Alternative spelling: Diadectimorpha
Parent taxon: Cotylosauria according to M. Laurin and R. R. Reisz 1995
See also Colbert 1946, Gauthier et al. 1989, Gauthier et al. 1988, Haughton and Brink 1954, Hay 1930, Huene 1954, Kissel and Lehman 2002, Kuhn 1946, Kuhn 1966, Lewis and Vaughn 1965, Martens et al. 2005, Olson 1947, Price 1947 and Romer 1956
Sister taxa: Amniota, Archeria, Bathyglyptus, Captorhiniformes, Captorhinomorpha, Chamasaurus, Conodectiformes, Datheosauri, Diadectiformes, Diadectosauria, Gilmoreichnus, Gymnarthriformes, Labidosauria, Limnoscelia, Pantyliformes, Pantyloidea, Pareiasauriformes, Procolophonipus, Sauraviformes, Solenodonsauridae, Tomicosaurus, Trilophosauria, Varanopus
Subtaxa: Diadectidae Diadectoidea Limnoscelidae Limnoscelops Limnoscelops longifemur Millerinidae Tseajaiidae