Stegosaurus Facts for Kids
STEG-oh-SORE-us · its name means “roofed lizard”
Big plates down its back and spikes on its tail.
Stegosaurus had big flat plates on its back. Its tail had sharp spikes. It ate plants close to the ground.
Stegosaurus had two rows of tall, flat plates along its back and four long spikes at the end of its tail. Its head was small and low to the ground, just right for nibbling ferns.
Its name means roofed lizard, because the first scientists thought the plates lay flat like roof tiles. Today scientists think the plates stood upright and may have helped it show off or warm up in the sun. The tail spikes were for defense. Stegosaurus lived long before T. rex.
Every dinosaur number is scientists’ best guess from bones, so each one says where it came from.
How big was Stegosaurus?
Stegosaurus in numbers
| Length (nose to tail) | 30 ft9 m1scientists' estimate |
|---|---|
| Height at the hips | no checked number yet |
| Weight | no checked number yet |
| When it lived | 150 million years ago150 million years ago2about; the Late Jurassic |
| What it ate | low plants such as ferns and mosses |
| Fossils found in | western North America, including Dinosaur National Monument in Colorado and Utah |
| What kind | a stegosaur: a plated plant-eater |
Wow!
- Its plates stood up in two rows along its back.
- Its brain was small for such a big animal.
- Stegosaurus lived long before T. rex.
🦴 Stegosaurus’s bones
Books about Stegosaurus, free at the library
Ask a grown-up to tap the button: it shows where to borrow a book about Stegosaurus for free.
Where was the land back then?
The continents were in different places when Stegosaurus lived, 150 million years ago. Open Planet Earth, pick Drifting continents, and slide back in time to see where the land was.
Its neighbours in time
Where these numbers come from
- Wikidata, from the Natural History Museum's Dino Directory, checked 30 October 2026.
- National Park Service, Dinosaur National Monument: dinosaurs, checked 30 October 2026.
- Wikidata, Stegosaurus (Q14388), checked 30 October 2026.
To read more: the Natural History Museum’s Dino Directory (see also, not copied).