formation of central Australia and that there are insufficient finds to support a Cambrian age. The small number of occurrences of skeletal fauna can be explained by inappropriate environments. There is no opportunity for confident belief in synchronism of age of the organic-walled acritarchs of the Siberian and East Europe platforms.

PALAEOECOLOGICAL INVESTIGATIONS ON THE QUARTERNARY MALACOFAUNA OF THE CARPATHIAN BASIN WITH THE AIM OF RECONSTRUCTING THE SURROUNDING ENVIRONMENTAL CONDITIONS Pal SUMEGI University of Szeged, Department of Geology and Paleontology, H-6722 Szeged\ Egyetem u.2-6., [sumegi@geo. u-szeged. hu] The Late Pleistocene environmental history of the Carpathian Basin (including Hungary) can be regarded as one of the missing links in our understanding of the last glacial development of Europe. Changes in the radiocarbon-dated Mollusc faunas of the Hungarian loess areas, along with the palaeogeographic interpretations implied by them seem to underlie the latest results gained from radiocarbon dated pollen analysis of the region. Changes in the Mollusc fauna refer to nine short-lived (1000 - 3000 years), cyclical palaeoclimatological alterations, which repeatedly transformed the palaeoecological conditions and vegetation in the Carpathian Basin between 3 4 - 1 2 kyr. On the basis of malacological data the presence of a major palaeoclimatic trend could be assumed for both the periods of warm up and cooling in the Carpathian Basin. The mildest July palaeotemperatures were recorded in the SW parts, while the coldest ones were recorded in the NE parts of the basin. Humidity and vegetation cover displayed a large-scale mosaic type heterogeneity reflecting the modifying effect of local factors. It seem that the Upper Weichselian environment was mosaic or mosaic-like in the Carpathian basin and the different plants and animals could spread from this different ecological spots during the climate change times when the distribution of the forest or grass or their ecotone or perhaps the tundra-like habit extended. This work has been supported by OTKA Grant T034392.

ON POSSIBLE FEEDING BASES OF PALAEOZOIC TERRESTRIAL QUADRUPEDS WITH FILTERING DENTITION D.L. SUMIN non-affiliated researcher, Moscow, Russia Together with animals possessing typical carnivore or herbivore dentition constituting Upper Palaeozoic faunas, there are many forms having peculiar types of dentition that were not for grinding vegetation or to hold or dissect prey. Teeth of these animals are often comb-like, though other structures also may be observed. Considering composition of the tooth-rows, filtering food from water must have been the most probable way of feeding. Such a mode of feeding is not a specialization in any specific group of quadrupeds; it occurs across most Upper Palaeozoic groups: pelycosaurs, therapsids, parareptiles and reptilio-morphs. Absence of any traces of wear on teeth (M.F. Ivakhnenko, V.I. Zhegallo) is a common feature of many representatives of these groups. This feature testifies against vegetable feeding as cells of all vegetable organisms have rough cellulose walls. So a filter-type dentition was used for feeding on animal organisms. This point is supported by the general structure of these organisms not differing much from close relatives reliably identified as predators, i.e. a version of the same structure used for dissecting prey. Analysis of dentition structure and other peculiarities of these animals indicates the following features of the prey they fed on: (1) The prey must form stable and long-existing masses, comparable in stability and distribution with vegetable forms; (2) Discrete structures with small elements 1 to 15 mm; (3) Aquatic habitat; (4) Animal composition; (5) Absence of hard shells. Accumulations of planktic phyllopods fit this description, particularly conchostracans frequent in Upper Palaeozoic and Lower Mesozoic sediments. These organisms often become numerous in modern reservoirs having cool waters saturated with organic matter. It suggests the possibility of a factor during the Upper Palaeozoic that was conducive to developing masses of planktic crustaceans possible under higher temperatures. This factor could have inhibited development of bacterial organic destructors compatible with lower temperatures. Natural bactericidity of gymnospermous and sporous vegetation dominating Upper Palaeozoic terrestrial communities may have been such a factor. Mass vegetal fall enriching flowing waters kept the waters free from bacteria, the main consumer of the vegetal organic remains, thus creating a favorable situation for planktic crustaceans. This would have made

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IPC2002 Poster Presentations the food chain shorter, raising the efficiency of energy transfer from lower to higher levels, and may have been the cause of different rhythms and regularities of tetrapod evolution in the Palaeozoic compared with those observed in more recent times.

ON THE NATURE OF DIVERSITY OF STROMATOLITE BUILDUPS E.L.SUMINA Moscow State University, Russia Experiments on model systems of stromatolite buildups conducted at the Institute of Microbiology (Moscow) cast new light on the nature and diversity of stromatolite buildups. The films of filamentous blue-green algae Oscillatoria terebriformis and Phormidium angustissimum considered usually as communities of colonial microorganisms, execute a number of functions typical of an integral organism, i.e. a community of a different type of organization (Sumina, 2001). Maintaining of a continuous and favorable position of an organism as a whole and its parts in space is among such functions. In organisms, this function is executed by a number of sustentacular structures (skeleton). The function of maintaining a stable spatial position of parts is closely related to the function of maintaining external borders of an organism. No permanent structures exercising these functions are known in most types of blue-green algae communities. Cyanobacterial films in modern mats are an example of this. Stromatolites differ radically from other blue-green associations with regard to the above functions—the community (= film) uses mineral sediment to create a sustentacular structure similar to skeletons of skeletal organisms. So formation of a stromatolite buildup may be considered as an adaptive reaction of the film as an integral organism to changes of environmental factors. Modern stromatolite buildups are distributed in warm climate areas and are not present in the moderate climatic areas, regardless of the wide distribution of blue-green algal mats. In moderate latitudes with relatively lower illumination and high solubility of gases in cool waters, the balance between photosynthetic oxygen accumulation and its dissolution in water prevents concentration of the gas in the film to an extent that would menace its coming to the surface and, eventually, destruction. So no need arises for the mat to develop anti-buoyancy adaptations. Additionally, owing to high dissolubility of gases, in particular of C0 2 , no carbonate sedimentation occurs, thus leaving no possibility for mats to have such adaptations. In low latitudes, in contrast, intense illumination drastically augments photosynthetic productivity, particularly in relation to oxygen production, whereas its dissolubility becomes lower. Under these conditions, a mat should necessarily react to avoid coming to the surface. Dissolubility of C0 2 also becomes lower causing sedimentation of carbonate material. This factor, being in some other respects unfavorable, becomes vitally important for films allowing them to stick to the seabed. In this case there is an opportunity for appearance of the structures playing the role of a skeleton. Further development of these structures is connected with diversity of action of carbonate sediment on the bacterial mat. On the one hand, it is unfavorable if sediment covers the mat; on the other, heavy sediment reduces buoyancy of the mat. Reaction of the film as an integral organism is directed to lowering the intensity of its coverage by sediments and to raise the efficiency of mineral structures favoring its life activity. In the model experiments on stromatolite buildups, it was observed that a blue-green algae film uses the extra-accumulation of gases to produce specific shapes on its surface. This testifies to high informational integrity of the film as an integral organism allowing combination of unfavorable actions in such a way that the integral result becomes positive. Two types of stromatolite buildups may be considered from this point of view. Stratified buildups are the simplest organizational type of stromatolites as they do not have structures delimiting the organism and structures connected with change in its position relative to the seabed. This type of buildups, in a strict sense, cannot be regarded as skeletal as it emerges owing to the ability of individual threads to penetrate between particles of sediment and no integral reaction of the community is observed. In fact, a stratified stromatolite represents a mat in conditions of increased sedimentation. One may suggest that the stratified type provides the background to skeleton formation. The buildup as whole plays an important skeletal role as the sediment in combination with the organic matrix prevents it coming to the surface, allowing the film to stay permanently on the bottom. As an initial stage of structure formation, stratified stromatolites develop regular folds and cusps. The community tends to create positive relief that is less intensely covered by sediment. Gas bubbles raising buoyancy of parts of the film are the structures responsible for change of surficial relief. Other parts remain attached to the bottom, thus forming depressed relief. As a result of such transformation, positive parts remain less covered with sediment in comparison with smooth surfaces, whereas the depressions accumulate sediment.

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IPC2002 Poster Presentations The next stage is signaled by isolation of parts of the film capable of maintaining permanent external borders. Instead of a continuous film, parts of the bottom appear covered with film shaping the elevated relief, and that intermingle with non-inhabited depressions where extra-sediment is accumulated. A new column-like form of buildups emerges in which the mineral constituent becomes precisely equivalent to the motion of the skeleton. All its parameters are determined and regulated by a blue-green algal film as an integral organism. In this case we observe in stromatolite-builders the formation of permanent structures responsible for maintaining the spatial position of an organism and its parts and formation of borders (columns, arcs, walls) connected with emergence of an internal medium in the organism. Further development of morphological structures of stromatolites is connected with their expansion of sedimentation zones, and growth of blue-green films as photosynthetic organisms.

