Anatomy: This ornithischian (bird-hipped) dinosaur had a bulky body, a very long skull with a frill (5 feet or 1.5 m long), a toothless beak, blunt cheek teeth, and a short tail. The openings in the bone of the frill were large, indicating that the frill was used more as a display than as a defense. Chasmosaurus was up to 16-26 feet tall (5-8 m) long. It weighed roughly 3.5 tons (3220 kg).

Fossils: Chasmosaurus was named in 1914 by Canadian paleontologist Lawrence Lambe. The type species is C. belli. Many fossils of this ceratopsian dinosaur have been found, in Alberta, Canada, and Texas, USA.