The word corythosaur, also known as Corythosaurus, is a name given to a genus of fossilized dinosaur that lived during the late Cretaceous period. It is a bipedal herbivore that belonged to the family of duck-billed dinosaurs known as Hadrosauridae. Synonyms for the word corythosaur include Trachodon, Cheneosaurus, Lambeosaurus, and Procheneosaurus. These synonyms were given based on similarities in skeletal structure and anatomical features. Some of these creatures were massive in size, with fossil evidence suggesting they may have grown up to 30 feet long. They were once prevalent throughout North America, and their fossils have been found in modern-day Canada and the United States.