†Altadema cryptocarina Mazaev 2003 (snail)
Full reference: A. V. Mazaev. 2003. The family Orthonemidae (Gastropoda) from the Middle and Upper Carboniferous of the central part of the Russian Plate. Ruthenica 13(2):89-100
Belongs to Altadema according to A. V. Mazaev 2003
Sister taxa: Altadema altadema, Altadema convexa, Altadema lira
Type specimen: PM RAS 4471/76/18, a shell
Ecology: epifaunal
Average measurements (in mm): shell 6.00 x 2.40