Corythosaurus casuarius dinosaurs, illustration. This dinosaur lived during the Upper Cretaceous, about 80 million years ago in what is now North America. It belonged to the Hadrosaurus (duck-billed dinosaur) family and was a herbivore. Corythosaurus had a large bony crest on top of its head. The nasal passages extended into the crest, and are thought to have been used to amplify sounds made by the dinosaur. Corythosaurus measured about 10 metres in length and weighed up to 4 tonnes.