| Species | Arietites semicostulatus REYNES |
| Author | REYNES |
| Group | Arieten |
| Horizon | rotiformis-horizon |
| Zone | rotiformis-zone |
| Stage | Lower Sinemur |
Description
The species is small-bodied, the coil cross-section round to highly oval. The body is involute and the flanks strongly convex. The innermost turn appears smooth or only very weakly ribbed, then waves and ribs appear, which can stand irregularly. The ribs run radially and are slightly curved forward. Near the external side they disappear and in good preservation continuing stripes can be seen crossing the venter. The ribbing may be more or less pronounced. Translated with www.DeepL.com/Translator (free version)
A faint raised keel can only be observed in very good condition.
Description according to Wähner (1884), supplemented
Compare
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Dimension
Dimensions with D= 20mm
Nw % v. D: ca. 45%
Wh % v. D: ca. 30%
Wb % v. D: ca. 35%
Literature
1884 Arietites semicostulatus Reyn. – Wähner, p. 212.
