One of the most popular and well-known dinosaurs, Stegosaurus was a very unique looking dinosaur, with its large armored plates and distinctive tail spines. It lived during the Jurassic Period (around 150 million years ago) in the same time and place as Allosaurus. Broken tail spines and wound marks in Allosaurus bones suggest that these two may have done battle with each other. Scientific Name: Stegosaurus (covered or roofed lizard) was named for the plates covering its back. Stegosaurus stenops is the type species. Characteristics: Stegosaurus is known from many complete skeletons, but the exact position of its tail spikes and dermal plates was long the subject of debate. It is now believed that the plates were arranged in an alternating pattern, with the tail spikes arranged in pairs, as our Stegosarusu toy depicts. Some paleontologists suggest that the arrangement of plates may have differed between Stegosaurus species.