The Ultimate Dinosaur Wiki

Stegosaurus is one of the most famous dinosaurs. It lived in the Jurassic Period, 145 million years ago, and was hunted by Allosaurus.

Fact File

Length: 9 metres

Height: 3 metres

Weight: 3 tonnes

Diet: Herbivorous


Stegosaurus' main defence was its tail spikes. On its tail were four, metre long spikes, two on each side of the tail. It could swing its tail side to side, to impale an Allosaurus. Along its back there were also two rows of upright plates, however, these are too

Stegosaurus, showing plates and tail spikes

weak to be used in defence, and were probably temperature controllers. They may also had flushed red when the dinosaur was angry.


Stegosaurus was a plant-eater, and would have eaten low-growing ferns, and other plants, however some scientists argue that it could rear up on its hind legs, while balancing on its tail, and eat higher up vegetation like small trees. No-one is really sure whether it did this or not.


Stegosaurus was nine metres long, but its brain was the size of a walnut. In other words, Stegosaurus was stupid. Its brain was so small, in fact, that to control its body, it needed a second 'brain' by the hind legs. This 'brain' was actually a bundle of nerves, but it served the same purpose as the brain - controlling the body. While the brain controlled the front half of the dinosaur, the bundle of nerves controlled the back half, including the tail.

Popular Culture

Stegosaurus featured in Walking With Dinosaurs, and Walking With Dinosaurs: The Arena Spectacular, as well as The Lost World: Jurassic Park.

Stegosaurus in Walking With Dinosaurs: The Arena Spectacular