Thousands of years ago only dinosaurs used to be on earth. They ruled earth. But dinosaurs died long before the humen came into this world. When humen came dinosaurs had completely extinct , we only know about their existince through their fossils.
What are fossils?
The remains of plants and animals which has been preserved in the rocks and we can still see them today. The fossil experts who dig up fossils and examine them are called palaeontologists. They take pictures of fossils and the place where thay are found. After that they wrap up the bones in plastic sheets and take them to the meuseum or wherever they have to . Some times they found the all the fossils of a dinosaurs and build the whole dinosaurs skelton by putting all parts together.

 

FORMATION OF FOSSILS:

1. First a dinosaurs dies. Its flesh is eaten by insects birds or whatever.
2. Then skeleton is caused by dust and mud layers of sand comes up and fossils go deep into the mud.
3. Gradually, the mud turns hard and eventually in rocks. Then the bones and remains become fossils.
4. And when a rock is turned into small pieces then the fossils reveal.

Fossils Includes:
Fossils does not mean only the bones and teeth of animals. It also includes the imprints of their skin which very scaly like aligator. Their footprints, their nest and eggs as well. By discovering all these things an palaeontologists can even tell that what these dinosaurs ate.

Still Unknown :
On one hand we have discovered alot of things about dinosaurs but still there are many things which are not confirm about them. The first one is there coloure, no one knows about their colour of skin. Few pieces of fossils dinosaurs skin have been found but because they are million years old and thousands of years they have been in the mud so their coloure faded. But we now assume that they must be of similar colours of reptiles today. Dinosaurs are the biggest animals that have ever lived on earth.