†family Thalassemyidae Rütimeyer 1878 (sea turtle)
Parent taxon: Chelonioidea according to R. L. Carroll 1988
Sister taxa: Cheloniidae, Dermochelyoidae, Desmatochelyidae, Nichollsemys, Oxemys, Pancheloniidae, Pandermochelys, Plesiochelyidae, Protostegidae
Subtaxa: Padiochelys
Ecology: aquatic omnivore