Words - 339 Reading Level - 4.0
Many, many millions of years ago, the world was a much wetter and warmer place than it is today. Much of the earth's land that is now meadow and hillside was covered with lakes and seas and flat, muddy marshes. All over the world, the weather was warm. Even the North Pole and South Pole were warm all year long.
The dinosaurs lived comfortably in this wet, warm world for over a hundred million years. They lived all over the globe wherever there was land for them to walk on. Then, about seventy million years ago, the last dinosaurs died out. They were dead a long, long time before the first men lived on earth. No man ever hunted a dinosaur; no dinosaur ever preyed on man. No man ever even saw a living dinosaur.
Then how do we know that there were dinosaurs? The way we know is from fossils that scientists have found.When dinosaurs died, their bodies sank down into the mud or sand. As years passed, some of their bones and teeth and bits of skin turned slowly into stone or mineral. Sometimes the eggs of dinosaurs turned to stone, too. These bones and teeth and eggs made of stone are the evidence we have that dinosaurs once roamed the face of the earth.
Dinosaurs often left footprints in the mud where they walked. This mud dried up and became stone, and we can still see the fossil footprints. We can tell how big dinosaurs were by the size of their bones and their footprints.
We can figure out what dinosaurs ate by the type of teeth they had. Some ate only hard plants while others ate only soft plants. Others ate small animals and insects. Some were cannibals; they ate other dinosaurs. By studying dinosaur bones we can find out all about what dinosaurs did to survive for so long in this world. Maybe humans will be able to learn from the dinosaurs--and also live comfortably for millions of years on this planet.