The Thyreophora is a group of armoured dinosaurs, better known as the Stegosaurians and the Ankylosaurs, that lived between the Early Jurassic and the Late Cretaceous. They are characterized by their body armour, which had many shapes and size, like back plates and large osteoderms. Some species, especially within the Stegosaurians, had extensive numbers of spikes on their back, tail and sides that were often used as defence or display. In general, the group consisted of strictly herbivorous species.