Radiocarbon age determinations of fossil Margaritifera auricularia (Spengler) from the River Thames in West London

In the early 1900s shells of a large freshwater mussel, Margaritifera auricularia (Spengler), were discovered in calcreted gravel dredged from the channel of the Thames at several sites between Mortlake and Battersea in west London. These specimens were said to have been associated with Neolithic polished stone axes, supposedly as food remains. M. auricularia is now extinct in Britain, but it has been reported living in several large rivers in southern Europe although apparently not in recent years. Three radiocarbon dates of 4140±50, 4340±45 and 4860±40 bp have been obtained from Thames specimens, supporting a Neolithic age for these shells. The theory that the shells represent debris from imported human food is discounted and it is considered more likely that M. auricularia was actually living in the Thames in Neolithic times. Its extinction in Britain should be seen as part of a general recession during the Post-glacial, as revealed by fossil occurrences to the north and east of its present-day range.     

Some chronological implications of a fossil molluscan assemblage from a neolithic site at Brook,Kent, England

The later post-glacial history of a valley in the chalk escarpment near Brook, Kent, is described, based on molluscan stratigraphy, archaeological evidence and radio-carbon dating. Differences in size and colour banding, respectively, of fossil and living representatives of two species of land snails, Pomatias elegans (Müller) and Cepaea nemoralis (L.), are correlated with climatic change during the post-glacial period. The problems of the use of fossil shells of these species as samples for radiocarbon dating are discussed.     

A proposed zonation scheme for late-glacial and postglacial deposits using land mollusca

The shells of non-marine molluscs are common in many calcareous deposits of the kind frequently associated with archaeological sites. The study of these fossils has hitherto centred mainly on their value as environmental indicators, but it is clear that they can also be used as the basis of a simple biostratigraphical zonation system, of value especially for the period prior to about 5000 BP. Such a scheme is proposed below, applicable to southern Britain, and spanning the period of the Devensian late-glacial and of the Flandrian (Postglacial).