TAPHOFACIES ANALYSIS OF MOLLUSCAN DEATH ASSEMBLAGES ON A MODERN ROCKY SHORE, SOUTHWESTERN HOKKAIDO, JAPAN Akihiko SUZUKI and Yuichi ITO Iwamizawa College, Hokkaido University of Education Taphofacies analysis of fossil assemblages is a powerful tool for reconstructing palaeoenvironments (Brett and Baird, 1988; Parson and Brett, 1991). Taphonomic analysis of modern death assemblages have often been done for soft-bottom habitats (Meldahl and Flessa, 1990) such as tidal flats and estuaries, but modern hard-substrate habitats (Rasmussen and Brett, 1985), such as coral reefs and rocky shores, have rarely been studied. Our study area in southwestern Hokkaido, northern Japan, is a tidal platform composed of Neogene finegrained sandstone along a moderately sheltered rocky shore. This shoreline is abundantly populated by both warm- and cold-water molluscs. The rocky tidal platform is divided into five zones, based on its benthic fauna: supratidal (= beach), high-tidal, mid-tidal, low-tidal, and subtidal zones. We quantitatively collected ten samples during two transects across the tidal platform in early July 2000. Dead mollusc shells were obtained from crevices in all five shore zones, and were counted after being sieved through a 2-mm-mesh screen. The faunal composition of the molluscan death assemblages does not correspond well to the local distribution of the living fauna in each zone. Taphofacies analysis of the molluscan death assemblages was performed for five taphonomic attributes, including disarticulation, abrasion, fragmentation, bioerosion, and encrustation. We examined taphonomic attributes of the outer surfaces of the bivalves Ruditapes philippinarum and Protothaca euglypta. The five rocky-shore zones can be characterized by the taphonomic attributes of these shells. Taphonomic gradients among the molluscan death assemblages in this sheltered, rocky-shore habitat reflect environmental gradients based on water depth (= submergence time) and wave action. Abrasion, bioerosion, and encrustation are particularly important indexes of taphofacies in this habitat. These taphonomic attributes are commonly preserved in fossil assemblages and therefore are useful for palaeoenvironmental reconstructions of sheltered, rocky-shore habitats.

TRILOBITE ASSEMBLAGES OF THE BODA LIMESTONE, DALARNA, SWEDEN Yutaro SUZUKI Institute of Geosciences Schizuoka University, Shizuoka 422-8529, JAPAN [ZXC02667@nifty.ne.jp]. Over 6000 trilobite specimens, collected from the "Upper Ordovician" Boda Limestone, Dalarna, Sweden, and counted from cranidia or pygidia (not both) for each species, are examined to document stratigraphically controlled assemblages. All trilobite species of the Boda Limestone were previously considered to be Cautleyan to Rawtheyan (middle to upper Ashgill) in age without definite stratigraphic evidence. Two main problems prevent us from further biostratigraphic understanding. First, the facies of the Boda Limestone is said to be massive wackestone without strata having a potential for correlation. This situation is one of the characteristics of the carbonate mud-mound type of buildups such as the Boda Limestone. Another problem is that the fossils are mostly concentrated in synsedimentary dykes or cavity systems (pocket), which makes stratigraphic controll impossible. To yield a further understanding of the stratigraphic distribution of the trilobites in the unit, the present study is aimed to present data of species composition at each sampling point, to try to group for making assemblages based on these data, and to classify the groupings broadly in a stratigraphic order.

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IPC2002 Poster Presentations Trilobite species occur in four assemblages. These are here termed as the Boda A, B, C, D assemblage. The Boda C assemblage contains specimens of Lichas lacinatus, Primaspis evoluta and a few Mucronaspis/Dalmanitina mucronata. These three species were collected from particular beds, and were never recognized in other assemblages. The Boda B assemblage is characterized by Dicranopeltis polytoma, Amphilichas wahlenbergi, etc. All of these were collected from beds below that yielding the Boda C elements. The Boda D assemblage consists of several genera and species such as Kosovopeltis sp., Scotoharpes sp., Youngia sp., Staurocephalus sp., etc., with "Bumastus" nudus, Dicranogmus aequalis, etc. The localities that yielded the species of the Boda D specimens are one bed and three pockets. The bed is situated about 5m above the level yielding the Boda C species. In addition to this, one of the pockets penetrates the beds that contain the Boda B and C elements. The Boda A assemblage includes the remaining species such as Eobronteus laticauda, Stenopareia linnarssoni, Amphilichas dalecarlichus, Hibbertia costata, etc., The Boda A elements were collected from 20 pockets and two grainstone lenses. The latter are situated far below the level with the Boda-B elements. Based on stratigraphic analysis of each sampling point, and the presence of stratigraphically useful species such as Mucronaspis/Dalmanitina in the Boda C, and D. polytome in the Boda B assemblage, the age of the assemblages is determined as follows: Boda A: Cautleyan to Rawtheyan (middle to upper Ashgill); Boda B: Lower Hirnantian; Boda C: Upper Hirnantian; Boda D assemblage: Lower Rhuddanian (basal Llandovery of the Silurian).

DIVERSITY CHANGE OF THE CRETACEOUS INOCERAMID BIVALVES IN JAPAN Akinori TAKAHASHI Division of Geology, Graduate School of Science and Engineering, Waseda University, 1-6-1 Nishiwaseda, Shinjuku-ku, Tokyo 169-8050, Japan, [601g5049@mn.waseda.ac.jp] Inoceramids being one family of the extinguished marine Bivalves occur from the Upper Albian to the Upper Maastrichtian (Cretaceous) in Japan. About 90 species classified were detected in Japan. Including undescribed species, the number of species is over 120. Although the species-diversity (=number of species) fluctuated in short-term, it increased gradually during Late Albian-Early Campanian on the whole. However, it decreased suddenly during Late Campanian-Late Maastrichtian. The purpose of this study is to clarify what environmental factors controlled inoceramids diversity. The diversity change pattern after Santonian of inoceramids resembles that of ammonoids in Japan shown by Toshimitsu and Hirano (2000). Moreover, it can be comparable with long-term (2nd order) eustatic sea level change shown by Haq et al. (1987). An increase in the diversity seems to have followed sea level rise. On the other hand, a decrease seems to have corresponded with sea level fall. The diversity change of inoceramids indicates a similar pattern to the carbon-isotope change (Jenkyns et al., 1994) during Early Cenomanian-Middle Turonian. Although the diversity does not decrease extremely after the Oceanic Anoxic Event 2 (OAE2) at the Cenomanian/Turonian boundary, no inoceramids that lived at Late Cenomanian survived after OAE2. Instead of them, the genus Mytiloides is dominant at Early Turonian. On the basis of the above-mentioned results, it is inferred that ammonoids and inoceramids declined due to the same cause at the end of the Cretaceous. The inoceramid diversity change should have a connection with area of shallow marine. As inoceramids are presumed to have fed on primary producers (phytoplankton), carbon-isotope change (nearly equal change to the amount of primary production) is expected to be relevant to the inoceramid diversity change. However, this issue remains as a matter to be discussed further. It seems quite probable that the genus Mytiloides was inhabitable under the environment that the other organisms were inhospitable like after the OAE2. HAQ, B. U., HARDENBOL, J. and VAIL, P. R., 1987, Chronology of fluctuating sea levels since the Triassic. Science 235, 1156-1167. JENKYNS, H. C., GALE, A. S. and CORFIELD, R. M., 1994, Carbon- and oxygen-isotope stratigraphy of the English Chalk and Italian Scaglia and its palaeoclimatic significance. Geological Magazine 131, 1-34. TOSHIMITSU, S. and HIRANO, H., 2000, Database of the Cretaceous ammonoids in Japan -stratigraphic distribution and bibliography-. Bulletin of the Geological Survey of Japan 51, 559-613.

FORAMINIFERAL BIOSTRATIGRAPHY OF THE EARLY CRETACEOUS MARINE TRANSGRESSION ACROSS THE CARNARVON BASIN, WESTERN AUSTRALIA. B.A. TAYLOR Department of Geology & Geophysics, The University of Western Australia, 35 Stirling Highway, WA 6009, Australia. [btaylor@geol.uwa.edu.au]

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Detailed biostratigraphic analysis of Early Cretaceous foraminifera from thirty-five outcrop and bore sections from the Carnarvon Basin reflect a deepening then shallowing bathymetric cycle from the Valanginian to early Aptian. The mid-latitude benthic foraminiferal assemblages are low to moderately diverse and are among the most common fossils found. Four foraminiferal assemblages were recognized, including the Gaudryinopsis Assemblage, Bykoviella sp. cf. B. elenae Assemblage, Hemirobulina cephalotes Assemblage and Ammobaculites hojkeri Assemblage. The Gaudryinopsis Assemblage is found in the Birdrong Sandstone on the Southern Carnarvon Platform and the Mardie Greensand and Tunney Members of the Muderong Shale in the Northern Carnarvon Basin. It is dominated by low diversity and moderate abundance of siliceous agglutinated species, and is associated with the Systematophora areolata to Muderongia testudinaria dinocyst Zones of Valanginian to early Barremian age. The foraminiferal assemblage and lithofacies analysis indicate depositional environments for the basal marine transgression from 1) estuarine to intertidal (possibly 2-10 m water depth), 2) shoreface to transitional (about 2-10 m water depth), to 3) upper shoreface (about 10-50 m water depth). Overlying the Gaudryinopsis Assemblage and associated with the maximum marine flooding interval that occurred during the Barremian on the platform and to the north in the Exmouth and Dampier Sub-basins and Peedamullah Shelf of the Northern Carnarvon Basin, is the Bykoviella sp. cf. B. elenae Assemblage. It is dominated by moderate diversity and high abundances of siliceous agglutinated species, and reflects an inner neritic, low oxygen depositional environment probably of water depths between 10-50 m. The Hemirobulina cephalotes Assemblage that is also associated with maximum flooding interval is found in the Barrow Sub-basin of the Northern Carnarvon Basin. The assemblage includes a high diversity of calcareous hyaline and calcareous agglutinated forms that indicative a mid to outer neritic, well-oxygenated, normal salinity depositional setting of water depth around 50-100 m. This assemblage is comparable to coeval assemblages known from Exmouth Plateau. The youngest foraminiferal assemblage studied, the Ammobaculites hojkeri Assemblage, is characterized by a low diversity of species, moderate to high abundances of agglutinated species and includes the first appearance of Ammobaculites hojkeri and abundant Rhizammina sp. The assemblage is associated with the Odontochitina operculata dinocyst Zone of late Barremian to early Aptian age. In the Northern Carnarvon Basin and northern part of the Southern Carnarvon Platform, the assemblage represents a return to restricted shoreline to transitional shelf conditions by the early Aptian.

