Carcharodontosauridae

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Carcharodontosaurids
Temporal range: Late JurassicLate Cretaceous,[1] 154–70Ma
Carcharodontosaurus.jpg
Cast of a Carcharodontosaurus saharicus skull, Santa Barbara
Scientific classification e
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Suborder: Theropoda
Clade: Carnosauria
Clade: Carcharodontosauria
Family: Carcharodontosauridae
Stromer, 1931
Type species
Carcharodontosaurus saharicus
Deperet & Savornin, 1925
Subgroups[4]

Carcharodontosaurids (from the Greek καρχαροδοντόσαυρος, carcharodontósauros: "shark-toothed lizards") were a group of carnivorous theropod dinosaurs. In 1931 Ernst Stromer named Carcharodontosauridae as a family, in modern paleontology this name indicates a clade within Carnosauria. Carcharodontosaurids included some of the largest land predators ever known: Giganotosaurus, Mapusaurus, Carcharodontosaurus, and Tyrannotitan all rivaled or slightly exceeded Tyrannosaurus in size.

Evolution[edit]

Giganotosaurus skeleton cast, Haifa

Along with the spinosaurids, carcharodontosaurids were the largest predators in the early and middle Cretaceous throughout Gondwana, with species also present in North America (Acrocanthosaurus), and Asia (Shaochilong).[5] Their ages range from the Barremian (127-121 million years ago) to the Turonian (93-89 million years ago). Past the Turonian, they might have been replaced by the smaller abelisaurids in Gondwana and by tyrannosaurids in North America and Asia. According to Fernando Novas and colleagues, the disappearance of not only carcharodontosaurids but also spinosaurids and other fauna in both Gondwana and North America seem to indicate that this faunal replacement occurred on a global scale.[6] However, some theropod teeth discovered in late Maastrichtian Marília Formation in Brazil, as well as a fragment of right maxilla discovered at the Campanian-Maastrichtian boundary of the Presidente Prudente Formation in Brazil, appear to belong to carcharodontosaurids, indicating the survival of this group until the latest Cretaceous.[1][7] In December 2011, Oliver W. M. Rauhut described a new genus and species of carcharodontosaurid from the Late Jurassic (late Kimmeridgian to earliest Tithonian faunal stage, about 154-150 million years ago) of Tendaguru Formation, southeastern Tanzania. Veterupristisaurus represents the oldest known carcharodontosaurid.[8]

Classification[edit]

The family Carcharodontosauridae was originally named by Ernst Stromer in 1931 to include the single newly discovered species Carcharodontosaurus saharicus. A close relative of C. saharicus, Giganotosaurus, was added to the family when it was described in 1995. Additionally, many paleontologists have included Acrocanthosaurus in this family (Sereno et al. 1996, Harris 1998, Holtz 2000, Rauhut 2003, Eddy & Clarke, 2011, Rauhut 2011), though others place it in the related family Allosauridae (Currie & Carpenter, 2000; Coria & Currie, 2002).

With the discovery of Mapusaurus in 2006, Rodolfo Coria and Phil Currie erected a subfamily of Carcharodontosauridae, the Giganotosaurinae, to contain the most advanced South American species, which they found to be more closely related to each other than to the African and European forms. Coria and Currie did not formally refer Tyrannotitan to this subfamily, pending a more detailed description of that genus, but noted that based on characteristics of the femur, it may be a giganotosaurine as well.[9]

In 1998 Paul Sereno defined Carcharodontosauridae as a clade, consisting of Carcharodontosaurus and all species closer to it than to either Allosaurus, Sinraptor, Monolophosaurus, or Cryolophosaurus. Therefore, this clade is by definition outside of the clade Allosauridae. The cladogram below follows the analysis of Brusatte et al., 2009,[5] although note that the placement of Neovenator has since been revised to outside of but near Carcharodontosauridae, in Neovenatoridae.[10]

Carcharodontosauridae

Neovenator





Acrocanthosaurus



Eocarcharia





Shaochilong



Tyrannotitan




Carcharodontosaurus


Giganotosaurinae

Giganotosaurus



Mapusaurus







Cladogram after Ortega et al., 2010[11]

Carcharodontosauridae

Eocarcharia




Concavenator




Acrocanthosaurus




Shaochilong




Tyrannotitan




Carcharodontosaurus



Giganotosaurus



Mapusaurus








Cladogram after Novas et al., 2013[3]



Allosaurus


Carcharodontosauridae

Neovenator



Eocarcharia



Concavenator




Acrocanthosaurus




Shaochilong


Carcharodontosaurinae

Carcharodontosaurus


Giganotosaurini

Tyrannotitan




Mapusaurus



Giganotosaurus









Mounted Acrocanthosaurus skeleton (NCSM 14345) at the North Carolina Museum of Natural Sciences.

