Mean atmospheric O2
Geologic Time Scale
This is how the Earth may have appeared 600 million years ago following the Cryogenian "Snowball Earth" period. The worldwide glaciers have melted and the ocean is largely liquid again. During this, the Ediacaran period, it is hypothesized that all of the Earth's landmasses had merged into a single supercontinent known as Pannotia, also known as the Vendian supercontinent. Surrounding this massive landmass is the vast Panthalassic Ocean, also known as Panthalassa.
While the ocean was home to a variety of evolving multicellular life forms including the ubiquitous Dickinsonia costata, it is not believed that life had moved to dry land with possible exception of bacteria and other microbial colonies.
Copyright © Walter B. Myers. All rights reserved.
[ Home | What's New | The Graphics | Information | Site Map | ]