Stereotoceras is a Middle and Upper Devonian genus in the oncocerid family Brevicoceratidae that formed a smooth, depressed, gyroconic shell with the dorsum much flatter that the venter.
Sutures are straight ventrally but have dorsal lobes.
Growth lines outline a ventral hyponomic sinus but are otherwise transverse.
The siphuncle in ventral, nummuloidal, with discrete, irregular, actinosiphonate deposits at the septal foramina.
This prehistoric cephalopod-related article is a stub.