Wikipedia
Melanopsidae
Melanopsidae, common name melanopsids, is a family of freshwater gastropods in the clade Sorbeoconcha. Species in this family are native to southern and eastern Europe, northern Africa, parts of the Middle East, New Zealand, and freshwater streams of some large South Pacific islands.
These snails first appeared in the Late Cretaceous and are closely related to Potamididae. As well as unidirectional evolutionary change from one species to the next over time, the process of hybridization plays a major role in the appearance of new Melanopsidae species.
According to the taxonomy of the Gastropoda by Bouchet & Rocroi (2005) the family Melanopsidae has no subfamilies.