Proterozoic Eon
An age which marks the evolution of multicellular life
The Proterozoic is the third eon in Earth's geologic history, which occurs after the Archean Eon, and before the Phanerozoic Era.
Geologic Age
2,500–538.8 million years ago
Subdivisions
Neoproterozoic (1,000–538 Ma)
Mesoproterozoic (1,600–1,000 Ma)
Paleoproterozoic (2,500–1,600 Ma)
What happened during this time?
Biological
The origin of eukaryotes through endosymbiosis; origin of glaucophytes
Increasing complexity of life
The first multicellular organisms
Molecular clock analyses have estimated the origin of the green algae lineage between 700 and 1,500 mya (Douzery et al. 2004, Hedges et al. 2004, Berney and Pawlowski 2006, Roger and Hug 2006, Herron et al. 2009)
Geophysical
Continental drift, in its present form, begins to happen
The build-up of large continents and orogeny (mountain building), with modern plate tectonics
Land had grown and become stable enough to allow large inland seas, and strata deposited in these areas is relatively well preserved.
The gradual change in the atmosphere with the build up of oxygen
This build-up of oxygen in the atmosphere should have also created an ozone layer
Although, UV radiation may have been greater than originally assumed during the early to middle Proterozoic (Cooke et al. 2022)
Several ice ages
Snowball Earth event(s)
Precambrian "Pangaea" event
