What are the evolutionary characteristics of the group super order Archosauria?
The Great Archosaur Lineage Other typical archosaurian characteristics include another opening in the lower jaw (the mandibular fenestra), a high narrow skull with a pointed snout, teeth set in sockets (called thecodont tooth implantation), and a modified ankle joint.
What features differentiate archosaurs?
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.
What is the meaning of Archosauria?
Definition of Archosauria : a large subclass of Reptilia comprising the dinosaurs, pterosaurs, and crocodilians all distinguished by possessing temporal openings separated from each other by a postorbitosquamosal arch.
When did archosaurs become extinct?
Extinction and survival Crocodylomorphs, pterosaurs and dinosaurs survived the Triassic–Jurassic extinction event about 200 million years ago, but other archosaurs had become extinct at or prior to the Triassic-Jurassic boundary.
Did archosaurs evolve crocodiles?
Along with pterosaurs and dinosaurs, crocodiles were an offshoot of the archosaurs, the “ruling lizards” of the early to middle Triassic period; needless to say, the earliest dinosaurs and the earliest crocodiles resembled one another a lot more than either resembled the first pterosaurs, which also evolved from …
How do Archosauria reproduce?
Reproduction. Most (if not all) archosaurs are oviparous. Birds and crocodilians lay hard-shelled eggs, as did extinct dinosaurs, and crocodylomorphs. Hard-shelled eggs are present in both dinosaurs and crocodilians, which has been used as an explanation for the absence of viviparity or ovoviviparity in archosaurs.
Are birds and crocodiles related?
Crocodiles are the closest living relatives of the birds, sharing a common ancestor that lived around 240 million years ago and also gave rise to the dinosaurs.
What did archosaurs evolve into?
About 250 million years ago, the archosaurs split into two groups: a bird-like group that evolved into dinosaurs, birds, and pterosaurs, and a crocodile-like group that includes the alligators and crocs alive today and a diversity of now-extinct relatives.
What is Archosauria?
Archosauria is defined as the group that includes the common ancestor of crocodiles and birds and all of its descendants. Because the group is defined this way, all archosaurs fall into one of two big clades: Ornithosuchia, or archosaurs on the evolutionary line to birds, and Pseudosuchia, or archosaurs on the evolutionary line to crocs.
What are the extinct archosaurs?
Extinct archosaurs include non-avian dinosaurs, pterosaurs, 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.
What are the characteristics of an archosaur?
Other typical archosaurian characteristics include another opening in the lower jaw (the mandibular fenestra), a high narrow skull with a pointed snout, teeth set in sockets (called thecodont tooth implantation), and a modified ankle joint. The ancestral archosaurs probably originated some 250 million years or so ago, in the late Permian Period.
What is the fenestra of the archosaur skull?
The archosaur skull includes two new fenestra (skull openings). The first of these is the mandibular fenestra, an opening through the jawbone. The other is the antorbital fenestra, a term that means “the opening in front of the eye.”