Age of fossils in the post was generally determined by radio-carbon method and other methods involve radioactive elements found the rocks. More precise methods, which were used recently and led to the revision of the evolutionary periods far different groups of organisms, includes:

Step-by-step solution

Electron Spin Resonance (ESR) measures number of charges occupying deep traps in crystal band gap. The basic principle of ESR is same as those for luminescence i.e., electrons become trapped and stored as a result of ionising radiations e.g., Dating of tooth enamel.