They mostly lived on the east half of modern day North America, but their remains have also been discovered in Portugal which suggests that their range was wider than we originally believed to be.

Time Period:

Stegosaurus existed during the late Jurassic period, 155-150 million years ago. The Jurassic Period was the second of the three periods which made up the Mesozoic Era also known as the age of the dinosaurs. Reptiles were the dominant animals of the age. This period had some of the largest dinosaurs to have ever existed which is easy to see in dinosaurs like Stegosaurus.


They could reach up to 9 meters (30ft) long, 4 meters (13ft) tall (about the same size as a bus) and weighed roughly 2.3 metric tons.


These were herbivores which fed low to the ground on bushes and shrubs such as conifers and ferns and possibly on fruit which had fallen from the trees above

Interesting Facts:

Stegosaurus has proven itself to be one of the most popular dinosaurs over the years. Particularly with the media having featured in films like King Kong and Jurassic Park II. This is mostly due to their distinctive appearance which has been reconstructed easily thanks to the great quality of their fossils some of which include near-complete specimens.

Stegosaurus means ‘roofed lizard’ because it was believed that the large, bony, plates (scutes) along their backs and tails lay flat like a roof. However, we now know that their 17 scutes ran in two rows along their backs pointing upwards. These plates were similar to those found on modern day crocodiles and weren’t attached to the skeleton but embedded in their skin. Their most likely functions were controlling body temperature, helping members of the same species to recognise each other and to attract mates. They also had spikes on the sides of their tails which are thought to have been used in defence against their predators. Stegosaurus had short front legs and so would have walked with it’s head held low to the ground and with it’s tail held up in the air.