Procymatoceras is a nautiloid cephalopod from the Middle Jurassic with a large, tightly involute, rapidly expanding shell.

Later, outer, whorls, and mature living chamber are flattened on the sides and venter.

Sutures have shallow ventral and dorsal lobes.

Probably gave rise to Cymatonautilus and is the likely ancestor of Cymatoceras and Paracymatoceras.

Procymatoceras has its origin in the earliest Nautilidae, in Cenoceras.