Ellipsocephalid trilobites from Cambrian Series 2 and Stage 4 by Universitetsforlaget

Peter Geyer, Ahlberg, H. Nilsson

Peter H.

Nilsson and John Ahlgren 24-03-2022 07:18:11 AND STRATAFOSSILS

Peter H.

Carin

and John Ahlgren

Per

interna onal monograph series of palaeontology and stra graphy Number 67 • September 2022 Ellipsocephalid Trilobites from Cambrian Series 2 and Stage 4

Cederström, Gerd

Cederström, Gerd Geyer, Per Ahlberg, Carin

interna onal monograph series of palaeontology and stra graphy Number 67 • September 2022 Ellipsocephalid Trilobites from Cambrian Series 2 and Stage 4

Nilsson and John Ahlgren AND STRATAFOSSILS

interna onal monograph series of palaeontology and stra graphy Number 67 • September 2022 Ellipsocephalid Trilobites from Cambrian Series 2 and Stage 4

AND STRATAFOSSILS

Cederström, Gerd Geyer, Per Ahlberg, Carin

DOI: Enquiries10.18261/9788215065779-2022aboutthispublicationmay be directed to: www.universitetsforlaget.nopost@universitetsforlaget.no.

ISBN electronic PDF edition: 978-82-15-06577-9

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Cover picture: Cranidium of Dellingia scanica (Ahlberg & Bergström, 1978) from provisional Cambrian Stage 4 at Gislövshammar, Scania, Sweden.

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FOSSILS AND STRATA

An international monograph series of palaeontology and stratigraphy

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Editor-in-Chief: Svend Stouge, Professor Emeritus, Geological Museum, University of Copenhagen, Denmark

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EllipsocephalidtrilobitesfromCambrianSeries2andStage 4,withemphasisonthetaxonomy,morphologicalplasticity andbiostratigraphicsigniﬁcanceofellipsocephalidsfrom Scania,Sweden by

PeterCederstro ¨ m,GerdGeyer,PerAhlberg,CarinH.Nilssonand JohnAhlgren

Acknowledgements

FinancialsupportforthepublicationofthisissueofFossilsandStratawas providedbytheLethaiaFoundation.

Mjøsaarea 8

Scanianlocalities 15

Gislovshammar 17

Epichalnipsus 23

Ellipsocephalidmorphologyanditsphylogenetic implications 28

Genus Kingaspidoides Hupe ´ ,emend.Geyer,1990b55 Kingaspidoidesnordenskioeldi (Linnarsson,1883)58 Kingaspidoideslunatus (Bergstrom&Ahlberg,1981)62 Kingaspidoides? obscurus (Thorslund&Westergård, 1938) 66

Ljubomlian 10

Ellipsostrenua 23

OrderRedlichiidaRichter,1932 31

Stratigraphicdiscontinuitiesandsequencestratigraphic signatures 5

Ontogeneticalandecologicalaspects 21

Geologicalsettingandstratigraphy 3

Morphologyofpalpebrallobes 29

Morphologyofpygidium 30

Epichalnipsuskullingi (Ahlberg&Bergstrom,1978)53

Genus Cambrosaurura Geyern.gen. 67 Cambrosaururausitata (Geyer,1990) 68 Cambrosaururarobusta Geyern.sp. 73 Cambrosaururabommeli Geyern.sp. 77 Cambrosaurura? todraensis (Geyer,1990) 79

Shapeofgenalspine 30

Intercontinentalcorrelation 13

Kybartaian 11

Ageandcorrelation 6

Transversereliefofcranidium 29

Acknowledgements 123 References 123 Appendix 130

Vergalian Rausvian 11

Epichalnipsusanartanus Geyer,Popp,Weidner& Forster,2004 43

Shapeofglabella 28

Hardeberga 20 Almbacken 21

CentralSweden 9

Synecology 24

Scania 7

Stagesubdivisionofthetraditional‘LowerCambrian’in Baltica 10

Ontogenyandautecology 21

Phylogeneticimplications 31

Lithostratigraphy 3

OlandandGotland 10

Sagittalconvexityofpreglabellararea 30

Forsemolla 19

Systematicpalaeontology 31

Dellingia 24

Contents

Trilobitepreservationandtaphonomy 26

SuperfamilyEllipsocephaloideaMatthew,1887 31 FamilyEllipsocephalidaeMatthew,1887 33

SubfamilyStrenuaevinaen.subfam. 37 Genus Strenuaeva Richter&Richter,1940 38 Strenuaevaprimaeva (Brøgger,1878) 40 Strenuaevainﬂata Ahlberg&Bergstrom,1978 41 Genus Epichalnipsus Geyer,Popp,Weidner&Forster, 2004 42

SubfamilyEllipsocephalinaeMatthew,1887 54

Introduction 2

ClassTrilobitaWalch,1771 31

Patternoflateralglabellarfurrows 28

SubfamilyAntatlasiinaeHupe ´ ,1953 34 Genus Berabichia Geyer,1990 34 Berabichiabaltica (Wiman,1903) 35

Brantevik 16

Genus Ellipsostrenua Kautsky,1945 82 Ellipsostrenuagripi (Kautsky,1945) 83 Ellipsostrenualinnarssoni (Kiær,1917) 87 Ellipsostrenuasularpensis (Ahlberg&Bergstrom,1978)92 Ellipsostrenuabrevifrons n.sp. 96 Ellipsostrenuasimrica n.sp. 100 Ellipsostrenua sp.A 103 Ellipsostrenuatroedssoni n.sp. 104 Ellipsostrenuagranulosa (Ahlberg,1984c) 107 Ellipsostrenuaspinosa (Ahlberg&Bergstrom,1978)109 Genus Dellingia n.gen. 112 Dellingiascanica (Ahlberg&Bergstrom,1978) 113 Dellingia cf. D.scanica (Ahlberg&Bergstrom,1978)117 SubfamilyProtoleninaeRichter&Richter,1948 119 Genus Cuneoaxiella n.gen. 119 Cuneoaxiellagrandis (Ahlberg&Bergstrom,1978)120

Kvasa 18

SwedishCaledonides 8

Materialsandmethods 31 Repository 31

Epichalnipsusbergstroemi n.sp. 45 Epichalnipsusrotundatus (Kiær,1917) 49

Peter Cederström [peter.cederstrom@telia.com], Axelvoldsvägen 27, SE‐241 35 Eslöv, Sweden; Gerd Geyer[gerd.geyer@uni-wuerzburg.de], Institut für Geographie und Geologie, Bayerische Julius‐Maximilians-Universität, Am Hubland, 97074 Würzburg, Germany; Per Ahlberg [per.ahlberg@geol.lu.se], Department of Geology, Lund University, Sölvegatan 12, SE-223 62 Lund, Sweden; Carin H. Nilsson [carin.nilsson1@telia.com], Odengatan 3E, SE‐241 31 Eslöv, Sweden; John Ahlgren [jompa.ahlgren@telia.com], Backlyckevägen 4B, SE‐533 94 Hällekis, Sweden.

EllipsocephalidtrilobitesfromCambrianSeries2andStage4, withemphasisonthetaxonomy,morphologicalplasticityand biostratigraphicsigniﬁcanceofellipsocephalidsfromScania, Sweden

Ellipsocephalid trilobites from Cambrian Series 2 and Stage 4, with emphasis on the taxonomy, morphological plasticity and biostratigraphic significance of ellipsocephalids from Scania, SwedenPETERCEDERSTRÖM,

GERD GEYER, PER AHLBERG, CARIN H. NILSSON AND JOHN AHLGREN

Cederström, P., Geyer, G., Ahlberg, P., Nilsson, C. H., & Ahlgren, J. 2022: Ellipsocephalid trilobites from Cambrian Series 2 and Stage 4, with emphasis on the taxonomy, morphological plasticity and biostratigraphic significance of ellipsocepha lids from Scania, Sweden. Fossils and Strata, No. 67, 1–131. https://doi.org/10.18261/ The9788215065779-2022.taxonomicallydifficult

PETERCEDERSTRÖM,GERDGEYER,PERAHLBERG,CARINH.NILSSONANDJOHNAHLGREN

ellipsocephalid trilobites from upper lower Cambrian (unnamed Stage 4) strata in Scandinavia are reviewed and revised. The suggested generic identities illustrate the diversification of the Ellipsocephalinae and advocate a modified correlation of the late to latest early Cambrian strata in Scandinavia and Baltica. The study is based primarily on material from the Gislöv Formation in Scania, southern Sweden, from which several species were originally known only from sparse and poorly preserved material. These are now described in more completeness and partly based on material that allows characterisation of ontogenetic developments. The hitherto inadequately characterized and poorly described genera and species include Epichalnipsus Geyer, Popp, Weidner & Förster, 2004 with E. bergstroemi n. sp. and E. rotundatus (Kiær, 1917), Kingaspidoides Hupé, 1953 with K. nordenskioeldi (Linnarsson, 1883) and K. lunatus (Bergström & Ahlberg, 1981), Ellipsostrenua Kautsky, 1945 with E. gripi (Kautsky, 1945), E. linnarssoni (Kiær, 1917), E. sularpensis (Ahlberg & Bergström, 1978), E. brevifrons n. sp., E. simrica n. sp., E. troedssoni n. sp., and E. spinosa (Ahlberg & Bergström, 1978), Dellingia n. gen. with D. scanica (Ahlberg & Bergström, 1978), and Cuneoaxiella n. gen. with C. grandis (Ahlberg & Bergström, 1978). In order to present a coherent concept of subfamilies and genera within the family Ellipsocephalidae, several genera and species from outside Scania and Sweden are reviewed and partly revised. Additional new taxa and new combinations include the subfamily Strenuaevinae n. subfam., Epichalnipsus kullingi (Ahlberg & Bergström, 1978), Berabichia baltica (Wiman, 1903), and Cambrosaurura n. gen. with C. usitata (Geyer, 1990), C. robusta n. sp., C. bommeli n. sp. and C.? todraensis (Geyer, 1990). Morphotype differentiation is recognized within Dellingia scanica and E. bergstroemi n. sp. Measured and calculated linear dimensions of the individual parts of the cranidium and the exoskeletal ornamentation have proven to be of taxonomic significance for distinguishing closely related species. The width/length ratio of cranidia and the dimensions of their individual parts also provides clues for the mode of growth, and the ontogenetic development is described in Ellipsostrenua linnarssoni and E. brevifrons. The revised taxonomy and more precise data of the species ranges in the Gislöv Formation suggest a revision of the biostratigraphy in Cambrian Stage 4 of Scania and Scandinavia in general, with a subdivision into a Holmia kjerulfi Zone (revised), an Ellipsostrenua spinosa Zone and a Dellingia scanica–Kingaspidoides lunatus Zone. Despite the extremely condensed development of the Gislöv Formation and the overlying beds, considerable differences can be detected in the sections in Scania. Regional and intercontinental correlations are discussed. It is shown that the Dellingia scanica–Kingaspidoides lunatus Zone and probably also the Ellipsostrenua spinosa Zone correlates with paradoxidine‐bearing strata in West Gondwana hitherto assigned to the middle Cambrian. Thus, the earliest paradoxidines from Scandinavia are late by comparison with those of several other regions. The regression which caused the hiatus between the traditional lower and middle Cambrian strata in Scania and Scandinavia does not correlate precisely with the gaps recorded in other Cambrian continents such as West Gondwana or eastern Laurentia, and the new term Baltic Basin Regression is suggested. □ Biostratigraphy, Cambrian Series 2, Ellipsocephalidae, Morocco, Sweden, systematics

Cederström, P., Geyer, G., Ahlberg, P., Nilsson, C. H., & Ahlgren, J. 2022: Ellipsocephalid trilobites from Cambrian Series 2 and Stage 4, with emphasis on the taxonomy, morphological plasticity and biostratigraphic signiﬁcance ellipsocephalidsof from Scania, Sweden. Fossils and Strata, No. 67, 1 131. https://doi.org/ 10.18261/9788215065779-2022

Peter Cederström [peter.cederstrom@telia.com], Axelvoldsvägen 27, SE 241 35 Eslöv, Sweden; Gerd Geyer[gerd.geyer@uni-wuerzburg.de], Institut für Geographie und Geologie, Bayerische Julius Maximilians-Universität, Am Hubland, 97074 Würzburg, Germany; Per Ahlberg [per.ahlberg@geol.lu.se], Department of Geology, Lund University, Sölvegatan 12, SE-223 62 Lund, Sweden; Carin H. Nilsson [carin.nilsson1@telia.com], Odengatan 3E, SE 241 31 Eslöv, Sweden; John Ahlgren [jompa.ahlgren@telia.com], Backlyckevägen 4B, SE 533 94 Hällekis, Sweden.

This work is licensed under the Creative Commons Attribution 4.0 International (CC BY 4.0). To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

The taxonomically difficult ellipsocephalid trilobites from upper lower Cambrian named(unStage 4) strata in Scandinavia are reviewed and revised. The suggested generic identities illustrate the diversification of the Ellipsocephalinae and advocate a modified correlation of the late to latest early Cambrian strata in Scandinavia and Baltica. The study is based primarily on material from the Gislöv Formation in Scania, southern Sweden, from which several species were originally known only from sparse and poorly preserved material. These are now described in more completeness and partly based on material that allows characterisation of ontogenetic developments. The hitherto inadequately characterized and poorly described genera and species include Epichalnipsus Geyer, Popp, Weidner & Förster, 2004 with E. bergstroemi n. sp. and E. rotundatus (Kiær, 1917), Kingaspidoides Hupé, 1953 with K. nordenskioeldi (Linnarsson, 1883) and K. lunatus (Bergström & Ahlberg, 1981), Ellipsostrenua Kautsky, 1945 with E. gripi (Kautsky, 1945), E. linnarssoni (Kiær, 1917), E. sularpensis (Ahlberg & Bergström, 1978), E. brevifrons n. sp., E. simrica n. sp., E. troedssoni n. sp., and E. spinosa (Ahlberg & Bergström, 1978), Dellingia n. gen. with D. scanica (Ahlberg & Bergström, 1978), and Cuneoaxiella n. gen. with C. grandis (Ahlberg & Bergström, 1978). In order to present a coherent concept of subfamilies and genera within the family Ellipsocephalidae, several genera and species from outside Scania and Sweden are reviewed and partly revised. Additional new taxa and new combinations include the subfamily Strenuaevinae n. subfam., Epichalnipsus kullingi (Ahlberg & Bergström, 1978), Berabichia baltica (Wiman, 1903), and Cambrosaurura n. gen. with C. usitata (Geyer, 1990), C. robusta n. sp., C bommeli n. sp. and C.? todraensis (Geyer, 1990). Morphotype differentiation is recognized within Dellingia scanica and E. bergstroemi n. sp. Measured and calculated linear dimensions of the individual parts of the cranidium and the exoskeletal ornamentation have proven to be of taxonomic significance for distinguishing relatedclosely species. The width/length ratio of cranidia and the dimensions of their individual parts also provides clues for the mode of growth, and the ontogenetic development is described in Ellipsostrenua linnarssoni and E. brevifrons. The revised taxonomy and more precise data of the species ranges in the Gislöv Formation suggest a revision of the biostratigraphy in Cambrian Stage 4 of Scania and Scandinavia in general, with a subdivision into a Holmia kjerulfi Zone (revised), an Ellipsostrenua spinosa Zone and a Dellingia scanica Kingaspidoides lunatus Zone. Despite the extremely condensed development of the Gislöv Formation and the overlying beds, considerable differences can be detected in the sections in Scania. Regional and intercontinental correlations are discussed. It is shown that the Dellingia scanica Kingaspidoides lunatus Zone and probably also the Ellipsostrenua spinosa Zone correlates with paradoxidine bearing strata in West Gondwana hitherto assigned to the middle Cambrian. Thus, the earliest paradoxidines from Scandinavia are late by comparison with those of several other regions. The regression which caused the hiatus between the traditional lower and middle Cambrian strata in Scania and Scandinavia does not correlate precisely with the gaps recorded in other Cambrian continents such as West Gondwana or eastern Laurentia, and the new term Baltic Basin Regression is suggested. □ Biostratigraphy, Cambrian Series 2, Ellipsocephalidae, Morocco, Sweden, systematics.

