What is used to estimate the age of a fossil?

There are several methods used to estimate the age of a fossil, including:

1. Radiometric dating: This method involves measuring the decay of radioactive isotopes in the fossil to determine its age. Commonly used isotopes for radiometric dating include carbon-14, potassium-argon, and uranium-lead.

2. Stratigraphy: This method involves studying the layers of rock in which the fossil was found to determine its relative age. Fossils found in deeper layers are generally older than those found in shallower layers.

3. Biostratigraphy: This method involves comparing the fossil to other fossils of known age to determine its relative age. Fossils of similar species found in different locations can be used to estimate the age of a fossil.

4. Paleomagnetism: This method involves studying the orientation of magnetic minerals in the fossil to determine its age. Changes in the Earth's magnetic field over time can be used to estimate the age of a fossil.

5. Fossil correlation: This method involves comparing the fossil to other fossils of known age found in the same location to determine its age. By correlating the fossil with other fossils in the same strata, scientists can estimate its age.