Rhynchonellata - Terebratulida - Cryptonellidae

Full reference: G. H. Girty. 1908. The Guadalupian fauna. United States Geological Survey Professional Paper 58:1-651

Belongs to Heterelasma according to G. A. Cooper and R. E. Grant 1976

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

Type specimen: USNM 118587a, a shell (Articulated shell)

Ecology: stationary epifaunal suspension feeder

Average measurements (in mm): shell 7.02 x 5.99