Tripteroceroides

Tripteroceroides is a pseudorthocerid from the Lower Carboniferous belonging to the family Spyroceratidae. Pseudorthocerids are nautiloid cephalopods with expanded siphuncle segments included in the superorder Orthoceratoidea.
Tripteroceroides has a depressed, apically curved, straight shell with the under side flatter than the upper. Sutures have slight lobes as they cross the upper and lower sides, and saddles on either flank. The suture is subventral, with flared out necks and subcylindrical segments, sharply reduced in diameter at either end.