This work is licensed under the Creative Commons Attribution 4.0 International (CC BY 4.0). To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

2 Cederströmetal. FOSSILSANDSTRATA

ThegenericafﬁliationformostoftheScandinavianellipsocephalidspecieshavebeenregardedas preliminary(Ahlberg&Bergström1978)orrevised (Geyer1990a).Geyer(1990a)suggestedthat:(1)

Introduction

ThetrilobitefaunafromtheCambrianStage4 GislövFormation(Bergström&Ahlberg1981) includesseveralellipsocephalidtaxa(Ahlberg& Bergström1978;Bergström&Ahlberg1981;Cederström etal.2012),locallyassociatedwithspeciesof theholmiidgenus Holmia (Bergström1973a)and theeodiscoid Calodiscuslobatus (Hall,1847)(see Ahlberg&Bergström1993;Cederström etal.2009). Anearliersystematicandphylogeneticrevisionof lowerCambrianellipsocephalidtrilobitesfromScandinavia(Ahlberg&Bergström1978)distinguished

19speciesandformsdescribedunderopennomenclature,assignedto ﬁvegenera.Thesegenera included Ellipsocephalus Zenker,1833, Comluella Hupé,1953, Proampyx Frech,1897, Strenuaeva Richter&Richter,1940and Strenuella Matthew,1887.

ThebiozonationofScandinavianstrataregardedas earlyCambrian(CambrianEpoch2)inagehasbeen basedonrelativelyfewfossilspecimensfromasurprisinglylownumberoflocalities.Thezonationhas undergoneafewminoramendmentsbuthas remainedmoreorlessthesameforalmostacentury. Inparticular,correlationoftheearliesttrilobite bearingstrataandthesupposedlatestearlyCambrianrocksintoregionsoutsideScandinaviaandBalticaremainedunsolvedproblems(Sundberg etal 2016).However, ﬁeldworkbyPeterCederström, CarinH.NilssonandJohnAhlgrenduringthepast threedecadeshasresultedincollectionsofseveral thousandspecimensoftrilobitesfromScania(in Swedish:Skåne),southernSweden,andvariouslocalitiesalongtheCaledonianFrontinSwedenandNorway(Fig.1).Recentstudies,largelybasedonthese collections,haverevealedimportantnewinformation onthedistributionandstratigraphicsigniﬁcanceof trilobitesinCambrianSeries2successionsinScandinavia(Moczydłowska etal.2001;Ebbestad etal. 2003;Axheimer etal.2007;Cederström etal.2009, 2011a,2012;Høyberget etal.2011,2015,2019; Weidner etal.2015;Ahlberg etal.2016).

Fig.1. MapofScandinaviashowinglocalitiesreferredtointhe textandthedistributionofallochthonousandautochthonous rocksintheScandinavianCaledonides.1,Mjøsaarea,SENorway; 2,FånånareaatLakeSörsjön;3,LakeStorumanarea;4,Laisvall miningdistrict;5,Torneträskarea.BasedonCederström etal. (2012, ﬁg.1).

FossiliferouslowerCambrianstrata,inparticular CambrianStage4successions,areprimarilyknown from ﬁveoutcropareasinScania,southernSweden (Fig.2).TheseincludecoastalsectionsatBrantevikandGislövshammar,southofthetownof Simrishamn,KvasanorthofSimrishamn,Forsemölla closethefamousAndrarumlocalityineasternScania,andtheHardebergaquarryareaeastofLund, southwesternScania(Nathorst1877;Grönwall1902; Troedsson1917;Hadding1958;Bergström&Ahlberg1981;Nielsen&Schovsbo2007,2011;Álvaro et al.2010;Cederström etal.2012).Severalborings throughlower middleCambrianstratainScaniaalso contributetothestratigraphicinformationfromthis interval(Fig.2;Westergård1942,1944;Christensen &Nielsen1998;Axheimer&Ahlberg2001,2003; Nielsen&Schovsbo2011).

Lithostratigraphy

ThetraditionaluppertouppermostlowerCambrianinScaniaisrepresentedbytheextremelythin GislövFormation(Fig.3),whichvariesinthickness between0.7and5.7m(seesectionsbelow)andwas formerlyknownasthe ‘greywackeshale’ sinceAngelin’s(1805 1876)days.TheGislövFormationisheterolithicinconsistingvariablyoffossiliferousclay andsiltstoneaswellassiltylimestoneandislocally richinglauconiteandphosphaticclasts(deMarino 1980b).Theformationrestsdisconformablyonthe RispebjergMemberandistodayexposedatonlyfour localities.ThetopoftheGislövFormationisrepresentedbyanerosionalsurfacethatdeﬁnesahiatus commonlyregarded(Nielsen&Schovsbo2015)as

Ellipsocephalus shouldbecharacterisedbyitsBohemiantypespeciesanditsrelativelyuniquepygidial morphology;(2)thegenericplasticityof Comluella is poorlyunderstoodandthatthegenusisbest restrictedtothetypespecies;(3) Proampyx mustbe restrictedtothelongknownmidandlatemiddle Cambrianspeciesassignedtothegenus(cf.Álvaro et al.2013);(4) Strenuaeva shouldbecharacterizedby themorphologyofitsfrontalarea;andthat(5)the genericconceptof Strenuella wasill deﬁned. Recently,Høyberget etal.(2015)assigned Ornamentaspis? linnarssoni (Kiær,1917)and Proampyx? sularpensis (Ahlberg&Bergström,1978),respectively, fromtheupperlowerCambrianintheMjøsaarea, Norway,to Ellipsocephalus Zenker,1833and,tentatively,to Ornamentaspis (Geyer,1990).

FOSSILSANDSTRATA Ellipsocephalidtrilobites(Cambrian)fromScania,Sweden 3

Thesuccessionrelevantforthisstudystartswiththe RispebjergMember(Grönwall1899;Surlyk1980)of the(upper)Læså Formation,athin(ca.1 3m)successionofslightlycalcareousmedium tocoarse grainedquartzsandstonewithoccasionalphosphoriteclastsandauthigenicphosphoriteinitsuppermostpart(deMarino1980a;Bergström&Gee1985; Pedersen1989;Álvaro etal.2010,2016).Bodyfossils areunknownfromtheRispebjergMemberexceptfor rarefragmentaryshells,butapoorichnofaunais knownfromnearthetopoftheformation(Lindström&Staude1971;Bergström&Ahlberg1981).

Thetraditionallower middleCambrianboundary intervalinScaniaischaracterisedbyatransition fromregressivetotransgressiveconditions,whichis difﬁculttoquantifybecauseofdeviousintermittent phases(seebelowunder ‘Stratigraphicdiscontinuities andsequencestratigraphicsignatures’).Theseconditionsareresponsibleforabasinevolutionthat startedwithproximalcoarse grainedsiliciclastic strataoftraditionallateearlyCambrianageand developedintodistalkerogen richshalespunctuated bydiscretecarbonatebedsintheearlymiddleCambrian.

MuseumcollectionsattheDepartmentofGeology,LundUniversity,Lund,Sweden(LO),the SwedishNaturalHistoryMuseum,Stockholm,Sweden(SMNH),theGeologicalSurveyofSweden, Uppsala,Sweden(SGU),andtheNaturalHistory Museum,Oslo,Norway(PMO),aswellasthematerialcollectedbyPeterCederström(PC),CarinH. Nilsson(CHN)andJohnAhlgren(JA)wereanalysedforthisstudytore evaluatethetaxonomic charactersofellipsocephalidspeciesandtheirreciprocalrelationshipsonsupra speciﬁclevelstogether withcriticalspeciesfromotherregionssuchasMoroccoandGermany.ThetaxonomicanalysisofellipsocephalidtrilobitesfromtheGislövFormationin Scaniaandroughlycoevalstrataofotherregionsin Scandinaviahasnotonlyledtoarevisionofthe genericassignmentoftheScanianspeciesbutforms thebasisforarevisedgenericsubdivisionwithinthe subfamilyEllipsocephalinae.Anumberofspecies previouslyassignedorquestionablyassignedto Proampyx, Ornamentaspis, Strenuaeva Richter& Richter,1940, Comluella and Ellipsocephalus are

transferredtothegenera Kingaspidoides Hupé,1953 (emend.Geyer1990a), Ellipsostrenua Kautsky,1945, Epichalnipsus Geyer etal.,2004, Dellingia n.gen., and Cuneoaxiella n.gen.Thetaxonomicrevision togetherwithdetailedsamplinghasresultedinsubdivisionoftheCambrianStage4ofScandinaviainto threebiozones:the Holmiakjerulﬁ, Ellipsostrenua spinosa, and Dellingiascanica Kingaspidoideslunatus zones.

Geologicalsettingandstratigraphy

Fig.2. MapofsouthernScaniashowingCambrianoutcropareas, localitiesanddrillingsitesreferredtointhetext.Modifiedafter Bergström&Ahlberg(1981, fig.3)andCederström etal.(2012, fig.7B).

Fig.3. LithologicalsuccessionsoftheHardebergaquarry,Forsemölla,GislövshammarandBranteviksectionsacrosstheGislövFormation anditsunder andoverlyingunits,withinterpretationofsequencestratigraphicsigniﬁcance.Internalunitsrefertothenomenclatureof Bergström&Ahlberg(1981).Occurrencesoftrilobitesbasedonnewdata.

TheGislövFormationisdisconformablyoverlain bythemiddleCambrian(MiaolingianSeries) throughlowerTremadocianAlumShaleFormation (Nielsen&Schovsbo2007).ThemiddleCambrian partofthisformation(20 30mthick)consistsofa darkgreytoblack,kerogen andsulphide richshale withdarkgreylimestonelensesorbeds.Prominent middleCambrianlimestonebedsaretheForsemölla, Exsulans,Hyolithes,andAndrarumlimestonebeds (Ahlberg1998;Ahlberg&Bergström in Ahlberg 1998;Axheimer&Ahlberg2003;Nielsen&Schovsbo 2007).

Inothersections,atBrantevikandGislövshammar,theGislövFormationisdisconformablyoverlainbythethin(<1m)ForsemöllaLimestoneBed (Nielsen&Schovsbo2007).Thisbedwasearlier knownasthe ‘fragmentlimestone’ orthe ‘trilobite coquina’.TheForsemöllaLimestoneBedhasyielded richfaunalassemblageswithtrilobites,linguliformeanbrachiopods,echinodermossicles,hyoliths, helcionelloids,lapworthellids,hyolithelminths, bradoriids,palaeoscolecidans,andconodont likeelements(Bengtson1976;deMarino1980b;Streng et al.2006,2008,2017;Álvaro etal.2010).Itisessentiallyabiocalcarenitewithaclayandcarbonatemud matrixoccupying50 70%involume.Fromamicrofaciesviewpoint,theremainingframeworkisvariably developedasapackstonewithsilt tomedium grainedsand sizedclasts,phosphoriteclastsof

anequivalentoftheHawkeBayEventofeastern Laurentia(PalmerandJames1980).Sandylimestone andbioturbatedcalcareoussiltstonebedsinthe lowerpartoftheGislövFormationappeartoindicate anotabledegreeofcondensation.TheGislövFormationisfurthercharacterizedbyahighcontentofpyriteandlocallyofphosphoritenodules(Bergström& Ahlberg1981;Álvaro etal.2010).

4 Cederströmetal. FOSSILSANDSTRATA

Ofparticularinterestisthedisconformablecontact betweentheGislövFormationandtheAlumShale Formation.Themagnitudeofthegapvariesconsiderablyasaresultoflocaltopographicandenvironmentaldifferencesduringdeposition.Inthe Forsemöllasection,theAlumShaleFormationcommenceswithathin(3 12cm)phosphoritic,

glauconiticandpartlyarenaceouslimestonefollowed byaca.50cmthickunitofmediumgreytoblack shale,whichistermed ‘ritskiffer’ or ‘drawingshale’ (Bergström&Ahlberg1981;Nielsen&Schovsbo 2007;Álvaro etal.2010).Thisunithasyieldedlinguliformeanbrachiopodsandhyoliths(Bergström& Ahlberg1981). Acadoparadoxides cf. A pinus (Westergård,1936)hasrecentlybeencollectedbyPCfrom the ‘drawingshale’,suggestingassignmenttothe middleCambrian(WuliuanStage) A pinus Zone.

Aseconddeepening upwardparasequencecanbe recognizedfortheupperpartoftheGislövFormation(TST2 ofÁlvaro etal.2010)andconsistsofdistinctlydifferentfaciesintheproximal distaltransect. IntheForsemöllasection,thisupperpartofthe GislövFormationisdevelopedalmostcompletelyas greylaminatedsiltyshalesofadeeperwaterfacies (unitB;Álvaro etal.2010;Fig.9).Itsconsiderably greaterthicknessof1.6mincomparisontotheother sectionsmustbeattributedtoadistalsituation.The proximaloutcropsatHardebergaandAlmbacken (poorlyaccessibleintheHardebergaIIsection;see Bergström&Ahlberg1981andbelow)aswellas BrantevikandGislövshammararecharacterisedat leastpartlybyadarkgreybiocalcarenite(8cminthe HardebergaIIsection;Figs3,6,7).Itshouldbe emphasized,however,thatthedetailedlithostratigraphicassignmentmustbemodiﬁedaspresented below.

