Dinosauriformes

Dinosauriformes Temporal range: Middle Triassic–Present, 245–0 Ma PreЄ Є O S D C P T J K Pg N
Mounted skeleton of Marasuchus, an early dinosauriform
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Clade:	Dinosauromorpha
Clade:	Dinosauriformes Novas, 1992
Subgroups
†Marasuchus †Nyasasaurus †Saltopus †Silesauridae Dinosauria †Ornithischia †Ornithopoda †Thyreophora †Marginocephalia Saurischia †Sauropodomorpha Theropoda

Dinosauriformes is a clade of archosaurian reptiles that include the dinosaurs and their most immediate relatives. All dinosauriformes are distinguished by several features, such as shortened forelimbs and a partially to fully perforated acetabulum, the hole in the hip socket traditionally used to define dinosaurs. The oldest known member is Asilisaurus, dating to about 245 million years ago in the Anisian age of the middle Triassic period.

Dinosauriformes was coined in 1992 by F.E. Novas, who used it to include the herrerasaurs, which he did not consider members of Dinosauria proper. Contrary to Novas, most paleontologists since 1992 have considered herrerasaurs to be true dinosaurs, though many other primitive, dinosaur-like reptiles fall within his definition of Dinosauriformes. Dinosauriformes fall within the clade Dinosauromorpha.

Cladogram simplified after Nesbitt (2011):

†Marasuchus

†Silesauridae

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