Corythosaurus
by Corinne I.
Mysteries of the past are being uncovered almost everyday. One mystery of the past is a dinosaur called the Corythosaurus. The Corythosaurus was an herbivore. They normally walked and ran on two legs, but could also move or get lower to the ground by going on all four limbs. One characteristic of the Corythosaurus is the big rounded crest on its head giving it the name Corythosaurus that in Latin means, “Helmet lizard.” The Corythosaurus was a very interesting animal that lived long into the past. The Corythosaurus had a very distinct look. The Corythosaurus had a long duckbill. Also, it had a round crest on top of its head, sort of like a Mohawk. It was 6’ 6” at the hips and weighed around 5 tons! A paleontologist, Barnum Brown, found its fossils in 1914. In Montana, USA and Alberta, Canada fossils of the species of the Corythosaurus were found. They lived from 80 to 65 million years ago. You wouldn’t want to see anything that size walking around today!
The Corythosaurus evolved a lot of fabulous traits that made its life much easier. The Corythosaurus started as a vertebrate, or an animal with a backbone. It also developed the trait of having a jaw, meaning it was a gnathostome. After, getting jaws, the Corythosaurus developed four limbs to walk on letting it inherit the name tetrapod. Also, they evolved a watertight egg and became part of the group called amniotes. Next, the Corythosaurus inherited the name sauropsids, or a pair of openings in the palate. Then, it acquired a hole in the hip socket allowing it to be called a very common name today, dinosaurs. Subsequently, this dinosaur developed a trait called ornithischians, or a backward-pointed pubis bone. Finally, it split off into a very little group with his cousin, the Saurolophus; this group was called Ornithopods, or better chewing teeth. With these traits the Corythosaurus was able to live easily because the traits were much more advanced than others like the Ostracoderm, who only took on the role of a vertebrate in this cladogram.
The Saurolophus and the Corythosaurus were most closely related, and their most advanced trait was acquiring chewing teeth. The only dinosaurs that developed those chewing teeth were the Saurolophus and the Corythosaurus. I use the cladogram to find out the Corythosaurus’ closest relative by following the line back to the most advanced node, the closest node to the Corythosaurus when you travel up the line, then I looked at the other creature that branched off of the Corythosaurus’ most advanced node. If the Saurolophus had the same most advanced trait as the Corythosaurus, which proves that the Saurolophus had the same exact traits as the Corythosaurus. The only major difference between the Saurolophus and the Corythosaurus is the shape of the head. The Saurolophus’ head ended in a bony crest too, except it was a point, compared to the Corythosaurus’ head that had a bony crest that looked a lot like a flattened helmet and covered the top of its head. All though the Saurolophus and the Corythosaurus were formed by the same traits, they could still be told apart by their diverse bony head crests!
Last updated April 7, 2007.