TheuppermostlowerCambrianbiostratigraphyof theGislövFormationcanbeconstrainedusing sequencestratigraphicsignatures.Abasicanalysisof thesedatahasbeenprovidedbyÁlvaro etal.(2010), largelybasedondatafromdeMarino(1980b)and Bergström&Ahlberg(1981).

ThefaciesdistributionoftheinvestigatedstratigraphicintervalsuggestsaproximalfaciesdevelopmentattheHardebergaquarryinthewestand slightlymoredistalfaciesintheBrantevik Gislövshammarareaintheeast(Martinsson1974; Álvaro etal.2010).However,thereinterpretationof theForsemöllasectionpresentedhereinsuggeststhat localtopographyservedforconsiderablemodiﬁcationofthissimplisticpattern.ContrastingtheinterpretationinÁlvaro etal.(2010),thenew biostratigraphicdataindicateasigniﬁcantcut outof thelowerpartoftheGislövFormationintheForsemöllaareawithathickenedupperpart(equivalentto TransgressiveSystemTractTST2)ratherthanaconsiderablethickeningofthelowerpart(= TST1) (Fig.3).

FOSSILSANDSTRATA Ellipsocephalidtrilobites(Cambrian)fromScania,Sweden 5

millimetretocentimetreinlength,andglauconitic peloids(Álvaro etal.2010).Itshowsconsiderable condensation(Streng etal.2006;Álvaro etal.2010). Nevertheless,paradoxididremainswerereported fromthebedanddeterminedasbelongingto Hydrocephalus sp.(Forsemöllasection;Bergström&Ahlberg1981)and Paradoxidesparadoxissimus (Branteviksection;Bergström&Ahlberg1981).Consequently,thereisahugestratigraphicgap,comprisingtheearlyWuliuan Acadoparadoxidesoelandicus SuperzoneintheBrantevik Gislövshammararea.

ThediscontinuityattheRispebjerg/Gislövcontact(D1ofÁlvaro etal.2010)ismarkedbyanerosivesurfacethatindicatesasharpchangefrom depositiononasiliciclasticplatformwithamalgamatedchannelsandshoalsoftheRispebjergMember(deMarino1980a;Bergström&Gee1985)toa mixedcarbonate siliciclasticplatformrepresented bytheGislövFormation.Thismixedcarbonate siliciclasticplatformstartedwithrelativelyshallow depositionalenvironmentswithepisodicshellpavementsandgraduallygradedtodeeperfacieswith

shalesgeneratedinmoredistalenvironments (Álvaro etal.2010).Thus,thedevelopmentindicatesanasymmetricdeepening upwardparasequence.Thistransgressivesystemstract(TST1 of Álvaro etal.2010)isrecognisableandmoreorless completeintheBrantevikandGislövshammarsections(unitAandBofÁlvaro etal.2010andunits B DofBergström&Ahlberg1981;Figs3,6,7) andmodiﬁedintheHardebergasections(unitsB andCofÁlvaro etal.2010andunitsB CofBergström&Ahlberg1981;Figs3,10).ItisnotrepresentedinthesiliciclasticallydominatedForsemölla section.

AtBrantevik,thecontactbetweenTST1 andTST2 ismarkedbyadiscontinuity(D2ofÁlvaro etal. 2010)thatsubdividestheGislövFormation.Thisdiscontinuityisdevelopedasarectilinearerosivesurfaceinoutcrop,butshowsareliefofupto15cm withoccasionalsteep,centimetre scaledownward cuttingincisionsandlocallydevelopedbasallagsand erosivetoolmarks(Álvaro etal.2010).Consequently,theGislövFormationcanbedividedinto twodistinctlithostratigraphicunitsintheBrantevik Gislövshammararea.

AtBrantevik,GislövshammarandForsemölla,the discontinuity(D2andD3,respectively,ofÁlvaro et al.2010)thatmarksthetopoftheGislövFormation isanerosiveunconformitywithanundulating topography.IntheForsemöllasection,itwaserroneouslytermedD3byÁlvaro etal.(2010),whereas thetopoftheGislövFormationisactuallyatthetop ofunitB(Figs3,10).

Stratigraphicdiscontinuitiesandsequence stratigraphicsignatures

IntheAlmbackendrillcorethereisaunitofdark greytoblackshalebetweentheGislövFormation andtheForsemöllaLimestoneBed(Axheimer& Ahlberg2003).Thisunitisanequivalenttothe ‘drawingshale’ atForsemöllaandhenceappearsto representpartofthe A.oelandicus Superzone(cf. Nielsen&Schovsbo2007).

ThebaseoftheForsemöllaLimestoneismarked byglauconiteandphosphatepeloidsandclasts.The substantialhiatus,whichintheBrantevik Gislövshammarareaisequivalenttotheentire

Acadoparadoxidesoelandicus Superzone,isregarded asaresultofapronouncedrelativesea levellowstand thatresultedinerosion,despitetheapparentabsence ofsurfaceswithsubaeriallyformedfeatures.Theerosivephasewasfollowedbyatransgressionthatwas responsiblefortheabrasionofanearly cemented shellysubstrate.IntheBranteviksection,levelGof Bergström&Ahlberg(1981, fig.5)(levelEinÁlvaro etal.2010, fig.3)isanupto2cmthicklayerof polyphaseintraclasticelementswithabundantglauconiteandphosphateclaststhatrestsontheD3erosiveravinementsurfaceandtestifiesthemiddle Cambriantransgressiveevent.However,thetransgressiveunitthatrepresentstheinitialphaseofTST4 (sensuÁlvaro etal.2010)consistsofanadditional condensedshellylimestonewhichiscomposedof denselypackedphosphatizedclastsandskeletal packstone/wackestoneinaglauconitic richmatrix.

Ageandcorrelation

Ingeneral,thebiostratigraphywasbasedondisparateassemblagesandgenerallypoorcontrolof zonalboundaries.Thus,Nielsen&Schovsbo(2011) unitedthe ‘Holmiakjerulﬁ Zone’ andthelowerpart ofthe ‘Ornamentaspis? linnarssoni Zone’ intothe H. kjerulﬁ ‘O. ’ linnarssoni Zone(seealsoCederström et al.2012;Høyberget etal.2015).Theyalsorecognised theupper ‘O.? linnarssoni Zone’ asadiscretesubzone characterisedby Comluella?(= Dellingia) scanica Ahlberg&Bergström,1978and Ellipsocephalus (= Kingaspidoides) lunatus Bergström&Ahlberg,1981.

Asnotedabove,theprominentdisconformityat thetopoftheGislövFormationisahiatuscommonlyregardedasanequivalentoftheHawkeBay event(Palmer&James1980)ofeasternLaurentia (e.g.Nielsen&Schovsbo2015).However,asequence stratigraphicanalysisand fine scalecorrelationindicatethatthesupposedlysub globalregressional developmentshaveregionaloracontinentalsignatureonlyandareoftemporalextensionthatdoesnot permitapreciseglobalcorrelationbasedonsea level fluctuations(Geyer1990c;Álvaro etal.2003;Geyer 2005;Sundberg etal.2016).Theyneedtobeponderedindividually,andthebreakindeposition betweenthetraditionallowerandmiddleCambrian inBalticadoesnotmatchthemuchearlierHawke BayRegressionineasternLaurentia.Nevertheless,it isobviousthatthestratigraphicgapinBalticaisof variablemagnitude.Despiteabetterunderstanding ofthebiostratigraphybelowthehiatusprovidedin thisstudy,profounddeficienciesinthebiostratigraphicalresolutionofthelower middleCambrian boundaryintervalinBalticaingeneralandScandinaviainparticularstillexist.Nevertheless,wesuggest thename BalticBasinRegression fortheeventonthe EarlyPalaeozoiccontinentofBalticaandthe Baltic Basinhiatus fortheresultingstratigraphicgapinthe region.

ﬁg.26),andthepositionsofthedrillingsareindicatedinFigure2.

ArecentproposalbyAhlberg etal.(2016)emphasizedthattheCambrianSeries2zonalassemblages inScandinaviaoftenreflectbiofaciesmorestrongly thantemporaldifferences.TheysuggestedminimizingambiguityofbiozonationbyreducingthebiostratigraphicdivisionoftheScandinavianSeries2 successionintofourinterval zones,the Schmidtiellus mickwitzi, Holmiakjerulfi, Strenuaeva?(= Ellipsostrenua) spinosa,and Chelediscusacifer zones,with eachzonebeingdefinedbythe firstappearanceofthe eponymousspeciesanddelimitedatthetopbythe

Furtherinformationonthespatialandtemporal distributionoffossilsanddetailsofthestratigraphy inthelower middleCambrianboundaryintervalin centralandsouth easternScaniahavebeenobtained fromdrillcores.TheseincludetheAndrarum 1and Gislövshammar 2(Westergård1942,1944),Fågeltofta 2(Christensen&Nielsen1998)andAlmbacken cores(Axheimer&Ahlberg2001,2003).Relevant studiesarereviewedbyNielsen&Schovsbo(2011,

Thefollowingchapterattemptstoanalysethe plethoraofstratigraphicinformationfromthestudiedupperlowerCambrianandthelower middle Cambrianboundaryintervalandtosummarizethe developmentofthevariousstratigraphicconcepts. Generally,weusehereforthespeciestherevisedtaxonomypresentedinthisstudy.Theoriginaltaxonomyfrompreviouspublicationsisappliedwhereit elucidatestheconcept,andthesedeterminationsare thenpresentedinsinglequotationmarks.

ThestandardbiozonationforstrataofthetraditionalupperlowerCambrian(CambrianStage4)in Scandinaviagoesbacktotheoccurrencesoftrilobites intheMjøsaarea,southernNorway.Kiær(1917) subdividedtheMjøsasuccessionintotwozones:a lower ‘Holmiakjerulﬁ Zone’ andanupper ‘Strenuella linnarssoni Zone.’ Thiszonationhasbeentransferred toandwidelyusedforregionalcorrelationofScandinaviansuccessionsforalmostacentury.Subsequent studiesonlateearlyCambriantrilobitesofScandinaviaandtheirspatialandtemporaldistributions werecarriedoutbyBergström(1973a),Ahlberg& Bergström(1978,1983,1993),Ahlberg(1980,1984a, 1984b,1984c,1985,1998),Bergström&Ahlberg (1981),Ahlberg etal.(1986),Ebbestad etal.(2003), Høyberget etal.(2015)andothers.

6 Cederströmetal. FOSSILSANDSTRATA

Thebiostratigraphicsigniﬁcanceofthelower middle CambrianboundaryintervalinScaniahasbeenrecognizedforthe ﬁrsttimeintheForsemölla section,withitsfossil bearingGislövFormationand theoverlyingAlumShaleFormation,includingthe ForsemöllaLimestoneBed(Bergström&Ahlberg 1981;Ahlberg1998;Nielsen&Schovsbo2007, 2011;Álvaro etal.2010).A ‘Comluella? scanica Ellipsocephaluslunatus Zone’ (revisedasthe Dellingiascanica Kingaspidoideslunatus Zoneherein)is hererepresentedinarelativelymonotonous ‘ greywackeshale’ (= GislövFormation),whichisoverlain byaglauconitic,phosphaticandpartlyarenaceous limestoneandthe ‘drawingshale’ whichisnowrecognizedasbelongingtothe Acadoparadoxidespinus Zoneofthe A oelandicus Superzone(Miaolingian Series,WuliuanStage).

Tosummarize,transgressivesystemstractTST1 (sensuÁlvaro etal.2010)ofthelowerportionofthe GislövFormation(Fig.3)includesafaunawith Cuneoaxiellagrandis, Ellipsostrenuasularpensis,and E. linnarssoni,whichisnowrecognizedfromthe HardebergaquarryaswellastheGislövshammar andBranteviksections(Figs3,5,6,7).Thefaunais relativelysparseinthelowerpartofTST1,butisparticularlyrichintheupperpartofTST1 inamoredistalfacies.Thispartincludes Calodiscuslobatus, Holmia?sp., Cuneoaxiellagrandis,Ellipsostrenuaspinosa, E.brevifrons, E.troedssoni, E.linnarssoni,and E.sularpensis.Apparently,thisassemblagedoesnot differsigniﬁcantlyfromthatoftheunderlyinglower partofTST1.

circumstances,arevised Ellipsostrenualinnarssoni Zonealmostcertainlywillleadtoconfusionwithno practicaladvantages.Consequently, Ellipsostrenua spinosa canbeusedasanimportantindexspecies withadistinctivemorphologyandanapparentlyrelativelyrestrictedstratigraphicrange,andwasproposedasazonalindexspeciesforScandinaviaby Ahlberg etal.(2016).

baseofthesucceedingzone.Ahlberg etal.(2016)also emphasizedthatthe firstappearanceof Strenuaeva primaeva nearlycoincideswiththe firstappearanceof H.kjerulfi andisthusausefulsecondaryindexfossil forthebaseofthe H.kjerulfi Zone.Inaddition, Calodiscuslobatus isreportedtohaveits firstappearancedatum(FAD)inScandinavianearlycoinciding withthatof Strenuaeva?(= Ellipsostrenua) spinosa Chelediscusacifer,aneodiscidspeciesfromWarwickshire,England,andsoutheasternNewfoundland,was alsofoundintheTorneträskFormation,northern SwedishLapland(Axheimer etal.2007).

AreﬁnedsubdivisionoftheGislövFormationin thisstudyisbasedmainlyon(i)are evaluationof theknownfaunasinrespecttoasequencestratigraphicsubdivisionofthelower middleCambrian boundarybedsaccordingtodatapartlypresented byÁlvaro etal.(2010);andon(ii)newextensive collectionsoftrilobitesfromtheBrantevik,Forsemölla,GislövshammarandHardebergaquarryoutcrops.

