Abstract
Review was made for the Tarkhanian and Chokrakian representatives of the family Amathinidae. Two genera were defined—Leucotina and Carinorbis. The species L. ventosa (Bajarunas, 1910), L. belskayae (L. Iljina, 1993), L. costata sp. nov., L. excussa sp. nov., L. ovata sp. nov. and L. ovatoides sp. nov. were described in a composition of the genus Leucotina. L. ventosa is known from the undoubted Tarkhanian and continues to live in the Chokrakian, whereas the rest species were collected from the Chokrakian only. Relationships between the species of Leucotina remain unclear, although they can be divided into several morphological groups. It is concluded that a Chokrakian biodiversity of the genus is result of earlier (Tarkhanian) prehistory of Leucotina. Genus Carinorbis is represented by the rare and juvenile shells, which occur in uppermost Tarkhanian and in lower Chokrakian. The shells were determined as a species C. clathrata (Philippi). A proposal was made that Carinorbis not had a reproducing population in the Eastern Paratethys, but its founds is a result of bringing of the larvae from the neighboring bassins (Central Paratethys or Mediterranean).