Alternative spelling: Anaspida
Full reference: S. W. Williston. 1917. The phylogeny and classification of reptiles. The Journal of Geology 25(5):411-421
Parent taxon: Reptilia according to O. W. M. Kuhn 1966
See also Alroy 2007, Carroll 1967, Carroll 1969, Carroll 1988, Daly 1973, Gauthier et al. 1989, Gauthier et al. 1988, Gow 1977, Haughton and Brink 1954, Heaton 1979, Lavina 1983, Lewis and Vaughn 1965, Olson 1966, Olson 1970, Peng et al. 2001, Roxo 1937, Sepkoski 2002, Stovall 1950, Thurmond and Jones 1981 and Williston 1917
Sister taxa: Amblyglossae, Anhomoiichnium, Apatomerus, Archaeosauria, Atremata, Chelydosauria, Cunichnoides, Dimetropus, Diplotremata, Dipnoa, Dolichobrachium, Dravidosaurus, Dravidosaurus blanfordi, Embolophorus, Enaliosauria, Eureptilia, Glauconia, Holosauria, Hyperosauria, Ichthyosaurus inexpectatus, Ischyrotherium, Isocampe, Kintneria, Lyognatha, Macelognatha, Metamosaurus, Monopnoa, Monotreta, Monozygocrotapha, Onychichnium, Oolithes, Ornithocephala, Pantestudines, Parareptilia, Pessopteryx arctica, Pessopteryx pinguis, Placodontomorpha, Plesiosaurus doedicomus, Poeciloglyptica, Polemarchus, Proganosauromorpha, Proreptilia, Prosauria, Protorosauria, Puercosaurus, Puercosaurus obtusidens, Rhamphosauria, Rhizodonta, Rhynchosauroidae, Saurichthys indicus, Saurophidia, Seps, Sillimanius, Squamata, Steropoides, Streptosauria, Svalbardosaurus, Svalbardosaurus crassidens, Testudinata, Theromorpha, Tocosauria
Subtaxa: Chelonomorpha
Ecology: