MAMMALIAN ASSEMBLAGES FROM LATE PLEISTOCENE SITES IN SUFFOLK SLATERFOUR & BOSWELL
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An analysis of the past habitats and palaeobiologies of each species was carried out and using this, the environmental conditions could be inferred. All the species found fit within what is termed the Mammuthus–Coelodonta Faunal Complex (Kahlke, 1999) and were capable of surviving in the cold, dry environment of what is described as ‘the mammoth steppe’ (Guthrie, 1990). The main evidence to support this comes from the presence of woolly mammoth, woolly rhino and reindeer at all four of the sites. These, combined with the other species that were found (spotted hyaena, cave lion, bison, horse and red deer) are all components of this faunal complex. The mammalian biostratigraphy of the Late Pleistocene was then examined in detail and based on the composition of the assemblages these four Suffolk sites were each found to correspond with the Pin Hole (Creswell Crags, Nottinghamshire) Mammal Assemblage Zone (MAZ), which dates to the period of the Middle Devensian known as Marine Isotope Stage 3 (MIS 3). The Pin Hole MAZ, dating between 60,000 and 26,000 BP is one of the best representation of the faunas of this time. The assemblage consists of woolly mammoth, woolly rhino, reindeer and bison, along with lion and spotted hyaena (Jacobi et al, 1998). The Pin Hole fauna can be viewed as a western extension of a Central Asian assemblage characteristic in the Late Quaternary. It indicates that extreme continental conditions of the ‘mammoth steppe’ reached Britain and the Atlantic seaboard. This cold, arid combination of steppe and tundra conditions was maintained by this distinctive community of species and has no modern analogue (Zimov et al., 2012). Upton Warren, in Worcestershire, also exhibits faunal remains contemporary with a Pin Hole assemblage. Lack of any trees such as birch Betula sps, pine Pinus spp and willow Salix spp in the pollen records here indicates an open, tundra environment and the presence of insects restricted to northern Russia and Scandinavia in the present day (Amara interstitialis, Dej. and Amara torrida, Ill.) infer colder climate conditions (Coope, 1962). MIS 3 represents the warmest part of the Last Glacial, though there were dramatic fluctuations in climate which occurred often at a decadal scale (Currant and Jacobi, 2011). However, modelled temperatures show that a typical ‘warm’ event would not have been warm relative to today: summer temperatures would have rarely exceeded 8–12°C, with winter temperatures falling to -8°C. Atmospheric circulation models over Europe project strong westerlies and the subsequent wind chill factor would have lowered temperatures further (Barron et al., 2003). Based on coleopteran assemblages, coldest months during MIS 3 could have plummeted to -27°C (Coope, 2002). These are therefore the conditions which are likely to have existed across Suffolk when the animals which are the focus of this study – the real counterparts of the famous woolly mammoth re-created in the Suffolk Wildlife Gallery of the Ipswich Museum – were alive and competing for survival.
Trans. Suffolk Nat. Soc. 50 (2014)