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© NHM London/Nicholls ( 2014



You can see this dinosaur in the Museum.


A large, slow moving plant-eater, Stegosaurus would have defended itself from predators like Allosaurus and Ceratosaurus with its powerful spiked tail.

The bony plates along its back were embedded in the skin of the animal, not attached to its skeleton, which is why in most fossil finds the plates are separated from the body.

When O C Marsh described the first fossil of a Stegosaurus, he concluded that the plates would have lain flat on its back. After finding a specimen that had been covered with mud, which had held the plates in place, Marsh realised that they stood vertically, alternately on either side of the spine.

Scientists are not exactly sure what the plates were used for. They may have warned off predators, or allowed members of the same species to recognise each other. Another suggestion is that the plates were used to regulate body temperature.

There are tiny grooves in the plate surfaces, possibly where blood vessels would have been. The amount of blood passing through these vessels would determine the amount of heat transfer.

Compared with the rest of its body, Stegosaurus had a small head and its brain was around the size of a plum!

A new star specimen

The most complete Stegosaurus skeleton ever found went on display in the Museum’s Earth Hall in December 2014.

Identified as a member of the species Stegosaurus stenops, this spectacular specimen is helping researchers gain new insights into what Stegosaurus would have looked like when it was alive, as well as how it walked, ate and behaved.

  • Discover

    The world's most complete Stegosaurus skeleton

  • Buy

    Stegosaurus toys and games

  • Watch

    A time-lapse video of the Museum's new Stegosaurus skeleton being put together.

  • Investigate

    Explore dinosaurs with the same body shape as Stegosaurus in the Dino Directory

  • Extra

    There may be more details in Wikipedia

Fact file

Meaning of name
roof lizard
When it lived
Late Jurassic
(156 - 144 million years ago)
Found in

Taxonomic details

Dinosauria, Ornithischia, Genasauria, Thyreophora, Stegosauria, Stegosauridae, Stegosaurinae, Stegosaurus
Named by
Marsh (1877)
Type species