Paleoproterozoic Era 2.5 to 1.6 bya

Summary

The Paleoproterozoic ("old first life") was a time when the continents finally stabilized, with modern land forms becoming recognizable.

This was the time of the most dramatic change ever in the nature of the Earth's atmosphere. Bacteria able to make use of sunlight for energy continued to grow, resulting in the great oxygen poisoning.

This might also have been the time when larger and more advanced cells (eukaryotes) first appeared.