Corythosaurus casuarius is one of a few lambeosaurines , along with Lambeosaurus lambei , Hypacrosaurus stebingeri and H. altispinus , to have had surviving fossilized juveniles assigned to it . Juveniles are harder to assign to species , because at a young age they lack the distinctive larger crests of adults . As they age , lambeosaurine crests tend to grow and become more prominent come maturity . In the Dinosaur Park Formation , over fifty articulated specimens have been found , coming from many different genera . Among them , juveniles are hard to identify at the species level . Earlier , four genera and thirteen species was recognized from the formation 's area , when paleontologists used differences in size and crest shape to differentiate taxa . The smallest specimens was identified as Tetragonosaurus , now seen as a synonym of Procheneosaurus , and the largest skeletons was called either Corythosaurus or Lambeosaurus ; an adult was identified as Parasaurolophus . Small lambeosaurines from the Horseshoe Canyon Formation was referred to Cheneosaurus .