Tainoceratidae

Tainoceratidae
Temporal range: Mississippian – Triassic
Scientific classification
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Order: Nautilida
Superfamily: †Tainocerataceae
Family: †Tainoceratidae
Hyatt, 1883

Tainoceratidae is a family of late Paleozoic and Triassic nautiloids that are a part of the order Nautilida, characterized by large, generally evolute shells with quadrate to rectangular whorl sections. Shells may bear ribs or nodes, or both.

The Tainoceratidae form the larger of the two branches of the Tainocerataceae derived from the Rutoceratidae around the end of the Devonian or early in the Mississippian (L Carb). The other is of the Koninckioceratidae which is confined to the Paleozoic. The Tainoceratidae on the other hand extend almost to the end of the Triassic and likely gave rise in the Early Permian to a small family, the Rhiphaeoceratidae.

The Tainoceratidae are contemporary with the Grypoceratidae, the dominant trigonoceratacean family, and with the Liroceratidae which dominate the Clydonautilaceae, all three of which have the same Carboniferous (L Miss) to Triassic range. Twenty-one genera are ascribed to the Tainoceratidae, of which 10 are confined to the Triassic while four cross into the Triassic from the upper Paleozoic. Seven are limited to the Paleozoic. Thus the Tainoceratidae is essentially a family of Triassic nautiloids, with some Paleozoic predecessors.

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