Chirostenotes
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 life restoration of Chirostenotes pergracilis
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Chirostenotes (pronounced KIE-ro-Sten-o-teez, named from greek 'narrow-handed') was an oviraptosaur from the late Cretaceous (80 million years ago) of Alberta, Canada. It was characterized by a beak, long arms ending in powerful claws, long, slender toes and a tall, rounded cassowary-like crest or casque. Chirostenotes was probably an omnivore or herbivore, although the beak is not as heavily constructed as in the asian Oviraptoridae. The type species is Chirostenotes pergracilis. A smaller species, C. elegans, has also been named from Alberta,[1] although it probably belongs to the closely-related Elmisaurus.[2] A large skeleton from the Horseshoe Canyon Formation has been referred to Chirostenotes pergracilis, although it may represent a new species. The first Chirostenotes was found in the Dinosaur Park Formation of Canada, which has yielded the most dinosaurs of any Canadian formation.
This dinosaur has a confusing history. It was given its first name, Chirostenotes, when a pair of hands were found in 1924.[3] The feet were then found, in 1932 and given the name Macrophalangia, meaning 'large toes'.[4] Later, they were correctly recognized as part of a meat-eating dinosaur but no-one was sure if they were from the same species. In 1936, its jaws were found and given the name Caenagnathus, meaning 'recent jaw' (the family of oviraptorosaurs containing Chirostenotes, the Caenagnathidae, still carries this name); they were first thought to be those of a bird.[5] In 1988, a specimen from storage since 1923 was discovered and studied. This fossil helped link the other discoveries into a single dinosaur. Since the first name applied to any of these remains was Chirostenotes, this is the only name that is recognized as valid.[6]
In life, the animal was about 9.5 feet long and 3 feet tall at the hips. It had an estimated weight of about 110 pounds. It probably ate small reptiles and mammals, as well as plants, eggs and insects.
Also, a set of jaws with strange teeth were originally thought to be part of Chirostenotes but, now that it is known that Chirostenotes was a toothless oviraptorosaur, the jaws have been renamed Ricardoestesia and are from an otherwise unknown dinosaur.[7]
[edit] References
- ^ Parks, W.A. (1933). New species of dinosaurs and turtles from the Upper Cretaceous formations of Alberta. University of Toronto Studies, Geological Series 34:1-33.
- ^ Currie, P.J. (1989). The first records of Elmisaurus (Saurischia, Theropoda) from North America. Canadian Journal of Earth Sciences 26(6):1319-1324.
- ^ Gilmore, C.W. (1924). A new coelurid dinosaur from the Belly River Cretaceous of Alberta. Canada Department of Mines Geological Survey Bulletin (Geological Series) 38(43):1-12.
- ^ Sternberg, C.M. (1932). Two new theropod dinosaurs from the Belly River Formation of Alberta. Canadian Field-Naturalist 46(5):99-105.
- ^ Sternberg, R.M. (1940). A toothless bird from the Cretaceous of Alberta. Journal of Paleontology 14(1):81-85.
- ^ 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.
- ^ Currie, P.J., Rigby, Jr., J.K., and Sloan, R.E. (1990). Theropod teeth from the Judith River Formation of southern Alberta, Canada. In: Carpenter, K., and Currie, P.J. (eds.). Dinosaur Systematics: Perspectives and Approaches. Cambridge University Press:Cambridge, 107-125. ISBN 0-521-36672-0.
