Archosauria (lit. ' ruling reptiles ') or archosaurs (/ ˈ ɑːr k ə ˌ s ɔːr / [3]) is a clade of diapsid sauropsid tetrapods, with birds and crocodilians being the only extant representatives.

archosaur, (subclass Archosauria), any of various reptiles, including all crocodiles and birds and all descendants of their most recent common ancestor.

Archosauria (the "ruling reptiles") is a major group of diapsids, differentiated from the other diapsids by the presence of single openings in each side of the skull, in front of the eyes (antorbital fenestrae), among other characteristics.

Gauthier redefined the Archosauria as a crown group, the last common ancestor of birds and crocodiles and all of its descendants: crocs + rocs. Generally speaking, this nomenclature has stuck. Above Archosauria were the Erythrosuchidae and other forms previously referred to as "Proterosuchia."

True archosaurs (the Archosauria proper), including the major stem groups Pseudosuchia (the crocodilians and their relatives) and the Ornithosuchia (the birds and their relatives) evolved yet more new features. The fifth toe in the foot, homologous with your "pinky toe" was reduced in size.

2010年3月12日 · Crown group Archosauria, which includes birds, dinosaurs, crocodylomorphs, and several extinct Mesozoic groups, is a primary division of the vertebrate tree of life. However, the higher-level phylogenetic relationships within Archosauria are poorly resolved and controversial, despite years of study.

2017年4月12日 · Birds and crocodylians, which are each other’s closest living relatives and form the clade Archosauria, diverged in the Triassic period 2,3.

Early archosaur evolution is characterized by high rates of homoplasy, long ghost lineages, and high rates of character evolution. These data imply that much of the early history of Archosauria has not been recovered from the fossil record.

2024年2月2日 · Archosaurs comprise a monophyletic clade called Archosauria. This means all archosaurs descended from a single common ancestor and share these derived features. Archosauria is divided into two major lineages:

A study on the phylogenetic relationships of pseudosuchian archosaurs, aiming to determine drivers of body size evolution in this group, is published by Stockdale & Benton (2021); [20] the study is subsequently criticized by Benson et al. (2022). [21] [22]The first occurrence of the track type "Chirotherium" lulli (inferred to be produced by a pseudosuchian archosaur) from western …