Absolute dating and relative dating
It is composed of rocks and sediments deposited over millions of years. It is the evidence of Earth's history over such a long span of time.
It is a perfect example of superposition (layers deposited one above the other) and lateral continuity (undisturbed and covering large distances).
Using relative dating the fossil is compared to something for which an age is already known.
This makes it ideal for dating much older rocks and fossils.
Studying the layers of rock or strata can also be useful. If a layer of rock containing the fossil is higher up in the sequence that another layer, you know that layer must be younger in age. This can often be complicated by the fact that geological forces can cause faulting and tilting of rocks.
Absolute dating is used to determine a precise age of a rock or fossil through radiometric dating methods.
Then after another 5,000 years half of the remaining parent isotope will have decayed.
While people are most familiar with carbon dating, carbon dating is rarely applicable to fossils.