Stegosaurus was an herbivore from the Jurassic. It may have eaten a variety of green plants including ferns, horsetails, and conifers. Some Scientist believed that the plates on its back allows it to cool down on hot days and warm up on cold days. It used its spiky tail as a weapon to deter large predators from eating them. It lived in North America during the Jurassic Period. Notable member is Morris.