Distribution and microsculpture of limnadiidae,falsiscidae, and glyptoasmussiidae (Conchostraca) of the terminal Permian of Siberia

New data on the distribution of conchostracans in volcanogenic deposits of the terminal Permian of the Tunguska Syneclise (Vyatkian and Taimyrian stages of the Tatarian Series) are presented. Based on the SEM study of these conchostracans their minute ornamentation patterns are described: microsculpture of Eulimnadia consisting of pits and cells with rounded cells separated by flattened interspaces, cellular microsculpture of Limnadia with rounded cells separated by convex interspaces (family Limnadiidae), honeycomblike cellular microsculpture of Falsisca (new family Falsiscidae), and microsculpture of Loxomicroglypta (?) consisting of small uniform rounded cells separated by narrow convex or angular interspaces (family Glyptoasmussiidae). The diagnoses of the genera and species are emended.