Archosauromorphs Temporal range: Lopingian - Holocene,[1] 254.7–0Ma PreꞒ Ꞓ O S D C P T J K Pg N
Mounted skeleton of a primitive archosauromorph (Trilophosaurus buettneri)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Clade:	Neodiapsida
Clade:	Archosauromorpha von Huene, 1946
Subgroups
†Prolacerta †Choristodera †Proterosuchidae †Protorosauria †Rhynchosauria †Trilophosauria Archosauriformes Pantestudines
Synonyms
Archelosauria?

Archosauromorpha (Greek for "ruling lizard forms") is an infraclass of diapsid reptiles that first appeared during the late Permian and became more common during the Triassic. It was defined by Jacques Gauthier, Arnold G. Kluge and Timothy Rowe (1988) as the group containing "archosaurs [i.e. Crocodylia, dinosaurs, birds, and several extinct orders] and all other saurians that are closer to archosaurs (s.s.) than they are to lepidosaurs (s.s.)" [i.e. tuataras, lizards, and snakes].^[2] In a later publication, Michel Laurin (1991) defined Archosauromorpha as the clade containing the most recent common ancestor of Prolacerta, Trilophosaurus, Hyperodapedon and archosaurs and all its descendants;^[3] David Dilkes (1998) formulated a more inclusive definition of Archosauromorpha, defining it as the clade containing Protorosaurus and all other saurians that are more closely related to Protorosaurus than to Lepidosauria.^[4]

Included in this infraclass are the groups Rhynchosauria, Trilophosauridae, Prolacertiformes and Archosauriformes. While superficially these reptiles vary in appearance (at one time they were even included in different subclasses – the trilophosaurs were considered euryapsids and the rhynchosaurs were considered lepidosaurs and were included in the same order as the tuatara), they are actually united by a number of small skeletal and skull-related details that suggest they form a clade that descended from a single common ancestor. Additional groups with uncertain phylogenetic position that are included in Archosauromorpha by some authors (and excluded from it by others) are Choristodera, drepanosaurs,^[4] thalattosaurs, ichthyopterygians, sauropterygians^[5][6][7] and turtles.^[8]

Of the taxa mentioned above, rhynchosaurs, trilophosaurs and prolacertiforms died out at or before the end-Triassic extinction. The choristoderans continued as a minor group until the Miocene, and the Archosauriformes were important factors in early Triassic environments before giving rise to the even more successful Archosauria.

Phylogeny[edit]

Below is a cladogram modified from the analysis by Sues (2003). It was provided with the original description of Teraterpeton. Like in other recent analyses, Prolacertiformes was recovered as polyphyletic, and was therefore replaced by Protorosauria.^[9]

The cladogram shown below follows the most likely result found by an analysis of turtle relationships using both fossil and genetic evidence by M.S. Lee, in 2013.^[10]

References[edit]

External links[edit]

• palaeos
• Paleofiles – lists taxa

Archosauromorphs Kingdom: Animalia Phylum: Chordata Class: Sauropsida Subclass: Diapsida   Major clades Archosauriformes Crurotarsi Pseudosuchia Avemetatarsalia Ornithodira Pterosauria Dinosauria   Rhynchosauria Basal rhynchosaurs Howesia Mesosuchus Noteosuchus Rhynchosauridae Rhynchosaurus Hyperodapedontidae Bentonyx Fodonyx Mesodapedon Otischalkia Stenaulorhynchus Hyperodapedontinae Ammorhynchus Hyperodapedon Isalorhynchus Supradapedon Teyumbaita   Protorosauria Basal protorosaurs Cosesaurus Fuyuansaurus Jesairosaurus Langobardisaurus Macrocnemus Malerisaurus Protorosauridae Aenigmastropheus Czatkowiella Protorosaurus Sharovipterygidae Sharovipteryx Tanystropheidae Amotosaurus Augustaburiania Dinocephalosaurus Gwyneddosaurus Protanystropheus Tanystropheus Tanytrachelos Drepanosauromorpha Hypuronector Kyrgyzsaurus  ?Longisquama Elyurosauria Vallesaurus Drepanosauridae Dolabrosaurus Megalancosaurinae Drepanosaurus Megalancosaurus   Other basal archosauromorphs Possible archosauromorphs Chelonii Choristodera  ?Helveticosaurus Indeterminate archosauromorphs Azendohsaurus Elachistosuchus Mecistotrachelos Prolacertoides Teraterpeton Trachelosaurus Trilophosauria / Trilophosauridae  ?Anisodontosaurus  ?Coelodontognathus Doniceps Spinosuchus Tricuspisaurus Trilophosaurus Variodens  ?Vitalia Prolacertidae Boreopricea Kadimakara Malutinisuchus Pamelaria Prolacerta Vritramimosaurus   Archosauriformes Proterosuchidae Ankistrodon Archosaurus Blomosuchus Chasmatosuchus Exilisuchus  ?Gamosaurus Kalisuchus Proterosuchus Tasmaniosaurus Vonhuenia Erythrosuchidae Chalishevia Erythrosuchus  ?Fenhosuchus Fugusuchus Garjainia Guchengosuchus  ?Jaikosuchus Shansisuchus Vjushkovia Uralosaurus Doswelliidae Ankylosuchus Archeopelta Doswellia Jaxtasuchus Tarjadia Vancleavea Euparkeriidae  ?Dorosuchus Euparkeria  ?Halazhaisuchus  ?Osmolskina  ?Wangisuchus Proterochampsia Proterochampsidae Barberenachampsa Proterochampsa Rhadinosuchidae Cerritosaurus Chanaresuchus Gualosuchus Rhadinosuchus Tropidosuchus Other basal taxa Arctosaurus Asperoris "Cinizasaurus" Collilongus Crosbysaurus Cuyosuchus Dongusuchus Energosuchus Eorasaurus Koilamasuchus Lucianosaurus Sarmatosuchus Scythosuchus Tecovasaurus "Teleocrater" Tsylmosuchus Uatchitodon Vjushkovisaurus Crurotarsi Phytosauria Phytosauridae Archosauria Brasileosaurus "Cryptoraptor" Jushatyria Protecovasaurus Razanandrongobe Sikannisuchus Smok Pseudosuchia Crocodilia Avemetatarsalia Pterosauria Dinosauria Aves   Related categories Archosaurs