| Species | Arietites ligusticus (COCCHI) |
| Author | COCCHI |
| Group | Arieten |
| Horizon | atanatense-horizon |
| Zone | marmoreum-zone |
| Stage | Upper Hettangian |
Description
The coils are much wider than high, the outer side strongly articulated. Already very
early, the keel, furrows and secondary keels are fully developed and give the species its characteristic appearance. The ribs start retroradiate at the coiling suture.
and then run in a wide arc over the flank to then merge strongly proradiatively into the secondary keels. They reach their greatest height at the highest point of the flank, which is shaped like a comb. The ribs are quite numerous.
The specimen shown does not quite correspond to those described so far. The ribs are straighter, the mentioned "crest" not so clearly developed. Because of the few specimens found so far, no statement can be made about the variability of this species.
Arietites ligusticus is very small and rare.
* Description according to KMENT (2000), supplemented
Compare
The species Arietites ligusticoides, newly described in 2000, was placed because a corresponding specimen is already illustrated and described by Wähner. The ribs are less numerous, the width of the coils smaller. The specimen illustrated here lies between these two species. Possibly they represent two extreme forms of a variable species.
It is difficult to confuse with Paracaloceras grunowi or Arietites subsalinarius; both species form keel and furrows much later. The WQ is also different when measured accurately.
Dimension
Dimensions with D= 25mm (according to Kment):
Nw % v. D: ca. 39%
Wh % v. D: ca. 34%
Wb % v. D: ca. 52%
Literature
- 1890 Arietites ligusticus Cocchi (Canav.). – Wähner, S. 191, Taf. 46.7-8
- 2000 “Arietites” ligusticus Cocchi – Kment S. 210, Taf. 3.14
