Gorgosaurus is one of the best understood tyrannosaurs yet found. At 26-30 feet in length and 2 tons, it was one of the biggest predators in it's environment. It lived alongside the contemporary Daspletosaurus. Daspletosaurus was more robust than Gorgosaurus and likely preyed on more heavily armored prey like ceratopsians. Gorgosaurus would probably use it's speed to catch the faster hadrosaurs. Gorgosaurus may have run as fast as 25-30 miles per hour. Gorgosaurus lived in North America about 75 million years ago.