While people are most familiar with carbon dating, carbon dating is rarely applicable to fossils. Carbon-14, the radioactive isotope of carbon used in carbon dating has a half-life of 5730 years, so it decays too fast. It can only be used to date fossils younger than about 75,000 years.

Can fossils be dated?

Fossils themselves, and the sedimentary rocks they are found in, are very difficult to date directly. Instead, other methods are used to work out a fossils age. These include radiometric dating of volcanic layers above or below the fossils or by comparisons to similar rocks and fossils of known ages.

How are old fossils dated?

To establish the age of a rock or a fossil, researchers use some type of clock to determine the date it was formed. Geologists commonly use radiometric dating methods, based on the natural radioactive decay of certain elements such as potassium and carbon, as reliable clocks to date ancient events.

What is a reliable maximum age limit for radiocarbon dating of fossils?

Radiocarbon has a short half-life of only about 5700 years, so it is only useful for dating materials no older than about 50,000 years (van der Plicht & Palstra, 2016). Of the radiocarbon that was present in an organism at the time of its death, no measurable amount remains after 100,000 years.