 Corythosaurus casuarius is widespread throughout the lower unit of the Dinosaur Park Formation . In it , Corythosaurus was found to be closely associated with the ceratopsid Centrosaurus apertus . Their associating was found in the Dinosaur Park , Judith River , and Mesaverde formations , and also in the Wind River Basin and the Wheatland County area . Corythosaurus lived alongside numerous other giant herbivores , such as the hadrosaurids Gryposaurus and Parasaurolophus , the ceratopsids Centrosaurus and Chasmosaurus , and ankylosaurids Scolosaurus , Edmontonia and Dyoplosaurus in the earliest stages of the formation , Dyoplosaurus , Panoplosaurus and Euoplocephalus in the middle age , and Euoplocephalus alone in later stages of the formation . Studies of the jaw anatomy and mechanics of these dinosaurs suggests they probably all occupied slightly different ecological niches in order to avoid direct competition for food in such a crowded eco @-@ space . The only large predators known from the same levels of the formation as Corythosaurus are the tyrannosaurids Gorgosaurus libratus and an unnamed species of Daspletosaurus . 
