†family Thalassemydidae Zittel 1889 (turtle)
Parent taxon: Cryptodira according to O. P. Hay 1908
Sister taxa: Acichelyidae, Adocusia, Bashuchelyidae, Chelydra, Chelydroidea, Chelyzoon, Chitracephalus, Cryptoderinea, Durocryptodira, Galvechelone, Glyptopidae, Glyptopsidae, Indochelyidae, Kayentachelyidae, Kinosternoidae, Meiolanidae, Neusticemys, Panchelonioidea, Pantrionychia, Planetochelys, Platysternoidea, Selmacryptodira, Sichuanchelys, Testudinidae, Toxochelyidae, Trionychia, Trionychoidea, Xinjiangchelys
Subtaxa: Catapleura, Erquelinnesia, Idiochelys, Lytoloma, Osteopygis, Rhetechelys, Sontiochelys
Ecology: aquatic omnivore