Temporal range: Early Cretaceous
Utahraptor ostrommaysorum for wikipedia by fredthedinosaurman-dbq2uyf.png
A restoration of Utahraptor ostrommaysorum
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Sauropsida
Superorder: Theropoda
Genus: Utahraptor
Kirkland, Gaston & Burge, 1993
Species: U. ostrommaysorum
Binomial name
Utahraptor ostrommaysorum
Kirkland, Gaston & Burge, 1993
Utahraptor (u·tah·rap·tor) is a dromaeosaurid from the Barremian Stage of the Early Cretaceous, living in what is now North America. Related to Deinonychus and Velociraptor, Utahraptor is the largest dromaeosaur known to science. Utahraptor is also a member of the Dromaeosaurinae, a group of dromaeosaurids that relied heavily on their jaws for killing prey rather than their claws alone. It is considered to be most closely related to Dromaeosaurus, Achillobator and Dakotaraptor among others based on cladistic analysis.

Physical AppearanceEdit

Utahraptor was a very large dromaeosaur. It was about 2-2.5 meters tall, 6 - 7 meters long, and weighed about 1,000 pounds /453 kg. It lived from 131 to 126 MYA during the Barremian Stage of the early cretaceous and is closely related to Achillobator and Dromaeosaurus. Its skeletal design was birdlike; with bones that were hollow, but strong. Recent fossil discoveries of more complete skeletons of Utahraptor by James Kirkland et al. paint a picture also of a dromaeosaur that was more heavily-built and stocky than the "typical" Deinonychus body plan generally associated with other dromaeosaurs. The legs were short and stocky, while the tail was also relatively short in comparison to that of related forms. The jaws were most unusual, with the front of the lower jaw bent forward and down in a case of convergence with the unrelated Masiakasaurus.

Utahraptor and other dromaeosaurs might have had binocular vision, like that of an eagle. Its hearing was probably excellent. Scientists recently discovered that raptors in general could best hear low frequency sounds. Dromaeosaurs like Utahraptor, regardless of size, were all covered in feathers according to cladistic analysis. Though feathers from the arms were known to be true feathers in other dromaeosaurs such as Dakotaraptor and Velociraptor, the rest of the dinosaur's plumage is speculative (though fossil finds of smaller species indicate protofeathers or true feathers, In Utahraptor, the exact plumage type is not known).

The feathers on the arms of young dromaeosaurids would have enabled a special type of locomotion called wing-assisted incline running, or WAIR for short. Discovered by Ken Dial, a Montana zoologist, this is a behavior used by modern birds that combines flapping the wings back and forth while running up the sides of trees. This flapping pushes the feet of the bird against the tree, allowing it to run vertically up the trunk. This indicates, but does not prove, that small dromaeosaurs lived part-time in the trees. In larger species, the wing feathers may have helped to maintain balance while attacking prey.


Utahraptor’s diet consisted predominantly of large herbivorous dinosaurs. In the formations where it was found (the Yellow Cat and Poison Strip members of the Cedar Mountain Formation, respectively), Utahraptor lived alongside such dinosaurs as Gastonia, Hippodraco, Cedrorestes, Iguanacolossus, Martharaptor, and Falcarius. Sauropods such as Venenosaurus and Cedarosaurus were also found here, as were other predators such as Nedcolbertia and Geminiraptor. Any one of these was a potential prey item, though the smaller animals such as Necolbertia would have been little in the way of a meal for such a predator as Utahraptor. As with all predators, Utahraptor likely targeted animals such as the infirm, weak and inexperienced. Scavenging was also a preferable opportunity when there was access to a carcass.

Speed and Agility Edit

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Utahraptor was likely an ambush predator. Given its robust, stocky build and short legs, it was not particularly fast, but given that its prey was likely slower, what it lacked in speed it made up for with power and agility.


Utahraptor's habitat was a series of floodplains and open woodlands with riverine forests. The wet season was short in this habitat and the climate was semi-arid. As Utahraptor was not fast, it likely used the available cover to lie in wait for prey.

Possible Social Nature Edit

The discovery of a group of six Utahraptor including a 16-foot adult, several juveniles and a 3-foot baby indicates pack-hunting might have been a possibility in this genus. The animals in question were pursuing prey that had become mired in quicksand when they themselves were trapped, leading to their death. The fossils were later found by Dr. James Kirkland et al., and are currently being studied, though progress is currently halted on the specimen after a decade of excavation. Whether all of the Utahraptor individuals were mired simultaneously or were lured in one-by-one is unclear, but the answer may yet come to light once crowdfunding efforts to bring in professional excavator Scott Madsen are completed.

In the Media Edit


Walking with Dinosaurs Utahraptor

Utahraptor appears in the Walking with Dinosaurs series shown hunting the herbivore Iguanodon.

Utahraptor makes an appearance in the 2008 video game Turok. They are most commonly a reddish color, but there are blue and green raptors as well. There are also grey colored Utahraptors, called Spitters, that have spines on its back and a yellow sac on its throat, and are capable of spitting acid, as well as Utahraptors that are albino that have pale white skin. Albino raptors are only active at night or in dark places.

Utahraptor new new

Primeval: New World Utahraptor

Turok Utahraptor

Turok Utahraptor

A Utahraptor appears in Jurassic Fight Club fighting a Gastonia.

It also appears in the popular PC game Zoo Tycoon 2 where it is inaccurately oversized.

In Primeval Series 1 ep 4, Helen Cutter mentions meeting a Utahraptor in the Jurassic, but in reality the dinosaur is actually from the Cretaceous. A Utahraptor is set to appear in Primeval: New World, where it fights a Pteranodon.

Jurassic Fight Club Utahraptor

An accurate version of Utahraptor appears in Dinosaur Revolution as a predator of Cedarosaurus.

The novel Raptor Red focuses on a female Utahraptor named Red.

Two panels of each Dinosaur Comics features a Utahraptor.There is a purple "Utahraptor" with yellow quills in Dinosaur King.

Utahraptor can be created in Jurassic Park: Builder. At first, it could only in the Jurassic card packs purchasable by real money. Since February 12th 2016, it became a DNA tournament limited edition. Unlike most dromaeosaurids in the Jurassic Park franchise, this depiction of Utahraptor has fur feathers all over its body and even wings.

Utahraptor can be created in Jurassic World: The Game. While it is accurately portrayed with a coat of feathers, it is shown inaccurately to be able to pronate it's hands.

the Utahraptor as anthromorphic in the Battlesaurs group in Toy Story That Time Forgot ,



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