What did archosaurs eat?

How are archosaurs different from other reptiles?

Unlike other living reptiles, whose teeth are set in a shallow groove, the teeth of archosaurs are set in sockets. Although most archosaurs were egg layers, there is evidence that some species gave birth to live young.

Are all archosaurians carnivores?

All were carnivorous except the armoured, herbivorous aetosaurs. The second archosaurian branch, the Ornithosuchia, includes birds and all archosaurs more closely related to birds than to crocodiles.

What is an archosaur?

Archosaurs (Greek for ‘ruling lizards’) are a group of diapsid reptiles that is represented today by birds and crocodiles and which also included the dinosaurs . There is some debate about when archosaurs first appeared:

How are archosaurs distinguished from other tetrapods?

Archosaurs can traditionally be distinguished from other tetrapods on the basis of several synapomorphies, or shared characteristics, which were present in their last common ancestor.

What are the characteristics of carnivorous reptiles in the Triassic period?

Carnivorous small reptiles arose in the Triassic period. 2. The hind legs were longer, slim skulls, and sharp teeth in sockets along the jaw edges. 3. Some were aquatic with features like modern crocodiles.

What is Archosauria?

Archosauria is normally defined as a crown group, which means that it only includes descendants of the last common ancestors of its living representatives. In the case of archosaurs, these are birds and crocodilians.

What are archosaurs classified as?

Archosaurs are broadly classified as reptiles, in the cladistic sense of term which includes birds. Extinct archosaurs include non-avian dinosaurs, pterosaurs, and extinct relatives of crocodilians.

Is Archosauria a diapsid?

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 are the vertebrates in the Triassic period?

Terrestrial reptiles and the first mammals. On land the vertebrates are represented in the Triassic by labyrinthodont amphibians and reptiles, the latter consisting of cotylosaurs, therapsids, eosuchians, thecodontians, and protorosaurs. All these tetrapod groups suffered a sharp reduction in diversity at the close of the Permian;

What dinosaurs were carnivorous in the Triassic period?

The first carnivorous dinosaurs in the Triassic period were the Eoraptor and Herrerasaurus. Both dinosaurs were small and bipedal, with powerful hind limbs and long tails for balance. The later Coelophysis was also a meat-eater.

What is Archosauromorpha?

Archosauromorpha ( Greek for “ruling lizard forms”) is a clade of diapsid reptiles containing all reptiles more closely related to archosaurs (such as crocodilians and dinosaurs, including birds) rather than lepidosaurs (such as tuataras, lizards, and snakes ).

What is the second branch of the archosaur family?

The second archosaurian branch, the Ornithosuchia, includes birds and all archosaurs more closely related to birds than to crocodiles. In addition to the dinosaurs (the group from which birds evolved and to which they formally belong), ornithosuchians include pterosaurs and some extinct Triassic forms such as lagosuchids and lagerpetontids.

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 ).

What are the marine invertebrate fossils found in Triassic rocks?

Other marine invertebrate fossils found in Triassic rocks, albeit much reduced in diversity compared with those of the Permian, include gastropods, bivalves, brachiopods, bryozoans, corals, foraminiferans, and echinoderms. These groups are either poorly represented or absent in Lower Triassic rocks but increase in importance later in the period.

What was the Early Triassic period dominated by?

The early Triassic was dominated by mammal-like reptiles such as Lystrosaurus. The Triassic Period (252-201 million years ago) began after Earth’s worst-ever extinction event devastated life.

What animals were there in the middle and Late Triassic period?

Modern groups whose ancestral forms appeared for the first time in the Middle and Late Triassic include lizards, turtles, rhynchocephalians (lizardlike animals), and crocodilians. The mammal-like reptiles, or therapsids, suffered pulses of extinctions in the Late Permian.

When did the dinosaurs begin to evolve from reptiles?

Dinosaurs began to evolve from the reptiles toward the end of the Triassic period, but great numbers of the creatures did not flourish until the Jurassic period. Why did the dinosaurs begin to thrive in the Late Triassic period?

What are the characteristics of dinosaurs of the Late Triassic period?

This group presumably gave rise to primitive dinosaurs belonging to the saurischian and ornithischian orders during the Late Triassic to Early Jurassic. The early dinosaurs were bipedal, swift-moving, and relatively small compared with later Mesozoic forms, but some, such as Plateosaurus ( see the figure ),…

Are archosauromorphs related to lizards?

Although the most diverse clade of living archosauromorphs are birds, early members of the group were evidently reptilian, superficially similar to modern lizards. When archosauromorphs first appeared in the fossil record in the Permian, they were represented by long-necked, lightly-built sprawling reptiles with moderately long, tapering snouts.

What is the difference between Lepidosauromorpha and Archosauria?

The new Lepidosauromorpha, are all those sharing a more recent common ancestor with living lizards, the Lepidosauria, than with Archosauria (Gauthier 1986). The new Archosauromorpha share more traits in common with living archosaurs (birds and crocs) than with Lepidosauria.

How many reptile groups are there in Archosauromorpha?

Since the seminal studies of the 1980s, Archosauromorpha has consistently been found to contain four specific reptile groups, although the definitions and validity of the groups themselves have been questioned. The least controversial group is Rhynchosauria (“beak reptiles”), a monophyletic clade of stocky herbivores.

What type of fossils are found in the Jurassic period?

Jurassic marine fossils include plankton, corals, many other marine invertebrates and rare sharks and bony fish. Jurassic land fossils include well-preserved tree stumps (Curio Bay, Southland). Fossil wood, leaves, seeds, spores and pollen have been documented from numerous layers.

What types of fossils are found in marine sedimentary rocks?

Fossils include representatives of most marine invertebrate groups. Vertebrate fossils of conodonts, fish and marine reptiles are generally rare. Dinoflagellates (a type of marine plankton) first appear in younger Triassic rocks. Plant fossils (wood and leaves), fossil seeds, spores and pollen are also present.