Corythosaurus

Corythosaurus (; ) is a genus of hadrosaurid "duck-billed" dinosaur from the Late Cretaceous period, about 77–75.7 million years ago, in what is now western North America. Its name is derived from the Greek word κόρυς, meaning "helmet", named and described in 1914 by Barnum Brown. Corythosaurus is now thought to be a lambeosaurine, thus related to Lambeosaurus, Nipponosaurus, Velafrons, Hypacrosaurus, and Olorotitan. Corythosaurus has an estimated length of and has a skull, including the crest, that is tall.

Corythosaurus is known from many complete specimens, including the nearly complete holotype found by Brown in 1911. The holotype skeleton is only missing the last section of the tail and part of the front legs, but was preserved with impressions of polygonal scales. Corythosaurus is known from many skulls with tall crests that resemble those of the cassowary and a Corinthian helmet. The most likely function of the crest is thought to be vocalization. As in a trombone, sound waves would travel through many chambers in the crest and then get amplified when Corythosaurus exhaled. One Corythosaurus specimen has even been preserved with its last meal in its chest cavity. Inside the cavity were remains of conifer needles, seeds, twigs, and fruits, suggesting that Corythosaurus probably fed on all of these.