Relative dating is used to determine a fossils approximate age by comparing it to similar rocks and fossils of known ages. Absolute dating is used to determine a precise age of a fossil by using radiometric dating to measure the decay of isotopes, either within the fossil or more often the rocks associated with it.Relative dating is used to determine a fossils approximate age by comparing it to similar rocks and fossils of known ages. Absolute dating

How old are fossils dated?

Scientists called geochronologists are experts in dating rocks and fossils, and can often date fossils younger than around 50,000 years old using radiocarbon dating.