Grypoceratidae

The Grypoceratidae is a family of lower Carboniferous (Mississippian) to Triassic coiled nautiloids included in the Trigonocerataceae with generally smooth, evolute to involute shells that have sutures with distinct ventral and lateral lobes.

Among the included genera are Grypoceras, Domatoceras, Epidomatoceras, Gryponautilus, Menuthionautilus, Stenopoceras, and Titanoceras.

The Grypoceratidae is thought to have its origin in the Centoceratidae, the primary family in the Trigonocerataceae, and to have given rise in the Permian to the Permoceratidae and in the Triassic to the Syringonautilidae.