Fossils are remains of a plant or animal that long ago in prehistoric time or even earlier. Fossils are formed by leaves, shells, skeletons, or other organic forms that were preserved death of a plant or animal. Tracks or trails left by moving animals also form fossils.
Fossils help scientists discover forms of life that existed in the past and how they lived. In this way scientist can study how life on earth has changed over time.
Fossils can provide a great deal of information about the appearance and ways of life of prehistoric organisms. One way of studying fossils of an animal or plant is by comparing them with living species. Study of Fossil that do not have close living relatives are more difficult to understand. One way to learn how such plant and animals lived is to compare their fossils to unrelated living species with similar shaped structures. The conditions under which fossil creatures died and were buried is also useful in determining how they lived. Fossils of tracks, trails, or burrows help scientists to figure out the behaviour of prehistoric animals. The location of fossils in the(layers of rocks helps to determine when a particular type of plant or animal lived.
Study of fossils also helps to determine how the earth's climate and landscape have changed over time. For instance, presence of a fossil of a particular type of plant in a specific place, and belonging to a specific time period indicates the that the climate was suitable for existence of that type of plant.
The nature of differences and similarities in characteristics of plant and animal life in different parts of the world at different times also helps to understand the nature of continental drifts that has taken place over millions of years.