Question

How can you use fossils to identify rock layers that were connected when they first formed? (please don't just copy from the internet)

Answer 1

Using the principle of faunal succession, if an unidentified fossil is found in the same rock layer as an index fossil, the two species must have existed during the same period of time (Figure 4). If the same index fossil is found in different areas, the strata in each area were likely deposited at the same time.