| Species | Vermiceras (Epammonites) cordieri (CANAVARI) |
| Author | CANAVARI |
| Group | Arieten |
| Horizon | atanatense-horizon |
| Zone | marmoreum-zone |
| Stage | Upper Hettangian |
Description
The sculpture is characteristic for this species: the keel formation starts very early, with deep furrows and narrow, high secondary keels. The sharp, high ribs start at the seam, run mostly radial and straight over the flanks and reach their greatest height at the outer bow. There they turn sharply forwards and merge into the secondary keels. The ribs do not form nodes at the point of bending, as can occur in other arietitides described by WÄHNER from Enzesfeld.
The cross-section of the coils is round to oval when young, highly oval when old and the flanks are flattened.
Bulging ridges are formed on the innermost coils, reminiscent of a nodule stage.
* Description according to KMENT (2000), supplemented
Compare
"Arietites" ophioides D'ORBIGNY also occurs alpine and is most similar.
The ribs, however, are more numerous and the double keels not quite as strong. All in all, A. ophioides is smaller. In V. (E.) cordieri the innermost convolutions are already strongly keeled with furrows, whereas in A. ophioides they have only a weak keel.
Vermiceras (Epammonites) cordieri is also somewhat similar to other vermicerates from the Gyrophioceras group. There, however, a clear nodule stage is present, the ribs are lower and the external side is not so strongly keeled.
The already mentioned keel formation, which starts very early, makes V. (E.) cordieri unmistakable.
Dimension
Dimensions with D= 50mm:
Nw % v. D: ca. 58%
Wh % v. D: ca. 24%
Wb % v. D: ca. 19%
Literature
- 1890 Arietites cordieri Canavari – WÄHNER S. 250, Taf. 47.1-4, 48.1-7
- 2000 Vermiceras (Epammonites) cordieri Canavari – KMENT S. 209, Taf. 3.20
