Grypoceratoidea Hyatt 1900

Superfamily Grypoceratoidea Hyatt, 1900 Diagnosis Superfamily of the suborder Domatoceratina with a discoidal, subinvolute to evolute conch. Whorl profile usually inverted trapezoidal with a distinct ventrolateral shoulder and a distinct umbilical margin. Derived species show a variation of modifications including a concave venter, a skid-like ventrolateral shoulder and an angular umbilical margin. Whorl overlap extremely small to moderate. Sculpture in most species lacking, in some species with short lateral ribs or ventrolateral nodes. Septa simply domed; suture line strongly dependent on the whorl profile, usually with broadly rounded lobes and narrowly rounded or subangular saddles (from Korn 2025). Included families Grypoceratidae Hyatt, 1900; Domatoceratidae Miller & Youngquist, 1949; new family to be described by Korn & Hairapetian (in press). Remarks A discussion of the Grypoceratoidea has been given by Korn (2025).