Fossils are the preserved remains or traces of any once-living organism. To be classified as a fossil that once-living organism typically needs to be older than 10,000 years. Paleontology is the study of the life on Earth using fossils to help piece together an organism’s origin, environment, and evolutionary history. There are two main types of fossils. Body fossils include such things as wood, bones, teeth, shells of once living organisms. While trace fossils are imprints, tracks, footprints or burrows left behind, as opposed to physical remains. Many fossils we find today are preserved in a water environment as those on land are easily destroyed.