Revueltosaurus ("Revuelto lizard") is an extinct genus of suchian pseudosuchian from Late Triassic (late Carnian to middle Norian stage) deposits of New Mexico, Arizona and North Carolina, United States. Many specimens, mostly teeth, have been assigned to Revueltosaurus over the years. Currently, three species are included in this genus, all of which were originally thought to represent monospecific genera of basal ornithischian dinosaurs. It was 1 meter (3.3 feet) long. Species Revueltosaurus callenderi R. callenderi was named by Adrian P. Hunt in 1989 and it is the type species of the genus. The generic name honors its type locality, Revuelto Creek, Quay County of New Mexico. Revuelto is derived from Spanish revuelta, "revolution", in reference to the importance of the Late Triassic period for terrestrial vertebrate evolution. The specific name honours the director of the New Mexico Museum of Natural History Jonathan F. Callender. R. callenderi was originally described as a basal ornithischian on the basis of 32 teeth: the holotype NMMNH P-4957 a nearly complete premaxillary (incisiform) tooth, the paratypes (NMMNH P-4958-9, a nearly complete maxillary or dentary tooth crown with root and a nearly complete premaxillary tooth crown) and 28 referred specimens. All specimens were collected from the type locality, from the Bull Canyon Formation, dating to the Norian stage. Later, other teeth were described by Padian (1990), Kaye and Padian (1994) and Hunt and Lucas (1994), from Chinle Formation of Arizona. Andrew B. Heckert (2002) redescribed the genus in detail and named a second species, R. hunti on the basis of teeth described by Hunt and Lucas (1994). He referred MNA V3690, an isolated tooth assigned by Kaye and Padian (1994) to R. callenderi from the Placerias/Downs quarry near St Johns, Arizona, to Tecovasaurus. Heckert listed the referred specimens CMNH PR1697-1699 originally described by Padian (1990) and the topotypes NMMNH P-4960, P-16573, P-33783-798. Four teeth were referred to aff. Revueltosaurus callenderi (NMMNH P-17362, P-17382 and P-17187). R. callenderi is known to date only from the Revueltian (early-mid Norian, the type locality dates back to the early Norian) of Bull Canyon Formation (Dockum Group, New Mexico) and the Painted Desert of the Petrified Forest Member (Chinle Formation, Arizona). Parker et al. (2005) described several partially complete skeletons of R. callenderi (PEFO 33787-95), including a nearly complete and a partial skulls, from the Revueltosaurus Quarry, Petrified Forest National Park. Other skeletons were discovered from the Painted Desert, including the