Archosauriformes

Crurotarsi is a clade of archosauriform reptiles that includes crocodilians and stem-crocodilians and possibly bird-line archosaurs too if the extinct, crocodile-like phytosaurs are more distantly related to crocodiles than traditionally thought. Prior to 2011, the group had invariably included only archosaurs closer to crocodilians than to birds and other dinosaurs. An equivalent term for the crocodilian side of the archosaur family tree is Pseudosuchia. This traditional definition of Crurotarsi assumed that phytosaurs were crown-group archosaurs and more closely related to crocodilians than

thumb|right|Rutiodon, one of the aquatic and superficially crocodile-like [[phytosaurs]] Thecodontia (meaning 'socket-teeth'), now considered an obsolete taxonomic grouping, was formerly used to describe a diverse "order" of early archosaurian reptiles that first appeared in the latest Permian period and flourished until the end of the Triassic period. All of them were built somewhat like crocodiles but with shorter skulls, more erect pose and usually somewhat lighter. The group includes the ancestors of dinosaurs, pterosaurs, and crocodilians, as well as a number of extinct forms that did not

Archosauriformes (Greek for 'ruling lizards', and Latin for 'form') is a clade of diapsid reptiles encompassing archosaurs and some of their close relatives. It was defined by Jacques Gauthier (1994) as the clade stemming from the last common ancestor of Proterosuchidae and Archosauria. Phil Senter (2005) defined it as the most exclusive clade containing Proterosuchus and Archosauria. Gauthier as part of the Phylonyms (2020) defined the clade as the last common ancestor of Gallus, Alligator, and Proterosuchus, and all its descendants. Archosauriforms are a branch of archosauromorphs which orig

Euparkeriidae is an extinct family of small carnivorous archosauriforms which lived from the Early Triassic to the Middle Triassic (Anisian). While most other early archosauriforms walked on four limbs, euparkeriids were probably facultative bipeds that had the ability to walk on their hind limbs at times. The most well known member of Euparkeriidae is the species Euparkeria capensis, which was named by paleontologist Robert Broom from the Karoo Basin of South Africa in 1913 and is known from several nearly complete skeletons. The family name was first proposed by German paleontologist Friedri

Sarmatosuchus is an extinct genus of archosauriform reptile found in sediments of Middle Triassic age and known from the single species Sarmatosuchus otschevi. It is one of the earliest stem-archosaur species known. The holotype and only specimen was found in lithified river deposits of the Donguz Formation exposed near the Berdyanka River, Orenburg region, Russia. The genus was originally included in the extinct family Proterosuchidae. However, later analysis by David Gower and Andrei Sennikov, the describing author, has removed it from the Proterosuchidae and designated it a basal archosauri

thumb|left|Extremely hypothetical life restoration Crosbysaurus is a genus of extinct archosauromorph that lived in the Late Triassic of Arizona, New Mexico, North Carolina, Texas, and Utah. It is known from the Chinle Formation and Dockum Group rock units from the southwestern United States. The type species is C. harrisae, and the only known material includes teeth. 11 specimens are known, each including a single tooth.

Lucianosaurus is an extinct genus of amniote of unknown affinities, known only from teeth. Initially described as a basal ornithischian dinosaur, subsequently reclassified as a member of the clade Archosauriformes of uncertain phylogenetic placement and later, taking into account the similarity of its teeth to the teeth of traversodontid cynodonts such as Dadadon (shared presence of teeth with sub-triangular crowns, enlarged denticles, and thecodont tooth implantation), as an amniote of uncertain affinities (though based on dissimilarities in gross morphology and geographic separation it is st

Vjushkovisaurus is an extinct genus of Middle Triassic archosauriform. It is known from the Anisian-aged Donguz Gorizont in Sol-Iletsk, Orenburg Oblast, Russia. The genus was named in 1982, with the type species being V. berdjanensis. Material has been collected in the Berdyanka II locality from a fossil assemblage called the Eryosuchus Fauna along the Berdyanka River, specifically in a sand-carbonate concretion in the upper part of the main river channel. Vjushkovisaurus is known only from the holotype PIN 2865/62 (formerly SGU 104/3871), a partial postcranial skeleton which consists of 12 pr

Kalisuchus ('Kali's crocodile') was a genus of basal archosauriform known from remains unearthed from the Arcadia Formation (Rewan Group) of the Early Triassic of the Crater, Southwest of Rolleston, south central Queensland, Australia. It was named after Kali, the Hindu goddess of destruction, a reference to the very fragmentary nature of its remains. The type species of Kalisuchus is K. rewanensis, which refers to the Rewan Group. The Arcadia formation is dated to the Induan age at the very beginning of the Triassic, making Kalisuchus one of the oldest archosauromorphs known in Australia.

Uatchitodon is an extinct genus of Late Triassic reptile known only from isolated teeth. Based on the structure of the teeth, Uatchitodon was probably a carnivorous archosauromorph. Folded grooves on the teeth indicate that the animal was likely venomous, with the grooves being channels for salivary venom. The teeth are similar to those of living venomous squamates such as Heloderma and venomous snakes. Uatchitodon and Microzemiotes are the earliest known potentially venomous reptiles.

Asperoris is an extinct genus of archosauriform reptile known from the Middle Triassic Manda Beds of southwestern Tanzania. It is the first archosauriform known from the Manda Beds that is not an archosaur. However, its relationships with other non-archosaurian archosauriforms are uncertain. It was first named by Sterling J. Nesbitt, Richard J. Butler and David J. Gower in 2013 and the type species is Asperoris mnyama. Asperoris means "rough face" in Latin, referring to the distinctive rough texture of its skull bones.

Tecovasaurus (te-KOH-va-SAWR-us) is an extinct Late Triassic amniote genus of unknown affinities, known only from teeth. It was initially described as a basal ornithischian dinosaur, subsequently reclassified as a member of the clade Archosauriformes of uncertain phylogenetic placement (Irmis et al. (2007), and later, taking into account the similarity of its teeth to the teeth of traversodontid cynodonts such as Dadadon (shared presence of teeth with sub-triangular crowns, enlarged denticles, and thecodont tooth implantation), as an amniote of uncertain affinities (Kammerer et al., 2012; thou