Recent and Ancient Death-assemblages of Molluscs in Lakes Eğirdir and Beyşehir (SW Anatolia, Turkey)

Abstract

In the summer of 2000 samples of beach deposits on the shore of Lake Eğirdir were collected. Subsequently, in August 2002, further samples were taken from a sequence exposed near Lake Beyşehir that was composed of carbonatic and gyttja layers containing abundant aquatic molluscs; these were dated to the end of the Middle Pleistocene. Species identification was made difficult by the fact that anatomical studies could not be made, and also because the taxonomy of Turkish molluscs still suffers from the effects of the once widespread habit of identifying Anatolian species as similar European species. The latter difficulty is well on the way to be resolved.<br />For much of the Middle-Upper Pleistocene and Holocene, Lake Eğirdir had characteristics similar to those of the large Beyşehir-Suğla Basin: a piedmont location enclosed by mountain ranges, large size and north-south orientation, maximum depth of about 15 m, variable water level and nutrient concentration (occasionally becoming a large pond), and probable increases in salinity. The qualitative and quantitative study of both malacofaunas, together with taphonomic observations on the shells,gave deeper insight into the formation processes of natural lacustrine shell accumulations and certain aspects of zooarchaeological interest, improving our understanding of such phenomena.