Dinosaurs were reptiles that lived on land between 220 and 65 million years ago, and which carried their legs beneath their bodies. Flying reptiles and ocean-living reptiles were related, but they were not biologically dinosaurs. Crocodiles and the ancestors of lizards began in this age, but they are different from dinosaurs because they walk with their legs against the sides of their bodies.

In the time just before the age of the dinosaurs, there was a terrible natural disaster, and most creatures died out. A new geological age started, and it was in this time that the dinosaurs began to rule the world.

The dinosaurs and related animals lived for an incredible length of time – 183 million years, nearly fifty times as long as all humankind (so far). Then, 65 million years ago, there was another worldwide catastrophe, and it was the dinosaurs' time to become extinct.

Their relations did not, however, become extinct. Although you may not at first realise it, there are millions of dinosaur ancestors, for every modern bird is descended from the dinosaur.

Dinosaurs were not the only creatures on the Earth. They lived among a huge variety of other creatures, many of which were also spectacular. Many dinosaurs hunted these other creatures. Some dinosaurs were also food for other dinosaurs. Others got their food from plants. Well-known dinosaurs include (and can be found in these books):
Iguanadon
Pterodactyl
Spinosaurus
Stegasaurus
Velociraptor