Gatunek typowy
Gymnothilda levata Schröder, 1995. Valanginian (Early Cretaceous), Wąwał near Tomaszów Mazowiecki, Poland.

Opis

Teleoconch broadly cone−shaped. Protoconch hyperstrophic, transaxial to weakly medioaxial, smooth or, in some species with adapical and abapical axial folds. Protoconch peristome with thickened outer lip. First teleoconch whorl with one to two spiral ribs. At least one of ribs changing into keel. Axial ribs present only on early teleoconch whorls, visible only on keel, or reduced. Microornamentation present only in some species and restricted to some places.

Synonimy

Zasięg czasowy

Valanginian (Early Cretaceous)

Literatura

Kaim, A. 2004. The evolution of conch ontogeny in Mesozoic open sea gastropods. Palaeontologia Polonica 62, 3–183.

Schröder, M. 1995. Frühontogenetische Schalen jurassicher und unterkretazischer Gastropoden aus Norddeutschland und Polen. Palaeontographica, Abteilung A238, 1–95.