Proterosuchidae Fossil range: Late Permian to Early Triassic
Chasmatosaurus, a derived proterosuchid.
Scientific classification
Class	Sauropsida
Subclass	Diapsida
Infraclass	Archosauromorpha
Order (Unranked)	Archosauriformes
Family	Proterosuchidae von Huene, 1914
Genera	See Taxonomy section.

Proterosuchidae (or Chasmatosuchidae) are an early, possibly paraphyletic, assemblage of basal archosauriformes whose fossils are known from the Latest Permian of Russia and the Early Triassic of southern Africa, Russia, China, Australia, and Antarctica. They were slender, medium-sized (about 1.5 meters long), long-snouted and superficially crocodile-like animals, although they lack the armoured scutes of true crocodiles, and in their skeletal features are much more primitive. Their most characteristic feature is a distinct down-turning of the premaxilla (the front of the upper jaw, which overhangs the lower jaw). the limbs are short and indicate a sprawling posture, like contemporary lizards but unlike most later archosaurs.

The Proterosuchids represent perhaps the earliest adaptive radiation of the archosaurs. They gave rise to the Erythrosuchidae some time in the Early Triassic.

Taxonomy Edit

• Infraclass Archosauromorpha
  • (unranked) Archosauriformes
    • Family Proterosuchidae
      • Archosaurus
      • Chasmatosaurus
      • Chasmatosuchus
      • Kalisuchus
      • Proterosuchus
      • Tasmaniosaurus

References Edit

• Benton, M. J. (2000), Vertebrate Paleontology, 2nd Ed.; (2004) 3rd edition Blackwell Science Ltd
• Carroll, R. L. (1988), Vertebrate Paleontology and Evolution, WH Freeman & Co.

External links Edit

• Proterosuchidae
• Proterosuchidae - list of species (Mikko's Phylogeny Archive)

Archosauromorphs

Primitive Archosauromorphs — Euparkeriidae • Erythrosuchidae • Proterochampsidae • Proterosuchidae • Choristodera • Prolacertiformes • Rhynchosauria • Trilophosauria Crurotarsi Archosaurs — Ornithosuchidae • Aetosauria • Phytosauria • Rauisuchia • Crocodylomorpha • Crocodilia Avemetatarsalia and Ornithodira Archosaurs — Scleromochlus • Pterosauria • Dinosauromorpha • Dinosauria • Ornithischia • Saurischia • Aves Avian Archosaurs — Avialae • Archaeopteryx • Confuciusornis • Ichthyornis • Enantiornithes • Hesperornithes • Neornithes • Paleognathae • Neognathae