Strepsodiscus


Strepsodiscus is an extinct genus of very primitive fossil snail-like molluscs from the early part of the Late Cambrian of North America. The coiled, slightly asymmetrical shells are about 3 cm in height. It is not known whether these are shells of gastropods or monoplacophorans, which are more primitive mollusks.
Bouchet & Rocroi divide the Bellerophontoidea into 8 families listed Paleozoic molluscs with isostrophically coiled shells of uncertain position within Mollusca
Knight, et al., 1960 included this genus within the Cyrtolitidae, a paraphyletic or polyphyletic assemblage of proto-gastropods and Tergomyan molluscs. Strepsodiscus may be too primitive to be a true gastropod.

Species

Species within the genus Strepsodiscus are as follows: