Wikipedia
Tylomelania
Tylomelania is a genus of freshwater snails which have an operculum, aquatic gastropod mollusks in the family Pachychilidae.
A sister group (the closest relative) of Tylomelania is genus Pseudopotamis (2 species living on the Torres Strait Islands). Tylomelania and Pseudopotamis split in the Middle Miocene c. 19.5 Mya.