Kingdom Animalia
Phylum Chordata
Superclass Tetrapoda
Class Reptilia
Subclass Diapsida
Superorder Dinosauria
Order Saurischia
Suborder Theropoda
Family Dromaeosauridae
Subfamily Dromaeosaurinae
Genus Utahraptor
1st Species Utahraptor ostrommaysi
Other attributes
Time Range 128-123.5 mya
Location United States of America
Name Meaning Utah's thief
Physical Dimensions 5.3 meters long
Weight 471 kilograms
Dietary Classification Carnivore
Utahraptor is a dromaeosaurid theropod dinosaur from the Early Cretaceous of the United States of America. It was named in 1993 by James Kirkland, Robert Gaston, and Donald L. Burge. It was the biggest dromaeosaurid to ever exist, as well as one of the most unique.


Utahraptor was a heavily-built dromaeosaur, with a bulky body, semi-short, stocky legs with a sickle-shaped claw on each foot, moderately long arms with 3 fingers on each hand, a short neck, and a large head with a mouth filled with lots of teeth. In comparison to other dromaeosaurs (such as Velociraptor and Deinonychus), which were lightly-built, Utahraptor was extremely robust to the point where it had a passing resemblance to larger theropods such as Tyrannosaurus and Giganotosaurus. Most of its body (excluding some of its legs, all of its snout, and possibly all of its head and neck) would have been covered in long, vaned feathers.


Utahraptor was a predator, preying on mid-sized ornithischians, mid-sized sauropods, and smaller theropods. Its teeth had knife-like serrations from back to back, and its sickle claw was used for stabbing larger prey and restraining smaller prey.


Unlike the other raptors, which were very lightly-built (and in some cases, fleet-footed), Utahraptor was a large, hulking juggernaut; its stocky legs and heavy build probably impeded its movement, but also allowed it to withstand and dish out a lot of force on its prey items, as well as to drive its killing claw deeper into the skin of its prey items. Due to this extreme girth, Utahraptor was possibly able to hunt more powerful game, such as armored ankylosaurs like Gastonia or even larger herbivores such as Iguanacolossus and juvenile Cedarosaurus. A massive block of sandstone containing many Utahraptor suspended around a Hippodraco was once discovered, and most likely represented a quicksand trap where all the dinosaurs died; due to having so many Utahraptor individuals, this block of sandstone may lead people to believe that Utahraptor definitely hunted in packs. However, while pack-hunting is suitable for any theropod, it is possible that the raptors were simply led to the drowning Hippodraco before getting caught in the trap, and were independent of each other's influences.

In popular cultureEdit

Utahraptor was first introduced to the public through the 4th episode of the 1999 documentary Walking with Dinosaurs, where it is depicted with scaly skin and a similar build to Deinonychus (based on outdated research); while this was somewhat acceptable at the time, it was depicted as living in what is now Spain (as opposed to what is now its namesake home state, Utah) and hunting down Iguanodon in small packs. This was another blatant error, similar to the 25 meter, 150-tonne Liopleurodon, the 12 meter Tropeognathus (referred to as an "Ornithocheirus"), and the extremely fanciful head restorations of the Allosaurus and Tyrannosaurus.

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