? Archosauromorpha | ||||||||||
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| Scientific classification | ||||||||||
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| Groups | ||||||||||
| Order Rhynchosauria Order Trilophosauria Order Prolacertiformes Order Choristodera? Plesion Archosauriformes Division Archosauria |
Archosauromorpha (Greek for "ruling reptiles form") are a diverse group or Infraclass of Diapsid reptiles that first appeared during the late Permian, but only became common during the Triassic. Included under this heading are Rhynchosauria, Trilophosauridae, Prolacertiformes, Archosauriformes, and, tentatively, the Choristodera. While superficially these reptiles are all pretty different (and indeed at one time were even included in different subclasses - the Trilophosaurs were considered Euryapsids, and the Rhynchosaurs lepidosaurs and included in the same order as the Tuatara - they are actually united by a number of small details in the skull and skeleton, which show that they form a monophyletic clade that descended from a single common ancestor.
Of the five taxa mentioned above, the first three died out at or prior to the end Triassic extinction, the Choristoderans continued as a minor group until the Miocene, and the Archosauriformes were important elements in early Triassic environments, before giving rise to the even more successful Archosauria.