Welcome to the Jurassic period! This is the Middle Age of the Dinosaurs, which began about 210 million years ago and lasted for 70 million years. Some of the largest and fiercest creatures roamed the earth at this time. Click on a dinosaur to learn all about it! When you’ve learned something about a bunch of dinosaurs, you might be ready to take our Jurassic quiz or play our Jurassic games.