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  Again millions of years later, the bodies of horse-like creatures dying in the area
                       are fossilised in rocks above these earlier rocks.
                     Much later, by erosion or water flow wears away some of the rock and exposes
                       the horse-like fossils. As we dig deeper, we will find older and older fossils.















































                        Fossils records show there is a link between birds & reptiles.
                        Fossils records show how evolution occurred in some mammals with time.

               Estimation of Age of Fossils
                  1.  Relative Dating: the fossils we find closer to the surface are more recent than the
                      fossils we find in deeper layers. Deeper the layer where the fossil is found, older
                      it is. Fossils at upper layers are more complex than that at lower layers.
                  2.  Absolute Dating/ Carbon Dating: by detecting the ratios of different isotopes of the
                      same element in the fossil material. Composition of the fossils helps in age
                      estimation. Age estimation detects ratios of isotopes of different elements. Each
                      isotope has a specific half-life. For example, C-12, C-14 are isotopes of Carbon.
                      Knowing the isotopes, we will know their half-lives. With that, we can calculate for
                      how long it has been there, which in turn estimates the age of fossil.


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