The largest dinosaurs were herbivores (plant-eaters), such as "Apatosaurus" and "Brachiosaurus". They were the largest animals to ever walk on dry land. Other plant-eaters such as Iguanodon had special weapons, to help them fight off the meat-eaters. For example, "Triceratops" had three horns on its head shield, "Ankylosaurus" was covered in boney plates, and "Stegosaurus" had spikes on its tail.