Prehistoric animals lived more than 5,000 years ago before people could read or write. Some of them looked a lot like the animals we can see today. But others were very different from the ones that live on our Earth now. Great dinosaurs that were up to 40 meters long and big flying reptiles with wingspans of 12 meters were among them.
Scientists have learned a lot about these prehistoric animals by studying fossils. They are signs of life that can be found inside an old rock. They may be shells, bones or animal tracks. Scientists remove the fossils from the rock and study them. By doing this they can tell where, when and how the animals lived.