Carcharodontosauridae
From Wikipedia, the free encyclopedia
| Carcharodontosaurids Fossil range: Early-Late Cretaceous |
||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
 Giganotosaurus skeleton at the Australian Museum, Sydney
|
||||||||||||||||||
| Scientific classification | ||||||||||||||||||
|
||||||||||||||||||
| Genera | ||||||||||||||||||
|
Acrocanthosaurus? |
Carcharodontosaurids (from the Greek Carcharodontosauros: "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 exceeded Tyrannosaurus in size.
Contents |
[edit] Evolution
Along with spinosaurids, carcharodontosaurids were the largest predators in the early and middle Cretaceous throughout Gondwana (and Europe, if Neovenator is included), and also in North America (Acrocanthosaurus). Their ages range from the Barremian (127-121 million years ago) to the Cenomanian (99-93 million years ago). It's possible they were also present during the Turonian (93-89 million years ago).
However, past the Turonian, there seem to be no signs of the presence of these animals anywhere on the world. They were replaced by the smaller abelisaurids in Gondwana and by tyrannosaurids in North America. 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.[1]
[edit] Systematics
[edit] Taxonomy
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), though others place it in the related family Allosauridae (Currie & Carpenter, 2000; Coria & Currie, 2002). Neovenator may also be a member of the Carcharodontosauridae (Rauhut, 2003; Holtz et al., 2004).
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.[2]
- Family Carcharodontosauridae
- Genus Acrocanthosaurus
- Genus Carcharodontosaurus
- Genus Eocarcharia[3]
- Genus Neovenator
- Genus Tyrannotitan
- Subfamily Giganotosaurinae
- Genus Giganotosaurus
- Genus Mapusaurus
[edit] Phylogeny
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 placement of Acrocanthosaurus and Neovenator is unclear, with some researchers favoring Carcharodontosauridae and others favoring Allosauridae. Bahariasaurus has also been proposed as a carcharodontosaurid, but it's 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.
[edit] References
- ^ Novas, de Valais, Vickers-Rich, and Rich. (2005). "A large Cretaceous theropod from Patagonia, Argentina, and the evolution of carcharodontosaurids." Naturwissenschaften,
- ^ a b Coria, R.A., and Currie, P.J. (2006). "A new carcharodontosaurid (Dinosauria, Theropoda) from the Upper Cretaceous of Argentina." Geodiversitas, 28(1): 71-118.
- ^ Sereno, P.C. and Brusatte, S.L. 2008. "Basal abelisaurid and carcharodontosaurid theropods from the Lower Cretaceous Elrhaz Formation of Niger". Acta Palaeontologica Polonica 53 (1): 15–46.
