Prestosuchidae

Taxobox
name = Prestosuchidae
fossil_range = Anisian to Carnian

---

image_width = 250px
image_caption = "Saurosuchus"
regnum = Animalia
phylum = Chordata
classis = Sauropsida
subclassis = Diapsida
infraclassis = Archosauromorpha
unranked_ordo = Crurotarsi
ordo = Rauisuchia
familia = Prestosuchidae
familia_authority = Romer, 1966
subdivision_ranks = Genera
subdivision = "Batrachotomus" "Karamuru" "Mandasuchus" "Prestosuchus" "Ticinosuchus" "Saurosuchus" "Yarasuchus"

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. They succeeded the Erythrosuchidae as the largest archosaurs of their time. While resembling Erythrosuchids in size and some features of the skull and skeleton, they were more advanced in their erect posture and crocodile-like ankle, indicating more efficient gate. Prestosuchids flourished throughout the whole of the middle, and the early part of the late Triassic, and fossils are so far known from Europe, India, Africa (Tanganyika), and Argentina. However experts agree regarding the phylogenetic relationships of the group, what genera should be included, and whether indeed the Prestosuchidae constitute a distinct family apart from the Rauisuchidae.

Classification

Alan Charig 1957 proposed a new family, the Prestosuchidae, to include genera like "Mandasuchus", "Prestosuchus", and "Spondylosoma".

In 1967, Alfred Sherwood Romer placed "Saurosuchus" and "Rauisuchus" within Erythrosuchidae and adopted the Prestosuchidae to include "Prestosuchus", "Procerosuchus", and Charig's "Mandasuchus"

Prestosuchidae have often been included within Rauisuchidae (e.g. Gauthier, 1986, Benton & Clark 1988, Benton & Walker 2002), although they have sometimes considered the sister group of the aetosaurs in a monophyletic Pseudosuchia (Juul, 1994), or as a small clade intermediate between basal Crurotarsi and more advanced archosaurs such as the Aetosauridae and Rauisuchidae (Gower 2002). J. Michael Parrish's 1993 cladistic analysis of crocodylotarsan archosaurs places the Prestosuchidae (including "Prestosuchus", "Ticinosuchus", and"Saurosuchus") outside the crocodylomorph - poposaurid - rauisuchid - aetosaur clade. In most cladograms Prestosuchids are considered more advanced (or "derived" in cladistic terminology) than phytosaurs and ornithosuchids, but usually less derived than the poposaurids and aetosaurs.

Evolution of the group

The earliest known prestosuchid is "Mandasuchus" from the Anisian of Tanganyika. This was already a large animal, about 4.75 meters long (Charig "et al." 1976). A similar but smaller form (perhaps the same genus) is "Ticinosuchus" of the Middle Triassic (Anisian-Ladinian) of Switzerland and Northern Italy, which was about 2.5 meters in length. The huge (6 meters long) "Batrachotomus" from the latest Middle Triassic (Late Ladinian) of Germany, and "Prestosuchus" of the early Late Triassic (Carnian) of South America may have been closely related animals. (Gower 2002). "Yarasuchus" was a lightly built animal from the Middle Triassic of India that also seems to belong to this group (Sen 2005). Finally, "Saurosuchus" was a huge carnivore, 6 or 7 meters long, whose fossils are known from the Late Carnian of Argentina.

References

* Benton, M. J. & Clark J.M. (1988), Archosaur phylogeny and the relationships of the Crocodilia in MJ Benton (ed.), "The Phylogeny and Classification of the Tetrapods" 1: 295-338. Oxford, The Systematics Assoc
* ----- & AD Walker (2002), Erpetosuchus, a crocodile-like basal archosaur from the Late Triassic of Elgin, Scotland, "Zool. J. Linn. Soc." 136: 25-47.
* Charig, AJ 1957, New Triassic archosaurs from Tanganyika, including Mandasuchus and Teleocrater: Dissertation Abstracts. Cambridge University.
* ----- , Bernard Krebs, Hans D Sues, Frank Westphal 1976, Handbook of Paleoherpetology: Thecodontia, Verlag Dr. Friedrich Pfeil, Munchen
* Gauthier J.A. 1986. Saurischian monophyly and the origin of birds. Memoirs of the California Academy of Sciences 8: 1-55.
* Gower, DJ (2002), Braincase evolution in suchian archosaurs (Reptilia: Diapsida): evidence from the rauisuchian Batrachotomus kupferzellensis, "Zool. J. Linn. Soc". 136: 49-76
* Juul, L (1994), The phylogeny of basal archosaurs. "Palaeontologia Africana" 31: 1-38
* Parrish, JM (1993), Phylogeny of the Crocodylotarsi, with reference to archosaurian and crurotarsan monophyly. "Journal of Vertebrate Paleontology" 13: 287-308
* Kasturi Sen, (2005) "A new rauisuchian archosaur from the Middle Triassic of India", "Palaeontology, Volume 48 Issue 1, November 07, 2005
* Sereno, P. C. 2005. [http://www.taxonsearch.org/Archive/stem-archosauria-1.0.php Stem Archosauria—TaxonSearch] [version 1.0, 2005 November 7]

External links

* [http://www.taxonsearch.org/dev/taxon_edit.php?Action=View&tax_id=412 Taxon Search - Prestosuchidae]
* [http://www.palaeos.com/Vertebrates/Units/270Archosauromorpha/270.650.html Rauisuchiformes: Prestosuchidae] at Palaeos