Specimen NHMW 1867/0008/0037 a (original illustration from Laube, 1867, pl. 3, fig. 2) from Mid Jurassic of Balin in apertural view.

Diagnoza

The shell is low trochospiral, with asymmetrically convex coils widest near the abapical suture, the sutures are sunk. The initially very low coils increase rapidly in height. On the last coil, a subsutural concavity forms. There is no sculpture on the shell surface but e spiral striation emerges in areas with exfoliated external layer of the shell is partially removed. The transition to the ventral side is broadly rounded. The base is slightly convex with prosocline growth lines. The aperture is round with an adapical taper. The widened inner lip also covers the center of the base.

Porównanie

The specimens from Russia are a bit more robust than those from from Balin. Ataphrus acmon d’Orbigny, 1853 with which Laube (1867) equates this species, is significantly more massive, with a higher spire and there is no concavity under the adapical seam. Chrysostoma sturi Uhlig, 1878 has the last coil that increases more in width, a more pronounced seam and a flat callus that covers the entire center of the base.

Autekologia

Występowanie geograficzne

Russia and Poland.

Zasięg czasowy

Mid Jurassic.

Materiały muzealne

Material from Russia and two specimens from Balin (NHMW 1867/0008/0037a, b  and NHMW 1853/0038/0085).

Literatura

Gerasimov, P. A. 1992. Gastropody jurskich i progranichnych nizhnemelovych otlożenij Evropejskoj Rossii. 190 pp. Rossiyskaja Akademija Nauk, Moskva.

Gründel, J. 2012. Neubearbeitung der von Laube 1867 beschriebenen Gastropoden fauna aus dem mittleren Jura von Balin/Polen. Annalen des Naturhistorischen Museums in Wien. Serie A, 114, 193–288.

Laube, G. C. 1867. Die Gastropoden des braunen Jura von Balin. Denkschriften der kaiserlichen Akademie der Wissenschaften, 28, 1–28.