Taxonomy and biostratigraphy of the Pleistocene ostracods of the Western Black Sea Shelf

The Pleistocene ostracod fauna in the studied region of the Black Sea shelf is subsaline, represented mainly by species of the genera Candona, Amnicythere, Euxinocythere, Loxoconcha,Tyrrhenocythere. 53 taxa of the species group are described, 12 of them being new for the science. On the basis of this fauna three assemblage zones are divided: 1. Candona Zone (Early PleistoceneTchaudinian); 2. Cryptocyprideis bogatschovi Zone (Middle Pleistocene - Oldeuxinian); 3. Loxoconcha lepida Zone (Late Pleistocene- Neoeuxinian). The first zone is characterized dominantly by subgeneric and species variability of g. Candona. The second is divided on the basis of the presence of species of g. g. Amnicythere, Euxinocythere and Loxoconcha. The third, uppermost zone is distinguished by an association of transite species with marked predominance in quantitative respect of Loxoconcha lepida or Loxoconcha gibboides.