Cymatoceratidae

Extinct family of molluscs

The Cymatoceratidae is a family of Mesozoic and early Cenozoic nautiloid cephalopods and the most abundant of their kind in the Cretaceous. They are characterized by ribbed, generally involute shells of varied forms - coiled such that the outer whorl envelops the previous one, as with Nautilus, and sutures that are variably sinuous.

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