Fossils are made from bones, shells, teeth, or plant leaves. These can be found in footprints, burrows, coprolites to become a fossil there has to be a death and it has to be peaceful. You need to get buried very quickly. A sediment needs to turn to rock and finally organic matter is replaced with minerals which takes at least 10,000 years.First they tell us about the past. We can see a little bit of what was alive then, but only about 1% of things become fossil. In order to know where the fossils lived or came from you need to see the type of rock. For example if you find a fossil in shale you know it lived in the ocean. When fossils appear and disappear you can match ammodytes in different ages.
One well known extinction is dinosaurs. This is called the KT extinction. What caused this was the boundary between cretaceous and tertiary time periods. We know that they once lived because we have found many fossils. These were found by paleontologists who study and research fossils. Mary Anning was the first female paleontologist and she was very good at what she did.
