Biostratigraphical distinction of interglacial coleopteran assemblages from southern Britain attributed to Oxygen Isotope Stages 5e and 7

Beetle assemblages are described from 14 interglacial sites in southern England, all of which post-date the Hoxnian Interglacial (in the broad sense) and which can safety be attributed to Oxygen Isotope Stages 5e and 7. The beetle faunas from these interglacial deposits are large and complex and together include at least 387 named species many of which are no longer found living in the British Isles. Almost all of the latter have modern geographical distributions exclusively to the south of Britain and some are predominantly Mediterranean. A few have their nearest relatives living today in North Africa or as far away as northern India. Some of these temperate beetle assemblages are remarkably similar to one another especially in their inclusion of diagnostic exotic species. Others., though indicative of a temperate climate, exhibit consistent differences so that the 14 assemblages clearly divide themselves into two groups; Group (a) and Group (b). based on differences in their species composition and abundance. Group (a) beetle faunas, from seven sites, may be termed classic Ipswichian (Eemian) since they closely resemble the assemblage from the type site at Bobbitshole near Ipswich and have unimpeachable stratigraphical contexts. All of these faunas can with confidence be attributed to an early phase of Oxygen Isotope Sub-Stage 5e. Group (b) beetle faunas, also from seven sites, are very different in their specific composition and are more of a puzzle because they include some fossil assemblages from deposits that have. in the past, been attributed to the latter part of the Ipswichian Interglacial and others that are undoubtedly from stratigraphical deposits that are earlier than the Ipswichian and which have been correlated with Oxygen Isotope Stage 7. It is with the deposits yielding Group (b) faunas that the greatest controversy arises. On-line appendix available at http://www.elsevier.com/locate/quascirev. (C) 2001 Published by Elsevier Science Ltd.