 There were formerly up to seven species described , including C. casuarius , C. <unk> Parks 1935 , C. <unk> Parks 1935 , C. <unk> Gilmore 1923 , C. <unk> Parks 1935 , and C. intermedius Parks 1923 . In 1975 Peter Dodson studied the differences between the skulls and crests of different species of lambeosaurine dinosaurs . He found that the differences in size and shape may have actually been related to the gender and age of the animal . Now only one species is recognized for certain , C. casuarius , although C. intermedius has been recognized as valid in some studies . It is based on specimen ROM <unk> , a skull found by Levi Sternberg in 1920 and was named by William Parks in 1923 , who had originally named it <unk> intermedius earlier that year . The specific name of C. intermedius is derived from its apparent intermediate position according to Parks . C. intermedius lived at a slightly later time in the Campanian than C. casuarius , and the two species are not identical , which supported the separation of them in a 2009 study . 
