Sinoceras

Sinoceras is an extinct genus of nautiloids from China included in the family Orthoceratidae that lived from the middle Ordovician until the Devonian. The type species, S. chinense, was originally described as a species of Orthoceras, but then moved by Shimizu and Obata to Sinoceras in 1935.

The shell of Sinoceras is like Michelinoceras in that it has a slender orthoconic shell but the camerae are shorter and septal necks proportionally longer, reaching nearly a third the camera length. The surface in some is marked either by very fine irregular striae or by sinuous transverse growth bands. Doubtfully distinct from Michelinoceras.