Corythosaurus dinosaur, illustration. This dinosaur lived in the Upper Cretaceous period, about 80 million years ago. It belongs to the Hadrosaurus (duck-billed dinosaur) family and was a herbivore. Corythosaurus had a large flattened 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.