T he Proterozoic Eon, spanning from 2,500 million to 539 million years ago, marked a transformative chapter in Earth's history.Often overshadowed by the more data-rich Phanerozoic Eon, this period ...

and the chemical environment in the current Phanerozoic Eon, which began approximately 540 million years ago. At the start of the Phanerozoic, carbon dioxide levels in the atmosphere were high ...

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.