Ellipsostrenuaspinosa wasoriginallybasedonlyon fourcranidiafromtheupperGrammajukkuFormationintheLaisvallarea,centralSwedishLapland. Extensive ﬁeldworkhasproducedacornucopiaof specimenssubsequentlycollectedfromtheGrammajukkuFormationatDelliknäsandMountAssjatjin theLaisvallarea,centralLapland,JiltjaurandTallträsk,southernLapland,theGislövFormationofthe Brantevik,GislövshammarandHardebergasections, Scania,andtheRingstrandFormationatRingstrand, Mjøsaarea,Norway(Cederström etal.2012; Høyberget etal.2015,2019)althoughthespeciesis rareinsomeoftheregions.Carefulinvestigations suggestthatallspecimenscomefromthelowerand middlepartofthetraditional Ellipsostrenualinnarssoni Zone.Theselowerandmiddlepartswere designatedbyHøyberget etal.(2015)asarevised Ellipsocephaluslinnarssoni Zone,whiletheupper partofthetraditionalNorwegian linnarssoni Zone wasdesignatedasthe Ellipsocephaluslunatus Zone. Albeit Ellipsostrenuaspinosa isfairlyinfrequentand thusnotanidealindexfossil,thesameistruefor Kingaspidoideslunatus.The E.linnarssoni Zone sensuHøyberget etal.(2015,2019)isaninterval zone,thepreciserecognitionofwhichdependson theoccurrenceofotherindexfossils,suchas K. lunatus,whichisequallyuncommonasandevenlessdistributedthan E.spinosa.Takingintoaccountthese

FOSSILSANDSTRATA Ellipsocephalidtrilobites(Cambrian)fromScania,Sweden 7

Aprofoundprobleminthebiostratigraphyofthe traditionaluppermostlowerCambrianofScandinaviaexistsinthefactthat Ellipsostrenualinnarssoni asrecognizedpriortotherevisionhereinappeared tohavearelativelylongstratigraphicrangeand seemedtopartlyoverlapwith Holmiakjerulﬁ,which isinuseastheprimaryindexfossiloftheunderlying H.kjerulﬁ Zone.Ithasbeensuggestedthattheoverlapbetweenthesetwospeciesisaresultofreworking ofolderdeposits(Høyberget etal.2015).InScania, however,holmiids,suchas Holmia?sp.,arerecognizedin E.linnarssoni bearingstrata(E spinosa Zone)intheGislövshammarsection,and Holmia? sulcata isknownfromsupposedlyyoungerstratain theForsemöllasection(Figs7,9).

Arelativelydiverseellipsocephalidfaunahasbeen recordedfromthetransgressivesystemstractTST2 oftheupperpartoftheGislövFormationinthe

Scania

MaterialrecentlycollectedfromtheTømten,Evjevik andSkybergmembersoftheRingstrandFormation intheLowerAllochthonatSkybergFarminthe Mjøsaarea,southernNorway(Fig.1),hasprovided importantinformationonthebiostratigraphicsubdivisionofthetraditionalupperlowerCambrian(Series2,Stage4)inScandinavia(Cederström etal 2012, ﬁg.8A;Høyberget etal.2015,2019). Holmia

Mjøsaarea

Thestratigraphicsuccessionandbiostratigraphic distributionoftrilobitesintheLakeStorumanarea, southernLapland(Fig.1),havebeenstudiedin muchdetailoverthelastdecade(Cederström etal 2012).Trilobitesareknownfromanumberofsectionsinthearea,andtheyoccurvariablyinsilty mudstonesaswellasindarklimestoneswithphosphaticnodules.Althoughabiostratigraphicsubdivisionappearstobepossibleinsomeofthesections, thesynthesisoftheoccurrencessuggeststhatdifferencesintherangesareobviouslyaresultoffacies preferencesandthattheassemblagesoverlyingstrata with Holmiakjerulﬁ and Strenuaevaprimaeva all representasinglefaunaofthelowerpartofthe

8 Cederströmetal. FOSSILSANDSTRATA

Gislövshammar,BrantevikandHardebergasections. Thisfaunaincludes: Dellingiascanica, Kingaspidoides lunatus, Ellipsostrenuasimrica, Epichalnipsusbergstroemi,and E. rotundatus.

Acritarchzonesappeartoreﬂectenvironmentally controlledphytoplanktonassemblagesratherthan truephylogeneticdevelopments.Inaddition,their resolutiondoesnotallowareﬁnedsubdivisionofthe lower middleCambrianboundarybedsinScania (Moczydłowska1991;Moczydłowska in Ahlberg 1998;Nielsen&Schovsbo(2011).

AcalcareousmudstoneatthetopoftheGärdsjönFormationintheFånånarea,northernJämtland,north centralSweden(Fig.1),hasyielded Calodiscuslobatus, Ellipsostrenuagranulosa, E linnarssoni, E gripi,and Luvsanodiscus cf. L. gammatus (Ahlberg1984c;Cederström etal.2009;Laibl etal.2018).Thetrilobitefauna isindicativeofthelower ‘Ornamentaspis? linnarssoni Zone’ sensuCederström etal.(2012).Thecalcareous mudstoneisoverlainbyblackshalesoftheAlumShale Formation(FjällbrännaFormation). Acadoparadoxides pinus and Macannaiaskybergi Høyberget&Bruton, 2008havebeenrecoveredfromalimestoneconcretion inthelowermostpartoftheAlumShaleFormation, ca.2mabovethetopoftheGärdsjönFormation(see Cederström etal.2009).

kjerulfi and Kjerulfialata arelargelyrestrictedtothe TømtenMember(Fauna2inFig.4),but K. lata rangesintothelowerlimestonebedoftheEvjevik Member(Høyberget etal.2015).Thislimestonebed bearsafairlydiversefaunawith Holmiakjerulfi (reworked), H.cf. H lapponica, Kjerulfialata, Ellipsostrenualinnarssoni,and Ellipsostrenuagripi (Fauna3inFig.4)thatisregardedtoindicatethebase ofthe ‘Ellipsocephaluslinnarssoni Zone’ sensuHøyberget etal.(2015).Thesiliciclasticshalefaciesofthe middlepartoftheEvjevikMemberispoorlyfossiliferous.Theonlytrilobiteremainswerefoundinthe upperpartandinclude Holmia cf. H. lapponica and Ellipsostrenuaspinosa,whereasthethinupperlimestonebedofthememberbearsamorediversefauna withthetrilobites E. linnarssoni, E. gripi, E. spinosa, E. sularpensis, Calodiscuslobatus,andtwoadditional unidentifiedforms.Thus,theentireEvjevikMemberis regardedasrepresentingthe ‘Ellipsocephaluslinnarssoni Zone’.TheoverlyingSkybergMemberhas onlyyieldedasingletrilobite, Kingaspidoides cf. K lunatus,suggestiveofthe ‘Ellipsocephaluslunatus Zone’ ofHøyberget etal.(2015)(Fauna4inFig.4).

Asimilarfaunahasbeenrecoveredfromthe lower middlepartoftheGislövFormationinthe Forsemöllasection,composedof Dellingia cf. D. scanica, Kingaspidoidesnordenskioeldi, Ellipsostrenua sp.A, Epichalnipsusbergstroemi, E rotundatus,and Holmia? sulcata.Thisassemblageseemstoshowthat probablytheentireGislövFormationrepresentedin theForsemöllasectioncorrelateswithonlytheupper partoftheformationintheotherknownsections andthusrepresentsonlyTST2.Theentiresuccession ofTST1 islackingbecauseofanon depositionduringthisintervalormusthavebeenerodedsubsequently.Thisisparticularlyastoundingbecausethe ForsemöllasectionhasthethickestknowndevelopmentoftheGislövFormation.

SeveraltrilobitesknownfromtheGislövFormationinScaniaoccuralsoinlowerallochthonous andautochthonusoutcropsalongtheCaledonian FrontinScandinavia.Theseincludethespecies Ellipsostrenualinnarssoni, E sularpensis, E.spinosa, Kingaspidoideslunatus,and Calodiscuslobatus.Caledonianoutcropareasare(1)theMjøsaareainsouthernNorway(Nielsen&Schovsbo2011;Høyberget etal.2015);(2)theFånånrivuletsouthofLakeSörsjöninNWJämtland(Ahlberg1984c;Cederström et al.2009;Nielsen&Schovsbo2011;Laibl etal.2018); (3)theStorumanarea(Ahlberg&Bergström1983; Nielsen&Schovsbo2011;Cederström etal.2012); (4)theLaisvallarea(Ahlberg,1984a;Nielsen& Schovsbo2011;Cederström etal.2012);and(5)the Torneträskarea(Ahlberg1979,1980,1984b,1985; Axheimer etal.2007;Cederström etal.2011a;Nielsen&Schovsbo2011)(Fig.1).

SwedishCaledonides

IntheLaisvallminingdistrict,asimilarassemblagewithtrilobiteshasbeenrecordedfromathin siltylimestoneintheupperthirdoftheGrammajukkuFormation,wheresectionsatMountAssjatj (Fig.1;MountAistjakk;e.g.Kautsky1945)and southwestofDelliknäs(Fig.1)yielded Holmia cf. H inusitata, Kjerulﬁapalpebra, Epichalnipsuskullingi, Ellipsostrenuaspinosa, Ellipsostrenuagripi, and Ellipsostrenualinnarssoni.Thisassemblage occurs5 10mbelowthetopoftheGrammajukku Formationthatisunconformablyoverlainbythe middleCambrianAlumShaleFormation(Cederström etal.2012).Asecondfossilassemblagewith Holmia? ljungneri,and Ellipsostrenuagripi occurs justbelowthetopoftheformation(Kautsky1945; Cederström etal.2012).Bothassemblagesappear tobetypicalforarelativelylowpartinthe(traditional) Ellipsostrenualinnarssoni Zone(Fauna9in Fig.4).

CentralSweden

TheLingulidSandstoneMemberoftheFileHaidar Formation,iswidelydistributedinVästergötland, ÖstergötlandandNärke.Weidner etal.(2015) describedafaunafromerraticbouldersfoundinDenmarkandnorthernGermanywithtrilobitessuchas Holmiella?sp., Epichalnipsusanartanus, Epichalnipsus sp.A, Epichalnipsus sp.B,and Berabichiaerratica,

Fig.4. CorrelationtableillustratingvariationinlithostratigraphyanddistributionofhiatusesinScandinavia,withrevisedstagesubdivisioninBaltica,acritarchandtrilobitezonationaswellassequencestratigraphicframeworksuggestedbyNielsen&Schovsbo(2011).BiostratigraphicallyusefulVergalian Rausvianfossilassemblagesindicated:(1) Holmiainusitata assemblage;(2) Holmiakjerulfi Kjerulfia lata Strenuaevaprimaeva assemblage;(3) Kjerulfialata Ellipsostrenualinnarssoni E.gripi assemblage(lowerpartofEvjevikMember) and Ellipsostrenualinnarssoni E.gripi E spinosa E sularpensis Calodiscuslobatus assemblage(upperpartofEvjevikMember);(4) Kingaspidoideslunatus assemblage;(5) Calodiscuslobatus Ellipsostrenuagranulosa E gripi E linnarssoni assemblage;(6) Dellingia? lapponica Strenuaevainflata Neocobboldia cf. N. dentata Chelediscusacifer assemblage;(7)horizonwith Holmia sp.;(8) Holmiakjerulfi Strenuaevaprimaeva assemblage;(9) Holmialapponica Kjerulfiapalpebra Epichalnipsuskullingi Ellipsostrenuagripi E spinosa E linnarssoni assemblage;(10) Holmiella? Epichalnipsusanartanus Berabichiabaltica assemblage;(11) Ellipsostrenuaspinosa E.brevifrons Calodiscuslobatus assemblage;(12) Dellingiascanica Kingaspidoideslunatus assemblage;(13) Kingaspidoides? obscurus fauna.Faunas indicativeofthe Holmiainusitata Zonemarkedbypurplebackground,thoseofthe Holmiakjerulfi groupZonebygreenbackground, thoseofthe Ellipsostrenuaspinosa Zonebyredbackground,thoseofthe Dellingiascanica Kingaspidoideslunatus Zonebybluebackground.The Holmiella? Epichalnipsusanartanus Berabichiabaltica assemblage(10,brown)isknownonlyfromerraticboulders,butwas showntocomefromtheLingulidSandstoneMemberwithhighcertainty(Weidner etal.2015).The Kingaspidoides? obscurus fauna(13, black)appearstorepresenttheyoungest,Kibartaianfauna.ThecolumnfortheMjøsaregionismodifiedtoincludenewdata(simplified) fromHøyberget etal.(2019)andincludesstratigraphicdatafromtheFlagstadelvaparautochthonousarea.Abbreviations:B.Fm., BorgholmFormation;Be,BråstadelvaMember;Bs,BrennsætersagaMember.

FOSSILSANDSTRATA Ellipsocephalidtrilobites(Cambrian)fromScania,Sweden 9

‘Ornamentaspis? linnarssoni Zone’ sensuCederström etal.(2012).ThisfaunaoftheLakeStorumanarea includes H.lapponica, Epichalnipsuskullingi, Ellipsostrenuagripi, E. spinosa and E. linnarssoni (Cederström etal.2012;Fauna9inFig.4).

Thestratigraphicsuccessionanddistributionof trilobitesatMountLuopakte(Fig.1)intheTorneträsk area,northernSwedishLapland,havebeenstudiedin muchdetailoverthelasttwodecades(Axheimer etal. 2007;Cederström etal.2011a).Trilobitesareknown fromthetraditional ‘Ornamentaspis? linnarssoni Zone’ andtheoverlying Chelediscusacifer ZoneofAhlberg et al.(2016).Recentstudiesshowthatthe ‘O.? linnarssoni Zone’ contains Ellipsostrenuagripi, E.linnarssoni and Kjerulﬁalata,whereasthe C. acifer Zonehasyielded C. acifer, Neocobboldia cf. N. dentata, Dellingia? lapponica, Strenuaevainﬂata,and Olenellus?spp.(= Holmia sp. in Axheimer etal.2007andCederström etal. 2011a).

Ljubomlian

ThelackofbiostratigraphicallyrobustdatafromseveralpartsofScandinaviahashamperedestablishmentofformalregionalstagesforthelower

ÖlandandGotland

CambrianofBaltica,althoughsuchstagesweremore orlessformallyintroducedforregionsofBalticaoutsideScandinaviaandparticularlyfortheBalticsyneclise(Areń etal.1979;Volkova etal.1979).Nielsen &Schovsbo(2011)presentedacomprehensivestudy ondepositionalenvironments,sequencestratigraphy andpalaeogeographyforthelowerCambrianofBalticaandintroducedtheRovnian,Lontovan,Dominopolian,Ljubomlian,Vergalian Rausvianand Kibartianstages,theboundariesofwhichwere mainlybasedonsequencestratigraphicalcriteria. Thesestagesareusefulalthoughtheydonotconform tothegenerallyagreedcriteriaoftheInternational CommissiononStratigraphy.

