Hydrophiloidea, known as water scavenger beetles, is a superfamily of beetles. Until recently it included only a single family, the Hydrophilidae (water scavenger beetles), but several of the subfamilies have been removed and raised to family rank.[1] Hydrophiliidae remains by far the largest member of the group, with nearly 3,000 described species. The other families have no more than 400 species.[2] The Histeroidea are closely related and sometimes considered part of a sensu lato Hydrophiloidea.[1] The majority of the clade is aquatic, which is thought to be the ancestral ecology of the group, with some lineages like Sphaeridiinae becoming secondarily terrestrial. Modern representatives of the group first appeared during the Late Jurassic.[3]