| Species | Euphyllites struckmanni NEUMAYR |
| Author | NEUMAYR |
| Group | Psiloceraten |
| Horizon | naumanni-horizon |
| Zone | calliphyllum-zone |
| Stage | Lower Hettangian |
Description
In E. struckmanni, after the strong nodule stage, a more or less strong corrugation of the shell sets in. This develops into a regular, coarse ribbing with increasing size. The ribs are straight and broad, slightly inclined forward and bend forward near the external side, where they almost extinguish. These beaded ribs often begin at the suture, so that the navel edge appears wavy.
Otherwise, the species shows the same characteristics as E. waehneri: irregular, sickle-shaped forward inclined accretion stripes, distinct constrictions on the inner coils, highly rectangular coil cross-section with distinctly flattened flanks and semicircular external side, conspicuously thick shell.
A species delimitation of both forms can be justified because no transitional forms have been found so far.
* Description according to LANGE 1952, supplemented
Compare
Identical in growth is Euphyllites wähneri, which is however unribbed. Euphyllites struckmanni is clearly distinguishable from all other ammonites in the lower Hettangian by its flat and strongly ribbed flanks.
Dimension
Dimensions at D= approx. 41mm:
Nw % v. D: ca. 39%
Wh % v. D: ca. 34%
Wb % v. D: ca. 24%
Literature
- 1897 Euphyllites struckmanni Neum. – WÄHNER S. 283, Taf. 22.4-5
- 1952 Euphyllites struckmanni (Neumayr) – LANGE S. 92, Taf. 11.2, Abb. 7
