Tyrannosaurius Rex

Dinosaurs lived on earth from about 227 million to 65 million years ago. Scientists call this the Mesozoic era. It is also called the Age of Reptiles or the Age of Dinosaurs. Dinosaurs were closely related to today's reptiles and birds. In fact, many scientists now think that birds evolved from a small meat-eating dinosaur that was a swift runner. All dinosaurs were land animals. This title of the Discovering Dinosaur series explores the Triceratops, a plant-eating animal, alongside detailed full-color illustrations.