Stegosaurus facts for kids

Meet Stegosaurus

Its name means roof lizard. Scientists first thought its plates lay flat along its back, like roof tiles.

It was a plant-eater about 9 metres long, with big bony plates along its back and spikes on its tail.

What were the plates and spikes for?

The plates along its back were set in its skin, not joined to its skeleton.

Stegosaurus probably swung its spiked tail to defend itself from meat-eaters such as Allosaurus. One fossil Allosaurus tail bone has a wound that matches the shape of a Stegosaurus spike. The spikes on the end of a Stegosaurus tail are nicknamed the thagomizer, a word first used in a cartoon.

How big was its brain?

Its head was small, and so was its brain: about the size of a plum, which is tiny for such a big animal.

When did Stegosaurus live?

In the Late Jurassic, about 150 million years ago, in what is now North America. It lived at the same time and in the same place as Diplodocus, Brachiosaurus and Allosaurus.

It never met T. rex. Stegosaurus had been gone for more than 70 million years when T. rex came along.

Stegosaurus in a nutshell

• Name means: roof lizard
• Lived: about 150 million years ago, in the Late Jurassic
• Ate: plants
• Length: about 9 metres
• Found in: USA and Portugal
• Lived at the same time as: Brachiosaurus, Diplodocus, Apatosaurus and Allosaurus

Quick quiz: Stegosaurus

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