''Ribeiria'' is a genus of rostroconch mollusc with a pegma, once interpreted as an intermediate between helcionellids (such as ''

Anabarella ''Anabarella'' is a species of bilaterally-flattened monoplacophoran mollusc, with a morphological similarity to the rostroconchs. Its shell preserves evidence of three mineralogical textures on its outer surface: it is polygonal near the crest ...

'' and ''

Latouchella ''Latouchella'' is an extinct genus of marine invertebrate animal, that is considered to be a mollusk and which may be a sea snail, a gastropod. It is a helcionellid from the Tommotian epoch of what is now Siberia. Its tightly coiled, spiral ...

'') and primitive scaphopods (such as '' Pinnocaris'').

References

Prehistoric mollusc genera Fossils of the Czech Republic Letná Formation Paleozoic life of Ontario Paleozoic life of Alberta Paleozoic life of Quebec {{paleo-mollusc-stub