Nautilida

Nautilida is an order of nautiloid cephalopods derived from the Oncocerida, with a range extending from the Devonian to Recent. Five superfamilies, Tainocerataceae, Trigonocerataceae, Clydonautilaceae, Aipocerataceae, and Nautilaceae, and some 22 families are involved.

Shells are mostly coiled, some simply curved, with various ornament. Coiling varies from gyroconic, with whorls not in contact, to evolute with all whorls exposed but in contact, to involute with the final whorl enclosing the earlier.