Stegosaurs

Stegosaurs were four-legged plant-eaters with two rows of plates or spikes along the back and sharp spikes on the tail. The tail spikes, nicknamed the thagomizer, were a defense against predators like Allosaurus.

They were most common in the Jurassic, in North America, Europe, Africa and China. Stegosaurus is the best known, with a small head and large, upright plates. Kentrosaurus from Tanzania had narrower plates that turned into spikes toward the tail.