What is a type of relative dating of fossils finnish dating practices
These include radiometric dating of volcanic layers above or below the fossils or by comparisons to similar rocks and fossils of known ages.
Knowing when a dinosaur or other animal lived is important because it helps us place them on the evolutionary family tree.
The main relative dating method is stratigraphy (pronounced stra-TI-gra-fee), which is the study of layers of rocks or the objects embedded within those layers.
This method is based on the assumption (which nearly always holds true) that deeper layers of rock were deposited earlier in Earth's history, and thus are older than more shallow layers.
The successive layers of rock represent successive intervals of time.
Since certain species of animals existed on Earth at specific times in history, the fossils or remains of such animals embedded within those successive layers of rock also help scientists determine the age of the layers.
Once Steno recognized that the fossils he was contemplating (sharks teeth and sea shells) were formed in the sediments of oceans he was able to work out the basic rules of stratigraphy.