Sixth Grade
Worksheets
Chasmosaurus
Chasmosaurus (KAZ-moe-sore-uss) was a dinosaur that lived about 70 million years ago. It had a huge, knobby neck frill. There were small, sharp bones sticking out from the edges of the frill on each side of its face. It had three horns, like Triceratops, on its face. It had a parrot-like beak used for tearing off plants. At the back of its mouth were rows of flat teeth that were used for chewing. It was as long as a large car and taller than a man. It was a quadruped; it walked on four legs. Each foot had four short toes. Its body shape was most like that of today's rhinoceros.
What was the neck frill used for? Did it protect the dinosaur's neck from predators? Was it used for display - to make Chasmosaurus look bigger and more frightening to other dinosaurs in its herd or to attract mates? It may have been used for both those things.
The frills were not made of solid bone. There were large openings inside the outer framework of bone. These openings gave Chasmosaurus its name. The openings probably were covered with muscle tissue. This made the large frill lighter in weight than solid bone would have been, but it also made it less effective as protection.
