Fossils are the remains of ancient life that have been preserved into rock. These remains can be tracks, burrows, or even skeletons. Generally, softer parts of a dead animal decompose, leaving only the skeleton and other “hard” parts of the body such as shells to be fossilized; But this is not always the case. Certain fossilizing processes begin almost immediately after death, and are able to capture near-complete copies of the living animal. Fossils are usually formed when remains of some sort are quickly and completely buried. Since outside influences such as air, water and/or scavengers can’t weather the body, the harder parts of the body cease the process of rotting and become locked. Once the remains are buried, there’s a chance that minerals gradually begin seeping into the gaps of the skeleton, and even begin replacing the skeleton, essentially turning the remains into stone.