Mollusc Species Composition in Shell Bearing Sites At Kalamatiya, Southern Sri Lanka

This paper discusses the mollusc species composition as revealed from the mid-late holocenecoastal shell bearing formations, which have not yet been widely considered. The primarygoal of the research was to study shell middens located in association with shell beds atKalamatiya in the southern Province. The range of species recorded from the site wasemployed as a criterion for define shell middens in the study. Excavation of a 1 m2 test unitwas employed to gather data while soil samples from each layer were sieved to obtain microremains. Total of 18 mollusc species recorded from the nine layers of a single site atKalamatiya (Named site 01) are discussed here.The most frequent species recorded was Meretrix sp. The layer six (shell midden) of site 01displays a greater species diversity within the site in comparison to low numbers identifiedbeneath layers. Layer six itself contained 12 species, i.e., Meretrix sp., Anadara sp., Donaxcuneata, Saccostrea sp., Cerithedia cingulate, Acavus heamestoma, Aulopoma hofmeisteri,Beddoma trifasiatus, Papyridea soleniformis, Eunaticina sp., and two unidentified bivalvespecies (nacreous and calcareous). Therefore it seems that none of the middens in theseformations is consisted of only one species. Total number of shells obtained from this layerwas 2,393, whereas 96.5% is Meretrix sp. and other 11 species share 3.5%. Species identifiedfrom other layers are Umbonium vestiarium, Oigospera polei, Lissachatina fullica, Tapessulcarius, Purpura persica and Cryptonatica operculata. In general, the shell bearing sitestend to produce a good approximation of the range of species indicating that the pre historicinhabitants gathered whatever was available. These species are from a wide range ofenvironments as littoral muddy sand, coastal sands, terrestrial and arboreal. Four of thespecies have one occurrence (n=1) while another four species appear less than eight innumber. Apart from building a taxonomical list, these data aid to study subsistence strategiesof prehistoric communities and reconstruct their environment. Further these data can be usedfor palaeo-environmental reconstructions as well.Keywords: Shells, Molluscs, Middens, Palaeo-environment