The Proterozoic is a geological eon representing a period before the first abundant complex life on Earth. The name Proterozoic comes from the Greek "earlier life." The Proterozoic Eon extended from 2500 Ma to 542.0 ± 1.0 Ma (million years ago), and is the most recent part of the old, informally named ‘Precambrian’ time.
The Proterozoic consists of 3 geologic eras, from oldest to youngest:
The well-identified events were:
- The transition to an oxygenated atmosphere during the Mesoproterozoic.
- Several glaciations, including the hypothesized Snowball Earth during the Cryogenian period in the late Neoproterozoic.
- The Ediacaran Period (635 to 542 Ma) which is characterized by the evolution of abundant soft-bodied multicellular organisms.
- Proterozoic - Palaeos
|Preceded by Archean eon||2.5 Ga - Proterozoic eon - 542 Ma||Followed by Phanerozoic eon|
|2.6 Ga - Paleoproterozoic era - 1.6 Ga||1.6 Ga - Mesoproterozoic era - 1.0 Ga||1.0 Ga - Neoproterozoic era - 542 Ma|