The Proterozoic eon was the gathering up of oxygen in Earth's atmosphere, and the Phanerozoic eon coincides with the major diversification of animals, plants, and fungi.

The Phanerozoic Eon began around 540 million years ago ... cooler than much of the Phanerozoic era. However, human-induced ...

Often overshadowed by the more data-rich Phanerozoic Eon, this period was characterized ... by low species turnover rates. Unlike later eras, Proterozoic life was smaller, softer, and less likely ...