Why Are They Gone?
Just as you change while you grow, the world and the things that live on it change, too. Most scientists believe that the earth has changed many times in the past, and that many kinds of animals have lived on our planet.
Once, there were scaly reptiles as big as houses. Once there were horses no bigger than cats. And, very long ago, no animals of any kind lived on land. All the animals lived in the ocean.
Dinosaurs were very important animals. They ruled the earth for more than 100 million years. They wallowed in great swamps and prowled through hot, damp forests.
Then something happened, and all the dinosaurs died. We don’t know why dinosaurs became extinct.
Some scientists think dinosaurs became extinct slowly. Swamps began drying up. New plants were taking the place of old ones. Perhaps dinosaurs could not live with these changes. Other scientists think Earth was struck by a huge asteroid. The air then filled with dust that blocked out the sun’s rays. Eventually, this changed the climate and led to the death of the dinosaurs.
Perhaps all these things, and others that we don’t know about, caused the dinosaurs to die out. It’s a great mystery.
Picture Credit : Google