Utahraptor

Utahraptor

Diet : Carnivorous

Habitat : Plains of the north America

Length : About 18-20 feet (5.5-6 meters)

Weight : About 660 lb (300 kg)

In 2007 an amazing, narrow, two-toed footprint of a bipedal dinosaur was found in Cedar Mountain Formation, in Arches National Park. The footprint was left by a huge raptor (dromaeosaurid) and it seems only kind of dinosaur in western North America, in the Early Cretaceous times, have made such a track. It was Utahraptor. The skeletal remains of Utahraptor were found in the same area and in the same geological formation. Such large dromaeosaurid tracks are labeled as Dromaeopodus, the kind of footprints until now was known from Asia.

The remains of Utahraptor were discovered in 1991 in Grand County, Utah, in the Cedar Mountain Formation. Utahraptor ostrommaysi was then named for the American paleontologist J. Ostrom from Yale University. Utahraptor is famous for its raptorial, sickle claw, and may have been the biggest raptor that ever lived. Utahraptor lived well before some of its smaller but more famous raptor cousins like Velociraptor. In this case a larger ancestors came before smaller descendants, the reverse of typical evolutionary trends.