| Species | Alpinoceras loki (WÄHNER) |
| Author | WÄHNER |
| Group | Alsatiten/Alpinoceraten |
| Horizon | seebachi-horizon |
| Zone | megastoma-Zone |
| Stage | Middle Hettangian |
Description
The shells are quite evolute and the WQ is wider than high for a long time. In adult specimens, however, the ratio can then be reversed in the end.
A broad, rounded keel with furrows and indicated secondary keels (Wähner speaks of "bulges") is formed very early. The keel is relatively low.
The flanks are only slightly arched, the ribs are strong and a little inclined forward (proradiate) and not as broad as the separating interspaces. The broad interspaces give the species a characteristic appearance. The ribs become weaker near the external side, bend forward there hardly noticeable and merge into the secondary "bulges".
* Description according to Wähner (1885), supplemented
Compare
Compared to the very similar Alpinoceras seebachi, the keel formation starts earlier and the navel width is smaller (the coils higher). The keel itself is wider than in A. seebachi. A. loki is much thicker than A. seebachi. In very small specimens, however, the risk of confusion is very high.
The specimen described by Kment (2000) is by no means an A. loki, because there is no keel with furrows, but rather a sharpening of the external side. It belongs to the Alsatites proaries family.
Dimension
Dimensions at D= 156mm (Wähner):
Nw % v. D: ca. 65%
Wh % v. D: ca. 19%
Wb % v. D: ca. 18%
Literature
- 1885 Arietites loki n.f. – Wähner S. 137, Taf, 17.1
- 1963 Arietites (Alsatites) loki Wähner – Blind S. 101, Taf. 3.5
- 2000 Alpinoceras loki Wähner – Kment S. 205
