Part of the Proterozoic Eon
Paleoproterozoic Era - Mesoproterozoic Era - Neoproterozoic Era
The Mesoproterozoic Era is the second era of the Proterozoic Eon. The Mesoproterozoic begins at the time from which the earliest sulphidic marine deposits are known and ends with the first appearance of δ13C anomalies (δ13C is an isotopic signature measuring the ratio of Carbon-12 to Carbon-13 isotopes). The era exhibited exceptional environmental stability and a reduction in deep oceans. The Paleoproterozoic supercontinent of Columbia (or Nuna) broke up at around 1500 MYA during this era, and was replaced by the new supercontinent of Rodinia at around 1100 MYA. The Grenville Orogeny, the first major episode of mountain building, occurred during this era.
With the first multicellular organisms having evolved during the Paleoproterozoic, the stage was set for the emergence of sexual reproduction to occur during the Mesoproterozoic. Oxygen levels increased to 1% of the modern levels early in this era, and continued to increase throughout its remainder. The Mesoproterozoic also saw the peak of stromatolites, before their Neoproterozoic decline.
The Mesoproterozoic has been subject to great revisions in the recent proposals followed here, and its three official periods may soon fall out of favor due to their chronometric nature, rather than basis on events or changes in the rock layer. The official periods of this era are the Calymmian, the Ectasian, and the Stenian. However, 90% of the Paleoproterozoic's Statherian and the entirety of the Neoproterozoic's Tonian would be included in the Mesoproterozoic in the new timescale.
The Mesoproterozoic is subdivided into one period: the Rodinian.
Mesoproterozoic Timescale:
Mesoproterozoic Era - 1780-720 MYA
-Rodinian Period - 1780-720 MYA