Stegosaurus was the largest of the Stegosauria, althought a few other species such as Dacentrurus could match or even perhaps exceed its length. It was 10-12 metres long, 3 metres tall and weighing 3-5 tonnes. It is one of the most easily recognisable dinosaurs, due to its tall plates and spiked tail. It was also one of the least intelligent dinosaurs - it had a brain the size of five walnuts!
Stegosaurus featured in the second episode of Walking with Dinosaurs - Time of the Titans. A male Stegosaurus arrived at a river, and then was attacked by an Allosaurus. It flushed its plates red, and scared the Allosaurus off. When the baby Diplodocuses ran past to escape the Allosaurus, it panicked, and, due to its small brain, killed one of the baby Diplodocus with its spiked tail.
Stegosaurus also featured in The Ballad of Big Al. Big Al was hunting a herd of Dryosaurus, but they were feeding near a Stegosaurus, and Big Al risked being killed by the Stegosaurus if he tried to get a Dryosaurus, so they survived. Stegosaurus is also seen on the fern prairies of the Jurassic during the special.
In Primeval S4 Prequel Episode 1, a Stegosaurus came out an anomaly and it went into a members bar in the House of Commons. It is unkown how many deaths it caused or returned back to its era. This was however not a real Stegosaurus. Its model was an Embolotherium that was reused and only its head was seen in low quality of the footage. The Scutosaurus and Gorgonopsid were also used in the footage of the Stegosaurus attack.