Though it's hard to believe, dinosaurs existed for a staggering 150 million years - whereas humans, by comparison, have only been around for 3-4 million years.

Read about the first dinosaurs, such as Eoraptor and Herrerasaurus, that evolved in the Triassic period. Learn about the giant, long-necked sauropods like Diplodocus that stomped around in the Jurassic period and meet the fearsome predatory dinosaurs like T. rex that ruled the late Cretaceous period.