NON-MARINE BIVALVES FROM THE MOSPYNE FORMATION (UPPER BASHKIRIAN) OF THE DONETS BASIN: TAXONOMY, PALEOECOLOGY, AND STRATIGRAPHIC SIGNIFICANCE

Remains of non-marine bivalves are widespread in the Carboniferous Donets Basin (Eastern Ukraine). The studies this group fauna important for stratigraphy, paleoecology and paleobiogeography. remains were found sediments Mospyne Formation; Carbonicola obtusa (Hind) Naiadites sp. roof shale g2 coal bed; Curvirimula trapeziforma (Dewar) C. tesselata (Jones) identified g12 bed, rectilinearis Trueman et Weir limax Wright siltstone below G12 limestone layer. upper part lower half Formation is attributed to Member, which probably corresponds lenisulcata Zone (Langsettian) Western Europe. limit member floor a thick sandstone bed 43 m boundary Member situated at pseudorobusta Zone, previously by M.T. Sergeeva as with fauna, distinguished between h61 bed. This zone communis Bivalves from layer lived shallow-water eutrophic freshwater or brackish lakes coastal accumulation lowland. These basins characterized significantly reduced aquatic organism assemblage hydrogen sulfide contamination silts and, possibly, bottom water column. Representatives genera these lakes. apparently led pseudoplanktonic lifestyle, attaching themselves various objects byssus. siltstones (Carbonicola) shallow-water, refreshed lagoon.