Carnosauria

Carnosaurs Temporal range: Middle Jurassic–Late Cretaceous, 171.6–70Ma PreЄ Є O S D C P T J K Pg N
Replica Allosaurus fragilis skeleton
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Dinosauria
Clade:	Theropoda
Clade:	Avetheropoda
Clade:	†Carnosauria von Huene, 1920
Subgroups
†Becklespinax? †Gasosaurus? †Sigilmassasaurus †Allosauroidea

Carnosauria is a large group of predatory dinosaurs that lived during the Jurassic and Cretaceous periods. While it originally contained a wide assortment of giant theropods that were not closely related, the group has since been defined to encompass only the allosaurs and their closest kin. Recently, scientists have discovered some very large carnosaurs in the carcharodontosaurid family such as Giganotosaurus and Tyrannotitan which are among the largest known predatory dinosaurs.

Distinctive characteristics of carnosaurs include large eyes, a long narrow skull and modifications of the legs and pelvis such as the thigh (femur) being longer than the shin (tibia).

Systematics

Modern cladistic analysis defines Carnosauria as those tetanurans sharing a more recent common ancestor with Allosaurus than with modern birds.^[1]

Taxonomy

Carnosauria has traditionally been used as a dumping ground for all large theropods, but analysis in the 1980s and 1990s revealed that other than size, the group shared very few characteristics, making it polyphyletic. Most former carnosaurs were reclassified as more primitive theropods. Others were placed in Coelurosauria if they were more closely related to birds, like the tyrannosaurids. Other former carnosaurs include the megalosaurids, the spinosaurids, and the ceratosaurs. Even non-dinosaurs have been considered carnosaurs, such as the rauisuchian Teratosaurus.^{[citation needed]}

Phylogeny

The clade Allosauroidea was originally proposed by Phil Currie and Zhao (1993; p. 2079), and later used as an undefined stem-based taxon by Paul Sereno (1997). Sereno (1998; p. 64) was the first to provide a stem-based definition for the Allosauroidea, defining the clade as "All neotetanurans closer to Allosaurus than to Neornithes." Kevin Padian (2007) used a node-based definition, defined the Allosauroidea as Allosaurus, Sinraptor, their most recent common ancestor, and all of its descendants. Thomas R. Holtz and colleagues (2004; p. 100) and Phil Currie and Ken Carpenter (2000), among others, have followed this node-based definition. However, in some analyses (such as Currie & Carpenter, 2000), the placement of the carcharodontosaurids relative to the allosaurids and sinraptorids is uncertain, and therefore it is uncertain whether or not they are allosauroids (Currie & Carpenter, 2000).

The cladogram presented here follows the 2010 analysis by Benson, Carrano and Brusatte.^[2]

"Carnosaurus"

"Carnosaurus" is an informal generic name, attributed to Friedrich von Huene, 1929, that is sometimes seen in lists of dinosaurs. It is probably a typographical error; von Huene intended to assign indeterminate remains to Carnosauria incertae sedis, but at some point in the process of publication, the text was revised to make it appear that he was creating a new generic name "Carnosaurus" (as described by George Olshevsky in a 1999 post to the Dinosaur Mailing List). The name is undescribed and has not been used seriously.

References

• George Olshevsky. "Re: What are these dinosaurs". Retrieved 2007-01-29.  (on "Carnosaurus")
• Currie, P. J.; Zhao, X. (1993). "A new carnosaur (Dinosauria, Theropoda) from the Upper Jurassic of Xinjiang, People's Republic of China". Canadian Journal of Earth Sciences 30 (10): 2037–2081. Bibcode:1993CaJES..30.2037C. doi:10.1139/e93-179. 
• Holtz, T. R., Jr. and Osmólska H. 2004. Saurischia; pp. 21–24 in D. B. Weishampel, P. Dodson, and H. Osmólska (eds.), The Dinosauria (2nd ed.), University of California Press, Berkeley.
• Sereno, P. C. (1997). "The origin and evolution of dinosaurs". Annual Review of Earth and Planetary Sciences 25: 435–489. Bibcode:1997AREPS..25..435S. doi:10.1146/annurev.earth.25.1.435. 
• Sereno, P. C. (1998). "A rationale for phylogenetic definitions, with application to the higher-level taxonomy of Dinosauria". Neues Jahrbuch für Geologie und Paläontologie Abhandlungen 210: 41–83. 

External links

Wikispecies has information related to: Carnosauria

• Media related to Carnosauria at Wikimedia Commons