Theoldestofthestagesrelevantforthisstudyisthe Ljubomlian,whichisdefinedbytheFADofthe Heliosphaeridiumdissimilare Skiagiaciliosa acritarchassemblage(Moczydłowska1991,1998,1999; Moczydłowska&Vidal1992),anditsupperboundarywasdefinedbyNielsen&Schovsbo(2011)bythe baseofthe Holmiakjerulfi ‘Ornamentaspis’ linnarssoni ZonesensuNielsen&Schovsbo(2011). Nielsen&Schovsbo(2011)wereawarethatthis modifiestheoriginalconceptoftheLjubomlstage (Jankauskas2002)and,atpresent,alsolacksrobust biostratigraphiccriteriabecausethe Heliosphaeridiumdissimilare Skiagiaciliosa acritarchassemblage ismostprobablyfaciesdependent(seeremarksin Landing etal.2013),andmetazoanbodyfossilsare presentlyunknownfromtheinterval.

Aformallithostratigraphicsubdivisionoftheupper lowerCambrian lowermiddleCambriansequences inwesternLithuaniaandtheadjacentKaliningrad regionhasbeenestablishedbySakalauskas(1966, 1968),whorecognizedanAyschyaGroup,subdivided intoseveralformations.TheGegéFormation(Gegé ‘Suite’;Sakalauskas1966)intheolderpartofthe AyschyaGroupremarkablyyieldedtwotrilobites reportedasellipsocephalids: Germaropyge? mendosa Chernysheva in Korkutis1971fromtheGargzdai 6 drill core(atdepth2095.5m)and Ellipsocephalus sp. fromtheGargzdai 4drill core(depth2112m).The speciesdescribedas Germaropyge? mendosa hasbeen comparedbyChernysheva(in Korkutis1971)witha speciesdescribedbySamsonowicz(1959)as Germaropygesanctacrucensis fromtheHolyCrossMountainsofPoland(seeOrłowski1975).However,the speciesfromLithuaniashowscharactersresembling Strenuaeva and Epichalnipsus andneedscareful reconsideration.Thespecimendescribedas Ellipsocephalus sp.doesnotprovideenoughfeaturesto allowaconﬁdentdeterminationtoevenagenus.

10 Cederströmetal. FOSSILSANDSTRATA

DataontrilobitesfromthetraditionallowerCambrianofÖlandandGotlandarescarceandcome exclusivelyfromdrillcores.TheterminalearlyCambrianisrepresentedbyan ‘easternlithofacies’ generallytermedtheFileHaidarFormation(Bergström& Gee1985).Tentativebiostratigraphicaldatacome from ﬁndingsof Mobergellaholsti and M.radiolata aswellas Mickwitziamonilifera intheVisby1drill core(Hedström1923)andtheFileHaidar1drill core(Thorslund&Westergård1938;Ahlberg1989), respectively,suggestingthatthesestratamaybeolder thanthe Ellipsostrenuaspinosa Zone.TheonlydeterminedlowerCambriantrilobitefromtheregionis ‘Strenuella’ obscura Thorslund&Westergård,1938 (now Kingaspidoides? obscurus)reportedfromthe FileHaidar1drill core(Thorslund&Westergård 1938),indicatingaterminalearlyCambrianage (Fauna13inFig.4).Inaddition,Ahlberg(1989) reportedathoracictergiteofanellipsocephalidtrilobitefromtheformationintheNär1deepwellcore ofGotland.

Stagesubdivisionofthetraditional ‘LowerCambrian ’ inBaltica

andsuggestedthattheboulderscontainingthisfauna arederivedfromtheLingulidSandstoneMember, probablyfromaroundVästergötlandbasedonlithologiccharacteristicsoftherock(Fauna10inFig.4).

Apparently,thesameassemblageisrepresentedinglacialerraticbouldersoftheGävleBayregionsasseen inthefaunapublishedbyWiman(1903).However, thetrilobitesareunknownfromoutcropsinthearea, andtheformsareendemicsothattheyposeastratigraphicproblem.Weidner etal.(2015)suggesteda biostratigraphicpositionofthefaunaequivalenttothe lowertomiddlepartofthetraditional ‘Ornamentaspis? linnarssoni Zone’,butperhapsfromaparticularhorizonandbiofaciesnotknowninScandinavia. Theassignmentofotherspecies(describedanddiscussedbelow)to Epichalnipsus E.bergstroemi n.sp., E.rotundatus (Kiær,1917), E.kullingi (Ahlberg& Bergström,1978),and Berabichiabaltica (Wiman, 1903) bracketsthebiostratigraphicinformation althoughitcannotbeassumedthattherangesofthese additionalspeciesareequivalenttothatof Epichalnipsusanartanus, Epichalnipsus sp.Aand Epichalnipsus sp.B.

Ellipsocephalus cf. E hoffi’ wasreportedfromthe RausvehorizonofthePrabutyandRadzyń drill cores(Lendzion1979,pl.82, fig.11,misspelled ‘Ellipsocepholus cf. E hoffi’,pl.63, fig.10and1983, pl.92, fig.11,pl.93, fig.10),butboth figuredspecimensappeartobelongto Kingaspidoides ratherthan Ellipsocephalus

AnothertrilobitefromtheVergalehorizonofthe Tłuszczdrill corewasbrieﬂydescribedas ‘Strenuella

TheVergalian Rausvianstagehasbeenemployedby Nielsen&Schovsbo(2011)fromtheRausveand VergalestagesofEstonia(Kala etal.1984;Pirrus 1986;Brangulis&Yankauskas1987)andLatvia (Lieldiena&Fridrikhsone1968;Brangulis1979, 1985).TheRausvestagecoincideswiththeoriginal Volkoviadentifera Liepainaplana acritarchassemblage(Moczydłowska1991)thebaseofwhichis assumedtocoincidewiththebaseofthe Holmia kjerulﬁ ‘Ornamentaspis’ linnarssoni Zonesensu Nielsen&Schovsbo(2011).Thelowestoccurrenceof trilobites,however,isclearlylinkedtoafaciesshift orliesaboveanunconformitysothatthisstageneeds toberegardedasprovisionalaswell.

The findingsincludeatrilobitedescribedas ‘Ellipsostrenua cf. E gripi’ and ‘Ellipsocephallus cf. E. gripi’,respectively,fromtheVergalehorizonofthe Radzyń drill core(Lendzion1979,pl.83, fig.7and 1983,pl.93, fig.7),whichrepresentsanellipsocephalinetrilobitebutappearstolackcharactersnecessary foraconfidentdetermination.Atrilobitefromthe VergalehorizonoftheTłuszczdrill corewasdeterminedas ‘Germaropyge aff. G. sancta crusensis’.The singlespecimen,analmostcompletedorsalexoskeleton(Lendzion1972,1979,pl.83, fig.5,1983,pl.93, fig.5),isanellipsocephalinetrilobitefromthe Ellipsostrenua cladewithafaintlytapering,moderately wideglabellathatappearstobelongtothe E.gripi E. linnarssoni group,butrequiresadditionalexaminationtoallowaprecisedetermination.

Lendzion(1979,pl.83, fig.7and1983,pl.93, fig.9)alsodescribestrilobitesfromtheRausvehorizonofthePrabutydrill holeas ‘Protolenus aff. P. annulatus’ (Lendzion1979,pl.83, fig.7)and ‘Protolenus sp. ’ (Lendzion1983,pl.93, fig.9),respectively. Protolenusannulatus wasoriginallydescribed as Ellipsocephalusannulatus Schmidt,1942from middleCambriandrillcorematerialintheDelitzsch Torgau DoberlugsynclineinSaxony,Germany, beingpartofWestGondwana.Thespecieswas assignedto Protolenus bySdzuy(1957),butitrepresentsaspeciesof Kingaspidoides intheconceptof Geyer(1990a).TheassignmentbyLendzion(1979, 1983)isbasedonasingleellipsocephaloidcranidium thatdoesnotprovideenoughdetailstoallowaprecisedeterminationeventothegenus.

Kingaspis (Kingaspis) borealis Lendzion,1972isa speciesdescribedonlyfromthehigherpart(‘Protolenus Zone’)oftheRausvehorizonoftheRadzyń drill core(Lendzion1972,pl.5, figs5,6;Lendzion 1979,pl.83, fig.12and1983,pl.93, fig.12).The holotypeandsingleknowncranidiumcouldindeed beattributedto Kingaspis,butpossiblyrepresentsa speciesof Kingaspidoides.Dorsoventralcompaction slightlyveilstheoriginalreliefandotherdetailsof themorphology.Asimilarspecies, Kingaspidoides borjensis Geyer,1990,hasbeendescribedfromthe Morocconusnotabilis ZoneoftheAnti Atlas.The speciesfromMoroccoisdistinguishedbyitslonger palpebrallobes.

Nielsen&Schovsbo(2011)furtherintroduceda ‘Kibartian’ stage,basedontheKybartianStageformallyintroduced1977fortheEastBalticareaasa

Strenuella aff. S salopiensis’ isanameappliedtoa singlecranidiumfoundintheVergalehorizonofthe Prabutydrill core.Thespecimen(Lendzion1979,pl. 83, ﬁg.8and1983,pl.93, ﬁg.8)appearstobelongto aspeciesof Ellipsostrenua,butrequirescarefulre examination.

Kybartaian

TrilobitesdescribedfromtheRausveandVergale stagesofthePodlyas BrestDepressionandtheLublin SlopeinsouthernPolandaregenerallycomparable withthosedescribedfromScandinaviaalthougha comprehensiverestudyofthematerialappearstobe needed.TheyallcomefromtheRadzyń Formation whichiscomposedofvariablydevelopedsandstone withintercalatedargillaceousandsiltybeds,oftenrich inglauconiteandwithrarephosphaticnodules(Lendzion1962).Themostfrequentlydiscoveredtrilobite hasbeenidentifiedas Strenuaevaprimaeva.Lendzion (1979,1983)notesthatsixtyspecimenswereknown atthattime,allfromtheVergalehorizonandthus suggestingacorrelationwiththeupperpartofthe Holmiakjerulfi ZoneofScandinavia.Thespecimens weremostlyrecoveredfromdrillcoresofnortheastern Poland,butadditionalmaterialwasalsorecorded fromcoevalstratainLatviaandtheUkraine.Preservationofthespecimensdoesnotpermitaconfident identification,butsomeofthemmayindeedbelongto S.primaeva.

‘

Ellipsocephalidtrilobites(Cambrian)fromScania,Sweden

Vergalian Rausvian

‘

exgr. polonica’.Lendzion(1979,pl.82, fig.6and 1983,pl.92, fig.10)assignedtwocranidiaandalibrigenatoit.Theonly figuredspecimencannotbe determinedwithanyconfidence,butappearsto resemblespeciesassignedto Epichalnipsus inthepresentstudy.

FOSSILSANDSTRATA

1Theconceptofolenellids(inbroadsense)asindicatinganearlyCambrianagegoesbacktoWalcott’smonograph(1890).Asdiscussedrepeatedly, thisconceptscontradictstheearlierconceptof Brøgger(1886),whoconsidered Paradoxides bearingstratainScandinavia(andelsewhere)as middleCambrianinage(Geyer1990b,1990c 1993,2005).Geyer&Landing(1995),Geyer etal (1995)andGeyer&Vincent(2015)showedthat thereisaconsiderableoverlapofolenellid and Paradoxides bearingstratathatareregardedas lowermosttolowermiddleCambrianinthe MoroccanAtlasranges.Thosestrataareslightly olderthantheoldestScandinavian Paradoxides (s.l.)speciesfromthe Eccaparadoxidesinsularis Zone.Thus,olenelloidscannotberegardedasreliablecriteriaforanearlyCambrianage.Thisis valid,e.g.forasupposedolenelloidreportedby Hagenfeldt(1989)fromtheHamnuddendrillcore atGotskaSandön,whichobviouslyliesevenabove theso calledHawkeBayunconformity.Itmust

Thebiostratigraphiccriterionfordefiningthe ‘Kibartian’ sensuNielsen&Schovsbo(2011)isthe affiliationtothe Eliasum Cristallinium acritarch assemblagezone.Rocksthatobviouslybelongtothis assemblagezoneareusuallydevoidoftrilobites,but anumberofrecordsexist.Nielsen&Schovsbo (2011)discussedtheseraretrilobite findingsand concludedthatthepresenceofolenellids(infact, holmiidremains)indicatesanearlyCambrianage forthoserecordsand,consequently,forthe ‘Kibartian’/Kybartaian.Thisconclusionhasinfactthree problematicaspects:

3Thepresenceofellipsocephaloidtrilobitesisused tentativelybyNielsen&Schovsbo(2011,p.225) tosuggestthatamassivepresenceofellipsocephalidsand ‘representativesofthe Comluella? Group’ indicateanearlyCambrianage.Thisruns intoadoublecircularargumentbecausethe authorsalsotendtoquestionthegenericassignment,butdonotcommentidentiﬁcationsof Ellipsocephalus fromthestratainquestionalthough theyseemtoagreethattruespeciesof Ellipsocephalus areindicativeformiddleratherthan lowerCambrianstrata.

alsobeassumedforolenellidfragmentsdescribed byTynni(1982)fromtheSöderfjärdenbasinin westernFinland,whichco occurwithafragment ofananteriorcephalicborderthatcertainlyrepresentsaprotolenineorevenmoreprobablyaparadoxididtrilobite(Tynni1982, ﬁg.3).However, carefulinvestigationsareneededtoreconstruct thelocalsituation.Severalgapsinnearshoreareas resultfrommultipleregressionsandtransgressionsandmaycontributetomisperceptionsofthe stratigraphy.Inaddition,fossiltrilobiteremains (andacritarchs)mayhavebeenreworked.

