Stegosaurus

Stegosaurus Temporal range: Late Jurassic, 155–150 Ma PreЄ Є O S D C P T J K Pg N ↓
Mounted skeleton of S. stenops, Natural History Museum, London
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Clade:	Dinosauria
Order:	†Ornithischia
Suborder:	†Stegosauria
Family:	†Stegosauridae
Subfamily:	†Stegosaurinae
Genus:	†Stegosaurus Marsh, 1877
Type species
†Stegosaurus stenops Marsh, 1887
Other species
†S. ungulatus Marsh, 1879 †S. sulcatus Marsh, 1887
Synonyms
Hypsirhophus Cope, 1879 Diracodon Marsh, 1881

Stegosaurus (/ˌstɛɡəˈsɔːrəs/) is a genus of armored dinosaur. Fossils of this genus date to the Late Jurassic period, where they are found in Kimmeridgian to early Tithonian aged strata, between 155 and 150 million years ago, in the western United States and Portugal. Several species have been classified in the upper Morrison Formation of the western U.S, though only three are universally recognized; S. stenops, S. ungulatus and S. sulcatus. The remains of over 80 individual animals of this genus have been found.Stegosaurus would have lived alongside dinosaurs such as Apatosaurus, Diplodocus, Brachiosaurus, Allosaurus, and Ceratosaurus; the latter two may have been predators of it.

These were a large, heavily built, herbivorous quadrupeds with rounded backs, short fore limbs, long hind limbs, and tails held high in the air. Due to their distinctive combination of broad, upright plates and tail tipped with spikes, Stegosaurus is one of the most recognizable kinds of dinosaur. The function of this array of plates and spikes has been the subject of much speculation among scientists. Today, it is generally agreed that their spikes were most likely used for defense against predators, while their plates may have been used primarily for display, and secondarily for thermoregulatory functions. Stegosaurus had a relatively low brain-to-body mass ratio. It had a short neck and a small head, meaning it most likely ate low-lying bushes and shrubs. One species, Stegosaurus ungulatus, is the largest known of all the stegosaurians (bigger than related dinosaurs such as Kentrosaurus and Huayangosaurus).