Proterosuchidae
Proterosuchidae Temporal range: Late Permian to Early Triassic, 252–247 Ma | |
---|---|
Restored skull of Archosaurus | |
Scientific classification | |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Reptilia |
Clade: | Archosauriformes |
Family: | †Proterosuchidae Huene, 1914 |
Genera | |
see below | |
Synonyms | |
|
Proterosuchidae is an early, possibly paraphyletic, assemblage of basal archosauriformes whose fossils are known from the Latest Permian and the Early Triassic of Europe, Asia, Africa, Australia and possibly South America. The name comes from Greek πρότερο- ("first") and σοῦχος ("crocodile").
Description
They were slender, medium-sized (about 1.5 meters long), long-snouted and superficially crocodile-like animals, although they lacked the armoured scutes of true crocodiles, and their skeletal features are much more primitive. The limbs are short and indicate a sprawling posture, like contemporary lizards but unlike most later archosaurs.
Their most characteristic feature is a distinct down-turning of the premaxilla (the front of the upper jaw, which overhangs the lower jaw).
Evolutionary history
The terminal Permian catastrophe, which killed off 95% of all types of life, cleared the world of all large therapsids and allowed the proterosuchids to take center stage as the top carnivore. Within the space of five million years the proterosuchids had evolved into a wide variety of terrestrial and semi-aquatic carnivores.[1] The proterosuchids represent perhaps the earliest adaptive radiation of the archosaurs. They gave rise to the Erythrosuchidae some time in the Early Triassic.
Classification
Genera
Genus | Status | Age | Location | Description | Images |
---|---|---|---|---|---|
Valid | Early Triassic | India | |||
Valid | Late Permian, Changhsingian | Russia and Poland | |||
Valid | Early Triassic, Induan | Russia | |||
Valid | Early Triassic | South Africa and China | |||
Valid | Early Triassic, Olenekian | Russia | |||
Valid | Early Triassic, Olenekian | Russia | |||
Valid | Early Triassic | Australia | |||
Valid | Early Triassic | South Africa and China | |||
Valid | Early Triassic | Australia | |||
Valid | Early Triassic, Induan | Russia | |||
Phylogeny
Some studies consider Proterosuchidae to be a paraphyletic grouping, meaning that it does not form a true clade with a single common ancestor and proterosuchids as its only descendants. Instead, they are a chain of successively basal archosauriforms. Below is a cladogram from Ezcurra et al. (2010):[2]
|
Proterosuchids |
Below is a cladogram from Nesbitt (2011):[3]
Archosauriformes |
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
References
- ↑ "Archosauria: Archosauriformes". Palaeos. Retrieved 29 October 2014.
- ↑ Ezcurra, M.D.; Lecuona, A.; Martinelli, A. (2010). "A new basal archosauriform diapsid from the Lower Triassic of Argentina". Journal of Vertebrate Paleontology 30 (5): 1433–1450. doi:10.1080/02724634.2010.501446.
- ↑ Nesbitt, S.J. (2011). "The early evolution of archosaurs: relationships and the origin of major clades" (PDF). Bulletin of the American Museum of Natural History 352: 1–292. doi:10.1206/352.1.
Further reading
- Benton, M. J. (2000), Vertebrate Paleontology, 2nd Ed.; (2004) 3rd edition Blackwell Science Ltd
- Carroll, R. L. (1988), Vertebrate Paleontology and Evolution, WH Freeman & Co.
External links
- Proterosuchidae
- Proterosuchidae - list of species (Mikko's Phylogeny Archive)
|