Tripteroceras, the type genus, named by Hyatt (1884) is characterized by a small, straight or slightly exogastric shell with a broad, depressed triangular cross section.

The venter, underneath, is flat, the dorsum, above, broadly rounded with a median ridge or keel and lateral angles acute.

Allumettoceras, from the Middle and Upper Ordovician of North America and northern Europe, is similar to Tripteroceras except the siphuncle which starts off suborthochoanitic becomes cyrtochoanitic with subspherical segments in the later growth stages.

The siphuncle, located between the center and ventral margin, is cyrtochoanitic; segments are expanded within the chambers and have faint annulosiphonate deposits lining the septal openings.

Rasmussenoceras, named by Foerste (1932); a tripteroceratid from the middle and upper Ordovician of North America and Greenland with a broadly lenticular section and sharp lateral angles, in which the ventral siphuncle is suborthochoantitic to orthochoantitic with segments only slightly expanded into the chambers.