Specimen NHMW 1867/0008/0014 a (original illustration from Laube, 1867, pl. 2, fig. 10) from Mid Jurassic of Balin in apertural view.

Diagnoza

Porównanie

The shell is highly trochospiral as for the genus. The coils are slightly asymmetrically convex with the greatest width near the abapical seam. A weak subsutural concavity forms on the final coil. The lines of growth are strongly prosocline and weakly prosocyrt by a slight adapical backward bend. The transition to the almost flat base is broadly rounded. The lines of growth on it run in a broad arc opisthocyrt. The aperture is round. The inner lip is widened in a callus and covers the middle of the base. Ataphrus halesus (d'Orbigny, 1853) and A. helius (d'Orbigny, 1853) have transitional flanks and the base with a a distinct edge. Ataphrus sp. 1 sensu Gründel 2003 has an early ontogenetic spiral sculpture, the transition to the base is more rounded and the subsutural concavity is clearer. Proconulus (P.) wagadensis Jaitly et al. 2000 has higher turns in relation to the width, the seam of the last coil sinks significantly, making the more rounded transition to the base above the seam visible.

Autekologia

Występowanie geograficzne

Balin

Zasięg czasowy

Mid Jurassic

Materiały muzealne

2 specimens:  NHMW 1867/0008/0014 and NHMW 1867/0008/0014a.

Literatura

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.