| Avemetatarsalians Temporal range: 247–0 Ma Middle Triassic to Present | |
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| Various dinosaurs | |
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| Various pterosaurs | |
| Scientific classification | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Sauropsida |
| Subgroups | |
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| Synonyms | |
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Avemetatarsalia is a clade of reptiles that includes dinosaurs, pterosaurs and their closest relatives. It appeared in the Middle Triassic epoch. It is one of the two main groups of archosaurs. The second one, Pseudosuchia, includes all archosaurs more related to crocodilians than to birds. Avemetetersalia contains a similarly defined subgroup, Ornithodira. Members of this group are characterized by an upright gait and S-curved neck, hence the name "Ornithodira" ("bird necks").
Pterosauromorpha contains Maehary, Scleromochlus, Lagerpetidae and Pterosauria, which are the famous flying reptiles, and as far as is known the first vertebrates capable of true flight. Most researchers think pterosaurians had neither an S-curved neck, nor an upright gait: the clade Ornithodira is defined on basis of ancestry, not characters – and it is always possible later descendants show a change in characters.
Dinosauromorpha contains more basal forms like Lagosuchus and Marasuchus and more derived forms like dinosaurs, which birds belong to as members of the theropods. Since the Cretaceous-Paleogene extinction, birds are the only living group of avemetatarsalians.
In media[]
- An unidentified avemetatarsalian flock can be seen in Disney's Dinosaur two times. At first, they fly near forest where Carnotaurus ambushed. Another flock fly away from the place where the meteorite impact happens. This flock could be primitive birds (like Ichthyornis) or pterosaurs.
- Several unidentified avemetatarsalians appear in Prehistoric Planet. In the episode "Coasts", one light colored avemetatarsalian flies over the trees in the background as the Tyrannosaurus flips the protostegid. Four other avemetatarsalians can be seen, also in the background, when the Hatzegopteryx come out of the forest to the beach in the episode "Forests". Since the events take place in the Late Cretaceous period, all these unidentified avemetatarsalians may be primitive birds or pterosaurs.