Ankylosauruses have few natural predators, as their bony hides are covered in spiked nubs that jut in many different directions to discourage larger creatures from biting them. They have mighty tails ending in an immense knot of bone, which they use to whip at threats with incredible speed and power. While these low-to-the-ground dinosaurs can trample human-sized or smaller foes, their relatively squat stance prevents them from doing so against larger targets. An ankylosaurus is about 30 feet long, 10 feet tall at the shoulder, and weighs over 3 tons.