Strepsodiscus is an extinct genus of very primitive fossil snail-like molluscs from the early part of the Late Cambrian (Dresbachian Age) of North America. The coiled, slightly asymmetrical shells are about 3 cm in height. It is not known whether these are shells of gastropods (sea snails) or monoplacophorans, which are more primitive mollusks. Bouchet & Rocroi (2005) divide the Bellerophontoidea into 8 families listed Paleozoic molluscs with isostrophically coiled shells of uncertain position within Mollusca (Gastropoda or Monoplacophora)