Permoceras

Permoceras Temporal range: Lower Permian
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Cephalopoda
Subclass:	Nautiloidea
Order:	Nautilida
Superfamily:	Trigonocerataceae
Family:	Permoceratidae
Genus:	Permoceras Miller and Collinson (1953)

Permoceras, the sole member of the Permoceratidae, is a coiled nautiloid with a smooth, compressed involute shell, whorls higher than wide, earlier whorls hidden from view. The venter is rounded as are the ventral and umbilical shoulders, the flanks flattened. The siphuncle is ventrally subcentral. The suture, which is most characteristic, has a deep, narrow pointed ventral lobe and large, asymmetrical pointed lobes on either side.

Permoceras is included in the nautilid superfamily, Trigonocerataceae, and is derived from the Mississippian (L Carb) - Triassic Grypoceratidae. Permoceras was first identified in the Lower Permian of Timur in the East Indies and named by Miller and Collinson in 1953

Permoceras almost precisely resembles Pseudonautilus from the Upper Jurassic.

See also

• Nautiloid
  • List of nautiloids

References

• Kummel 1964; Nautiloidea-Nautilida, Treatise on Invertebrate Paleontology, Part K Nautiliodea, Geological Society of America and University of Kansas press
• Sepkoski, J.J. Jr. 2002. A compendium of fossil marine animal genera. D.J. Jablonski & M.L. Foote (eds.). Bulletins of American Paleontology 363: 1–560. Sepkoski's Online Genus Database (CEPHALOPODA)