Type species Trimorphoceras absolutum Ebbighausen, Korn, Bockwinkel 2010

Diagnosis. Shell shape pachyconic in juvenile and preadult, and a discoidal adult ; conch involute or subinvolute in juveniles and the adult stage, iumbilicus open at middle stages; venter rounded; aperture low or moderately high in the juvenile and preadult stage, high in adults; umbilical wall often flattened, umbilical shoulder narrowly rounded or subangular. growth lines very fine, concavo-convex rectiradiate, with subangular ventrolateral projection and deep ventral sinus; constrictions often present following growth lines. External lobe very narrow, parallel-sided, median saddle low; ventrolateral saddle broadly rounded; adventive lobe V-shaped, symmetric.