OCCURRENCES OF FOSSIL DIPNOI IN BRAZIL AND THEIR STRATIGRAPHIC AND CHRONOLOGIC DISTRIBUTIONS Carlos Eduardo Vieira TOLEDO & Reinaldo J. BERTINI NEPV-DGA-IGCE-UNESP Rio Claro-SP-Brasil; [cetoledo@ms.rc.unesp.br; rbertini@ms.rc.unesp.br] Until recently, lungfish were not very well studied in Brazil due to lack of specimens and apparent limited palaeogeographic distribution. This scenario has changed in the last few years with discovery of new localities. Lungfish have now been identified from the following basins in Brazil: Parana Basin in states of Rio Grande do Sul (Lower/Middle Triassic), Parana (Middle/Upper Devonian and Upper Permian) and Sao Paulo (Upper Permian); Bauru Basin, state of Sao Paulo (Upper Cretaceous); Parnaiba Basin, state of Maranhao (Lower Permian); Araripe Basin, state of Ceara (Upper Jurassic/Lower Cretaceous); Sao Luis Basin, state of Maranhao (mid-Cretaceous); Acre Basin, state of Acre (upper Miocene/lower Pliocene). The Palaeozoic of the Parana Basin is the most important interval regarding palaeobiogeographic distribution of Brazilian Dipnoi. Five localities including the Ponta Grossa Formation (Devonian: Emsian to Frasnian) in the State of Parana are now known—with evidence of the most ancient lungfish known from Brazil: a vertical tubular vertical burrow in a marine environment. The biggest concentration of Dipnoi dental plates (associated with other vertebrate remains) is from a bone-bed formed by storm events in the Upper Permian Corumbatai Formation in the Parana Basin of the state of Sao Paulo (Rio Claro municipality). This locality has large numbers and great morphologic diversity. Two other localities in the Corumbatai Formation in the state of Sao Paulo are storm-event bone beds with similar concentrations of dental plates. In the Upper Permian Rio do Rasto Formation there are two localities with Dipnoi dental plates: the Santo Antonio da Platina and Sao Gabriel units, respectively in Parana and Rio Grande do Sul states. The latter is associated with a conglomerate of continental origin, with fish remains (Xenacanthiformes, Hybodontiformes, Palaeonisciformes), Temnospondyli amphibians and some Permian amniotes such as Dinocephalia. Also in the Parana Basin, in Sao Joaquim do Polesine municipality, in the state of Rio Grande do Sul, Dipnoi dental plates, scales and teeth of Palaeonisciformes, and bones of Amphibia were identified in the Middle Triassic Santa Maria Formation.

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IPC2002 Poster Presentations Other basins have also yielded important fossils. Remains of Neoceratodus sp were found in the Adamantina Formation in the Upper Cretaceous Bauru Basin in the state of Sao Paulo. In the Parnaiba Basin, in the Early Permian Pedra de Fogo Formation in the sate of Maranhao, three families of Dipnoi were recognized (Sagenodontidae, Lepidosirenidae and Ceratodontidae) based on isolated dental plates. They are associated with Xenacanthiformes, Ctenacanthiformes, Petalodontida, Palaeonisciformes, Coelacanthida, and were collected in a layer with limonitic cement, precipitated under high-energy conditions. In the Araripe Basin (State of Ceara), dental plates identified as Neoceratodus sp were collected from the Upper Jurassic/Lower Cretaceous Brejo Santo Formation. In the Sao Luis Basin (Maranhao state) a concentration called the "Laje do Coringa", of mid-Cretaceous age were collected from a highly fossiliferous conglomerate. The assemblage consists of plant stems, fish (including Dipnoi dental plates assigned to Neoceratodus africanum), crocodylomorphs and dinosaurs. In the Miocene-Pliocene Acre Basin, a partial cephalic skeleton (part of the neurocranium, right mandibular ramus and isolated dental plates) was collected from the Purus River margins, and named Lepidosiren megalos. This taxon occurs with other fish, turtles, crocodylomorphs and mammals. Brazilian Dipnoi are distributed from Devonian to Pliocene. The most important occurrences, considering major concentrations of specimens, are situated in the Rio Claro municipality (Sao Paulo state), Sao Luis Basin (Maranhao state) and the area around Rio Branco City (Acre state). The Petalodontida/Dipnoi association in the Permian of the Parana and Parnaiba basins is intriguing, suggesting that palaeoecologic conditions may have been similar. The time-stratigraphic interval for occurrence of Petalodontida has helped re-evaluate the age of the Corumbatai Formation of the Parana Basin; it is Permian rather than Triassic.

THE TAPHONOMIC TUMBLING BARREL - A METHODOLOGICAL REVIEW TO UNDERSTAND PRESERVATIONAL BIASES IN THE FOSSIL RECORD Fernanda de Freitas TORELLO 2 ' 3 , Marcello Guimaraes SIMOES3 & Jose Raimundo de Souza PASSOS 3 IG/USP, Programa de Pos-graduaqao (GSA); sUNESP, Instituto de Biociencias, Distrito de Rubiao Jr. s/n, CEP 18618000 Botucatu, SP, Brazil, [torello@zaz.com.br]

Since the early 1960s, the taphonomic tumbling barrel has been used in experimental palaeontological studies, following on from the pioneer studies by Keith Chave. A search indicated that only 16 papers used this methodology and, surprisingly, no detailed description or critical review of methodology had been presented. Thus, it is difficult to reproduce some experiments, causing lack of comparability between results from different authors. In order to establish a taphonomic tumbling protocol, different barrels were set up, and 3 experiments carried out (including 3 treatments with trials). The tumbling barrels were made of stainless steel in 3 sizes (13.8, 27, 40.15 cm long) and diameters (7.7, 15 and 22 cm). Preliminary analysis attempted to establish adequate barrel rotation for a given diameter. This parameter was defined by a formula suggested by Mikos & Jaeggi (1995). Following this, the first experiment was carried out to determine the most appropriate barrel diameter; this consisted of 3 treatments (diameter 7.7, 15 and 22 cm) using shells of the bivalve Anomalocardia brasiliana. The results, using the Non Linear Regression model, showed the 15 cm diameter barrel best fits ce requirements for the intended shell abrasion analysis. After this, in order to verify the effect of sample size in the final results, a second experiment was carried out. This included 3 treatments using variable sample sizes, such as: 3, 10 and 15 shells. Statistical analysis (non-linear regression model) shows 10 to be the most adequate sample size. The most appropriate sediment, according to our results, is medium sand collected from the same place as the shells (N coast of Sao Paulo Time in hours State, Brazil)—approximating tumbling experiments under natural conditions. Our results strongly suggest that using a taphonomic tumbling barrel with diameter of 15 cm, rotation of 60 rpm and sample size of 10 shells was best for accomplishing our goals. In order to demonstrate an application, comparative analysis of resistance to abrasion between shells of bivalve mollusks (A. brasiliana) and articulate brachiopods (Bouchardia rosed) is presented (Fig. 1). The curves obtained are statistically different; different non-linear regressi on models were

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IPC2002 Poster Presentations necessary to adjust them. These results indicate that brachiopod shells are more prone to destruction by physical agents (abrasion) than bivalve shells (venerids), leading to several biases (e.g. per taxonomic group) in the fossil record. Project financially supported by FAPESP (grant: 00/05846-5). Figure shows Bivalve and brachiopod shell responses to abrasion in a tumbling barrel experiment. MlKOS, M.; JAEGGI, M.N.R., 1995. Experiments on motion of sediment mixtures in a tumbling mill to study fluvial abrasion. Journal of Hydraulic Research 33 (6), 751-772

CONODONT GEOCHEMISTRY - IN-SITU CHEMICAL PROFILING OF SINGLE CONODONT ELEMENTS USING LA-ICPMS Julie A. TROTTER1, Stephen M. EGGINS1, Malcolm T. MCCULLOCH1 & Christopher R. BARNES2 1 The Australian National University, ACT, Australia; 2The University of Victoria, British Columbia, Canada Major and trace element compositions of a suite of Ordovician conodonts have been determined in the context of conodont histology by mapping relationships between chemistry, growth structure and mineralised tissue types (lamellar and albid). These studies are being undertaken to clarify the potential of conodonts as chemical tracers of palaeoseawater composition. Laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) analyses have provided continuous, high-resolution profiles through individual conodont elements. Electron Microprobe analysis has been used to determined major element compositions and to verify sodium and strontium data determined by LA-ICPMS. The concentrations of some trace and minor elements (eg. strontium, barium) vary systematically, becoming depleted or enriched toward the growth axis. The magnitudes of these changes vary according to the position (aboral—>oral, anterior—•posterior) of the ablation traverse and appear to be related to the concentric growth structure of the conodont elements. Variations in chemical concentrations also occur according to tissue type - rare earth elements, yttrium, uranium and lead are consistently depleted in albid tissue compared to hyaline tissue from the same specimen and completely hyaline species. Although the significance of these results has yet to be determined the observed profiles are not analytical artefacts. Discrimination against the uptake of particular chemical elements appears to be dependent on tissue type and this may have implications for determining primary palaeocean signatures. Studies are continuing to discriminate diagenetic effects from potential primary palaeocean composition, by utilizing biostratigraphically well-constrained specimens from, both spatially and temporally, different stratigraphic sections. Data deemed to be [near] primary, will be interpreted in this context to determine proxies for reconstructing palaeoenvironment, and possible relationships to geo- and bioevents (extinctions and radiations).

