| Prehistoric Scratchpad|
Tonian Period Web PagesEdit
- Neoproterozoic Era (1000-540 MYA) - Era from which we have the first multicellular fossils.
- Ediacaran Period (635–541 MYA) - A period of the beginnings of complex multicellular life that coincided with a slow 1% to 10% modern level 100 MY rise in Oxygen levels. Followed the Sturtian Glaciation and saw increase in Oxygen contents due to Sturtian glaciers melting and adding nutrients to the sea floor. Oxygen went from 1% to present day (enough to support small sponge-like creatures) to 10% in 100 Million Years (shortly into Cambrian). A relatively mild glaciation interrupts this period, after which oxygen levels rose again, and strange pizza-shaped creatures lived on the seafloor.
- Cryogenian Period (720–635 MYA) - A period dominated by the greatest Ice Ball Earth glaciations, with a respite between.
- Tonian Period (1000–720 MYA) - A period that saw the end of the "Boring Billion" and the continued evolution of simple life. Eukaryote predation may have driven its diversification.
- Era that saw the development of sexual reproduction.
- Era that saw the Great Oxygenation Event, followed by the first Snowball Earth period.
- Event: Boring Billion (1.8-0.75 BYA) - Period where oxygen levels dropped and continued to decline and evolution stagnated. During this time, the Earth remained warm with no glaciations, despite supercontinent formation and breakup. The period shows unprecedented and unrepeated stability. Starts with development of Eukaryotes and ends with their diversification. Plate tectonics were stable during this time (little destruction of crust) and restarted at the end.
Tonian Period In the NewsEdit
Algae Cloud Causing Caused Snowball Earths (2015)Edit