The Salyan Formation (Upper Burdigalian-Lower Langhian) of K. Mara., Turkey contains thick-bedded deposits of oysters. Bioerosion structures found on the Early-Middle Miocene oyster specimens
Crassostrea gyrphoides (Schlotheim, 1813) from the Northwestern K. Mara. Basin area are much affected by the boring of micro-organisms. The borings, represented by three ichnogenera, are assigned
to Renichnus isp., Caulostrepsis isp., and Entobia isp. The activity of Clionid sponges, Polychaete worms and vermetid gastropods have also been observed.