Specimen MZ VIII Mg 4243/1 from the Callovian (Mid Jurassic) of Łuków (block in glacial drift), in lateral and apical view,

Diagnoza

Smooth protoconch of about three whorls. First 1.5 whorls  nearly planispiral. Teleoconch whorls with weak concavity under adapical suture, enhanced growth lines and numerous spiral lirae, present also on base. Umbilical chink present. Inner lip with concave columellar area.

Porównanie

Similar to B. obtusa and differs only in lacking the distinct axial ribs and the continuous transition from the protoconch to the teleoconch.

Autekologia

Występowanie geograficzne

Europe; in Poland found only in Łuków (block in glacial drift).

Zasięg czasowy

Mid to Late Jurassic; in Poland only Callovian.

Materiały muzealne

Material from Europe and one incomplete shell (MZ VIII Mg 4243/1) from Łuków, Poland.

Literatura

Gründel, J. 1998a. Archaeo− und Caenogastropoda aus dem Dogger Deutschlands und Nordpolens. Stuttgarter Beiträge zur Naturkunde, Serie B (Geologie und Paläontologie) 260, 1–39.

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