Holotype ZPAL Ga.9/262 from the Mid Bathonian (Mid Jurassic) of Gnaszyn in lateral and apical view.

Diagnoza

Shell broadly cone-shaped, 1.6 times as high as broad. Protoconch almost medioaxial, with adapical and abapical axial folds. Teleoconch starting with two prominent and one subsutural spiral rib. Medial rib becoming keel on first teleoconch whorl. Number of  spiral ribs stable on known whorls of teleoconch. Spiral ribs crossed by weakly prosocline axial ribs (62–63 ribs per whorl). Surface of teleoconch covered by spiral microornamentation.

Porównanie

This species has characters typical of Carinathilda (e.g., presence of the keel and spiral microornamentation) but simultaneously also has a medioaxial protoconch. This feature is more typical for Promathildia and Mathilda. Probably represents an intermediate form between Promathildia and Carinathilda and is ancestral to the keeled species of Gymnothilda with medioaxial to transaxial protoconchs.

Autekologia

Występowanie geograficzne

Only in type locality.

Zasięg czasowy

Morrisiceras morrisi Zone, Mid Bathonian (Mid Jurassic).

Materiały muzealne

One shell.

Literatura

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