Pleuronautilus

Pleuronautilus is a Nautiloid genus; family Tainoceratidae, order Nautilida.

The shell is evolute, discoidal; whorl section subquadrade, flanks generally straight but may converge toward the venter. Inner flanks have course ribbing, outer have rows of nodes. Sutures have shallow ventral, lateral, and dorsal lobes. Its siphuncle is small and approximately central.