When did the Archosauria live?
about 245 million years ago
Archosauria: Fossil Record The first archosauromorphs (relatives of the true archosaurs) appear in the fossil record in the Early Triassic; about 245 million years ago, just after the great end-Permian extinction.
What does the word synapsid mean?
Definition of synapsid : any of a subclass (Synapsida) of terrestrial vertebrates (such as the pelycosaurs and therapsids) having a single pair of lateral temporal skull openings. Note: Traditional classifications typically consider synapsids to be mammal-like, extinct reptiles ancestral to mammals.
What is the meaning of diapsid?
Diapsids (“two arches”) are a group of amniote tetrapods that developed two holes (temporal fenestra) in each side of their skulls about 300 million years ago during the late Carboniferous period. The diapsids are extremely diverse, and include all crocodilians, lizards, snakes, tuatara, turtles, and birds.
Can birds have breasts?
Birds don’t have nipples, as they are not mammals. Although, we talk about birds’ breasts they don’t have mammary glands which mammals use to feed their young milk. Here the term breast is used to describe the pectoral muscles birds use for flight.
How tall is a archosaur?
They were 2–4 m (TL) gharial-like animals. However, their teeth were small and remained inside the mouth when closed, and their nostrils were on a raised bony mound at the base of the long, narrow snout.
What is the meaning of archosaur?
Definition of archosaur. : any of a subclass (Archosauria) of reptiles comprising the dinosaurs, pterosaurs, and crocodilians.
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 is the only living group of archosaur?
Unsourced material may be challenged and removed. Birds and crocodilians (in this case a yellow-billed stork and a Nile crocodile) are the only known living archosaur groups. † Incertovenator?
What are the two clades of Archosauria?
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 ).