Lambeosaurus was a large hadrosaur with a distinctive crest. At 30-33 feet long and 3 tons in weight, it was an average sized herbivore. Some hadrosaur skeletons that may belong to Lambeosaurus have been found and they suggest larger sizes of nearly 40 feet and 5 tons, but they are not yet confirmed Lambeosaurus skeletons. It's crest is the shape of an ax blade, but was not a weapon. It was probably for display. Lambeosaurus lived in North America about 65-70 million years ago and would have been a likely prey item for Tyrannosaurus rex.