A mysterious dinosaur skull found in the Utah desert in 2004 is a new species, scientists say, and was "the Arnold Schwarzenegger of duck-billed dinosaurs." Gryposaurus monumentensis had such powerful jaws it could have chomped straight through tree branches, the New Scientist reports of the dinosaur, thought to have lived 75 million years ago in southern Utah.
Volunteers from a California museum found the skull at Grand Staircase Escalante National Monument and classified it as a duckbill. But paleontologists noticed it was different in monumental ways. The skull was bigger and had a shorter jaw than its nearest relatives. "When you shorten the jaw you increase power without increasing the size of the muscle," one scientist said.