Specimen MZ.VIII Mg 4242/3 from Callovian (Mid Jurassic) of Łuków (block in glacial drift) in lateral view.

Diagnoza

Shell slender with slightly convex whorls. Protoconch 2  cylindrical with dome−shaped apex; sculptured with short collabral threads only by the adapical suture. Demarcation between protoconch and teleoconch well−developed. Teleoconch ornamented with numerous opisthocline ribs and weak spiral lirae.

Porównanie

The dome-shaped to subconical protoconchs of Bralitzia foersteri Gründel (1998) better fit the Rissoinidae then Iravadiidae. Moreover, the teleoconchs in the Iravadiidae have a predominant spiral sculpture, not an axial one as in B. obtusa.

Autekologia

Występowanie geograficzne

Europe; in Poland found only in Łuków.

Zasięg czasowy

Mid Jurassic; in Poland only Callovian.

Materiały muzealne

Three juvenile shells from Callovian of Łuków (block in glacial drift).

Literatura

Gründel, J. 1999. Truncatelloidea (Littorinimorpha, Gastropoda) aus dem Lias und Dogger Deutschlands und Nordpolens. Berliner Geowissenschaftliche Abhandlungen, Reihe E30, 89–119.

Hudleston,  W.H.  1892. British  Jurassic  Gasteropoda.  Gasteropoda  of  the  Inferior  Oolite. Part  16,  273–324.  Palaeontographical Society, London.

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

Lycett, J. 1850. Tabular view of Fossil Shells from the middle division of the Inferior Oolite in Gloucestershire.The Annals andMagazine of Natural History. Second series6, 27–425.