The document describes several types of dinosaurs. It notes that the stegosaurus was 9 meters long with bony plates on its back and spikes on its tail. It discusses herbivorous dinosaurs like Camarasaurus and Brachiosaurus and carnivorous dinosaurs like T-Rex, Allosaurus, and Allosaurus. The document states that many believe dinosaurs went extinct when a large meteor hit Earth, exploding on impact and wiping out half the dinosaur species. It also describes the Ankylosaurus as having stone-hard plates on its back and a powerful bonenocker tail club.