New Species of Crassatellidae (Bivalvia) from the Middle Eocene of Ukraine

详细

Three new species of Crassatellidae: Crassatella ballista sp. nov., C. calva sp. nov., and Eucrassatella depulsoris sp. nov. from the Middle Eocene deposits of the western slope of the a quarry of the Ingulets Ore Mining and Processing Enterprise (Ingulets, Ukraine), which are correlated with the Lutetian Stage, are described. The study of valves of Crassatella parisiensis Orbigny, 1852 from the Middle Eocene deposits of the Parisian Basin has shown that it differs from the species C. illustris Berezovsky, 2004, which was previously described as a subspecies of C. parisiensis. The study of variation of Crassatellidae provided substantiation of the species rank of C. artacosta Berezovsky, 2004, which was previously described as a subspecies of C. densicostata Berezovsky, 1998.