Millions and millions of years ago dinosaurs roamed the Earth. Then suddenly they all died out. Dinosaurs lived so very long ago, how do we know they really existed? How do we know what they looked like? We know from fossils. For a long time people didn't know about dinosaurs. At first they laughed at the idea of giant reptiles. But scientists kept gathering fossils and studying them, carefully piecing together evidence they needed to prove that dinosaurs really had existed. And with every find, they learned more and more about dinosaurs and their world.
