Tetanurae

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Tetanurans
Temporal range:
Late Triassic–Present, 201–0Ma
Sinosaurus triassicus skull.JPG
Skeleton of the basalmost tetanuran, Sinosaurus triassicus
Keel-billed toucan woodland.jpg
Keel-billed Toucan perched on a branch
Scientific classification e
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Suborder: Theropoda
Clade: Averostra
Clade: Tetanurae
Gauthier, 1986
Subgroups[2][3]
Synonyms

Avipoda Novas, 1992

Tetanurae, or "stiff tails", is a clade that includes most theropod dinosaurs, including birds. Tetanurans (or tetanurines) first appear during the early or middle Jurassic Period.

Definition[edit]

Illustration of a megalosauroid (Monolophosaurus)

Tetanurae meaning "stiff tails", was named by Jacques Gauthier on cladistic grounds in 1986 for a large group of theropod dinosaurs. Gauthier's paper was the first serious application of the science of cladistics to vertebrate paleontology.

Tetanurae are defined as all theropods more closely related to modern birds than to Ceratosaurus (e.g. Padian et al., 1999). Gauthier considered it to consist of Carnosauria and Coelurosauria, although many of what he considered carnosaurs have been regarded as coelurosaurs or basal tetanurans by subsequent workers (but see Rauhut, 2003). Paul Sereno (1999) named Neotetanurae for the node joining Carnosauria (his Allosauroidea) and Coelurosauria, excluding other tetanurans such as megalosauroids. Padian et al. (1999) gave a synonymous definition for Gregory Paul's (1988) Avetheropoda, but this definition was published slightly later.

Classification[edit]

The cladogram presented below follows a phylogenetic analysis published by Zanno and Makovicky in 2013.[4]

Tetanurae

Cryolophosaurus



Sinosaurus




Chuandongocoelurus



Monolophosaurus


Orionides
Megalosauroidea

Piatnitzkysauridae


Megalosauria

Spinosauridae



Megalosauridae




Avetheropoda

Coelurosauria


Allosauroidea

Metriacanthosauridae


Allosauria

Allosauridae


Carcharodontosauria

Neovenatoridae



Carcharodontosauridae









Range[edit]

It is not entirely clear where the origins of Tetanurae are. Cryolophosaurus has been claimed as the first true member of the group (although this identification has been disputed and Cryolophosaurus may be closer to the dilophosaurids). Even if Cryolophosaurus was a tetanuran, this leaves no true tetanuran fossils from the Triassic, when the group should have originated based on the presence of coelophysoids (if the old definition of Ceratosauria is used). This gives heavier validity to the more recent view of tetanurans and ceratosaurs sharing a common ancestor and forming a clade of advanced theropods together.

Large, predatory spinosaurids and allosaurids flourished during the Late Jurassic and Early Cretaceous, especially in Gondwana, but seem to have died out before the end of the Cretaceous, possibly due to competition from abelisaurid ceratosaurs and tyrannosaurid coelurosaurs. The diverse coelurosaurs persisted until the end of the Mesozoic Era, when all except for crown clade avians died out. Modern birds are the only living representatives of the clade Tetanurae.

References[edit]

  1. ^ Benson, R. B. J.; Radley, J. D. (2010). "A New Large-Bodied Theropod Dinosaur from the Middle Jurassic of Warwickshire, United Kingdom". Acta Palaeontologica Polonica 55: 35. doi:10.4202/app.2009.0083.  edit
  2. ^ Hendrickx, C.; Mateus, O.V. (2014). Evans, Alistair Robert, ed. "Torvosaurus gurneyi n. sp., the Largest Terrestrial Predator from Europe, and a Proposed Terminology of the Maxilla Anatomy in Nonavian Theropods". PLoS ONE 9 (3): e88905. doi:10.1371/journal.pone.0088905. PMC 3943790. PMID 24598585.  edit
  3. ^ Carrano, M. T.; Benson, R. B. J.; Sampson, S. D. (2012). "The phylogeny of Tetanurae (Dinosauria: Theropoda)". Journal of Systematic Palaeontology 10 (2): 211–300. doi:10.1080/14772019.2011.630927.  edit
  4. ^ Zanno, L. E.; Makovicky, P. J. (2013). "Neovenatorid theropods are apex predators in the Late Cretaceous of North America". Nature Communications 4. doi:10.1038/ncomms3827.  edit