MORHOLOGY OF SKELETAL ELEMENTS OF DEVONIAN CYSTIMORPH RUGOSE AND ITS SYSTEMATICAL IMPORTANCE Vladimir S. TSYGANKO Institute of Geology of the Komi Science Center Ural Division RAS, Syktyvkar, Russia Skeletons of cystimorphs have a complex structure. It consists of the vertical and horizontal elements. The first of them are the septal apparatus formed by ectoderma of mesenteries. In majority of rugose of this group the septal apparatus is represented with the spines or a number of spines of different structure (holacanth, monacanth, rabdacanth et al.), different forms, length and orientation. The development of lamellar (mainly monolamellar) septa of different structure in marked in other group of cystimorphs, widespread mainly in Devonian (Digonophyllum, Dialithophyllum, Atelophyllum and some others). The septal apparatus of some devonian rugose is characterized with combination the lamellar septa with arch lamellar, developed on the periphery of the corallites (Mesophyllum, Scissoplasma). The horizontal skeletal elements of all cystiphyllida are repressented with vesicular endothecal formations - dissepiments and also with stereoplasma crusts developed in some genera (Tsyganko, 1972). The development of these formations testify about important functional peculiarities inherent to the polips of this group cystimorphs (Tsyganko, 1996). Apparently it is the feature of high order. Among the stereoplasma crusts we distinguished earlier the complete and incomplete crusts depending on the degree of their development (Tsyganko, 1972). Functionally complete stereoplasma crusts were connected with basal and lateral ectoderma of polyps. The formation of the incomplete stereoplasma crust is connected with the

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IPC2002 Poster Presentations vital processes proceeding in basal (descendente crust) or in lateral (ascendente crust) ectoderma (Tsyganko, 1981, 1996). Accordingly to the character of dissepimentarium, building the internal cavity of the corallite there are the forms with differentiation of the dissepiments on the sizes, orientation and the forms with two or three distinct zones dissepiments. It is necessary to use as the basis of the classification of cystimorphs the following features (accordingly to degree of their importance): 1) the form of existence ("solitary" and "colonial"); 2) the type of the septal apparatus; 3) the presence or the absense of stereoplasma crusts; 4) the chatacter of stereoplasma crust; 5) the character of the dissepiments. The type of the septal apparatus (acanth or lamellar) is inherent to the different suborders of cystimorph rugose. True coloniality and pseudocoloniality is the features of high order. They characterize suborders or families as a last resort. The presence or the absence of stereoplasma crusts as a degree of development of dissepimentarium are characteristic for the family. It is necessary to consider the peculiarities of septa microstructure, the character of stereoplasma crusts (complete or incomplete - descendent or ascendent) and the character of dissepiments as the features of genus. Structure of septal apparatus (a number of septa and so on), frequence and thickness of the stereoplasma crusts are the features of species. TSYGANKO, V.S., 1972., "Septal cones" of the tetracorals and their functional significance.- Paleontological Journal, 4:31-43 (in Russian). TSYGANKO, V.S., 1981., Devonian Rugosa of the North Ural.- Leningrad, Nauka: 220 p. (In Russian) TSYGANKO, V.S., 1996., Genesis stereoplasnatic crust of the paleozoic corals Rugosa.- In: Abstracts of the Second International Seminar "Mineralogy and Life: Biomineral Internactions". Syktyvkar: 49. (In Russian)

'FISH KILLS1 AS UNUSUAL TAPHONOMIC EVENTS: A NEW DATABASE FOR GONDWANA Susan TURNER Queensland Museum, P.O. Box 3300, South Brisbane, QLD 4101 The 500-million year evolution of Australia's fish communities has seen changing fortunes for diverse fishes and the emergence of advanced sarcopterygians as land-dwelling vertebrates, against the background of the shifting Gondwana continents. Much of what we now know of this evolution comes from studies of mass death horizons - fossilized 'fish kills' or phosphatic bonebeds. The components are fish remains, either whole or disarticulated. Dissociated microfossil elements such as teeth, scales and small dense bones are physicochemically resilient, usually <5 mm. (Turner & Burrow 1999). A new proposed research programme will build up a geological database to complement modern and historical data and help explain the natural periodicity and causes of major catastrophic fish deaths. The database will store information on content, biodiversity and significance, both palaeoclimatic and palaeogeographical, of Australian bonebeds. Such deposits have not been studied in toto and they provide a rich resource for understanding aspects of geology as well as enhancing the history of vertebrates on this continent. For comparison, dramatic fish kills in the Northern Hemisphere, e.g., the Ludlow Bonebed in Britain (c. 415 Ma), mid-Devonian bonebeds of the USA, the Rhaetic Bonebed across Europe (c. 195 Ma), will also be investigated. Study of bonebeds contributes to knowledge of chronology, bio- and sequence stratigraphy, geochemistry and sedimentology not available elsewhere. Bonebeds also offer unparalleled opportunities to examine aspects of vertebrate palaeontology, palaeoecology and behaviour (Fiorello & Rogers 1999). Certain bonebeds, conservation lagerstatten, are outstanding refugiae of perfectly preserved fossils; Australian sites include Gogo and Talbragar. In the last 30 years there have been increasing numbers of fish kills world wide, some think related mostly to human influence (Hallegraeff 1994). Most of the time, however, they are due to natural causes, related to weather. Blooms of unicellular planktonic algae have been associated with fish kills since biblical times. These natural poisonings are and have been regular events, linked to phenomena such as the El NinoLa Nina Cycle (e.g. Suplee 1999). Most blooms are harmless and merely colour the water but some become dense enough to initiate "red tides", caused by dinoflagellate and other species that produce toxins, which kill nearby marine life. Even with apparently nontoxic taxa, cell concentration and the decay process of a dying bloom depletes oxygen by bacterial respiration, producing ammonia, sulphides and other harmful toxins. Within the non-marine environment (rivers, lakes and possibly lagoons), natural fish kills are of three basic seasonal types. These are winterkill, from late winter to early spring, which is the most common, springkill, and summerkill, which occurs on the hottest days of mid summer. There have been fish kills for as long as there have been fishes, and there are many causes other than algal blooms. Mass accumulations occur in a wide range of marine to non-marine facies. Brongersma-Saunders (e.g. 1957) was the first to categorise mass fish mortality, emphasizing red tides and their importance in forming bonebeds, and noting their input to oil production, especially in upwelling sites. Some bonebeds form during major upheavals such as extinction events, which have a widespread effect. Storm and other rapid burial events are important processes for their formation, but lag concentrates, which accumulate more

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IPC2002 Poster Presentations slowly, are also more common than realized. Bonebeds can be densely packed or have patchy distribution (both types are seen, for example, in the Carboniferous of the Drummond Basin of Queensland). By considering possible causes of Australian bonebed formation, I hope to show their relationship to palaeoclimatic events. BRONGERSMA-SAUNDERS, M., 1957. Mass mortality in the sea. Geological Society of America Memoir 67, 941-1010. FIORILLO, A.R. & ROGERS, R.R., 1999. Bonebeds: a nomenclatural and historical overview. Journal of Vertebrate Paleontology 19 (Supp. To 3) September 1999, 44A. HALLEGRAEFF, G.M., 1994. On the global increase of harmful algal blooms. Memoirs of the Queensland Museum 34, 560. SUPLEE, C., 1999. El Nino-La Nina, Nature's VICIOUS Cycle. National Geographic ? 195, 73-95. TURNER, S. & BURROW, C.J., 1999. Micropaleontology, vertebrate. Pp. 740-749. In R. Singer (ed.), Encyclopedia of Paleontology. Fitzroy Dearborn Publishers, Chicago.

