''Ophiceras'' is an

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of smooth, evolute

ceratitid Ceratitida is an order that contains almost all ammonoid cephalopod genera from the Triassic as well as ancestral forms from the Upper Permian, the exception being the phylloceratids which gave rise to the great diversity of post-Triassic ammon ...

ammonite Ammonoids are extinct, (typically) coiled-shelled cephalopods comprising the subclass Ammonoidea. They are more closely related to living octopuses, squid, and cuttlefish (which comprise the clade Coleoidea) than they are to nautiluses (family N ...

s from the

Griesbachian The Induan is the first age of the Early Triassic epoch in the geologic timescale, or the lowest stage of the Lower Triassic series in chronostratigraphy. It spans the time between 251.9 Ma and 249.9 Ma (million years ago). The Induan is someti ...

(

Early Triassic The Early Triassic is the first of three epochs of the Triassic Period of the geologic timescale. It spans the time between 251.9 Ma and Ma (million years ago). Rocks from this epoch are collectively known as the Lower Triassic Series, which ...

), with a rounded venter. Fossils of the genus have been found in Armenia, Azerbaijan, China, Greenland, and India.''Ophiceras''
at

Fossilworks Fossilworks was a portal which provides query, download, and analysis tools to facilitate access to the Paleobiology Database, a large relational database assembled by hundreds of paleontologists from around the world. History Fossilworks was cr ...

.org

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.

Taxonomy

''Ophiceras'' is included in the

Ophiceratidae The Ophiceratidae is a family in the ammonoid order Ceratitida from the Lower Triassic, previously included in the Otocerataceae but now placed in the Noritiaceae as revised. The Ophiceratidae produced sepenticones with compressed elliptical who ...

according to the

Treatise on Invertebrate Paleontology The ''Treatise on Invertebrate Paleontology,'' published from 1953–2007 by the Geological Society of America and the University of Kansas, then 2009–present by the University of Kansas Paleontological Institute, is a definitive multi-authore ...

, but was earlier placed in the

Xenodiscidae The Xenodiscidae are the earliest of the Ceratitida and comprise Middle and Upper Permian genera characterized by compressed, discoidal, evolute shells with rounded to acute venters and commonly with lateral ribs. Sutures are goniatitic to weakly ...

. Five subgenera are recognized (in brackets): ''Ophiceras'' (''Ophiceras''), ''O.'' ('' Acanthophiceras''), ''O.'' ('' Discophiceras''), ''O.'' ('' Lytophiceras''), ''O.'' ('' Metophiceras''). ''Ophiceras'' probably gave rise to ''

Flemingites ''Flemingites'' is an extinct genus of evolute ammonoid from the Smithian (Lower Triassic) with spiral ridges on the shell. Diagnosis The shell of ''Flemingites'' is evolute so that all whorls show externally. Whorls are robust, slightly embr ...

'', which it somewhat resembles.

References

{{Taxonbar, from=Q18357742 Otoceratina Ceratitida genera Triassic cephalopods Early Triassic ammonites Triassic animals of Asia Ammonites of Asia Triassic Armenia Triassic Azerbaijan Triassic China Triassic India Fossils of Armenia Fossils of Azerbaijan Fossils of China Fossils of India Fossil taxa described in 1880 Induan life