Dinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, Learn about dinosaurs with KidsDinos. Find out which dinosaur was the largest, which was the smallest, which had the most horns, the longest neck. Mad about dinosaurs? Now you can see them in 3D, get the facts in our dino directory, test yourself in our quiz and play the games that bring them to life.