Bitaunioceras

Bitaunioceras Temporal range: Permian
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Cephalopoda
Subclass:	Nautiloidea
Order:	Orthocerida
Superfamily:	Orthocerataceae
Family:	Orthoceratidae
Subfamily:	Michelinoceratinae
Genus:	Bitaunioceras Shimizy & Obata, 1936

Bitaunioceras is a genus of Permian orthocerids with a gradually expanding, straight, orthodontic shell with straight transverse sutures and a small, subcentral siphuncle with straight tubular orthochromatic necks. The shell surface of Bitaunioceras has a few, shallow, rounded constrictions and numerous, unequal, prominent transverse wire-like lirae. Bitaunioceras species have been found in Texas in the United States, Coahuila in Mexico, Sicily, Timor, and the south Urals in Russia.

References

• Sweet, Walter C. 1964. Nautiloidea-Orthocerida. Treatise on Invertebrate Paleontology, Part K. Geological Soc of America, and Univ Kansas Press.