| Species | Megastomoceras rahana (WÄHNER) |
| Author | WÄHNER |
| Group | Psiloceraten |
| Horizon | curviornatum-horizon |
| Zone | megastoma-Zone |
| Stage | Middle Hettangian |
Description
After a distinct nodule stage, strong, straight and retroradiate ribs begin to cross the flanks straight and bend forward near the external side and extinguish. From a diameter of about 50 mm, this forward bending is no longer visible. Sometimes secondary ribs may appear, which is quite characteristic of this species.
M. rahana has strongly flattened flanks and a closely rounded umbilical edge.
* Description according to Wähner (1883), supplemented
Compare
M. rahana differs from other related forms by strongly flattened flanks and the irregular ribbing.
Dimension
Dimensions with D= 50mm
Nw % v. D: ca. 45%
Wh % v. D: ca. 32%
Wb % v. D: ca. 23%
Literature
- 1883 Aegoceras rahana n.f. – Wähner S. 105, Taf. 321.1-4
