Definitions / Explanation : Fossil & Geological time

 

The term fossil refers to the petrified remains or impressions of organisms that lived in past and got preserved in sedimentary rock. Bones, teeth, shell, impression or imprints in the soft mud or the moulds and casts of entire organism are some examples of fossils

It is a chronological order or history of evolution based upon the study of fossils. It has been divided into eras, periods and epochs.