12 Cederströmetal. FOSSILSANDSTRATA

2Therecordofthe Eliasum Cristallinium acritarch assemblagezoneremainsproblematicforanumberofthetrilobiteoccurrencesassignedtothe ‘Kibartian’/Kybartaian.Wiman’s(1903)trilobite remainsfromerraticbouldersintheGävleBayas wellasareportof Kjerulfialata fromtheDigermulenPeninsulainFinnmark,northernNorway (NikolaisenandHenningsmoen1990)mustbe regardedasdoubtfuloruncertaininrespecttoa Kybartaianassignment.NewdatabyEbbestad et al.(2017)recordthepresenceof Elliptocephala n. sp.and Kjerulfia n.sp.intheDuolbasgáissáFormationwithinthe Heliosphaeridiumdissimilare Skiagiaciliosa AcritarchZonesothatthisassemblagemostprobablyrepresentsthe Holmiakjerulfi GroupZone.ThespecimensdescribedbyNikolaisenandHenningsmoen(1990)fromthesame localitywastentativelyassignedbyEbbestad etal. (2017)to Kjerulfia n.sp.aswell.

stageequivalenttotheAmganontheSiberianPlatform(Brangulis1985;Mens etal.1990;Jankauskas 2002).Thisunit,however,isbasedontheKybartai Formation(Sakalauskas1966,1968)oftheAyschya GroupinwesternLithuaniaandtheadjacentKaliningradregionsothatthecorrectnameisKybartaian (althoughMens etal.1990usedthespelling ‘Kibartai Stage’).Nielsen&Schovsbo(2011)brieﬂydiscussed thecorrelationofthestage,relevantfortheposition ofthelower middleCambrianboundaryinScandinaviaandBalticaingeneralandplacedthebaseof themiddleCambrianatthetopofthestage,although intheEastBalticareathebaseofthetraditionalmiddleCambrianisdrawnatthebaseoftheoriginal KibartianStage(seealsoNielsen&Ahlberg2019). Nielsen&Schovsbo(2011)concludedthatearlier reportsofmiddleCambriantrilobitesshouldbe regardedasmisleadingandtentativelyassignedmost oralloftheir ‘Kibartian’ asofearlyCambrianage. Revisedconsiderationsarediscussedinthefollowing paragraphs.

Thecriticaltrilobiteswereusuallyreportedfrom whatiscommonlytermedthe ‘Protolenus Zone’ in PolandandtheBalticarea,whichisonlyfoundin thewesternpartoftheBalticBasin.TheKybartai Formation(originallytermedthe ‘KyrbartaiSuite’) correspondstothis ‘Protolenus Zone’.Remarkably,a considerablepartoftheformationconsistsofdark shaleswithinterbeddedsandstonehorizonsand glauconiticbedsthatarereminiscentoftheOelandicusbedsofÖlandandcouldberegardedasanear shoredevelopmentofthesestrata.Typicalso called

determinedas Ellipsocephalus cf. E polytomus and Strenuaevaprimaeva are figured(Brangulis1985,pl. 3, fig.aand б, в, г,respectively)andcomefroma drill coreatLiepāja,westernLatvia(fromdepths 1382.0and1449.5m,respectively).Thespecimens determinedas Ellipsocephalus cf. E polytomus isa cranidialfragmentofanellipsocephalinetrilobite andmayindeedbelongto Ellipsocephalus.Theother specimensarerenderedhereasundeterminableto genusandveryprobablybelongtoatleasttwodifferentspecies.Subsequentmentionsof Ellipsocephalus cf. E. polytomus Linnarsson,1877, Ellipsocephalus puschi Orłowski,1959, Strenuella(Comluella)samsonowiczi Orłowski,1964,and Strenuella(Comluella?)hypei fromtheKibartyanstageinEastBaltic drill coresbyBrangulis(1985),Mens(1981),Mens et al.(1990)andothersseemtobebasedonthesedata. TheVergalian RausvianRadzyń Formationofthe Podlyas BrestDepressionandLublinSlope(discussedabove)isoverlainbytheKostrzyń Formation (Lendzion1962)withoutareadilydetectablemajor hiatus.Thus,atleastthelowerpartoftheformation shouldbeaboutofKybartaianage.Therare findings oftrilobitesreportedfromthatformationinclude Ellipsocephaluspolytomus, Acadoparadoxidespinus andotherfragmentsofparadoxidinesaswellas solenopleuridremains,allindicatingasolidOelandicusStageage.ThisfaunaisaccordinglynotoftraditionalearlyCambrian(Kybartaian)age.

InLatvia,theKibartyanstageisrepresentedbythe TebrFormationinthewesternpartandbypartsof theTsirmstrataintheeasternpart. Strenuella (Comluella) insolita N.Tschernyscheva, S.(C.) samsonowiczi Orłowski, Strenuella (Comluella?) hypei Orłowski,and Ellipsocephalus? politomus Linnarsson (originalassignment)havebeenreportedfromthe TebrFormation, Strenuaevaprimaeva fromtheNadskaMemberoftheBentavFormation(VergaleStage) in Brangulis(1985,p.39, ﬁg.9).Specimens

‘kråksten’ (‘crowstone’)texturesarereportedfrom thebestknownsectionintheparastratotypeofthe Kybartai 22drill core(Korkutis1984).

Intercontinentalcorrelationbasedonpolymerid trilobitesfromthelowerCambrianofBaltoscandia ishamperedbytheirpronouncedendemism.The overwhelmingmajorityofthetrilobitespeciesare endemicandrestrictedtoBaltoscandia(Ahlberg et al.1986).However,eodiscoidtrilobites(Ahlberg 1984c;Axheimer etal.2007;Ahlberg etal.2007; Cederström etal.2009,2012,2014),bradoriids (DiesÁlvarez etal.2008)andhelcionelloidmolluscs (Ebbestad etal.2009;Cederström etal.2014; Høyberget etal.2015)mayhavepotentialforintercontinentalcorrelations.Particularlyimportantare thefewrepresentativesoftheEodiscoideaknown fromScandinaviaandfromotherCambriancontinents.Theseformsinclude:

TrilobitescleritesreportedfromtheKybartaiFormationandthe ‘Protolenus Zone’,respectively, include Ellipsocephalus sp.fromtheGargzdai 4drill coreofLithuania(depth2112.0m;seeKorkutis 1984,pl.2, fig.2),representedbyasmoothellipsocephalid(figuredupsidedownontheplate!), whichisdifficulttodeterminebutseemsindeedto beattributableto Ellipsocephalus andthuspointstoa middleCambrianageforthispartofthecore.In addition,Korkutis(1971,1984)reportsatrilobite describedas Strenuellainsolita N.Tschernyscheva in Korkutis1971fromthe Protolenus ZoneofthePavilostadrill coreofLatvia.Theoriginalphotoofthe cranidium(assignedhereasthelectotype)from depth1324.0minKorkutis(1971,pl.18, fig.1) showsthecharactersofanellipsocephaloidtrilobite withataperingandrelativelyelevatedglabellareminiscenttosomespeciesof Ellipsostrenua witharelativelyslenderanddistinctlytaperingglabella. Althoughmoreandbetterpreservedmaterialwillbe neededtoprovideareliablepictureofthespecies,it isclearthatitisnotconspecificwithanyoftheScandinavianspeciesof Ellipsostrenua.ThesamecranidiumisillustratedinKorkutis(1984,pl.1, fig.13)but indicatedtocomefromdepth1329.5mofthePavilostadrill core.Anincompletethoraxfromdepth 1307.0massignedto Strenuellainsolita aswell(in Korkutis1971,pl.18, fig.2)belongstoanellipsocephaloidtrilobite,butitremainsspeculative whetheritcanbeattributedtothesamespecies.The samespecimenwas figuredbyKorkutis(1984,pl.2, fig.1),butnowlistedtocomefromdepth1312.5m ofthePavilostadrill core.

Intercontinentalcorrelation

TheoverlyingDeymenaFormation(‘Deymena Series’ ofSakalauskas1966),whichwascorrelated withthebaseofthetraditionalmiddleCambrianin SwedenbyNielsen&Schovsbo(2011)andthus withtheOelandicusShale/lowestpartoftheAlum ShaleFormationconsistsoflight colouredsiliceous quartz areniteswithrareandthinintercalationsof bituminousshales(Sakalauskas1966;Korkutis1971, 1984).

1 Calodiscuslobatus,whichisrecordedfromthe GislövFormation,Scania(seeabove),theGärdsjönFormationinJämtland(Ahlberg1984c;Cederström etal.2009),Sweden,andtheEvjevik MemberoftheMjøsadistrict,Norway(Høyberget etal.2015);

FOSSILSANDSTRATA Ellipsocephalidtrilobites(Cambrian)fromScania,Sweden 13

4 Chelediscusacifer isaspecies ﬁrstdescribedfrom thePurleyShalesoftheNuneatonarea,Warwickshire,centralEngland(Rushton1966).Theassemblage,inwhich C.acifer wasfound,includes trilobitessuchas Cobboldites and Tannudiscus? balanus,correlativewiththe Geyerorodeshowleyi faunainAvalonianNewfoundland. C.acifer also occursinAvaloniansoutheasternNewfoundland, whereitisafaunalelementofthe Geyerorodes howleyi ZonesensuFletcher(Fletcher2003,2006) thatcorrelateswiththelowerpartofthe Morocconusnotabilis ZoneoftheMoroccanAtlas ranges.InScandinavia, C.acifer wasfoundinthe uppermostpartoftheTorneträskFormationof theLuobáktisection,Torneträskarea,northern SwedishLapland(Axheimer etal.2007).The assemblagewith C.acifer furtheryieldedspecies determinedas ‘Orodes?’ (nowreferredtoas

2 Luvsanodiscus cf. L. gammatus (Korobov,1980) fromnearthetopoftheGärdsjönFormationof Jämtland,Sweden(Cederström etal.2009);

1Thestratigraphicutilityof Calodiscuslobatus has beendiscussedinseveralpublications,including therangeofthespeciesinScandinavia(Ahlberg 1984c;Ahlberg&Bergström1993;Ahlberg etal. 2007;Cederström etal.2009),andelsewhere(e.g. Fletcher1972;Geyer1988;Blaker&Peel1997).In general, C.lobatus isadistinctrepresentativeofa discretesubglobal ‘temporalband’ characterised byatrilobiteassemblagewith Serrodiscusbellimarginatus, Triangulaspisannio, Hebediscusattleborensis andothers,recognizableinTaconic Laurentia,northernLaurentiaandLaurentian Newfoundland,westernandeasternAvalonia, WestGondwana,andSiberia(Robison etal.1977; Geyer2005). Calodiscuslobatus,however,hasalso beenrecordedfromstratathatareslightlyoreven distinctlyyounger,inareassuchastheTaconic regionofNewYorkState(Pagetides assemblage; Rasetti1967),theWelshBorderlandsofEngland (Protolenus LimestoneofComley;Hinz1987), andtheHighAtlasofMorocco(inthe Hupeolenus andpossibly Morocconusnotabilis zones;Geyer 1988;Geyer&Landing1995).Thisseemstoindicatethat C.lobatus hasalongstratigraphicrange (Landing1992;Cederström etal.2009).Analternativeinterpretationoftheapparentlydisjunct rangedifferencesof C.lobatus isthatthemorphologymimicsasinglespecieswithafairdegree ofplasticity,whereasinrealitydifferentspecies arelumpedtogether.Indeed,thetypical C.lobatus morphologycanbeseenasafeaturalcondition withinadevelopmentalseriessothatitmaybe seeninimmatureindividualsofotherspeciesof Calodiscus aswell,asin Calodiscusmeeki (Ford, 1876).

GärdsjönFormationattheFånånrivuletinJämtland,whereitco occurswith Calodiscuslobatus, Ellipsostrenuagranulosa andpygidialfragments whichweretentativelyattributedto Kootenia (Cederström etal.2009).Correlationwitha nearbysectionattheFånånrivuletthatalsoyields Ellipsostrenuagripi and E.linnarssoni indicates that Luvsanodiscus cf. L. gammatus doesnotoccur laterthanthesespecies,perhapsevenslightlyearlier(Cederström etal.2009, ﬁg.2)(Fauna5in Fig.4).TherecordfromJämtland,however,was basedonasingleimmaturecranidiumthatshows featuressimilartoimmaturespecimensof Hebediscus spp.aswell. Luvsanodiscusgammatus isa speciesdescribedexclusivelyfromlateearlyCambrianstrataofMongolia(Korobov1980).

3 Runcinodiscus cf. R. index Rushton in Bassett etal. 1976,fromtheTømtenMember,Mjøsadistrict, Norway(Ahlberg1983a;cf.Høyberget etal 2015);

2 Luvsanodiscus cf. L gammatus (Korobov,1980) hasbeenidentiﬁedfromtheuppermostpartofthe

3Aspecimendescribedas Weymouthianobilis by Kiær(1917,pl.3, ﬁg.12,12a,12b)hasbeen revisedanddeterminedas Runcinodiscus cf. R index byAhlberg(1983a). Runcinodiscusindex isa speciespreviouslyreportedonlyfromtheso calledProtolenusLimestoneofComley,Shropshire,England.TheProtolenusLimestone(now theupperpartofAc5 oftheComleyLimestone; Rushton2011)yieldsafaunathatcanbecorrelatedpreciselywiththe Morocconusnotabilis Zone oftheMoroccanAtlasrangesandcoevalstrata with Ovatoryctocaragranulata inwesternAvalonia.Asdiscussedindetailby,e.g.Geyer(1989), Geyer&Landing(1995,2004),Geyer&Peel (2011)andGeyer&Vincent(2015),thislevelis notonlycharacterisedbyanabundanceofellipsocephalidtrilobitesinWesternGondwana,but alsoyieldstheoldestspeciesof Acadoparadoxides inMorocco(Geyer&Vincent2015)sothatitfeaturesatypicalmiddleCambrianassemblagein theseareas.

14 Cederströmetal. FOSSILSANDSTRATA

Thebiostratigraphicsigniﬁcanceoftheseoccurrencesisbrieﬂydiscussedbelow.

4 Chelediscusacifer Rushton,1966,fromthetopof theTorneträskFormation,northernSwedishLapland(Axheimer etal.2007);and

5 Neocobboldia cf. N. dentata (Lermontova,1940), alsoknownfromthetopoftheTorneträskFormationinnorthernSwedishLapland(Axheimer etal. 2007;Cederström etal.2014).

Scanianlocalities

included.Nevertheless,Sundberg etal.(2016)indicatethatthefaunasofthetraditional Proampyx or ‘Ornamentaspis’ linnarssoni Zonemayindeedbe considerablyyoungerthanpreviouslyassumed.This isafﬁrmedbythedatadiscussedherein.Thepresenceof Kingaspidoides,althoughwithspeciesnot knownfromelsewhere,and Chelediscusacifer,as wellasthereinterpretationoftheKybartaian,clearly suggeststhattherevised Ellipsostrenuaspinosa and Dellingiascanica Kingaspidoideslunatus (and Chelediscusacifer)zonescorrelatewiththelower middleCambrianboundaryintervalelsewhere. Stratawith Dellingiascanica, Kingaspidoideslunatus and Chelediscusacifer canalmostcertainlybecorrelatedwiththe Hupeolenus ormoreprobablythe lowerpartofthe Morocconusnotabilis Zonein Morocco,i.e.itcanbecorrelatedwith Paradoxides bearingstrataandwouldthusbeofmiddleCambrianageaccordingtoBrøgger’s(1886)stratigraphic concept.Althoughthenamewaschosenbasedona wrongassumptioninbothstratigraphicandtaxonomicaspects,theoldterm ‘Protolenus Zone’ thus becomescorrectinabiostratigraphicrespect althoughno Protolenus (eveninbroadsense)is knownfromBaltica.

