Ophiceras

Ophiceras
Temporal range: Early Triassic (Scythian)
Scientific classification
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Subclass: Ammonoidea
Order: Ceratitida
Superfamily: Otoceratoidea
Family: Ophiceratidae
Genus: Ophiceras
Griesbach, 1880

Ophiceras is a smooth, evolute ceratitid ammonite from the Lower Triassic, with a rounded venter.

Diagnosis

The shell of Ophiceras evolute, whorls all showing, slowly increasing in height, and slightly embracing the previous. Umbilicus, wide and moderately deep. Surface ornamented with faint folds, which in some develop into coarse ribs in the mature growth stage, and transverse striae. Suture is ceratitic, lobes and saddles usually long and narrow. (Smith, 1932. Arkell, 1957)

Taxonomy

Ophiceras is included in the Ophiceratidae according to the American Treatise (Arkell, 1957) but was earlier placed in the Xenodiscidae in Smith (1932.

Five subgenera are recognzied. Ophiceras (Ophiceras), O. (Acanthophiceras), O. (Discophiceras), O. (Lytophiceras), O. (Metophiceras).

Ophiceras is the probably source of Flemingites , which it somewhat resembles.

References

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