The earliest cowries: the origin of cypraeoid gastropods

Cowries, the family Cypraeidae, form a diverse and conspicuous group of gastropods living in tropical to subtropical seas. Their shell is convolute (last whorl covers all previous ones) with a narrow, slit-like siphonate aperture bearing denticles (“teeth”). When extended, a large part of their shell surface is covered by a soft fleshy mantle. The earliest cowries were reported from the Upper Jurassic of Sicily: Cypraea tithonica and Cypraea gemmellaroi. Subsequently, these species had been assigned to various cypraeid genera. Examination of the type material of Cypraea tithonica reveals that this species represents a new genus: Coffeacypraea Nützel & Schneider. Cypraea gemmellaroi also belongs to this new genus and is potentially synonymous with Coffeacypraea tithonica. The Upper Jurassic caenogastropod genera Colombellina and Zittelia (family Colombellinidae) also have narrowly elongated siphonate apertures and are closely related to Cypraeidae but their shells are not convolute. The origination of Cypraeidae and Colombellinidae contributed considerably to the Mesozoic–Cenozoic caenogastropod radiation.