Geologic Time is a crucial concept to understanding the history of the earth—including the evolution of life. Many different representations of the timeline have been created, and many approaches ...

Prehistoric time line, geologic time scale, photos, facts, maps, and more from National Geographic. Humans have walked the Earth for 190,000 years, a mere blip in Earth's 4.5-billion-year history.

The International Chronostratigraphic Chart, the famous diagram depicting ... It is the official keeper of geologic time and it proposed three stages be introduced to denote the epoch's upper ...