1. Although the Stegosaurus dinosaur was over 9 yards long, its brain was only the size of a walnut.

2. Dinosaurs thrived for 150 million years.

3. Dinosaurs became extinct over 60 million years before the first humans existed.

4. Some dinosaurs may have lived for 200 years.

5. Although dinosaurs were reptiles, much of their behavior, such as agile running, has more in common with mammals.

6. The name ornithomimosaur means - bird-mimic reptile.

7. While the dinosaurs ruled the land, their reptile relatives, the pterosaurs, ruled the air above, and the ichthyosaurs and plesiosaurs ruled the oceans. Dinosaurs did not fly or live in water.

8. Dinosaurs are divided into two groups based on the shape of their hips, saurischians (lizard-hipped) and ornithischians (bird-hipped).

9. There were about thirty times more herbivores than carnivores.

10. Several groups of reptiles existed before dinosaurs appeared.

11. When running, Tyrannosaurus rex would have held its tail rigid for balance.

12. Africa is a rich source of dinosaur fossils. A site in Tanzania has held some major discoveries.

13. Dinosaurs held their legs directly beneath the body, unlike other reptiles, which crawl with their legs held out from the sides of the body.

14. Tyrannosaurus rex is the largest land-living carnivore we know of.

15. Brain size is not always a sign of intelligence, but big-brained Troodon was probably one of the smartest dinosaurs.

16. The cheek teeth of Stegosaurus were leaf-shaped.

17. Some of the plants dinosaurs ate, such as pine trees, ferns, and cycads, still grow today.

18. The earliest known dinosaur, Eoraptor, first appeared 228 million years ago.

19. Scientists now recognise birds as the closest living relatives of dinosaurs.

20. The fastest dinosaur could run 45 MPH.

21. Crocodiles were around before the dinosaurs, and are still alive today.

22. Heavier than eight elephants and more than 80 ft (24 m) long, Barosaurus was one of the biggest dinosaurs.

23. Crests, frills, horns, and spikes adorned the heads of many dinosaurs. These decorations helped dinosaurs identify one another and were sometimes used for signaling.

24. Dinosaur embryos have been found fossilised in their eggs.

25. We do not know if dinosaurs could see in color.

26. The first dinosaurs were all carnivores.

27. Dinosaurs became extinct around 65 million years ago.

28. Stegosaurus had a brain no larger than a golf ball.