Paleontology
Paleontology is packed with mysteries about living things such as plants and animals that lived thousands, millions, and billions of years before the first modern humans. To solve these mysteries, paleontologists use fossils. Fossils are the remains or traces of ancient life that are usually buried in rocks. Examples include bones, teeth, shells, leaf impressions, nests, and footprints. This evidence reveals what our planet was like long ago. Fossils also show how animals changed over time and how they are related to one another.