Rauisuchia

	Email		Print
	Bookmark		Link

Rauisuchia

Rauisuchia are a poorly known assemblage of predatory and mostly large (often 4 to 6 meters) Triassic

Triassic

The Triassic is a geologic period that extends from about 251 to 199 annum . As the first period of the Mesozoic Era, the Triassic follows the Permian and is followed by the Jurassic....
archosaur

Archosaur

Archosaurs are a group of diapsid reptiles represented by modern birds and crocodilians. This group also includes extinct non-avian dinosaurs, pterosaurs and relatives of crocodiles....
s. Originally it was believed that they were related to erythrosuchids

Erythrosuchidae

Erythrosuchidae are a family of large Basal archosauromorph carnivores that lived from the later Early Triassic to the early Middle Triassic ....
, but it is now known that they are crurotarsans

Crurotarsi

The Crurotarsi are a group of Archosauria, whose name was erected as a Cladistics#Cladistic classification by Paul Sereno in 1991 to supplant the old term Pseudosuchia....
. Three families are generally recognised: Prestosuchidae

Prestosuchidae

Prestosuchidae are a group of Triassic carnivorous archosaurs. They were large active terrestrial apex predators, ranging from around 2.5 to 6 or 7 meters in length....
, Rauisuchidae

Rauisuchidae

Rauisuchidae are a group of large predatory Triassic archosaurs, and constitute advanced representatives of the larger group Rauisuchia. There is some disagreement over which genera should be included in the Prestosuchidae, which in Rauisuchidae, and which in the Poposauridae, and indeed whether these should even be thought of as separate F...
, and Poposauridae

Poposauridae

The Poposauridae are a Family of large carnivore archosaurs which lived alongside dinosaurs during the Late Triassic. They are known from fossil remains from North and South America....
, as well as a number of forms (e.g. those from the Olenekian

Olenekian

The Olenekian is a faunal stage of the Early Triassic epoch . It spans the time between 249.7 ? 0.7 annum and 245 ? 0.7 Ma . The Olenekian is divided into the Smithian and the Spathian age....
of Russia) that are too primitive and/or poorly known to fit in any of these groups. There has been considerable suggestion that the group as currently defined is paraphyletic, representing a number of related lineages independently evolving and filling the same ecological niche of medium to top terrestrial predator.

Discussion

Ask a question about 'Rauisuchia'

Start a new discussion about 'Rauisuchia'

Answer questions from other users

Full Discussion Forum

Encyclopedia

Rauisuchia are a poorly known assemblage of predatory and mostly large (often 4 to 6 meters) Triassic

Triassic

Archosaur

Erythrosuchidae

Erythrosuchidae are a family of large Basal archosauromorph carnivores that lived from the later Early Triassic to the early Middle Triassic ....
, but it is now known that they are crurotarsans

Crurotarsi

Prestosuchidae

Prestosuchidae are a group of Triassic carnivorous archosaurs. They were large active terrestrial apex predators, ranging from around 2.5 to 6 or 7 meters in length....
, Rauisuchidae

Rauisuchidae

Poposauridae

Olenekian

Crocodilia

Crocodilia is an order of large reptiles that appeared about 84 million years ago in the late Cretaceous Period . They are the closest living relatives of birds, as the two groups are the only known survivors of the Archosauria....
than to prestosuchids. In a more recent study, Nesbitt presented a different phylogeny with a monophyletic Rauisuchia. The group may even be something of a "wastebasket taxon". Determining exact phylogenetic relationships is difficult because of the scrappy nature of a lot of the material. However, recent discoveries and studies such as those of Batrachotomus
Batrachotomus

Batrachotomus is an extinct genus of rauisuchian, a group of predatory and large Triassic archosaurs. It lived during the Middle Triassic of Germany, about 230 million years ago, and was possibly an early relative of Postosuchus....
and restudies of other forms such as Erpetosuchus are shedding light on the evolutionary relationships of this poorly known but fascinating group.

