描述
Hypacrosaurus at 30 ft long and weighing 4 tons was almost but not quite as large as Tyrannosaurus. It was a genus of duckbill dinosaur and had a tall, hollow rounded crest. It is known from the remains of two species from 75 to 67 million years ago from the Late Cretaceous of Alberta, Canada, and Montana, United States. It was an obscure genus until the discovery in the 1990s of nests, eggs, and hatchlings belonging to H.stebingeri.