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Paleoproterozoic Era

Part of the Proterozoic Eon
Neoarchean Era - Paleoproterozoic Era - Mesoproterozoic Era

The Paleoproterozoic Era is the first era of the Proterozoic Eon.  The Paleoproterozoic begins at the time from which the oldest known glacial deposits are from, and ends with the first appearance of sulphidic marine deposits.  Early photosynthesis would cause the Great Oxygenation Event that would mean extinction for most of the planet's anaerobic bacteria, allowing for aerobic lifeforms to become dominant (or as dominant as microbes could be) and eventually evolve into multicellular life, as the first multicellular Eukaryotes evolved during this era.  The era would also see the formation of the supercontinent of Columbia (or Nuna), which would last into the Mesoproterozoic.  It has been measured that years lasted 450 days towards the end of this era (approximately 1800 MYA).

The Paleoproterozoic faces major revision in the most recent proposals followed here.  Officially, the Paleoproterozoic includes four periods: the Siderian and the Rhyacian - which were previously proposed to be moved to the new Eoproterozoic Era - and the Orosirian and the Statherian.  However, these periods were defined chronometrically (as some of the Hadean subdivisions used here are) rather than being marked by changes in the rock layer or an event, and could fall out of favor in the near future.  However, 40% of the Siderian would be included in the Archean Eon and 90% of the Statherian would be included in the Mesoproterozoic Era in the new time scale.

The Paleoproterozoic is subdivided into three periods: the Oxygenian, the Jatulian, and the Columbian.

Paleoproterozoic Timescale:
Paleoproterozoic Era - 2420-1780 MYA
-Oxygenian Period - 2420-2250 MYA
-Jatulian Period - 2250-2060 MYA
-Columbian Period - 2060-1780 MYA