†family Tethyidae Gray 1867 (demosponge)
Parent taxon: Protomonaxonida according to R. M. Finks et al. 2004
Sister taxa: Choiidae, Halichondritidae, Hamptoniidae, Hazeliidae, Leptomitidae, Lobatospongia, Piraniidae, Sollasellidae, Takakkawiidae, Ulospongiellidae, Wapkiidae
Subtaxa: Tethya
Ecology: stationary intermediate-level epifaunal suspension feeder