| Species | Megastomoceras euptychum (WÄHNER) |
| Author | WÄHNER |
| Group | Psiloceraten |
| Horizon | curviornatum-horizon |
| Zone | megastoma-Zone |
| Stage | Middle Hettangian |
Description
The cross-section of the windings is oval, still flat-oval in small specimens, but quite thick in larger ones. The flanks and outer side are then strongly curved.
The numerous ribs run radially to very slightly retroradiate over the flanks, bending quite strongly forward, quickly weakening and uniting externally "in a strip convex towards the front".
The lobe line is strongly slit, quite typical for Megastomoceras.
M. euptychum is found very rarely.
* Description according to Wähner (1882), supplemented
Compare
The closest to this species is Megastomoceras stenoptychum, which also has flattened flanks when old. However, the ribbing is very similar.
M. stenoptychum is a little narrower forked.
Other megastomoceras are more wide-nibbed and less numerous.
Dimension
Dimensions with D= 45mm
Nw % v. D: ca. 38%
Wh % v. D: ca. 36%
Wb % v. D: ca. 27%
Literature
- 1882 Aegoceras euptychum n.f. – Wähner S. 83, Taf, 20.3-5
