Holotype ZPAL Ga.9/257 from the Valanginian (Early Cretaceous) of Wąwał in lateral and apical view

Diagnoza

Shell  elongate, 1.39 as high as broad. Protoconch almost transaxial, ornamented  withadapical and abapical axial folds. Protoconch half-immersed in teleoconch. Teleoconch starting with two prominent spiral ribs and about twelve spiral lirae. Later in ontogeny, number of lirae and their strength increasing. Whorls angulated with two keel-like spiral ribs crossed by opisthocline axial ribs (about 68–69 per whorl).

Porównanie

This carinate mathildid can be classified as Carinathilda, especially from the lineage which leads to the genus Gymnothilda as it has a medial keel, a transaxial protoconch, and spiral lirae resembling the spiral microornamentation of the carinathildids. It is classified under Mathilda because its teleoconch begins with spiral ornamentation composed of numerous elements and it has a keel-like medial rib, similar to that of some Late Cretaceous, e.g., M. pentalira Dockery, 1993, and Recent mathildids, e.g., M. sansibarica Thiele, 1925.

Autekologia

Występowanie geograficzne

Only in type locality.

Zasięg czasowy

Sample D1, Busnardoides campylotoxus Zone, Early Valanginian (Early Cretaceous.

Materiały muzealne

One shell from the type locality.

Literatura

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