How do the scientists know how old a fossil is?

Scientists determine the age of fossils primarily through two methods: relative dating and absolute dating. Relative dating involves examining the layers of rock (strata) where the fossil is found, allowing scientists to establish a chronological sequence based on the position of the layers. Absolute dating, often using techniques like radiometric dating, measures the decay of radioactive isotopes in the surrounding rock or the fossil itself to provide an estimated age in years. Together, these methods help create a clearer picture of the fossil's age and the environmental conditions of its time.