Utahraptor ostrommaysorum is a theropod dinosaur that roamed the Plains of North America during the upper Barremian Stage of the Early Cretaceous Period (130to 120 million years ago). The length of this carnivorous dinosaur is almost 23 feet and weighs at about 1,500 pounds. The diet of this animal is composed of meat and they hunt their prey with the help of their large claws on their feet. Utahraptor is the Greek term for Utah thief.
In 1975, fossils of this deadly raptor were discovered by Jim Jensen in the Dalton Wells Quarry in Utah’s east-central region but were disregarded by the scientific community. But when Carl Limoni has discovered a big foot-claw in October 1991, other scientists have also uncovered further skeletal remains in the Gaston Quarry in the Grand County Utah which is part of the Cedar Mountain Formation.
The large claws on their feet are distinguished characteristics of these meat-eating dinosaurs which they use to kill their prey. These claws make this dinosaur a very dangerous opponent and predator as when this large and pointed weapon caught their prey means death and meal for them.
Utahraptor ostrommaysorum is considered by many paleontologists as the largest raptor that has ever roamed the Earth with its almost 23 foot long length when measured from its head up to the tail. The weight of the utahraptor is almost half of a ton. The weight of this carnivore may not be enough when compared to those multi-ton sauropods and ornithopods of the Early Cretaceous Period. But when you realize the presence of another popular raptor, the Deinonychus (which starred in the Jurassic Park movies of Steven Spielberg) which weighed at about 200 pounds, the size of the utahraptor ostrommaysorum would be enough.
Given its massive size, the hind feet of the utahraptor ostrommaysorum were equipped with big single claws that corresponds their behemoth built. The length of the claws on the hind feet of the utahraptor is about a foot long and is very dangerous to any prey that they stalked. They used their claws to slash and rip their prey. A lot of scientists believe that the utahraptor ostrommaysorum have hunted like the saber-toothed tiger which inflict puncturing and deep gash wounds during sudden ambushes and suddenly withdraws from the ambush site leaving the unfortunate prey while bleeding to their end.
It very odd that the utahraptor ostrommaysorums lived for millions of ages before their more famous descendants of raptors, terrorizing a lot of quivering and running herbivores at the early stage of the Cretaceous Period rather than on the Late Cretaceous Period. It is more often to happen that tiny ancestors of dinosaurs will have descendants with massive sizes, but when it comes to the raptors, their evolution appeared to have different effect as they happened in reverse mode.
The utahraptor ostrommaysorum was closely related to Achillobator which is a raptor of the central Asian region. This big feathered theropod has roamed ancient Earth for almost 40 million years after the utahraptor ostrommaysorum.