Rhynchonellata - Terebratulida - Cryptonellidae

Full reference: G. A. Cooper. 1953. Sponges, Brachiopoda, Pelecypoda, and Scaphopoda. Permian fauna at El Antimonio, western Sonora, Mexico. Smithsonian Miscellaneous Collections 119(2):21-80

Belongs to Heterelasma according to G. A. Cooper 1953

Sister taxa: Dielasma (Heterelasma) semitarium, Heterelasma angulatum, Heterelasma concavum, Heterelasma contortum, Heterelasma geniculatum, Heterelasma gibbosum, Heterelasma glansfagea, Heterelasma lenticularia, Heterelasma magnum, Heterelasma ngariensis, Heterelasma pentagonum, Heterelasma quadratum, Heterelasma shumardianum, Heterelasma solidum, Heterelasma sulciplicatum, Heterelasma venustulum

Type specimen: USNM 115507. Its type locality is USNM806f, Cerros de los Monos, El Antimonio, Sonora, which is in a Wordian marine limestone in the Antimonio Formation of Mexico.

Ecology: stationary epifaunal suspension feeder

Average measurements (in mm): shell 14.4 x 10.9