Long ago, before there were any humans, there were dinosaurs. Dinosaurs lived on the earth for over 165 million years but then they strangely became extinct, this means they all stopped living.
There were lots of different kinds of dinosaurs that lived at different times. Some were huge and some were much smaller. Some dinosaurs could move quite quickly on two legs. Others walked on four legs in a slow and clumsy way. Some dinosaurs could fly. The biggest complete dinosaur found by historians is the Brachiosaurus. It was about the length of two large school buses. The smallest dinosaur, the Compsognathus, was about one metre long and slightly bigger than a chicken.
Different dinosaurs liked to eat different things. Dinosaurs like the Diplodocus liked to eat leaves and plants: these types of dinosaurs are called herbivores. Some dinosaurs like the T-Rex liked to eat meat: these types of dinosaurs are called carnivores.