PLEISTOCENE CONTINENTAL MAMMALS OF NORTHERN URUGUAY (SOUTH AMERICA): BIOGEOGRAPHIC AND CLIMATIC CONNOTATIONS Martin UBILLA Dpto. Paleontologia, Ingepa, Facultad de Ciencias. Igua 4225. 11400. Montevideo. Uruguay [Ubilla@fcien. edu. uy] The Pleistocene continental fossiliferous beds, which outcrop at northern Uruguay, have a rich content of vertebrate, mollusc and vegetable fossils.The northern area of Uruguay is located between the 30° to 32°S and the 56° to 58°W of South America. The large number of fluvial bodies provides a wide surface area of exposition of the fossil bearing deposits, Sopas Formation, which outcrops at river, stream and creek sides and develops up to 12 meters high stratigraphic profiles.The sedimentological features of the Sopas Formation include conglomerates with clay and calcareous matrix, conglomerate-sandstones, siltstones and sandy-siltstones. Carbonate is very frequent as dust, concretions or duricrusts. There are greyish green silty and clayey lenses of centimeter and meters extension. In general, this unit has a predominantly brownish colour and unconformably overly mesozoic beds (Arapey and Tacuarembo formations). Despite the fact that fluvial contexts (channels, bars, plain-floods) are the predominant depositional environment, there are in some places palaeosoils, which developed in general on abandoned alluvial plains. The mammalian assemblage includes died out taxa and also extant species of the Neotropical region, some of them living in the present in geographic areas located far from Uruguay. It is correlated to the Lujanian Stage of Late Pleistocene in age.14C ages of 43.000 and 45.000 y BP, which are considered to be minimal ages, based on wood and fresh water mollusc shell samples are available. The vertebrates of the Sopas unit are indicative of diverse environments (fluvial and lacustrine habitats, grasslands and wooded open areas and riparian forest as well) possibly in answer to the existence of a large ecotone with influence of brazilians forms which inhabited the region in the late Pleistocene. A remarkable fact is that some mammals included in Sopas Formation do not ocurred in the Pleistocene of Buenos Aires province, particularly in the fluvial deposits of the Guerrero Member of the Lujan Formation, which yield the typical lujanian mammals, and this might have palaeobiogeographic and palaeoclimatic connotations. It is widely accepted the correlation of the fluvial deposits of the Guerrero Member to the Last Maximum Glacial, which have mammal taxa adapted in the Recent to the cold and arid conditions of the Central and Patagonian areas. On the contrary, some of the taxa of the Sopas Formation, have in the Recent tropical and temperate distribution, such the nine-banded armadillo Dasypus novemcinctus and the capybara Hydrochoerus hydrochaeris. A porcupine, Coendou magnus, belongs to the family Erethizontidae, which in South America is related to tropical to subtropical contexts. Additionally, it must be noted that Tapirus terrestris and Tayassu pecari are mammals living in the Recent in tropical and temperate areas of the Neotropical region. The present southernmost limit of distribution of Tapirus terrestris, Lundomys molitor, Dasypus novemcinctus and the family Erethizontidae is in relation with the 8°C and 15°C July isotherms and 22°C and 25° January isotherm. However, there are in the Late Pleistocene northern sediments of Uruguay some mammal taxa which live today under arid conditions such the extant species of the genus Microcavia, Lama {Vicugna) sp. and Dolichotis. They are distributed in Patagonian, Central to northern argentinian region {Microcavia and Dolichotis) and in central andean "puna" (Lama vicugna). These extant taxa are longer found in the surrounding area of northern Uruguay. It is applied the term "disharmonius" or "nonanalog" to the fauna possesing assemblages of extant taxa that are now allopatric. The Sopas formation yield fauna with disharmonius elements involving Dasypus novemcinctus, Lundomys molitor, Ozotoceros bezoarticus and Tapirus terrestris which do not overlap the ranges of Lama (Vicugna) sp. and Microcavia. A likely explanation of disharmonius fauna assumes that some climatic regimes of the Pleistocene probably do not exist today. Nevertheless, due to the influence of some factors acting on Pleistocene record (rate of deposition of sediments, rapids environmental changes, reworked materials, etc.), it is necessary to develop

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IPC2002 Poster Presentations more accuracy fieldwork to test this hypothesis. Some taxa as Microcavia and Galea clearly changed its range of distribution in the Pleistocene-Recent interval probably as a result of individual responses to climatic changes accordingly with the nonanalog fauna concept. Contribution to the project "Cenozoico continental del Uruguay" (CSIC-M.Ubilla) and to the project IGCP-449.

EARLY DEVONIAN (LATEST EMSIAN) RADIOLARIANS FROM THE SILVER GULLY FORMATION, NORTHERN NSW, AUSTRALIA M. UMEDA1. T.M. FUREY-GREIG2 R. MAWSON2 and J. TALENT2 1 Higashi-Osaka Junior College, Nishizutsumi 3-1-1, Higashiosaka, Osaka, 577-8567, Japan; 2Macquarie University Centre for Ecostratigraphy and Paleobiology, Department of Earth and Planetary Sciences, Macquarie University 2109, Australia Profound faunal changes occurred in radiolarian faunas during the late Early Devonian (Umeda, 2002), but stratigraphic alignment of Early and Middle Devonian radiolarian faunas lacks precision. As a contribution towards remedying this situation, various Early and Middle Devonian horizons have been sampled for radiolarians. Of special interest is the Silver Gully Formation (Tamworth Group), New England Foldbelt, NE New South Wales. It has produced radiolarians found in association with previously documented patulus Zone (latest Emsian) conodonts (Mawson et al., 1995). The Silver Gully Formation, consists predominantly of tuffs, mudstones, sandstones and conglomerates and limestones (predominantly allochthonous), though with infrequent cherty horizons and extremely rare and thin autochthonous limestones prospective for radiolarians and conodonts respectively. Abundant wellpreserved radiolarians were extracted from dark green tuffaceous mudstones of the basal portion of the formation (TL-35, 36) "Loop Rd" opposite Lot 1, and from Norman Close, Loomberah Heights (TL-34). The fauna of TL-35 and 36 is characterized by Circulaforma admissarius Stratford & Aitchison, Circulaforma sp., Ceratoikiscum calvum Stratford & Aitchison, Palaeoscenidium cladophorum Deflandre, Trilonche grandis (Nazarov) and Tr. hindea Aitchison & Stratford. TL-34 is characterized by Circulaforma davidi Stratford & Aitchison, Pa. cladophorum Deflandre, Tr. grandis (Nazarov) and Tr. hindea (Hinde). Conodonts from the basal portion of the Silver Gully Formation indicate the serotinus Zone (late Emsian), and those from a thin limestone layer at Loomberah Heights indicate patulus Zone (latest Emsian) (Mawson etal, 1995). Four radiolarian zones—the Futobari solidus, Trilonche (?) sp. A., Glanta fragilis and Protoholoeciscus hindea zones in ascending order—were proposed based on Devonian tuffaceous successions in Japan (Umeda, 1998b). The former two zones were regarded as the Pragian to Emsian based on comparison with early Emsian radiolarians from Germany. The latter two zones were assigned to the Eifelian because Protoholoeciscus was reported from a horizon regarded as Eifelian in Japan (Umeda, 1996). However, the Silver Gully faunas equate with radiolarian associations from stratigraphically higher than the Pr. hindea Zone. The first occurrence of Circulaforma is also stratigraphically higher than the Pr. hindea Zone (Umeda, 1998a). This indicates that the G. fragilis and Pr. hindea zones should be placed in the middle or late Emsian, with Protoholoeciscus ranging into the Eifelian. Reduction in radiolarian diversity occurred in the early Emsian Trilonche (?) sp. A. zone followed by recovery in the middle or late Emsian Glanta fragilis Zone. This profound radiolarian faunal change may have been a consequence of the middle Emsian Daleje Event marked by global transgression and faunal change in goniatites (House, 1985) and reduction in diversity of benthic biota.

ORDOVICIAN ACRITARCH DIVERSITY IN RELATION TO CHANGING PALAEOGEOGRAPHY IN PERIGONDWANA (NORTH AFRICA) Marco VECOLI Domaines oceaniques, UMR 6538 du CNRS, Universite de Bretagne Occidental, Av. Le Gorgeu, B.P. 807, 29285 Brest cedex, France. Ordovician evolution of acritarch diversity in North Africa is plotted against the major palaeogeographical/palaeoenvironmental changes occurring in Perigondwana and related terranes, using the correlation chart developed by the IGCP N°410. Peaks in acritarch diversity coincide with periods of marine transgressions and intense tectonic activity. The highest diversity was attained during a period of maximum palaeogeogrphical dispersal. No clear extinction event is recorded among acritarchs during Hirnantian times.

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QUALITATIVE AND QUANTITATIVE ANALYSIS OF CALCAREOUS NANNOFOSSILS AND ISOTOPIC ANALYSIS FROM A MULTICORE SITUATED IN SOUTHWESTERN ATLANTIC OCEAN M.D. WANDERLEY.1 and J.F. MCMANUS2 1 LabMicro/Depto de Geologia/IGEO/UFRJ; Av. Brigadeiro Trompowsky, si J2018, CEP:21.949-900, Rio de Janeiro, RJ. Brasil; 2 Woods Hole Oceanographic Intitution, 121 Clark MS#23, Woods Hole, MA 02543, USA Qualitative and quantitative data of calcareous nannofossils and 0 1 8 /0 1 6 isotopic data obtained on shells of foraminifers from MC 58 core were compared. The samples were collected at base-of-slope in South Brazilian Continental Margin, Santos Basin, Southwest Atlantic, 4,015 m depth. The studied core is located in a relatively small sedimentary sub-basin limited by continental slope (West), Sao Paulo Plateau (North), Rio Grande Rise (East) and by a basement structural high (South), which also separates Santos and Pelotas basins (Gomes et al 1993). These features correspond to morphological obstacles that influence both oceanic circulation and sedimentation in this sub-basin. The main thermohaline currents acting in Southwestern Atlantic, after Hogg et al (1996), are: Antarctic Intermediate Water (AAIW, 700-1100m depth), North Atlantic Deep Water (NADW, 2000-3000m depth), and Antarctic Bottom Water (AABW, 3500-4300m depth). In this area superficial water masses corresponds to Subtropical-Subantarctic Convergence Zone (Boltovskoy, 1981). Samples were collected by the research team of Woods Hole Oceanographic Institution (WHOI) in cooperation with LAGEMAR-UFF, on board of R.V. Knorr, during cruise 159-5, and core was kindly given to be studied by the research team of Micropalaeontology Laboratory LabMicro/UFRJ (Federal University of Rio de Janeiro, Brazil). The samples were collected using a multicore sampler at station MC 58. The core studied is 50 cm long and is constituted of a plastic mud, whose degree of compaction is higher from middle towards bottom. A total of 12 samples were collected through core at vertical intervals of 2cm, since 11cm to 47cm. The bedding at top was tilted due to moving when core was removed. Therefore, core top was not sampled because of unconsolidated, mixed character of sediment. A set of 12 smear slides was prepared in order to

