| Triceratops used its giant, bony frill on its head to defend itself against predators and to compete against other dinosaurs. The plant-eating, three-horned, massive sized Triceratops roamed westren North America and parts of Asia about 65 to 70 million years ago during the end of the Cretaceous Period. |
Tyrannosaurus Rex is easily one of the most recognizable of all the dinosaurs. It is also one of the largest meat-eating dinosaurs with a voracious appetite. The most complete T-Rex skeleton ever preserved can be found at the Field Museum of Natural History in Chicago, IL. Her name is Sue. |
Stegosaurus' name means “roofed lizard.” Early paleontologists thought its armored plates looked like the shingles on a roof. Despite Stegosaurus being up to nine feet tall, about 30 feet long, and weighing up to 7,000 pounds, this gargantuan plant-eating dinosaur had a brain the size of a walnut. |
Allosaurus’ name means “different lizard.” It was one of the most dangerous predators during the Jurassic period. Discovered by scientist Othniel C. Marsh, the Allosaurus was one of the earliest dinosaurs discovered, making their fossils plentiful for amateur paleontologists and fossil hunters. |
Scientists still debate the purpose of Iguanodon’s thumb spikes to this very day. Combat? Feeding? A display of friendly approval? Paleontologists think that these spiked thumbs were used as a defense against predators while others believe the thumbs were a tool for eating vegetation. |
| Ankylosaurus was a massive dinosaur, weighing up to four tons. Its wide, flat body and heavy armor made it a tough mouthful for potential predators. Ankylosaurus lived about 70 million years ago during the Cretaceous Period. Scientist Barnum Brown discovered it in the early 1900s. |
The discovery of Deinonychus fossils bearing quill knobs suggests that it and its relatives may have been feathered like birds. This vicious hunter has retractable claws on each foot that it used to inflict stab wounds on its prey. Deinonychus was nearly twice the size of the Velociraptor. |
The research of historian Adrienne Mayor suggests that Protoceratops fossils may have given rise to ancient Greek legends of griffins. This plant-eating dinosaur weighed about 400 pounds and had a frill on its head. Its main enemy during the Cretaceous period was the Velociraptor. |
Pachycephalosaurus had a thick, domed skull that may have been used in head-butting contests for dominance. This was a plant-eating dinosaur that was about 15 feet long and weighed up to 1000 pounds. This massive dinosaur lived during the Cretaceous period about 70 million years ago. |
The gigantic, meat-eating Spinosaurus hunted in both land and water, much like a modern crocodile does. Spinosaurus had 7-foot long spines growing on its back that resembled a sail on a boat. This was one of the very few dinosaurs capable of swimming and had a diet of fish and carcasses. |
