Real-world information
One of the most famous, popular and recognizable dinosaurs, Stegosaurus lived in North America during the Late Jurassic. Its remains have been found (among other places) at the Morrison Formation in the midwest United States.
Stegosaurus InGen File
Stegosaurus measured about 9 metres long and 4 metres tall (if the plates are included), and weighed around 4,5 tons. These lumbering beasts were herbivores, and are thought to have fed mostly on cycads. There has also been some speculation as to whether or not it could rear up on its hind legs to browse from taller foliage or intimidate predators.
It had an alternating row of large, asymmetrically arranged and sized plates running down its back. The purpose of these plates is unknown, but the inside of them contained a vast, honeycomb-like network of blood vessels. The plates were thin and delicate, meaning they were not true body armour, and so must've had another purpose. Suggested uses include sexual display and threat displays to predators (by pumping the plates full of blood to turn them red), and thermoregulation. Palaeontologist Robert Bakker has suggested that the plates may have been covered in horn.
Stegosaurus also had two pairs of thick, bony spikes on the end of its tail, that formed a structure called a thagomizer. Puncture wounds on an Allosaurus skeleton, as well as the fact that many Stegosaurus specimens have slightly damaged tail spikes, suggest that this was a defensive weapon, swung at attackers to discourage and/or injure them.
Stegosaurus also had a "mesh" of small bony studs just under the skin on its throat. It's thought that this worked as a sort of chainmail-like "neck guard", giving the dinosaur a bit of additional protection.
The brain of Stegosaurus was tiny (about the size of a walnut), and weighed around 80 grams.
JP Information
Despite its fearsome-looking tail spikes, Stegosaurus is actually quite docile (and a bit gullible) unless fending off predators or defending their young. These herbivores can live in large herds, small family groups, or even on their own. Stegosaurs are specialized cycad-eaters, and their digestive systems produce natural antidotes to counter all but the most potent of cycad toxins.
Perhaps due to slight degradation of the DNA strand over millions of years, InGen's Stegosaurus is considerably larger on average than typical specimens in the fossil record, measuring around 12 metres long and 4.5 metres tall.
In order to house Stegosaurus, you will need a large, well vegetated area consisting of a mix of open plains and forest. These dinosaurs also enjoy swimming and mud-bathing, so a large watering hole in the enclosure is ideal.
In-game Information
This dinosaur will be added in the next major update (2.2A).