2. Look at the picture of the ceratopsians above. What do they have in common? The most obvious similar characteristics they share is their heads and beaks. Besides their head, they had a few other characteristics that made a dinosaur belong to the ceratopsia family.

3. They were four legged herbivores. Earlier cousins of the ceratopsians didn’t have horns or frills on their heads. The later and more famous ones had horns and frills. Their jaws were shaped like a parrot’s beak.

4. The herbivores known as the ceratopsians (horned faces), lived mostly on North America. Some of the earlier cousins lived on Asia.

5. PssitacosauridaeProtoceratopsidaeCeratopsidae

7. Hey! Where are you going? We’re about to go meet all of the other ceratopsians. Here they come!

8. Psittacosaurus This Psittacosaurus (parrot lizard) was one of the earliest types of ceratopsian. It was between 3 and 6 feet (1-2 meters) long and between 50 and 175 pounds. They probably walked on four legs as a youth and two legs as an adult. They most likely cared for their young after they hatched.

9. Protoceratops The Protoceratops (first horned face) was about 6 feet (2 meters) long and weighed 400 pounds. Even though its name says otherwise, it did not have a horn on its face. It wasn’t even the first ceratopsian. They lived in large herds in Asia. Some of the herds had populations into the thousands. They were regular meals for the Tyrannosaurs and Raptors.

10. Torosaurus The Torosaurus (pierced lizard) was about 25 feet (7.5 meters) long and weighed about 4 tons. It had two long horns over its eyes and a huge frill. It lived on North America. The Triceratops was a close cousin and some paleontologists think the Torosaurus and Triceratops were the same dinosaur.

11. Triceratops The Triceratops (three-horned face) is one of the most famous of all dinosaurs. It was one of the last dinosaurs to die after the K/T event, when all of the dinosaurs went extinct. It was about 30 feet (9 meters) long and weighed 5 tons. Their skulls fossilize fairly easily and usually don’t break apart enabling better study. Some Triceratops skulls are worth millions of dollars! The T-rex enjoyed trying to eat a Triceratops every once in a while.

12. Centrosaurus Like the fictitious unicorn, the Centrosaurus had one large long horn on its nose. The horn was probably used to defend itself against predators and to fight with other Centrosaurus’. It lived in western North America. The Centrosaurus (pointed lizard) was about 20 feet (6 meters) long and weighed about 3 tons.

13. Chasmosaurus The Chasmosaurus (cleft lizard) was about 15 feet (4.5 meters) long and weighed about 2 tons. Its frill was enormous and rectangular but it had short and stubby horns. The Chasmosaurus lived at the same time and in the same places as the Centrosaurus. Scientists think the two ceratopsians were opposite in appearance so they would know to stay away from each other.

14. Styracosaurus The Styracosaurus (spiked lizard) was about 17 feet (5 meters) long and weighed about 3 tons. It had 6 large spikes coming out of its large frill, a large horn coming out of its nose, a large horn coming out of its nose, and two small horns sticking out of its cheeks. and two small horns sticking out of its cheeks. It lived between 70 and 75 million years ago, during the late Cretaceous Period.

15. Pentaceratops The Pentaceratops (five-horned face) was about 20 feet (6 meters) long and weighed 2-3 tons. Its head was about 10 feet (3 meters) long, making it one of the biggest heads of all time! It lived during the late Cretaceous Period, between 65 and 75 million years ago. Like other ceratopsians, it had teeth in its cheek enabling it to chew many kinds of plants.

16. T-rex vs. Triceratops  Weighed 7-8 tons  Ferocious bite with many sharp teeth  Great sense of smell, sight, and hearing  Horrible breath  Extremely short arms  Weighed 3-4 tons  Two sharp horns on its head and one on its nose  Low to the ground making it hard to knock over  Large protective frill  Not very smart Using what you know about the two dinosaurs, which one do you think would win in a fight? Explain your answer on the next page.

17. T-rex vs. Triceratops ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________

18. Chasmosaurus and Centrosaurus Scientists think the two ceratopsians were opposite in appearance so they would know to stay away from each other. Can you observe some of the ways they were different in appearance? Can you think of some other reasons they would evolve to be opposite in appearance?

19. Chasmosaurus and Centrosaurus ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ Name _________________ Date _________________