Longest geological era.

Our planet has existed for several billion years, and this period is usually divided into geological eras. This division occurs based on whether life existed at this stage of the planet’s development or not, and what forms of life were present. And the extinction of animals living in this period of time serves as the border of an era. So, the longest of the eras is the Paleoproterozoic, which lasted about nine hundred million years. At this time, organisms lived on Earth that did not breathe oxygen, and the day lasted 20 hours.