 <unk> have been found in the upper Oldman Formation and lower Dinosaur Park Formation of Canada . The Oldman Formation dates to the Campanian , about 77 @.@ 5 to 76 @.@ 5 million years ago , and the Dinosaur Park Formation dates from 76 @.@ 6 to 74 @.@ 8 million years ago . Corythosaurus lived from ~ 77 – 75 @.@ 7 million years ago . In the Dinosaur Park Formation C. casuarius lived from 76 @.@ 6 to 75 @.@ 9 mya , with C. intermedius living from 75 @.@ 8 to 75 @.@ 7 mya . In the Oldman Formation C. casuarius , the only species of Corythosaurus from the deposits , lived about 77 to 76 @.@ 5 mya . The holotype specimen was clearly a <unk> that had floated up on a beach , as <unk> shells , water @-@ worn bones , and a <unk> turtle were preserved all around . Corythosaurus probably lived in a woodland forest , and might have occasionally wandered into swampy areas . 
