archosaur
Sign in to saveArchosauria or archosaurs () is a clade of diapsid sauropsid tetrapods, with birds and crocodilians being the only known extant representatives. Although broadly classified as reptiles, which traditionally exclude birds, the cladistic sense of the term includes all living and extinct relatives of birds and crocodilians such as non-avian dinosaurs, pterosaurs, phytosaurs, aetosaurs and rauisuchians as well as many Mesozoic marine reptiles. Modern paleontologists define Archosauria as a crown group that includes the most recent common ancestor of living birds and crocodilians, and all of its des
AI overview
Archosaurs are a major group of reptiles whose living members include only birds and crocodilians, though the group also encompasses many extinct relatives like dinosaurs and pterosaurs. They matter because understanding archosaurs helps us trace the evolutionary history of some of today's most significant animals and reveals the incredible diversity of reptilian life that dominated the Mesozoic era.
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Article
21 sectionsContents
- Distinguishing characteristics
- Origins
- Archosaurian domination in the Triassic
- Main forms
- Classification
- Modern classification
- History of classification
- Phylogeny
- Extinction and survival
- Archosaur lifestyle
- Hip joints and locomotion
- Diet
- Land, water and air
- Metabolism
- Respiratory system
- Reproduction
- See also
- Notes
- References
- Sources
- External links
Archosauria or archosaurs () is a clade of diapsid sauropsid tetrapods, with birds and crocodilians being the only known extant representatives. Although broadly classified as reptiles, which traditionally exclude birds, the cladistic sense of the term includes all living and extinct relatives of birds and crocodilians such as non-avian dinosaurs, pterosaurs, phytosaurs, aetosaurs and rauisuchians as well as many Mesozoic marine reptiles. 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). Older definitions of the group Archosauria rely on shared morphological characteristics, such as an antorbital fenestra in the skull, serrated teeth, and an upright stance. Some extinct reptiles, such as proterosuchids and euparkeriids, also possessed these features yet originated prior to the split between the crocodilian and bird lineages. The older morphological definition of Archosauria nowadays roughly corresponds to Archosauriformes, a group named to encompass crown-group archosaurs and their close relatives.