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IPC2002 Poster Presentations observe calcareous nannofossils. The succession of calcareous nannofossil associations was described and studied in order to interpret the sediments biostratigraphy and palaeoecology. The study encompassed identification of the nanofossils species, including guide species, quantification of the individuals, relative abundance and diversity determination. This procedure also allowed the recognition of the "Emiliania Huxleyi" acme biozone in the Pleistocene/Holocene interval. The isotopic data obtained along the core were compared with the abundance data for Rhabdosphaera clavigera, a warm water indicative species, in order to evaluate usefulness of quantitative data of R. clavigera for palaeotemperature interpretations. It was observed an increase in number of R. clavigera specimens coincident with lowest values of 0 / 0 isotopic curve. 18

8 0 values x depth ( ) number of R.clavigera specimens x depth ( 18

Depth

S 0

12.5 15.5 18.5 21.5 24.5 27.5 30.5 33.5 36.5 39.5 42.5

1.265 1.035 1.107 0.911 1.431 1.274 1.017 1.137 1.857 1.927 2.069

R. clavigera

)

280 250 230 290 200 270 300 290 130 290 240

120 0.8

160

200 1.2

240 1.6

280

320

2.4

SEQUENCE STRATIGRAPHIC CORRELATION AND EUSTATIC EVENTS FROM LATEST CAMBRIAN TO EARLY EARLY ORDOVICIAN BETWEEN NORTH CHINA AND YANGTZE PLATFORMS WANG Haifeng , ZHANG Junming, LI Guoxiang, WANG Wei Nanjing Institute of Geology and Palaeontology, the Chinese Academy ofScience, Nanjing ,210008 Four orthosequences have been recognized both from the Yeli Formation to the lower Liangjiashan Formation in northern and northeastern North China platform and from the upper Wuduhe Formation to the Fenxiang Formation in central Yangtze platform during the latest Cambrian to earliest Ordovician (from the Fryxellodontus inornatus Subzone to Paltodus deltifer Zone). 8 C value of carbonates from C. proavus Zone to C. angulatus Zone shows three rise and drop cyclic changes. Similar changes can be recognized during this interval in the 8 C profiles at Black Mountain (Australia), Lawson Cove (USA) and Batyrbay(Kazkhstan). The simultaneous changes in carbon isotopes are useful in international correlation of the Cambrian-Ordovician boundary strata. Based on the biostratigraphic data of conodonts and graptolites, and on carbon isotopic stratigraphic data, four third-order sequences could be well correlated on both platforms. During the latest Cambrian to earliest Ordovician (from Fryxellodontus inornatus Subzone to Paltodus deltifer zone), there existed 6 eustatic events: (1) the eustatic event (equivalent to the Lange Ranch Eustatic Event in North America) between the Fengshan Formation and the Yeli Formation, and in the upper part of the Wuduhe Formation (Lower C. proavus; (2) the eustatic event between the First Member and the Second Member of the Yeli Formation and between the Wuduhe Formation and Xilingxia Formation (between C. proavus Zone and C. intermedius Zone); (3) the regression event in the upper Xilingxian Formation on the Yangtzi platform (equivalent to the Aceroceras regression event in Australia); (4) the eustatic event between the Xilingxia Formation and the Nanjingguan Formation (between C. lindstromi Zone and C. angulatus Zone), equivalent to the Black Mountain eustatic event in Australia; (5) the eustatic event between the Second Member and the Third Member of the Yeli Formation, and between the Nanjingguan Formation and the Fenxiang Formation, the maximum transgression during Tremadocian occurred in the Psigraptus Zone to Adelograptus Zone; (6) the eustatic event between the lower and the middle Liangjiashan Formaion, and 13

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IPC2002 Poster Presentations between the Fenxiang formation and the Honghuayuan Formation (between Paltodus deltifer Zone and Serratognathus Zone). At the Dayangcha section, in the lower C. lindstromi Zone which represents a maximum transgression period, there abundantly occurred the planktonic graptolite fauna of the Rhabdinopora flabelliformis parabola Zone which is significant for the global correlation. The maximum flood surface near this graptolite zone and below the FAD of C. prolindstromi could be taken as an important inference boundary for the Cambrian-Ordovician Boundary. Iapeognathus fluctivagus in 23 bed of the Green Point section, Canada, has a limited distribution, and is not practical to be taken as an index fossil for the global correlation. PERMIAN 8 C R B STRATIGRAPHY IN SOUTH CHINA 1 3

C A

WANG Wei. CAO Changqun, JIN Yugan Nanjing Institute of Geology and Paleontology, Chinese Academy of Sciences, Nanjing210008, China Studies on 8 C fluctuation of the Permian sections were mostly focused on the Permian-Triassic interval with little attention to the main part the Permian. Existing 8 C profiles of the whole Permian were generated from literature surveys in a scale of 5 m.y or 20 m.y. for the purpose of exhibiting secular change of 8 C. As a consequence, the scenario of Permian 8 C fluctuation and it's relation to physical and biotic events remains unclear because of lacking Permian 8 C profile developed with precise biostratigraphic constrain and adequate data of associated flora and faunas. Here we reported a Permian S C b profile integrated two extensively studied Permian sections in Guangxi, South China. It confirms a rapid decreasing of 8 C b during the late Changhsingian and a dramatic depletion of 4.5 %o at the major extinction level of the endPermian, that is, the Permian-Triassic boundary clay in South China. It reveals for the first time a brief negative excursion from 3%o to -0.5%o followed by a fast recovery around the Guadalupian-Lopingian boundary, which is coincident with the first episode of the end-Permian Extinction. Two positive 8 C b excursions from 3%o to 5%o respectively in the Late Roadian and Late Wuchiapingian appear in association with the reef beds. 8 C b kept stable around 3%o during the Cisuralian and Guadalupian Epoch; only minor shift appears across the Carboniferous-Permian boundary and the Artinskian-Kungurian boundary. In combination with the Pennsylvanian 8 C profile, it forms the longest interval of stability of 8 C b in the Phanerozoic. As an effective proxy of oceanic chemistry fluctuation, this 60 m.y. long stability of 8 C b is consistent with the steadiness of development of marine biota. However, the stability of S C b could reflect the burial of a massive volume of organic carbon and thus, overturn of anoxic deep waters towards the end of the Permian would have liberated large volumes of poison carbon dioxide. 13

car

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RECONSTRUCTED EARLY TAPHONOMIC HISTORY OF AMMONOIDS IN NORTHWESTERN HOKKAIDO, JAPAN Ryoji WANI National Science Museum, 3-23-1, Hyakunincho, Shinjuku-ku, Tokyo 169-0073, Japan. [ryoji_wani@hotmail. com]. The ammonoid taphonomic attributes in northwestern Hokkaido, Japan, are documented. Those are fragmentation patterns, infilling sediment in phragmocones, and dependence of fragmentation rate on facies. Based on the documented taphonomic attributes, early taphonomic history of ammonoids is reconstructed. After the burial of shells, sediment loading worked as a causal factor of fragmentation. Some fragmented shells were reworked during probably storm events, and reburied. Then, shell fragments and the phragmocones of damaged shells were separated. Each taphonomic attribute supports the reconstructed scenario as follows: The fragmentation patterns of living Nautilus were experimentally reproduced. Based on the comparison between the fragmentation patterns of the ammonoids and the experimental results, the fragmentation patterns of ammonoids are extremely similar to the experimental result of sediment loading. Thus, the fragmentation mechanism of most ammonoids is supposed as sediment loading. In the experiment, the fragments of body chambers remain near to the phragmocones. In the case of the fossil ammonoids, the eighty-eight percents of the fragmented shells show the separation of phragmocones from their fragments of body chambers. The high rate of the fragment separation can be explained by reworking events after fragmentation within sediment. The infilling sediment in some phragmocones shows geopetal structures. Some shells show the geopetal with two different directions in a single specimen (Wani, 2001). These shells should be reworked.

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IPC2002 Poster Presentations For the purpose of clarifying the dependence of fragmentation rate on facies, the fragmentation rate on different facies is compared. The fragmentation rate is: individual number of fragmented shells / total individual number. That increases toward the shallower facies. The higher fragmentation rate means a more frequent separation of fragments from their phragmocones. Thus, the fragmentation rate would reflect that there are more reworking events in the shallower facies. This is in harmony with the relationship of the higher energy level in the shallower facies. WANI, R., 2001. Reworked ammonoids and their taphonomic implications in the Upper Cretaceous of northwestern Hokkaido, Japan. Cretaceous Research 22, 615-625.

