 Corythosaurus casuarius is one of a few lambeosaurines , along with Lambeosaurus lambei , Hypacrosaurus <unk> and H. <unk> , to have had surviving <unk> 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 were recognized from the formation 's area , when paleontologists used differences in size and crest shape to differentiate taxa . The smallest specimens were identified as Tetragonosaurus , now seen as a synonym of <unk> , and the largest skeletons were called either Corythosaurus or Lambeosaurus ; an adult was identified as Parasaurolophus . Small lambeosaurines from the Horseshoe Canyon Formation were referred to <unk> . 
