What does the study of fossils in different sedimentary layers reveal?

Step-by-step solution

Fossils are described as the remains of the hard parts of life-forms found in rocks.Rocks form sediments and a cross-section of earth's crust indicates the arrangement of sediments one over the other during the long history of earth. Different-aged rock sediments contain fossils of different life-forms who probably died during the formation of the particular sediment. The study of fossils in different layers shows that life-forms varied over time and that new forms arose at different periods in Earth’s history. A s