Fossils can provide clues to how vegetation and animals lived up to now – what they looked like, what they ate, what environments they lived in, and how they advanced and went extinct. For lots of of tens of millions of years, the stays of organisms (as properly as tracks, trails, and burrows – known as trace fossils) have been nearly all of the clues left behind in Earth’s fossil document. A fossil may be studied to determine what type of organism it represents, how the organism lived, and the method it was preserved.