Oligocene gastropods

Planorbis is a genus of air-breathing freshwater snails, aquatic pulmonate gastropod molluscs in the family Planorbidae, the ram's horn snails, or planorbids. All species in this genus have sinistral or left-coiling shells.

Clavilithes is an extinct genus of fossil sea snails, marine gastropod mollusks in the family Fasciolariidae, the tulip snails and spindle snails.