Xainzanoceras

Xainzanoceras is a genus of nautiloid cephalopods from the Upper Ordovician of China, assigned to the tarphyceratid family Lituitidae. The type, Xainzanoceras xaizangense Chen resembles the ophidioceratid genus Ophioceras. The shell is evolute, discoidal, serpenticonic; whorl section rounded, covered with thick, straight, close spaced, radial ribs that curve slightly forward at the ventral margin where they become quickly reduced or lost.

Xainzanoceras
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Cephalopoda
Subclass:	Nautiloidea
Order:	Tarphycerida
Family:	Lituitidae
Genus:	Xainzanoceras Chen, 1987

References

• Chen Ting Yan, 1987. Ordovician Nautiloids from Xainza: Nanjing Institute of Geology and Paleontology Series 11:133-191,1987.