5Thefaunawith Chelediscusacifer fromthetopof theTorneträskFormationintheLuobáktisection, Torneträskarea,Lapland,alsoyieldedaneodiscoid assignedto Neocobboldia cf. N. dentata (Lermontova1940)byAxheimer etal.(2007)andCederström etal.(2014). Neocobboldiadentata isa characteristicandwidespreadspecies,knownfrom anumberofareasontheSiberianPlatformandthe Sayan AltayFoldbelt.InSiberia,thespeciesranges fromtheBotoman Bergeroniellusmicmacciformis Erbiella tothe Bergeroniellusasiaticus Zone.As emphasizedbyAxheimer etal.(2007),thematerial fromSwedishLaplanddiffersfromtypicalspecimensofSiberia(e.g.Pegel’ etal.2016,pl.11, figs13,16,17,20)inhavingasagittallylonger occipitalring,awider(sag.)anteriorborderand morepronouncedeyeridges.Severalotherdifferencescanbeidentified,andtheSwedishmaterial mayrepresentanewspeciesof Neocobboldia.Nevertheless,itsstratigraphicsignificanceforcorrelationisnotaffectedbecausewithitsfairlylong range N.dentata moreorlesscoverstheentirelife timeofallspeciesof Neocobboldia.Amajorproblem,however,arisesfromthefactthattheSiberian Botomanisregardedasolderthanthe Geyerorodes howleyi and Morocconusnotabilis zonesinAvaloniaandWestGondwana.

FOSSILSANDSTRATA Ellipsocephalidtrilobites(Cambrian)fromScania,Sweden 15

Dellingia?) lapponica, Strenuaevainﬂata, Neocobboldia cf. N dentata andapartialholmiidcephalonassignedto Holmia sp.(= Olenellus?sp.)by Axheimer etal.(2007).Thisassemblage(Fauna6 inFig.4)wasassigned(Axheimer etal.2007)to the ‘Ornamentaspis? linnarssoni Zone’ inthetraditionalsense,anditisdirectlyoverlainbyadistinctunconformitythatseparatestheTorneträsk FormationfromtheAlumShaleFormationina typicalfaciesdevelopment.Theco occurrenceof C.acifer and Dellingia? lapponica appearstore enforcethecorrelationwiththe Geyerorodeshowleyi ZoneinwesternAvalonia.However,thegenericafﬁliationof ‘Orodes?’ lapponica shouldbe revisedanditishereinquestionablyassignedto Dellingia.Materialofthisspeciespresentedby Axheimer etal.(2007)suggeststhatitmayrepresentanewundescribedgenus.

Morocconusnotabilis ZoneequivalentsinIberia andGermanyyield Acadoparadoxides aswell.The Hupeolenus and Morocconusnotabilis ZoneinMoroccoandequivalentsinWestGondwanaandAvaloniahaveanacmeofellipsocephaloidtrilobitesboth infrequencyanddiversity.Apossibleevengreater diversityofellipsocephaloidsinScandinaviawas plausiblyeradicatedbythesubsequenterosionof Kybartaian agestrataduetotheerosiveunconformitydistributedinmostofScandinavia.Asaconsequence,theearliestparadoxidinesofScandinaviain thelowerhalfofthe Acadoparadoxides/Baltoparadoxidesoelandicus Superzone(MossbergaMember ofÖland,Sweden)andatthebaseofthe Eccaparadoxidesinsularis Zone,onceregardedastheearliest representativesofthegroup,areinfactlatearrivals ratherthanearlybirds.

Thelocalitiesthatprovidecriticaldataforthisstudy (Brantevik,Forsemölla,Gislövshammar,Kvasa, Hardeberga,andtheAlmbackendrillcore)are brieﬂydescribedbelow.Brantevik,Forsemölla, GislövshammarandHardebergahavebeendescribed indetailinBergström&Ahlberg(1981)andAhlberg (1998),dataofwhicharepartlyupdatedandcomplementedherein.

Sundberg etal.(2016)recentlyattemptedacorrelationofthelateearly earlymidCambrianfaunas ofBaltica,exempliﬁedbyScandinaviandata,into otherCambriancontinentsinthecontextofthe searchforasuitablebaseandGSSPfortheCambrianSeries3andStage5.Thisstudywasbasedon publisheddataandhencetherevisedconceptsand additionaldataavailableforthisstudywerenot

16 Cederströmetal. FOSSILSANDSTRATA

Location. ThestratotypelocalityfortheGislöv Formation(Bergström&Ahlberg1981)islocated about1kmSWofthevillageofBrantevik(Figs2,5) and2530mSEofÖ.Nöbbelövchurch,Scania,on thetopographicalmapsheets1EÖrnahusenNVand 2ESimrishamnSV,andonthegeologicalmapsheets Aa109Simrishamnand2DTomelillaSO(WGS coordinates55°30′6.7″N,14°19′49″E).

Fig.6. Branteviksection:lithologicalsuccessionandstratigraphicaldistributionoftrilobitesandbradoriidarthropods(Beyrichonatinea). A filledbarrepresentsapreciselylocalized findofatleastonespecimen,andanopenbarindicatestheapproximatestratigraphicposition ofatleastonespecimen.BasedondeMarino(1980b, fig.3),Bergström&Ahlberg(1981, fig.5)andDiesÁlvarez etal.(2008, fig.2),with additionaldata.

theregionaluppermostlowerandbasalmiddleCambrianstrataareexposedattwooutcropsseparatedby adistanceofca.30m(seedetails in Calner etal 2013, ﬁg.16).Numerouslargebouldersfromthetop ofthesection(levelsE HinBergström&Ahlberg 1981, ﬁg.5)areeasilyrecognizedclosetothetype locality(Fig.6).

Characteristics. Thesectionisaccessibleonlyat extremelowtide.Thestratatraditionallyassignedto

Brantevik

Previouswork. Thesectionwas firstdescribedby Törnquist(1876,pp.45,46)andsubsequentlydealt withbyHolst(1892,pp.16 18),Grönwall(1902, pp.174 176),Hadding(1929,p.97;1932, fig.26; 1958,pp.69 71, figs47 50),Hansen(1937,pp.156,

Fig.5. LocationofsectionsstudiedintheGislövshammar(A)andBrantevik(B)areas,southeasternScania(seeFig.2).

Ellipsocephalidtrilobites(Cambrian)fromScania,Sweden

FOSSILSANDSTRATA

atthebase(levelGinBergström&Ahlberg1981, ﬁg.5).Severalattemptshavebeenmadetoextract phosphaticfossilsfromtheForsemöllaLimestone Bed(Bergström&Ahlberg1981;Streng etal.2006, 2008,2017).Thefaunacomprises,e.g.hyolithelminths,lapworthellids,linguliformeanbrachiopods, protoconodonts,andisolatedpalaeoscolecidsclerites.

Gislövshammar

Stratigraphicsuccession. Themajoroutcrop exposesca.90cmofstrataoverlyingtheRispebjerg SandstoneMember(Calner etal.2013, ﬁg.20). Theseareofvariablelithology,consistingofcalcareousquartzarenite(basal10cm),siltyshalestolaminatedsiltstones,andlighttodarkgrey,siltyand clayeylimestones(Fig.6).Thetopofthesectionis formedbytheForsemöllaLimestoneBed(‘fragment limestone’ or ‘trilobitecoquina’ ofearlierpublications)developedasmediumtodarkgreyphosphatic biocalcarenite(deMarino1980b;Bergström&Ahlberg1981;Calner etal.2013, ﬁg.21).

TheForsemöllaLimestoneBed(levelsG Hin Bergström&Ahlberg1981, ﬁg.5; ‘fragmentkalksten’ , ‘fragmentlimestone’ or ‘trilobitecoquina’)formsthe baseoftheAlumShaleFormationintheBrantevik Gislövshammararea.AtBrantevikitformsaca.20 cm thickunitconsistingofaphosphaticbioclastic limestonewithathin(2 3cm)glauconiticlimestone

LevelsEandFaredominatedbylimestonesandseparatedbyathin(5cm)siltymudstone.LevelEconsistsofa10 cm thick,lighttomediumgrey,silty biocalcarenitetobiocalcirudite.Aboveliesahitherto unrecognizedbarrenlayeroflaminatedmudstone. LevelFconsistsofadarkgreyglauconiticandphosphaticlimestone,whichistruncatedbyanerosional surfaceatthetop.LevelsEandFhaveyieldedthe followingtrilobites: Kingaspidoideslunatus, Dellingia scanica n.sp., Epichalnipsusbergstroemi n.sp. (‘Strenuaeva n.sp. ’ ofBergström&Ahlberg1981), E. rotundatus,and Ellipsostrenuasimrica n.sp. Organophosphatictubularfossilsreferredto Hyolithellus cf. H micans havealsobeenreported fromtheselevels(Bergström&Ahlberg1981).A bradoriidarthropod, Beyrichonatinea,wasdescribed fromlevelFbyDiesÁlvarez etal.(2008).

Trilobiteswerecollectedfromthelowerpartof theGislövFormation(levelsCandD;seeBergström &Ahlberg1981, ﬁg.5;Fig.6herein),butwerealso recoveredfromlooseboulders(levelsE HinBergström&Ahlberg1981, ﬁg.5).LevelC(30cm)has yieldedarichfaunawith Ellipsostrenuaspinosa, E. brevifrons n.sp.(Proampyx cf. P sularpensis inAhlberg&Bergström1978andBergström&Ahlberg 1981), E.linnarssoni,Cuneoaxiellagrandis and Calodiscuslobatus E.linnarssoni and C.grandis rangeupintotheoverlyinglevelD(ca.10cm).

157and179),Regnéll(1960, fig.6),Lindström& Staude(1971, fig.2),Vortisch&Lindström(1972, fig.1),Martinsson(1974,p.216),deMarino (1980b),Bergström&Ahlberg(1981),Ahlberg (1998),DiesÁlvarez etal.(2008)andÁlvaro etal. (2010).AdetailedmapisshowninCalner etal (2013, fig.16).

Location. TheGislövshammarsectionissituated alongtheshorearound600mNNEofthehamlet Gislövshammarandca.2900mSSEoftheÖ.Nöbbelövchurch,about600mNoftheharbourof Gislövshammar(topographicalmapsheets1EÖrnahusenNVand2ESimrishamnSV,geologicalmap sheetsAa109Simrishamnand2DTomelillaSO) (Figs2,5;WGScoordinates55°29′35″N,14°19′7.5″ E).

Fig.7. Gislövshammarsection:lithologicalsuccessionandstratigraphicaldistributionoftrilobites.BasedondeMarino(1980b, fig.4),Bergström&Ahlberg(1981, fig.8)andCederström etal (2012, fig.8B),withadditionaldata.Forlegend,seeFig.6.

Previouswork. TheGislövshammarsectionhas beendescribedbyMoberg(1899),Westergård (1929),Hansen(1937),Vortisch&Lindström(1972) andothers.Stratigraphiccolumnsfromthislocality havebeenprovidedbydeMarino(1980b),Bergström&Ahlberg(1981),Ahlberg(1998)andCederström etal.(2009).SeealsoNielsen&Schovsbo (2007,2011)andCederström etal.(2012).

irregularbeddingplaneswithfragmentedtrilobite sclerites(levelsE GinFig.7).Thetrilobitesrecoveredfromtheselimestonesinclude Epichalnipsus bergstroemi n.sp., E. rotundatus, Kingaspidoides lunatus, Dellingiascanica,and Ellipsostrenuasimrica n.sp.Thenon trilobitefaunafromtheselimestones includes,e.g. Hyolithellus cf. H micans and Magnicanalis sp.(Bergström&Ahlberg1981, ﬁg.8).

Characteristics. Relevantstrataofthetraditional ‘Ornamentaspis? linnarssoni Zone’ areeasilyaccessibleinthesectionabovethewaterline.Theupperpart ofthesection,representingthetraditional ‘Comluella? scanica Ellipsocephaluslunatus Zone’ (levelG inBergström&Ahlberg1981, ﬁg.8)is,however, accessibleonlyatverylowtide.Unfortunately,the lowerpartoftheGislövshammarsuccessionisoften coveredbystorm generatedsandoralgaldebris.

Kvasa

Stratigraphicsuccession. Thesectionexposesa prominentdisconformityattheuppersurfaceofthe RispebjergFormation,loadedwithphosphoritenodulesandrichinpyrite(seeHadding1929, fig.13; Lindström&Staude1971,pl.1, fig.6;seealsoCalner etal.2013, fig.19).TheGislövFormationhasa thicknessof +70cmandrestsontheRispebjerg Member.Thetopoftheformationisnotexposed, butcanbestudiedinlocalboulders.Theseboulders showthattheGislövFormationisdisconformably overlainbytheMiaolingianForsemöllaLimestone Bed(5cminthickness;Fig.7).IntheGislövshammardrillcore(Westergård1942,1944),theGislöv Formationissucceededbya0.4 m thicksuccession dominatedbyadarkgreen,thinlybeddedglauconitic andcalcareoussandstone.

18 Cederströmetal. FOSSILSANDSTRATA

Characteristics,previousworkandstratigraphy. Thesectionispresentlynolongeraccessible.A simpliﬁedstratigraphiccolumnispresentedinFigure8,largelybasedondatabyNathorst(1877), Grönwall(1902)andHadding(1958).TheGislöv FormationrestsdisconformablyontheRispebjerg Sandstoneandhasathicknessofca.1.4m.Itis Fig.8. Kvasasection:tentativelithologicalsuccessionandprobablestratigraphicaldistributionoffossils(=openbars).Basedon Nathorst(1877),Grönwall(1902)andHadding(1958).For legend,seeFig.6.

IntheGislövshammarsection,thebaseoftheformationconsistsofalightgrey,highlycalcareous, phosphorite bearingandpyritiferousquartz arenite (5 7cm)with Hyolithellus cf. H micans andbrachiopodsidentiﬁedas Magnicanalis sp.(Bergström &Ahlberg1981).Itisoverlainby10 12cmoflight greycalcilutitewithscatteredquartz grainsand greenish grey,clayeyandpyritiferouscalcareoussiltstone,fromwhich Ellipsostrenualinnarssoniand Cuneoaxiellagrandis havebeenidentiﬁed.Theoverlyingca.30cmsuccessionconsistofgrey,calcareous laminatedsiltstoneswithcarbonatenodulesinthe upperpart(levelsC DinFig.7).Thispartofthe successionhasyieldedhelcionelloidmolluscsanda trilobiteassemblagewith Holmia?sp., Cuneoaxiella grandis, Ellipsostrenuaspinosa, E brevifrons n.sp., E. troedssoni n.sp., E.linnarssoni and Calodiscuslobatus.Abovethisfairlytrilobite richunitfollowsca. 20 30cmofmediumgrey,siltyorclayeybiocalcarenitetobiocalcirudite,eithermassiveorwith

Location. TheKvasalocalityissituatedca.3km SEofS.Mellbychurch,ontheshore lineoftheBaltic Sea(Fig.2;WGScoordinates55°40′51″N,14°15′14″ E).

