Dinosauriformes

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Dinosauriformes
Temporal range:
Middle TriassicPresent, 245–0 Ma
Marasuchus.JPG
Mounted skeleton of Marasuchus, an early dinosauriform
Scientific classification e
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Clade: Dinosauromorpha
Clade: Dinosauriformes
Novas, 1992
Subgroups

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.[1]

Etymology[edit]

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.

Phylogeny[edit]

Cladogram simplified after Nesbitt (2011):


Dinosauriformes

MarasuchusMarasuchus flipped.jpg


unnamed

SilesauridaeSilesaurus opolensis flipped.jpg


Dinosauria

OrnithischiaTriceratops liveDB.jpg


Saurischia

SauropodomorphaBarapasaurus DB.jpg



TheropodaMeyers grosses Konversations-Lexikon - ein Nachschlagewerk des allgemeinen Wissens (1908) (Antwerpener Breiftaube).jpg







References[edit]

  1. ^ Nesbitt, S.J.; Sidor, C.A.; Irmis, R.B.; Angielczyk, K.D.; Smith, R.M.H.; Tsuji, L.M.A. (2010). "Ecologically distinct dinosaurian sister group shows early diversification of Ornithodira". Nature. 464 (7285): 95–98. doi:10.1038/nature08718. PMID 20203608. 

Sources[edit]

  • Ezcurra, M.D. (2006). "A review of the systematic position of the dinosauriform archosaur Eucoelophysis baldwini Sullivan & Lucas, 1999 from the Upper Triassic of New Mexico", USA. Geodiversitas, 28 (4): 649-684.
  • Hutchinson, J.R. & Gatesy, S.M. (2000). "Adductors, abductors, and the evolution of archosaur locomotion". Paleobiology 26 (4): 734-751
  • Novas, F.E. (1996). "Dinosaur Monophyly". Journal of Vertebrate Paleontology 16 (4): 723-741.
  • Sereno, P.C. and Arcucci, A.B. (1994). "Dinosaur precursors from the Middle Triassic of Argentina: Lagerpeton chanarensis". Journal of Vertebrate Paleontology 13: 385-399.

External links[edit]