The time units used by scientists to divide
Earth's history are part of the geological time scale. The geological time
scale measures the timing and the relationships of specific occurrences in the
history of the Earth. It is used mostly by geologists and paleontologists. They
define the earth's history by studying the Earth's composition then connect
facts to major geological or paleontological events. <span>
<span>Through
the use of a geological time scale, scientists have found discoveries and put
together the missing pieces of the past. Probably, the most distinguishable event discovered through
the geological time scale is mass extinction of species.</span> </span>
