Early Eocene Caenogastropods (Mollusca, Gastropoda) from Haymana-Polatli Basin, Central Anatolia (Turkey): taxonomy and palaeoecology

This study describes 21 species of Caenogastropoda collected in the Macunköy section from the upper part of the Kırkkavak Formation (Haymana-Polatlı Basin, SW of Ankara). The known stratigraphical range of the studied species is consistent with an early Ypresian (early Eocene) age of the deposits, indicated by Cerithium puigcercosensis (Cossmann, 1897) n. comb. and Tympanotonos turris (Deshayes, 1833). This result supports previous biostratigraphic studies based on benthic foraminifers. Among the caenogastropods from the Macunköy section, two new species are described: Bellatara ankaraensis n. sp. and Vicinocerithium seni n. sp. Furthermore, Cerithium puigcercosensis n. comb. is described as a new combination. The gastropod assemblage of the Macunköy section indicates a mangrove-fringed, wet coastal ecosystem with euryhaline conditions, connected to coastal swamps and a delta system.