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Caenagnathus

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Caenagnathus
Temporal range: Late Cretaceous, 75 Ma
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Saurischia
Clade: Theropoda
Superfamily: Caenagnathoidea
Family: Caenagnathidae
Subfamily: Caenagnathinae
Genus: Caenagnathus
Sternberg, 1940
Species:
C. collinsi
Binomial name
Caenagnathus collinsi
Sternberg, 1940

Caenagnathus ('recent jaw') is a genus of oviraptorosaurian dinosaur from the late Cretaceous (75 million years ago). It is known from a single lower jaw, found in the Dinosaur Park Formation of Alberta, Canada.

Classification

This dinosaur has a confusing history. In 1936, a set of jaws were found, and later given the name Caenagnathus, meaning 'recent jaw'; they were first thought to be those of a bird.[1] In 1988, a specimen from storage since 1923 was discovered and studied. This fossil were used to link the discoveries of several fragmentary oviraptorosaur species into a single dinosaur, which was assigned to the genus Chirostenotes, originally named for a pair of hands that were long considered to come from the same animal as Caenagnathus. Since the first name applied to any of these remains was Chirostenotes, this is the only name that is recognized as valid.[2] However, further study cast doubt on the idea that all of these fossils belonged to the same creature: while Chirostenotes was an advanced oviraptorosaurian and possibly an oviraptorid, Caenagnathus was shown to have been a more primitive animal.[3]

Recently, it was found that Caenagnathus is probably the closest related genus of Anzu. The possible species, found in the study to be "Caenagnathus" sternbergi, was found to be sister taxon to the grouping of Anzu and Caenagnathus collinsi. When species known only from limb bones, such as the potential synonym Chirostenotes pergracilis, were included in the analysis, the relationships among these species became unresolved. The authors of the analysis stated that further study would need to be done in order to match species known from limb bones with those known from jaw bones as potential synonyms.[4]

Caenagnathoidea
Caenagnathidae

Microvenator celer

Gigantoraptor erlianensis

Caenagnathasia martinsoni

Alberta dentary morph 3

Leptorhynchos gaddisi

"Caenagnathus" sternbergi

Anzu

Caenagnathus collinsi

Oviraptoridae

References

  1. ^ Sternberg, R.M. (1940). A toothless bird from the Cretaceous of Alberta. Journal of Paleontology 14(1):81-85.
  2. ^ Currie, P.J., and Russell, D.A. (1988). Osteology and relationships of Chirostenotes pergracilis (Saurischia, Theropoda) from the Judith River (Oldman) Formation of Alberta, Canada. Canadian Journal of Earth Sciences 25:972-986.
  3. ^ Holtz, Thomas R. Jr. (2010) Dinosaurs: The Most Complete, Up-to-Date Encyclopedia for Dinosaur Lovers of All Ages, Winter 2010 Appendix.
  4. ^ Attention: This template ({{cite doi}}) is deprecated. To cite the publication identified by doi:10.1371/journal.pone.0092022, please use {{cite journal}} (if it was published in a bona fide academic journal, otherwise {{cite report}} with |doi=10.1371/journal.pone.0092022 instead.
  • Cracraft, J. 1971. Caenagnathiformes: Cretaceous birds convergent in jaw mechanism to dicynodont reptiles. Journal of Paleontology 45:805-809.
  • Senter, P.; Parrish, J.M. (2005) Functional analysis of the hands of the theropod dinosaur Chirostenotes pergracilis: evidence for an unusual paleoecological role. PaleoBios 25: 9–19
  • Sues, H.D., 1997, "On Chirostenotes, a Late Cretaceous oviraptorosaur (Dinosauria: Theropoda) from Western North America", Journal of Vertebrate Paleontology 17(4): 698-716