A fossile was once a living thing that has now turned to stone.By studying fossils,scientists can learn more about the past and how animals,such as dinosaurs,used to live.It takes millions of years to make a fossil.When an animal dies,it may be buried by sand.The soft parts of its body rot away,leaving just bones,teeth or shells.These slowly turn to rock and a fossil is made.fossils are very very hard if you look carfully you may find one.