Utahraptor

Utahraptor; Temporal range: Early Cretaceous, 126 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
	Artist's impression
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Superorder:	Dinosauria
Order:	Saurischia
Suborder:	Theropoda
Family:	Dromaeosauridae
Genus:	Utahraptor; Kirkland, Gaston & Burge, 1993
Species
	U. ostrommaysi Kirkland, Gaston & Burge, 1993 (type);

Utahraptor (meaning "Utah's predator")^[1] is the second largest known member of the theropod dinosaur family Dromaeosauridae, and dates from the upper Barremian stage of the early Cretaceous period (about 126 million years ago).^[1]

Description

The holotype of Utahraptor is fragmentary, consisting of skull fragments, a tibia, claws and some caudal (tail) vertebra. The few elements suggest an animal about twice the size of Deinonychus.^[1] Like other dromaeosaurids, Utahraptor had a huge curved claw on the second toe; one is preserved at 22 centimetres (8.7 inches) in length and is thought to reach 24 centimetres (9.4 inches) restored. Up to 6.5 m (21 ft) long, 2 m (6.6 ft) tall, and 700 kg (1,500 lb) in weight, Utahraptor would have been a formidable predator.^[1]

It is thought that Utahraptor may be closely related to the much smaller Dromaeosaurus and the giant Mongolian dromaeosaurid Achillobator.^[1]^[2]

Discovery

James Kirkland, Rob Gaston, and Don Burge discovered Utahraptor in 1991 in Grand County, Utah, within the Yellow Cat and Poison Strip members of the Cedar Mountain Formation.^[1] The type specimen is currently housed at the College of Eastern Utah Prehistoric Museum, although Brigham Young University currently houses the largest collection of Utahraptor fossils.

The type species (and only known species of Utahraptor), Utahraptor ostrommaysi, was named for the American paleontologist John Ostrom, from Yale University's Peabody Museum of Natural History, and Chris Mays, of Dinamation International. Sculptor Raymond Persinger was included in James Kirkland's original abstract referencing Mr. Persinger's concepts regarding the claw structure.

In popular culture

Model of the foot, showing specialized claw

The novel Raptor Red, by Robert Bakker, tells the story of a Utahraptor from the perspective of the animal. Other speculative reconstructions of Utahraptor lifestyle and behavior were presented in the BBC television series Walking with Dinosaurs and the History series Jurassic Fight Club. Both of the television series portrayed Utahraptor as almost completely featherless, (apart from a small crest of feather spikes on their heads) and the History series contained further anatomical inaccuracies including pronated hands. Two Utahraptor appear as villains in The Land Before Time XI: Invasion of the Tinysauruses. A Utahraptor is one of the main characters in the webcomic Dinosaur Comics. This Utahraptor appears without feathers.

References

^ ^a ^b ^c ^d ^e ^f Kirkland, J.I., Burge, D., and Gaston, R. (1993). "A large dromaeosaur [Theropoda] from the Lower Cretaceous of Utah." Hunteria, 2(10): 1-16.
^ Turner, Alan H. (2007). "A basal dromaeosaurid and size evolution preceding avian flight". Science. 317: 1378–1381. doi:10.1126/science.1144066. PMID 17823350. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)

[Kirkland93-1] ^ ^a ^b ^c ^d ^e ^f Kirkland, J.I., Burge, D., and Gaston, R. (1993). "A large dromaeosaur [Theropoda] from the Lower Cretaceous of Utah." Hunteria, 2(10): 1-16.

[turneretal2007a-2] Turner, Alan H. (2007). "A basal dromaeosaurid and size evolution preceding avian flight". Science. 317: 1378–1381. doi:10.1126/science.1144066. PMID 17823350. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)

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