 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 <unk> . Their associating was found in the Dinosaur Park , Judith River , and <unk> formations , and also in the Wind River Basin and the <unk> County area . Corythosaurus lived alongside numerous other giant herbivores , such as the hadrosaurids Gryposaurus and Parasaurolophus , the ceratopsids Centrosaurus and Chasmosaurus , and <unk> Scolosaurus , <unk> and <unk> in the earliest stages of the formation , <unk> , <unk> and <unk> in the middle age , and <unk> 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 <unk> <unk> <unk> and an unnamed species of Daspletosaurus . 