Cambrosaurura robusta Geyer n. sp...................73 Cambrosaurura bommeli Geyer n. sp.................77 Cambrosaurura? todraensis (Geyer, 1990) ........79 Genus Ellipsostrenua Kautsky, 1945.......................82 Ellipsostrenua gripi (Kautsky, 1945) ...................83 Ellipsostrenua linnarssoni (Kiær, 1917) .............87 Ellipsostrenua sularpensis (Ahlberg & Bergström, 1978) ...................................................92 Ellipsostrenua brevifrons n. sp. ............................96 Ellipsostrenua simrica n. sp. ...............................100 Ellipsostrenua sp. A .............................................103 Ellipsostrenua troedssoni n. sp. ..........................104 Ellipsostrenua granulosa 1984c) ......107 Ellipsostrenua spinosa (Ahlberg & Bergström, 1978) .................................................109 Genus Dellingia n. gen. ..........................................112 Dellingia scanica (Ahlberg & Bergström, 1978) .....................................................................113 Dellingia cf. D scanica (Ahlberg & Bergström, 1978) .................................................117 Subfamily Protoleninae Richter & Richter, 1948 ....119 Genus Cuneoaxiella n. gen. ...................................119 Cuneoaxiella grandis (Ahlberg & Bergström, 1978) AppendixReferencesAcknowledgements.....................................................................120.....................................................123....................................................................123......................................................................130

Cambrosaurura usitata (Geyer, 1990)................68

FOSSILS AND STRATA Number 67 • September 2022 Introduction .....................................................................2 Geological setting and stratigraphy ..............................3 Lithostratigraphy ........................................................3 Stratigraphic discontinuities and sequence stratigraphic signatures ..............................................5 Age and OntogeneticalScanianIntercontinentalStageÖlandCentralSwedishMjøsaScaniacorrelation.........................................................6............................................................................7area....................................................................8Caledonides..................................................8Sweden...........................................................9andGotland...................................................10subdivisionofthetraditional‘LowerCambrian’inBaltica....................................10Ljubomlian.................................................................10Vergalian–Rausvian..................................................11Kybartaian..................................................................11correlation........................................13localities...........................................................15Brantevik....................................................................16Gislövshammar.........................................................17Kvasa...........................................................................18Forsemölla..................................................................19Hardeberga................................................................20Almbacken.................................................................21andecologicalaspects.........................21Ontogenyandautecology........................................21 Epichalnipsus..........................................................23 Ellipsostrenua .........................................................23 Dellingia EllipsocephalidTrilobiteSynecology..................................................................24.................................................................24preservationandtaphonomy......................26morphologyanditsphylogeneticimplications...............................................................28Shapeofglabella........................................................28Patternoflateralglabellarfurrows.........................28Morphologyofpalpebrallobes...............................29Transversereliefofcranidium................................29 Sagittal convexity of preglabellar area....................30 Shape of genal spine .................................................30 Morphology of pygidium.........................................30 Phylogenetic implications........................................31 Systematic palaeontology .............................................31 Materials and methods .............................................31 Repository ..................................................................31 Class Trilobita Walch, 1771 .........................................31 Order Redlichiida Richter, 1932..................................31 Superfamily Ellipsocephaloidea Matthew, 1887 .......31 Family Ellipsocephalidae Matthew, 1887...................33 Subfamily Antatlasiinae Hupé, 1953 ..........................34 Genus Berabichia Geyer, 1990 ................................34 Berabichia baltica (Wiman, 1903) ..........................35 Subfamily Strenuaevinae n. subfam. ..........................37 Genus Strenuaeva Richter & Richter, 1940 ...........38 Strenuaeva primaeva (Brøgger, 1878) ................40 Strenuaeva inflata Ahlberg & Bergström, 1978 .........................................................................41 Genus Epichalnipsus Geyer, Popp, Weidner & Förster, 2004 ..............................................................42 Epichalnipsus anartanus Geyer, Popp, Weidner & Förster, 2004 ......................................43 Epichalnipsus bergstroemi n. sp. ..........................45 Epichalnipsus rotundatus (Kiær, 1917) ..............49 Epichalnipsus kullingi (Ahlberg & Bergström, 1978) .......................................................................53 Subfamily Ellipsocephalinae Matthew, 1887 .............54 Genus Kingaspidoides Hupé, emend. 1990b...........................................................................55Geyer, Kingaspidoides nordenskioeldi (Linnarsson, 1883) .......................................................................58 Kingaspidoides lunatus (Bergström & Ahlberg, 1981) .......................................................................62 Kingaspidoides? obscurus (Thorslund & Westergård, 1938) .................................................66 Genus Cambrosaurura Geyer n. gen. .....................67 Cambrosaurura usitata (Geyer, 1990)................68 Cambrosaurura robusta Geyer n. sp...................73 Cambrosaurura bommeli Geyer n. sp.................77 Cambrosaurura? todraensis (Geyer, 1990) ........79 Genus Ellipsostrenua Kautsky, 1945.......................82 Ellipsostrenua gripi (Kautsky, 1945) ...................83 Ellipsostrenua linnarssoni (Kiær, 1917) .............87 Ellipsostrenua sularpensis (Ahlberg & Bergström, 1978) ...................................................92 Ellipsostrenua brevifrons n. sp. ............................96 Ellipsostrenua simrica n. sp. ...............................100 Ellipsostrenua sp. A .............................................103 Ellipsostrenua troedssoni n. sp. ..........................104 Ellipsostrenua granulosa (Ahlberg, 1984c) ......107 Ellipsostrenua spinosa (Ahlberg & Bergström, 1978) .................................................109 Genus Dellingia n. gen. ..........................................112 Dellingia scanica (Ahlberg & Bergström, 1978) .....................................................................113 Dellingia cf. D scanica (Ahlberg & Bergström, 1978) .................................................117 Subfamily Protoleninae Richter & Richter, 1948 ....119 Genus Cuneoaxiella n. gen. ...................................119 Cuneoaxiella grandis (Ahlberg & Bergström, 1978) AppendixReferencesAcknowledgements.....................................................................120.....................................................123....................................................................123......................................................................130 ISSN print: 0300-9491 ISSN online: 2637-6032 This book is also available open access at Idunn. ISBN printed edition (print on demand): 978-82-15-06576-2 FOSSILS AND STRATA Number 67 • September 2022 Introduction .....................................................................2 Geological setting and stratigraphy ..............................3 Lithostratigraphy ........................................................3 Stratigraphic discontinuities and sequence stratigraphic signatures ..............................................5 Age and OntogeneticalScanianIntercontinentalStageÖlandCentralSwedishMjøsaScaniacorrelation.........................................................6............................................................................7area....................................................................8Caledonides..................................................8Sweden...........................................................9andGotland...................................................10subdivisionofthetraditional‘LowerCambrian’inBaltica....................................10Ljubomlian.................................................................10Vergalian–Rausvian..................................................11Kybartaian..................................................................11correlation........................................13localities...........................................................15Brantevik....................................................................16Gislövshammar.........................................................17Kvasa...........................................................................18Forsemölla..................................................................19Hardeberga................................................................20Almbacken.................................................................21andecologicalaspects.........................21Ontogenyandautecology........................................21 Epichalnipsus..........................................................23 Ellipsostrenua .........................................................23 Dellingia EllipsocephalidTrilobiteSynecology..................................................................24.................................................................24preservationandtaphonomy......................26morphologyanditsphylogeneticimplications...............................................................28Shapeofglabella........................................................28Patternoflateralglabellarfurrows.........................28Morphologyofpalpebrallobes...............................29Transversereliefofcranidium................................29 Sagittal convexity of preglabellar area....................30 Shape of genal spine .................................................30 Morphology of pygidium.........................................30 Phylogenetic implications........................................31 Systematic palaeontology .............................................31 Materials and methods .............................................31 Repository ..................................................................31 Class Trilobita Walch, 1771 .........................................31 Order Redlichiida Richter, 1932..................................31 Superfamily Ellipsocephaloidea Matthew, 1887 .......31 Family Ellipsocephalidae Matthew, 1887...................33 Subfamily Antatlasiinae Hupé, 1953 ..........................34 Genus Berabichia Geyer, 1990 ................................34 Berabichia baltica (Wiman, 1903) ..........................35 Subfamily Strenuaevinae n. subfam. ..........................37 Genus Strenuaeva Richter & Richter, 1940 ...........38 Strenuaeva primaeva (Brøgger, 1878) ................40 Strenuaeva inflata Ahlberg & Bergström, 1978 .........................................................................41 Genus Epichalnipsus Geyer, Popp, Weidner & Förster, 2004 ..............................................................42 Epichalnipsus anartanus Geyer, Popp, Weidner & Förster, 2004 ......................................43 Epichalnipsus bergstroemi n. sp. ..........................45 Epichalnipsus rotundatus (Kiær, 1917) ..............49 Epichalnipsus kullingi (Ahlberg & Bergström, 1978) .......................................................................53 Subfamily Ellipsocephalinae Matthew, 1887 .............54 Genus Kingaspidoides Hupé, emend. 1990b...........................................................................55Geyer, Kingaspidoides nordenskioeldi (Linnarsson, 1883) .......................................................................58 Kingaspidoides lunatus (Bergström & Ahlberg, 1981) .......................................................................62 Kingaspidoides? obscurus (Thorslund & Westergård, 1938) .................................................66 Genus Cambrosaurura Geyer n. gen. .....................67 Cambrosaurura usitata (Geyer, 1990)................68 Cambrosaurura robusta Geyer n. sp...................73 Cambrosaurura bommeli Geyer n. sp.................77 Cambrosaurura? todraensis (Geyer, 1990) ........79 Genus Ellipsostrenua Kautsky, 1945.......................82 Ellipsostrenua gripi (Kautsky, 1945) ...................83 Ellipsostrenua linnarssoni (Kiær, 1917) .............87 Ellipsostrenua sularpensis (Ahlberg & Bergström, 1978) ...................................................92 Ellipsostrenua brevifrons n. sp. ............................96 Ellipsostrenua simrica n. sp. ...............................100 Ellipsostrenua sp. A .............................................103 Ellipsostrenua troedssoni n. sp. ..........................104 Ellipsostrenua granulosa (Ahlberg, 1984c) ......107 Ellipsostrenua spinosa (Ahlberg & Bergström, 1978) .................................................109 Genus Dellingia n. gen. ..........................................112 Dellingia scanica (Ahlberg & Bergström, 1978) .....................................................................113 Dellingia cf. D scanica (Ahlberg & Bergström, 1978) .................................................117 Subfamily Protoleninae Richter & Richter, 1948 ....119 Genus Cuneoaxiella n. gen. ...................................119 Cuneoaxiella grandis (Ahlberg & Bergström, 1978) AppendixReferencesAcknowledgements.....................................................................120.....................................................123....................................................................123......................................................................130 let_v47_i67_cover.indd 1 202267STRATAANDFOSSILS 4STAGEAND2SERIESCAMBRIANFROMTRILOBITESELLIPSOCEPHALID FOSSILS AND STRATA Number 67 • September 2022 Introduction .....................................................................2 Geological setting and stratigraphy ..............................3 Lithostratigraphy ........................................................3 Stratigraphic discontinuities and sequence stratigraphic signatures ..............................................5 Age and OntogeneticalScanianIntercontinentalStageÖlandCentralSwedishMjøsaScaniacorrelation.........................................................6............................................................................7area....................................................................8Caledonides..................................................8Sweden...........................................................9andGotland...................................................10subdivisionofthetraditional‘LowerCambrian’inBaltica....................................10Ljubomlian.................................................................10Vergalian–Rausvian..................................................11Kybartaian..................................................................11correlation........................................13localities...........................................................15Brantevik....................................................................16Gislövshammar.........................................................17Kvasa...........................................................................18Forsemölla..................................................................19Hardeberga................................................................20Almbacken.................................................................21andecologicalaspects.........................21Ontogenyandautecology........................................21 Epichalnipsus..........................................................23 Ellipsostrenua .........................................................23 Dellingia EllipsocephalidTrilobiteSynecology..................................................................24.................................................................24preservationandtaphonomy......................26morphologyanditsphylogeneticimplications...............................................................28Shapeofglabella........................................................28Patternoflateralglabellarfurrows.........................28Morphologyofpalpebrallobes...............................29Transversereliefofcranidium................................29 Sagittal convexity of preglabellar area....................30 Shape of genal spine .................................................30 Morphology of pygidium.........................................30 Phylogenetic implications........................................31 Systematic palaeontology .............................................31 Materials and methods .............................................31 Repository ..................................................................31 Class Trilobita Walch, 1771 .........................................31 Order Redlichiida Richter, 1932..................................31 Superfamily Ellipsocephaloidea Matthew, 1887 .......31 Family Ellipsocephalidae Matthew, 1887...................33 Subfamily Antatlasiinae Hupé, 1953 ..........................34 Genus Berabichia Geyer, 1990 ................................34 Berabichia baltica (Wiman, 1903) ..........................35 Subfamily Strenuaevinae n. subfam. ..........................37 Genus Strenuaeva Richter & Richter, 1940 ...........38 Strenuaeva primaeva (Brøgger, 1878) ................40 Strenuaeva inflata Ahlberg & Bergström, 1978 .........................................................................41 Genus Epichalnipsus Geyer, Popp, Weidner & Förster, 2004 ..............................................................42 Epichalnipsus anartanus Geyer, Popp, Weidner & Förster, 2004 ......................................43 Epichalnipsus bergstroemi n. sp. ..........................45 Epichalnipsus rotundatus (Kiær, 1917) ..............49 Epichalnipsus kullingi (Ahlberg & Bergström, 1978) .......................................................................53 Subfamily Ellipsocephalinae Matthew, 1887 .............54 Genus Kingaspidoides Hupé, emend. 1990b...........................................................................55Geyer, Kingaspidoides nordenskioeldi (Linnarsson, 1883) .......................................................................58 Kingaspidoides lunatus (Bergström & Ahlberg, 1981) .......................................................................62 Kingaspidoides? obscurus (Thorslund & Westergård, 1938) .................................................66 Genus Cambrosaurura Geyer n. gen. .....................67