Clues to the Past F ossils provide clues to what life was like in Minnesota in ancient times. Fossils are the remains of plants and animals found in rock. F ossils form when animals that have died are quickly buried by sand, mud or another sediment. The soft parts of the animals are destroyed by bacteria, leaving only the hard parts, such as teeth, shells and bones. Other fossils are formed when footprints or other depressions that were created by animals long ago are quickly covered by sediments.
Plants can also become fossils.
The best fossils are found in sedimentary rock formations that have remained relatively undisturbed since they were deposited. F ossils can tell us many things about the past. We can see how dramatically life has changed through time. We can also use fossils to develop a history of the earth and its living inhabitants by recognizing the fossils of the ancestors of plants and animals that are living today. Many plant and animal fossils have no living relatives.