PAIRED FINS OF EARLY DEVONIAN VERTEBRATES SUGGEST ANTEROPOSTERIOR OVERLAP AND COMPARTMENTALIZATION IN FIELDS OF GENE EXPRESSION Mark V. H. WILSON, and Gavin F. HANKE Laboratory for Vertebrate Paleontology, Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9 Canada Paired fins historically have been considered to be one of the most important innovations of the Gnathostomata (vertebrates with jaws). Modern studies of gene expression give evidence for antero-posterior patterning of the vertebrate body during development of the embryo by means of distinct fields of expression of genes such as Hox genes. The similarity of the pectoral and pelvic limbs of vertebrates has suggested similar mechanisms of development in both, and studies of gene expression show that Hox genes 9 through 13 (Tabin and Laufer, 1993) are expressed during development in both pairs of appendages. However, the evolutionary origin of paired fins is far from clear. One early idea was the "fin-fold" theory (Balfour, 1875), according to which pectoral and pelvic fins were derived from a single pair of long fin folds, pectoral fins being derived from the anterior part and pelvic fins from the posterior part. This theory appealed to molecular developmental biologists (e.g., Tabin and Laufer, 1993) because it seemed compatible with distinct antero-posterior fields of expression of Hox genes. Moreover, some early vertebrates (e.g., Shu et al., 1999) appear to possess a paired fin fold of some kind. Two remarkable Early Devonian gnathostomes (Gagnier and Wilson, 1996a, b) from the MOTH locality (Delorme Group, Mackenzie Mountains, Northwest Territories, Canada) demonstrate two important aspects of inferred fields of expression of genes that influenced paired-fin development: antero-posterior overlap and compartmentalization. Kathemacanthus Gagnier and Wilson, 1996a, is a primitive acanthodian-like animal with two distinct series of paired fins and fin spines. The pectoral series consists of large, paired pectoral fins, each with a large spine, along with several pre-pectoral spines in a necklace-like arrangement. The pelvic series consists of paired pelvic fins, each with spine, and several pairs of pre-pelvic spines. Pectoral fins are rounded and lobate, whereas pelvic fins are broad-based. In Kathemacanthus, the two spine-plus-fin series are anatomically distinct, overlap antero-posteriorly, and yet are both well developed. Brochoadmones Bernacsek and Dineley, 1977, is a primitive acanthodian with a pair of delicate pectoral fins situated on its flanks, each preceded by a tiny pectoral spine, but lacking any other members of the prepectoral spine series. The pelvic series, in contrast, is represented by a large pelvic fin and spine and a series of 5 or 6 paired, well-developed, pre-pelvic spines. Remarkable new specimens show that each pre-pelvic spine supported a flap of scale-covered skin, i.e., a finlet. These are the first vertebrates to show more than two pairs of fin-like structures. Moreover, the pre-pelvic series begins anteriorly at a point beneath the gill slits, far anterior to the pectoral fins, demonstrating antero-posterior overlap compared to the pectoral series. The antero-posterior overlap of the pectoral and pelvic series in Kathemacanthus and Brochoadmones suggests that pectoral and pelvic fins of gnathostomes are not specified strictly in separate antero-posterior fields. The two paired-fin series also demonstrate compartmentalization, in that expression of one series can be enhanced or suppressed independently of the other. In the case of Kathemacanthus, both series are well expressed, whereas in Brochoadmones the pelvic series is fully expressed, but the pectoral series is greatly reduced. Climatiid acanthodians represent an intermediate condition, not previously recognized. For the classical fin-fold theory of paired-fin origins to be applicable to patterns of Hox-gene expression, the two paired-fin series should not overlap antero-posteriorly. That they do so in these early vertebrates raises questions about simple models of gene expression in paired fins of early gnathostomes and about the validity of a simple fin-fold theory for paired-fin origins. BALFOUR, F. M., 1875. A comparison of the early stages in the development of vertebrates. Quarterly Journal of Microscopical Science (n. s.) 15,207-226. BERNACSEK, G. M. and DINELEY, D. L., 1977. New acanthodians from the Delorme Formation (Lower Devonian) of N.W.T., Canada.

Palaeontographica, Abteilung A, 158, 1-25.

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IPC2002 Poster Presentations GAGNIER, P.-Y. and WILSON, M. V. H., 1996. Early Devonian acanthodians from northern Canada. Palaeontology 39:241-258. GAGNIER, P.-Y. and WILSON, M. V. H., 1996. An unusual acanthodian from northern Canada: revision of Brochoadmones milesi. Modern Geology 20, 235-251. SHU, D.-G., LUO, H. L., Conway Morris, S., Zhang, X.-L., Hu, S.-X., Chen, L., Han, J., Zhu, M., Li, Y. and CHEN, L.-Z., 1999. Lower Cambrian vertebrates from south China. Nature 402,42-46. TABIN, C. and LAUFER, E. 1993. Hox genes and serial homology. Nature 361, 692-693.

EVOLUTION OF RESPIRATORY PROTEINS WITH REFERENCE TO EARLY METAZOAN DIVERSIFICATION Qun YANG and Baozhong LU Nanjing Institute of Geology & Palaeontology, Chinese Academy of Sciences [qunyang@nigpas.ac.cn]; Shanghai Cancer Institute, Shanghai 200032, People's Republic of China Recent advances in molecular chronology for animal divergence (Wray et al1996; Ayala et al1998) and new palaeontological findings (Xiao et al1998; Chen et al2000) reveal that the Cambrian explosion was most likely preceded by a prolonged period of animal evolution or a "phylogenetic fuse" which has left little fossil record due to the metazoans' very small size and lacking skeletons (Fortey, 2001). The question why the metazoans suddenly increased their body size, acquired skeletons and quickly radiated at the base of Cambrian remains a challenge. A genetic foundation is necessary for potential morphological diversification, whereas (favorable) environmental events could smooth the selective landscape, thus releasing the morphogenetic potential. Molecular oxygen (0 ) level might be a critical candidate for such an environmental trigger (Knoll & Carroll, 1999). Geobiochemical studies of Proterozoic rocks indicate that 0 increased in the late Proterozoic (Canfield & Teste, 1996). 0 is a vital factor for metabolism of all aerobic organisms. Therefore, apart from other genetic mechanisms, acquisition of a means to efficiently utilize 0 must have been a key step in early metazoan diversification (Yang & Lti, 2001). (1) The simplest and least efficient way animals obtain 0 is by diffusion at their body surface. These organisms have developed no specialized respiratory proteins and are most likely representative of primitive metazoans, including modern coelenterates, cnidarians and poriferans. Their body size can only increase via increasing surface area. They have limited ability for active locomotion due to limited metabolic efficiency under this respiratory mechanism. We suggest, their morphology, that the Precambrian Ediacarans also belonged to this category. (2) Hemerythrin is a non-heme iron protein capable of 0 -transport in polychaete Annelida, Priapulida, Siphunculida and Brachiopoda. Although it transports 0 rather inefficiently, hemerythrin may be the first molecular lung to have evolved in early metazoans. With this, organisms increased their metabolic efficiency, thus acquiring greater ability for locomotion and competition for resources. These organisms probably diversified corresponding with the 0 increase in the late Proterozoic; their potential for quicker movement could only be realized with availability of sufficient 0 . (3) A MORE efficient molecular lung - hemocyanin, a copper containing protein, evolved in Mollusca and Arthropoda that dominated the Cambrian oceans. These metazoans are often capable of active locomotion and predation. With potentially higher respiratory efficiency and greater mobility, the hemocyanin animals must have diversified in the presence of even higher 0 levels in the environment, thus, were probably later than the hemerythrin animals. (4) HEMOGLOBINS are the most familiar 0 -transporting proteins, widely represented in metazoans. There is a wide range of hemoglobins, of which invertebrate hemoglobins or erythrocruorins are less efficient, whereas vertebrate hemoglobins are considered the most advanced molecular lung; it probably evolved during the post-Cambrian explosion time. In conclusion, we postulate that the evolution of respiratory proteins played an important role in early metazoan diversification. The 0 rise during late Proterozoic could have triggered the Cambrian explosion by activating and promoting the function of molecular lungs. Our analysis indicates that the hemocyanin animals should have diversified later than hemerythrin animals. This hypothesis needs further testing by more rigorous palaeontological investigations near the Precambrian-Cambrian boundary and further detailed studies of molecular-clock dating within relevant animal phyla to trace the age of their root. 1

AYALA, F.J., RZHETSKY, A. & AYALA, F.J., 1998. Origin of the metazoan phyla: molecular clocks confirm paleontological estimates. Proceedings of the National Academy of Sciences USA 95, 606-611 CANFIELD, D.E. & TESKE, A., 1996. Late Proterozoic rise in atmospheric oxygen from phylogenetic and stable isotopic studies. Nature, 382, 127-132. FORTEY, R., 2001. The Cambrian explosion exploded? Science 293,438-439.

JUN-YUAN CHEN, PAOLAOLIVERI, CHIA-WEI LI, GUI-QINGZHOU ,et al., 2000. Precambrian animal diversity: Putative phosphatized embryos

from the Doushantuo Formation of China. Proc. Natl. Acad. Sci. USA 97,4457-4462. KNOLL, A.H. & CARROLL, S.B., 1999. Early animal evolution: emerging views from comparative biology and geology. Science, 284, 2129-2137.

WRAY, G., LEVINTON, J.S. & SHAPIRO, L.H., 1996. Molecular evidence for deep Precambrian divergences among the metazoan phya. Science 274, 568-573.

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IPC2002 Poster Presentations YANG QUN & Lu BAOZHONG, 2001. Molecular respiratory mechanisms in the Cambrian metazoans. Journal of Genetics and Molecular Biology, 12(1): 10-11.

