| Species | Pseudaetomoceras castagnolai (COCCHI) |
| Author | COCCHI |
| Group | Arieten |
| Horizon | seebachi-horizon |
| Zone | megastoma-Zone |
| Stage | Middle Hettangian |
Description
The species is quite wide-branched and has a highly oval WQ, weakly rounded flanks and an extremely sharpened external side. A sharp keel is developed.
The strong ribs start slightly retroradiate at the navel edge, run in a forward open curve slightly retroradiate over the flanks to then turn strongly forward near the external side and end in the keel.
P. castagnolai occurs together with A. marmoreum, whereas P. abnormilobatus seems to occur mainly (or only?) in the next higher ammonite horizon with D. atanatense.
* Description according to Wähner (1886), supplemented
Compare
Characteristic for this species is the strong sharpening of the external side and the course of the ribs. A development from Alsatites doetzkirchneri via Pseudaetomoceras castagnolai to P. abnormilobatus can be seen, whereby the sharpening of the external side and the winding height constantly increase and the navel width decreases.
P. abnormilobatus also differs in having much straighter ribbing on the flanks.
Dimension
Dimensions with D= 76mm (according to Kment):
Nw % v. D: ca. 45%
Wh % v. D: ca. 29%
Wb % v. D: ca. 18%
Literature
- 1886 Arietites castagnolai Cocchi – Wähner S. 146, Taf, 37.3, 38.2-3
- 2000 Pseudaetomoceras castagnolai Cocchi – Kment S. 206, Taf. 3.2
