Articles relating to the [[Archosaur]]s, a [[clade]] of [[diapsid]]s, with [[birds]] and [[crocodilian]]s as the only living representatives. Archosaurs are broadly classified as [[reptile]]s, in the cladistic sense of term which includes birds. Extinct archosaurs include non-avian [[dinosaur]]s, [[pterosaur]]s, and extinct relatives of crocodilians. Modern paleontologists define Archosauria as a [[crown group]] that includes the [[most recent common ancestor]] of living birds and crocodilians, and all of its descendants. The base of Archosauria splits into two clades: [[Pseudosuchia]], which includes crocodilians and their extinct relatives, and [[Avemetatarsalia]], which includes birds and their extinct relatives (such as non-avian dinosaurs and [[pterosaurs]]).