Holotype MZ VIII Mg 4246/1 from the Late Callovian (Mid Jurassic) of Łuków (block in glacial drift); lateral and apical view; white arrow indicate demarcation between protoconch and teleoconch.

Diagnoza

Protoconch ornamented with strong, opisthocyrtic axial ribs and  weak spiral lirae. Teleoconch ornamented with opisthocyrtic axial ribs and equally strong spiral ribs. Whorls of teleoconch flattened.

Porównanie

Most similar to C. antiquum but it differs in having the protoconch ornamented with convex axial ribs and spiral lirae. C. polonicum also has four spiral ribs on the teleoconch and their number remains stable during ontogeny.

Autekologia

Występowanie geograficzne

Only in type locality

Zasięg czasowy

Quenstedtoceras lamberti Zone, Late Callovian (Mid Jurassic).

Materiały muzealne

3 shells.

Literatura

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