JURASSIC (LIASSIC) DEPOSITIONAL CONDITIONS AND PALAEOENVIRONMENT FACTORS RELATED TO THE TRACE FOSSILS FROM CENTRAL IRAN Mehdi YAZDI and Hossein Vaziri MOGHADAM Department of Geology, Faculty of Sciences, University of Isfahan, Iran [m.yazdi@sci.ui.ac.ir] Liassic trace fossils assemblages in Isfahan Province can be reported as: Urohelminthoida, Paleodictyon, Planolites, Dendrotichnium and U-Horizontal burrow. This assemblage of ichnofauna represents the Nereites ichnofacies. The presence of these four trace fossils indicates that the depositional condition related to the Liassic sediments in Isfahan province may be deeper than documented before. Since coal seams are cropping out within the Rheto-liassic sequences in the northern part of Isfahan (continental condition) but, there is no no trace of coal seams with Paleodictyon fossils, we believe that a deep shelf or basin depositional condition was dominated at the time of Liassic in Isfahan province. Elements related to this assemblage can be collected from several sections in the Isfahan province, e.g. Abbassi Dam (west of Isfahan city), Alavijeh area (north-west of Isfahan), Ziar and Kolah-Ghazi areas (south-east of Isfahan city). Low-grade metamorphism affected Jurassic sequences southeast of Isfahan (this phenomena had been reported as Palaeozoic age before) and Paleodictyon fossils can be seen with metamorphosed sequences, in this research we are proposing the age of this phenomena as post-Jurassic metamorphism not Palaeozoic.

LATE CARBONIFEROUS TO EARLY PERMIAN FLORA FROM CENTRAL IRAN (ABADEH & ISFAHAN) Mehdi YAZDI Department of Geology, University of Isfahan, Isfahan, Iran [m. Yazdi@sci.ui.ac.ir] Remains of Late Carboniferous to Early Permian flora related to Dicridum and lycopods were recovered from two localities in Central Iran (Abadeh and Soh areas). Remains of lycopods were discovered from a sandy bed within the Nachaft section in Soh area (north of Isfahan) for the first time. Specimens related to Dicridum and Sphenophytes were collected from Abadeh area (Kavier six refractory mine). Remains or transported wood related to trunks or trees from Soh area can be assigned to subgenus Subsigillaria and Lepidodenron tree. These remains are similar to the subgenus Eusigillaria that had been reported by Stewart & Rothwell (1993, p. 146). A considerable number of related lycopods tree were collected from Soh area. Since these remains were transported from their original place extra research should be done on the palaeoenvironment.

ADVANCES IN STUDY OF PERMINERALIZED BIOTA FROM THE NEOPROTEROZOIC DOUSHANTUO FORMATION AT WENG'AN, GUIZHOU PROVINCE, SOUTH CHINA YIN Chongyu & GAO Linzhi Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, China In late Neoproterozoic times, the Weng'an area was situated near a persistent palaeotopographic high, the Upper Yangtze Oldland. Regionally, the Doushantuo Formation commonly overlies the metamorphic Qingshuijiang Formation of the Banxi Group, or may overlie the sporadically distributed Nantuo diamictites. In the stratotype of Sinian System in the Yangtze Gorges area, the Doushantuo Formation underlies the Dengying dolomites that contain, in their uppermost beds, basal Cambrian skeletal fossils. The Doushantuo succession in the Weng'an area is divided into two members by a subaerial exposure surface in the middle part, each containing a phosphate-rich bed (the lower and upper ore-beds). The lower member consists of a series of manganiferous dolomite - psammitic phosphorites - dolomite and represents a shallowing-upward sequence. The upper member is composed of dolorudite phosphorites with matrix phosphate - phosphatic

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IPC2002 Poster Presentations dolomite interbedded with phosphorites - phosphatic dolomite with phosphorites and cherty beddings, which records a second shallowing-upward sequence. Comparative study of microfossils from two kinds of sediments: chert intercalations (studied in thin section) and phosphorite/phosphatic carbonate (in thin section and maceration) from the upper Neoproterozoic Doushantuo phosphorites in the Weng'an area, Guizhou Province, South China, shows that phosphatized Megasphaera ornata Xiao & Knoll 2000 and chert-preserved Tianzhushania tuberifera Yin, Gao & Xing 2001 should be regarded as the same taxon preserved by different mineralization processes. The outer wall is often peeled off in phosphatized fossils with the ornamented middle wall preserved. Some phosphatized specimens isolated from the matrix and thin sections of phosphorites show a partly preserved outer wall with spines, which can be compared to the thin-sectioned Tianzhushania tuberifera from the chert beds. The small pits usually seen on the surface of the ornamented middle wall of Megasphaera ornata correspond to attachment spots of spines on the outer wall. The presence of a spiny outer wall is a characteristic of Tianzhushania. As Megasphaera ornata was named before Tianzhushania tuberifera, T. ornata (Xiao & Knoll) is the valid name for the taxon. The proposed resting-egg nature of the latter, based mainly on ornament type of the middle wall (Xiao & Knoll, 2000), cannot be entirely excluded, but presence of a spiny outer wall suggests that the affinity of T. ornata needs further investigation. Globular fossils from Doushantuo phosphorites in the Weng'an area are identified for the first time as the gastrulation stage of phosphatized embryos (Yin, Yue & Gao, 2001). They are obtained from fossiliferous remains after acetic acid maceration. The fossils are found together with formerly reported animal resting eggs and embryos of an earlier cleavage stage. The oblate-shaped fossils of the same size as those reported as embryos invaginate at the middle part into the embryos; they show the characteristics of the late blastula to the early gastrula stage of embryo development. This proves the existence of animal embryos of Doushantuo age and offers new facts for studying the affinity of related fossils, but which are still controversial at present. Discovery and study of the phosphatized spherical fossils from the Doushantuo Stage at Weng'an provides a rare chance to understand the early evolution of multicellular organism including metazoan fauna. PALAEOZOIC RADIOLARIAN FAUNA AND THEIR TECTONIC SIGNIFICANCE IN THE SOUTHERN TIANSHAN, XINJIANG, NORTHWESTERN CHINA Yu Liu School ofEarth and Space Sciences, Peking University, Beijing 100871, P. R. China There have long been different opinions regarding the age of the ophiolite in the South Tianshan, Xinjiang Uygur Autonomous Region. Abundant, well-preserved radiolarians have now been obtained from siliceous rocks at the top of the ophiolite from a sequence dominated by interbedded sandstone and shale deposited at the same time as the ophiolite suite. Some workers believed the ophiolite suite to be Middle-Devonian, others that it was Upper Silurian-Lower Devonian, but our data indicates Early Carboniferous (Tournaisian-Visean). Four radiolarian assemblages have been discriminated: Triaenosphaera palimbola, Entactinia vulgaris, Belowea cf. variabilis and Archocyrtium sp. These assemblages can be correlated with faunas from the Early Carboniferous of Germany and North America but, because there is conspicuous absence of Allbaillella, the names of the assemblages are different. The South Tianshan radiolarian sequence is similar to that established in Germany by Andreas Braun—the taxa making up each assemblage zone and their sequence are very similar. The South Tianshan radiolarian taxa are widely distributed in the Lower Carboniferous of North America and southern China. The enclosing rock of the four radiolarian assemblages is a red-purple, thin-bedded siliceous rock high in ferric iron with magnetite occurring in euhedral and anhedral forms. The environment is interpreted to have been hydrothermal. The radiolarians are small and thin, and occur in association with sponge spicules and conodonts; the conodont assemblages are of Nandan type. Based on these analyses, the environment is suggested to have been low latitude, warm waters of normal salinity. On the basis of the sediments, radiolarians, associated fauna and petrochemistry, we believe the ophiolite to represent a slowly expanding ocean. Further research is warranted for elucidating the evolution of the South Tianshan.

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IPC2002 Poster Presentations LATE CARBONIFEROUS-EARLY PERMIAN CONODONT AND FUSULINID ZONES AND THEIR STRATIGRAPHIC SIGNIFICANCE IN BOREHOLES FROM THE TARIM BASIN, CHINA ZHANG Shiben HUANG Zhibin, DU Pingde, GAO Qinqin, LI Meng & TANG Zhejin Tarim Oilfield Company ofPetroChina, Korla 841000, Xinjiang, China 1

The Upper Carboniferous-Lower Permian in boreholes from the Tarim Basin consists (in ascending order) of the top part of the Klashayi Formation (the Limestone Member), the Xiaohaizi Formation and the Nanzha Formation. The lower-middle part of the Limestone Member yields two conodont zones: Gnathodus bilineatus Zone, Idiognathodus delicates-Idiognathoides corrugata-Neognathodus elongatus Zone and the fusulinid Eostaffella ikensis Zone. The upper part of the Limestone Member and the Xiaohaizi Formation yield the conodont Streptognathodus suberectus-S. parvus-Gondolella bella Zone and the fusulinid Fusulina-Fusulinella Zone. Therefore, the top part of the Kalashayi Formation and the Xiohaizi Formation ranges in age from Late Carboniferous Bashkirian to Moscovian. The lower part of the Nanzha Formation yields the conodont Streptognathodus elongatus- S. wabaunsensis-S. isolatus zone and the fusulinid Pseudoschwagerina Zone. It is Early Permian Asselian in age. The upper part of the Nanzha Formation yields the Sweetognathus whitei-Neostreptognathodus pequopensis Zone and the Eoparafusulina Zone. It is Early Permian Sakmarian-Artinskian in age.

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