Real Daspletosaurus were tyrannosaurs from Canada who lived during the Late Cretaceous period, from 77 to 74 million years ago. It was a close relative of Tyrannosaurus rex, but was a smaller and less powerful animal, reaching a length of 9 metres. It had the longest arms, in comparison to body size, of any tyrannosaur. Some scientists believe that these dinosaurs hunted in packs, like wolves and lions do today. The name Daspletosaurus means "frightful lizard".