Holotype MZ VIII Mg 4239/1 from the Callovian (Mid Jurassic) of Łuków (block in glacial drift); lateral and apical view.

Diagnoza

Teleoconch ornamented with axial ribs (approx. 16–17 per whorl) and 2–3 spiral ribs. Uppermost spiral rib (situated medially) keel-like, forming angulation of whorl. At body whorl, ornament only at adapical part of whorl. Base not demarcated by angulation of whorl, bearing two spiral ribs. Surface of teleoconch covered by densely packed fine lirae.

Porównanie

Differs from B. calloviana in having less distant axial ribs, larger size, and two spiral ribs on the teleoconch..

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.