Allosaurus was one of the largest carnivores of the late Jurassic. At 26-33 feet long and 1.5-3 tons, it was massive. These predators also had massive claws. The claws on their hands were nearly 7 inches long! Some evidence suggests Allosaurus was a group hunter. Allosaurus was the most common large theropod of the late Jurassic by far. It lived 150 million years ago and it's remains have been found in North America, Africa, and Europe.