| Utahraptor | |
|---|---|
| |
| Reconstructed skeleton in BYU Museum of Paleontology | |
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Clade: | Dinosauria |
| Clade: | Saurischia |
| Clade: | Theropoda |
| Family: | †Dromaeosauridae |
| Clade: | †Eudromaeosauria |
| Subfamily: | †Dromaeosaurinae |
| Genus: | †Utahraptor Kirkland, Gaston & Burge, 1993 |
| Type species | |
| †Utahraptor ostrommaysi Kirkland et al., 1993
| |
Utahraptor (meaning "Utah's predator") is a genus of large dromaeosaurid (a group of feathered carnivorous theropods) dinosaur that lived during the Early Cretaceous period from around 135 to 130 million years ago in what is now the United States. The genus was described in 1993 by American paleontologist James Kirkland and colleagues with the type species Utahraptor ostrommaysi, based on fossils that had been unearthed earlier from the Cedar Mountain Formation of Utah. Later, many additional specimens were described including those from the skull and postcranium in addition to those of younger individuals.
The genus contains a single species, Utahraptor ostrommaysi. It is the largest-known member of the family Dromaeosauridae, measuring about 6–7 metres (20–23 ft) long and typically weighing less than 500 kilograms (1,100 lb), though some specimens may have exceeded 770 kilograms (1,700 lb). As a heavily built, ground-dwelling, bipedal carnivore, its large size and variety of unique features have earned it attention in both pop culture and the scientific community. The jaws of Utahraptor were lined with small, serrated teeth that were used in conjunction with a large "killing claw" on its second toe to dispatch its prey. Its skull was boxy and elongated, akin to other dromaeosaurids like Dromaeosaurus and Velociraptor.
Utahraptor is in the subfamily Dromaeosaurinae, which contained the biggest of the dromaeosaurs in the form of Utahraptor as well as Austroraptor, Dakotaraptor and Achillobator. Being a carnivore, Utahraptor was adapted to hunt the other animals of the Cedar Mountain Formation ecosystem such as ankylosaurs and iguanodonts. Evidence from the leg physiology supports the idea of Utahraptor being an ambush predator, in contrast to other dromaeosaurs that were pursuit predators.