Molluscan Fauna from Klasies River, South Africa

Molluscan faunal remains from the main site at Klasies River, South Africa, provide evidence for the exploitation of marine shellfish by Middle Stone Age inhabitants during the Late Pleistocene. Samples from recent excavations provide a record of changes in the range and size of taxa represented in the cave deposits. Within the upper part of the sequence there is a marked decline in the quantity of marine shell per unit volume of excavated deposit. guela current. By contrast, P.pema (the brown mussel) was used as an indicator of relatively warmer waters since it is today distributed primarily on the southern and eastern coasts of southern Africa, associated with the Agulhas cur- rent. Voigt concluded that the Howiesons Poort deposits were associated with a warm interval since in this unit the brown mussel was relatively more abundant than the other (cold-indicator) species. This conclusion differs from the finding by Shackleton (1982), based on oxygen isotope ratios measured from a series of Klasies shell samples, that the Howiesons Poort corresponded to a relatively cold period. (At the time of final analysis of the molluscan samples, Voigt (pers. comm.) did not have access to Shackleton's results). The contradictory conclusions from these independent analyses need to be explained. Such ex- planation is necessary if the conclusion that the composi- tion of the samples reflects changing collecting practices and preferences is to be supported, and if the role of en- vironmental change is to be ruled out as a factor affecting availability.