Arnioceras

Arnioceras
Temporal range: Early Jurassic
Arnioceras acuticarinatu
Scientific classification
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Subclass: Ammonoidea
Order: Ammonitida
Superfamily: Psilocerataceae
Family: Arietitidae
Genus: Arnioceras
Hyatt, 1897
Species
  • A. falcaries
Wikimedia Commons has media related to Arnioceras.

Arnioceras is an extinct genus of large, evolute, discoidal ammonite from the Lower Jurassic. The shell is normally coiled so that all whorls are exposed. Sides bear strong sharp ribs that are straight until reaching the ventrolateral edge where they swing forward and fade. The rim (venter) is keeled and free of grooves.

Arnioceras, named by Alpheus Hyatt, is included in the arietitid family of the Psilocerataceae, an ammonitid supefamily. Its distribution is fairly worldwide, having been found in Europe, south Asia, and North and South America.

References

This article is issued from Wikipedia - version of the 10/4/2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.