The placement of Acrocanthosaurus is unclear, with most[12] researchers favoring Carcharodontosauridae and others favoring Allosauridae. In 2011, a redescription of Kelmayisaurus by Stephen L. Brusatte, Roger B. J. Benson and Xing Xu found it to be valid genus of Carcharodontosauridae. A phylogenetic analysis of Tetanurae recovered K. petrolicus as a basal carcharodontosaurid in a trichotomy with Eocarcharia and a clade comprising more derived carcharodontosaurids.[2] Bahariasaurus has also been proposed as a carcharodontosaurid, but its remains are too scarce to be certain. It appears to be synonymous with the ceratosaur Deltadromeus.

Carcharodontosaurids have been proposed as more closely related to abelisaurids, as opposed to the allosaurids. This is due to these two clades sharing some cranial features (see link below). However, these similarities appear to derive from parallel evolution between these two groups. A larger number of cranial and postcranial characters support their relationship with allosaurids.

References[edit]

  1. ^ a b Rodrigo P. Fernandes de Azevedo, Felipe Medeiros Simbras, Miguel Rodrigues Furtado, Carlos Roberto A. Candeiro and Lílian Paglarelli Bergqvist (2013). "First Brazilian carcharodontosaurid and other new theropod dinosaur fossils from the Campanian–Maastrichtian Presidente Prudente Formation, São Paulo State, southeastern Brazil". Cretaceous Research 40: 131–142. doi:10.1016/j.cretres.2012.06.004. 
  2. ^ a b Stephen L. Brusatte, Roger B. J. Benson and Xing Xu (2011). "A reassessment of Kelmayisaurus petrolicus, a large theropod dinosaur from the Early Cretaceous of China". Acta Palaeontologica Polonica. in press (1): 65. doi:10.4202/app.2010.0125. 
  3. ^ a b Novas, Fernando E. (2013). "Evolution of the carnivorous dinosaurs during the Cretaceous: The evidence from Patagonia". Cretaceous Research 45: 174–215. doi:10.1016/j.cretres.2013.04.001. 
  4. ^ Holtz, Thomas R. Jr. (2012) Dinosaurs: The Most Complete, Up-to-Date Encyclopedia for Dinosaur Lovers of All Ages, Winter 2011 Appendix.
  5. ^ a b Brusatte, S., Benson, R., Chure, D., Xu, X., Sullivan, C., and Hone, D. (2009). "The first definitive carcharodontosaurid (Dinosauria: Theropoda) from Asia and the delayed ascent of tyrannosaurids." Naturwissenschaften, doi:10.1007/s00114-009-0565-2 PMID 19488730
  6. ^ Novas, de Valais, Vickers-Rich, and Rich. (2005). "A large Cretaceous theropod from Patagonia, Argentina, and the evolution of carcharodontosaurids." Naturwissenschaften,
  7. ^ Carlos Roberto Candeiro, Philip Currie and Lílian Bergqvist (2012). "Theropod teeth from the Marília Formation (late Maastrichtian) at the Paleontological Site of Peirópolis in Minas Gerais State, Brazil". Revista Brasileira de Geociências 42 (2): 323–330. doi:10.5327/z0375-75362012000200008. 
  8. ^ Rauhut, Oliver W. M. (2011). "Theropod dinosaurs from the Late Jurassic of Tendaguru (Tanzania)". Special Papers in Palaeontology 86: 195–239. doi:10.1111/j.1475-4983.2011.01084.x. 
  9. ^ Coria, R.A.; Currie, P.J. (2006). "A new carcharodontosaurid (Dinosauria, Theropoda) from the Upper Cretaceous of Argentina". Geodiversitas 28 (1): 71–118. 
  10. ^ Benson, R.B.J.; Carrano, M.T; Brusatte, S.L. (2010). "A new clade of archaic large-bodied predatory dinosaurs (Theropoda: Allosauroidea) that survived to the latest Mesozoic". Naturwissenschaften 97 (1): 71–78. Bibcode:2010NW.....97...71B. doi:10.1007/s00114-009-0614-x. PMID 19826771. 
  11. ^ Ortega, F.; Escaso, F.; Sanz, J.L. (2010). "A bizarre, humped Carcharodontosauria (Theropoda) from the Lower Cretaceous of Spain". Nature 467 (7312): 203–206. Bibcode:2010Natur.467..203O. doi:10.1038/nature09181. PMID 20829793.  Supporting Information
  12. ^ Eddy, Drew R.; Clarke, Julia A. (2011). Farke, Andrew, ed. "New Information on the Cranial Anatomy of Acrocanthosaurus atokensis and Its Implications for the Phylogeny of Allosauroidea (Dinosauria: Theropoda)". PLoS ONE 6 (3): e17932. Bibcode:2011PLoSO...6E7932E. doi:10.1371/journal.pone.0017932. PMC 3061882. PMID 21445312. 

External links[edit]