Final answer:
A fossil is any trace of an ancient organism preserved in rock. They can be the remains, impressions, or traces of living things from a former geologic age. Fossils provide important evidence of past organisms and environments.
Step-by-step explanation:
A fossil is any trace of an ancient organism preserved in rock due. Fossils can be the remains, impressions, or traces of living things from a former geologic age. They are mainly made up of bones, teeth, shells, or plant impressions that have mineralized over time. Fossils are important in studying the history of life on Earth and provide evidence of past organisms and environments.