| Species | Megastomoceras stenoptychum (WÄHNER) |
| Author | WÄHNER |
| Group | Psiloceraten |
| Horizon | curviornatum-horizon |
| Zone | megastoma-Zone |
| Stage | Middle Hettangian |
Description
After a distinct nodule stage, numerous retroradiate low ribs begin, crossing the flanks in an s-shape and extinguishing near the external side. The larger the shells become, the more the s-shaped ribbing disappears. In general, all Storthoceras/Megastomoceras relatives have only very simple and straight ribs when old, often only hinted at. The cross-section of the coils is oval with flat flanks and a flattened outer side. The width of the coils is quite large. The species grows quite large.
* Description according to Wähner (1882), supplemented
Compare
The highly rectangular winding cross-section in combination with the s-shaped curved ribs is characteristic.
Dimension
Dimensions with D= 40mm
Nw % v. D: ca. 35%
Wh % v. D: ca. 38%
Wb % v. D: ca. 32%
Literature
- 1882 Aegoceras stenoptychum n.f. – Wähner S. 82, Taf. 20.2
- 1952 Storthoceras stenoptychum Wähner – Lange, S. 130, Taf. 16.1
