A carnivorous Utahraptor. With lethal claws, this five-metered killer is well armed and long fingers help them to latch on to swift moving larger prey.
— Allen, describing Utahraptor

Utahraptor (yoo-tar-rap-tore; meaning "Utah Thief") is the largest known member of the theropod dinosaur family Dromaeosauridae (raptor), and dates from the Early Cretaceous period (130-100). Utahraptor is known from a well-preserved skeleton found in 1991 in Utah, USA and fragmentary remains from South America.

It was 5-8 meters (15-24 feet) long in length, 2-3 meters in height, and 1000 kilograms in weight, it is the biggest member of its family found so far, much bigger than its later kin, such as the more famous Velociraptor. This size was great enough to enable these monstrous raptors the potential to attack, at best, even small Sauropods.

However, just like the later raptor species, Utahraptor was armed with sickle-like claws on its hind legs and it had self-replenishing teeth in its jaws (and also  on its wings.). Thus, these killers were well armed.



Utahraptor was not only the biggest, but also the oldest known dromaeosaur. It was the first raptor ever to evolve. It lived during the Early and through out the Middle Cretaceous period from 130100 million years ago. Hence it's name, it was discovered in the state of Utah and is known from a well-preserved skeleton found in 1991 in Utah, USA and fragmentary remains from South America.


Utahraptor was arguably the largest dromaeosaur that ever existed. They stood 6 feet (2 m) tall, measured 1524 feet long (5–8 m) and weighed in at over 1,500 lbs., as heavy as a bear. It was the largest of a group of lightlybuilt carnivores, called the dromaeosaurs (‘swift lizards’).

Utahraptor had large eyes and long grasping hands with large, sharp ripping claws. Its toe joints were specially enlarged so that its massive claw could be raised upward and backward to avoid damage while running.

But when used in attack, its huge slashing claw flexed forward as the animal kicked out. Swinging in a wide arc its huge 20 cm slashing claw would produce terrible wounds enabling a Utahraptor to cripple and kill animals much larger than itself.

With lethal claws, these five-meter killers were well armed, and long fingers allowed them to latch onto swift moving, larger prey. Raptors have the short legs of a sprinter and do not pursue their prey for long.

The unique wrist-joints of the dromaeosaurs allowed the hands to pivot sideways, an action similar to the folding of a bird’s wing.



Utahraptor pack eating a dead Iguanodon

Like all predatory dinosaurs and all species of raptors, even Utahraptor hunted in packs; in numbers of up to three individuals at least.

They also had a hard time going without a kill for more than over a week. Whenever they made a kill, they ate as much as 100 kilograms in each sitting and whenever they ate, there was a strict pecking order in their feasts, and the large adults come first, whereas they younger and weaker of the three Utahraptors would be nearby and they would have to wait their turn.