Temporal range: Middle Jurassic - Early Cretaceous
Known colloquially as stegosaurs, the Stegosauria are a group of herbivorous dinosaurs of the Jurassic and Early Cretaceous Periods, being found mostly in the Northern Hemisphere, predominantly in what is now North America and China. Their geographical origins are unclear; the earliest stegosaurs have been found in China, although fragmentary material hails from southern England. The genus Stegosaurus, from which the group acquires its name, is by far the most famous stegosaurian. Stegosaurids appeared in the Middle Jurassic, 165 mya and died out in the Early Cretaceous, 125 mya.
All stegosaurs have rows of special bones, called osteoderms, which develop into plates and spines along the back and tail (forming the so-called "thagomizer"). Many also have intermediate spines, called 'splates'.
Stegosauria ├──Huayangosaurus └──Stegosauridae └──┬─?Chungkingosaurus └──┬──Chialingosaurus └──┬──┬──Wuerhosaurus │ └──┬──Dacentrurus │ └──Hesperosaurus └──┬──Tuojiangosaurus └──┬──┬──Kentrosaurus │ └──Lexovisaurus └──┬──Stegosaurus stenops └──S. ungulatus (=?S. armatus)