Both José Bonaparte

José Bonaparte

Jos? Fernando Bonaparte, Doctor of Philosophy , is an Argentina paleontology who discovered a plethora of South American dinosaurs and mentored a new generation of Argentine paleontologists like Rodolfo Coria....
and Michael Benton

Michael J. Benton

Michael J. Benton is a Fellow of the Royal Society of Edinburgh and professor of vertebrate paleontology in the Department of Earth Sciences at the University of Bristol....
argue that rauisuchians such as Saurosuchus
Saurosuchus

Saurosuchus is an extinct genus of archosaur reptile belonging to the rauisuchian order. With a length of 7 m , it was the largest member of the group, except perhaps for the less well known Fasolasuchus....
developed an erect stance independently of and differently to dinosaur

Dinosaur

Dinosaurs were the dominant vertebrate animals of Landform ecosystems for over 160 million years, from the late Triassic Period until the end of the Cretaceous Period , when most of them became extinct in the Cretaceous?Tertiary extinction event....
s, by means of having the femur

Femur

The femur, or thigh bone, is the most proximal bone of the leg in vertebrates capable of walking or jumping, such as most land mammals, birds, many reptiles such as lizards, and amphibians such as frogs....
vertical and angling the acetabulum

Acetabulum

The acetabulum is a :wikt:concave surface of the pelvis. The femur head meets with the pelvis at the acetabulum, forming the hip joint....
ventrally, rather than having an angled neck or curve in the femur. They refer to this as the pillar-erect posture.

The erect gait indicates that these animals were clearly active, agile predators, with locomotor superiority over the kannemeyerid dicynodonts and abundant rhynchosaur

Rhynchosaur

Rhynchosaurs were a group of unusual Triassic diapsid reptiles related to the Archosauria. They were herbivores, and at times abundant , with stocky bodies and a powerful beak....
s on which they fed. They were successful animals, the largest with skulls up to a meter or more in length, and continued right until the end of the Triassic, when, along with many other large archosaurs, they were killed off by the end Triassic extinction event

Triassic-Jurassic extinction event

The Triassic?Jurassic extinction event marks the boundary between the Triassic and Jurassic periods, , and is one of the major extinction events of the Phanerozoic eon, profoundly affecting life on land and in the oceans....
. With their demise, theropod dinosaurs were able to emerge as the sole large terrestrial predators. Meat-eating dinosaur footprints suddenly increase in size at the start of the Jurassic

Jurassic

The Jurassic is a geologic period that extends from about annum to Ma, that is, from the end of the Triassic to the beginning of the Cretaceous....
, when rauisuchians are absent.

Well-known Rauisuchians include Ticinosuchus
Ticinosuchus

Ticinosuchus is an extinct genus of rauisuchian archosaur that was about 3 m long.Its whole body, even the belly, was covered in thick, armored scutes....
of the Middle Triassic of Europe (Switzerland and Northern Italy), Saurosuchus
Saurosuchus

Saurosuchus is an extinct genus of archosaur reptile belonging to the rauisuchian order. With a length of 7 m , it was the largest member of the group, except perhaps for the less well known Fasolasuchus....
of the late Triassic (Late Carnian

Carnian

The Carnian is the lowermost stage of the Upper Triassic series . Its boundaries are not characterized by major extinctions or biotic turnovers, but a climatic event occurred during the Carnian and seems to be associated with important extinctions or biotic radiations....
) of South America (Argentina), and Postosuchus
Postosuchus

Postosuchus was a basal archosaur which lived in what is now North America during the middle through to the late Triassic period . It was a Rauisuchia, a cousin of crocodilia and came from the same ancestry as dinosaurs....
of the late Triassic (Late Carnian

Carnian

Norian

The Norian Stage was a portion of the Triassic geological period. It dates from 216.5 ? 2.0 to 203.6 ? 1.5 Mya . It was preceded by the Carnian Stage and succeeded by the Rhaetian Stage....
) of North America (SW USA). One rauisuchian, Teratosaurus
Teratosaurus

Teratosaurus was a genus of rauisuchian known from the Triassic Stubensandstein of Germany and from the Krasiej?w of Poland. The type specimen was described by Christian Erich Hermann von Meyer on the basis of a left maxilla with large teeth, which he declared to be distinct from Belodon....
, was for a long time even considered an early theropod dinosaur , but was later shown to be nondinosaurian .

Rauisuchia

External links

Other references