8 sacrals, and 61+ caudals; possession of dorsal spines of a medium height; high anterior caudal spines; long chevrons; long scapulae, possessing a blade of medium width; a radius considerably longer than humerus; comparatively short metacarpals; an anteriorly decurved ilium; a long ischium with a foot-like terminal expansion; a pubis with an anterior blade that is short and broadly expanded at end; a femur that is longer than the tibia; the phalanges of pes are short; that the integument over the sides and tail composed of polygonal tuberculate scales without pattern but graded in size in different parts of the body; and a belly with longitudinal rows of large conical limpet-like scales separated by uniformly large polygonal tubercles. Again, the presumed traits of the snout are incorrect because Brown confused the praemaxillae with the nasal bones and the nasal bones with the frontals. Most of the postcranial traits are today known to be shared with other lambeosaurines. Classification Originally, Brown referred to Corythosaurus as a member of the family Trachodontidae (now Hadrosauridae). Inside Trachodontidae were the subfamilies Trachodontinae and Saurolophinae. Brown classified Hadrosaurus, Trachodon, Claosaurus, and Kritosaurus in Trachodontinae, and Corythosaurus, Stephanosaurus, and Saurolophus in Saurolophinae. Later, Brown revised the phylogeny of Corythosaurus, and found that it was closely related, and possibly ancestral to Hypacrosaurus. The only differences he found between them were the development of the vertebrae, and the proportions of the limbs. During a study of dinosaurian ilia in the 1920s, Alfred Sherwood Romer proposed that the two orders of dinosaurs might have evolved separately, and that birds, based on the shape and proportions of their ilia might truly be specialized ornithischians. He used both Tyrannosaurus and Corythosaurus as a base model to analyze which theory is more likely true. He found that even though birds are thought of as saurischians, it is very plausible for them to have evolved their specific pelvic musculature and anatomy if they evolved from ornithschians like Corythosaurus. However, even though the pelvic structure of Corythosaurus and other Ornithischians does bear a greater superficial resemblance to birds than the Saurischian pelvis does, birds are now known to be highly derived Maniraptoran theropods. Corythosaurus is currently classified as a hadrosaurid, in the subfamily Lambeosaurinae. It is related to other hadrosaurs such as Hypacrosaurus, Lambeosaurus and Olorotitan, with the exception of Olorotitan they all share similar looking skulls and crests. However, research published in 2003