| Species | Arietites ligusticoides (KMENT) |
| Author | KMENT |
| Group | Arieten |
| Horizon | subsalinarius-horizon |
| Zone | rotiformis-zone |
| Stage | Lower Sinemur |
Description
The dimensions and ornamentation largely correspond to those of the "Arietites" ligusticus. Deviating from this
- the Wb lower,
- of the WQ broad oval, without the "crest" of the "A." ligusticus mentioned by WÄHNER (1890).
- the keel stronger, the secondary keels more indistinct,
- the ribs are less retroradiate, almost radial, especially at their beginning at the coiling suture.
- as the most distinct difference to A. ligusticus the ribs are less numerous.
On the basis of the width of the coils, the number of ribs and their course, KMENT clearly separated A. ligusticoides from A. ligusticus in 2000. The ammonite illustrated by WÄHNER (1890) on plate 46, fig. 10 was also placed with it.
Arietites ligusticoides is very small and rare.
* Description according to Kment (2000), supplemented
Compare
As already mentioned in the description of A. ligusticus, there are some discrepancies between the few new specimens and the two species described. The specimen shown here, for example, has few ribs (as is typical for the species), but a comb-like elevation of the coil near the navel. This is not observed on the holotype.
It is possible that it is only one, variable species.
Dimension
Dimensions at D= 24mm (according to Kment):
Nw % v. D: ca. 39%
Wh % v. D: ca. 35%
Wb % v. D: ca. 46%
Literature
- 1890 Arietites n.f. aff. ligusticus Cocchi (Canav.). – Wähner, S. 193, Taf. 46.10
- 2000 “Arietites” ligusticoides sp.n. – Kment S. 210, Taf. 3.15
