Precambrian
The Precambrian consists of several parts. The name Precambrian is not an "eon"anymore is the most recent stratigraphic charts. In the Archaeļc (3800 to 2500) fossils ara found from cyanobacteria in sea deposits.; stromatolites . From the lower and middle Proterozoļc (2500 to 1000) colony forming bacteria (without nucleus) are known followed by Eucariotic bacteria (with nucleus). From the upper Proterozoļc (1000 to 542) the first colony forming animals are known like sponges.
| Eon:
| Era:
| Period:
| Age (in Milion years) *
| 
| Proterozoic
| Neoproterozoic
| Ediacarian
| 542 - 630
| Cryogenian
| 630 - 850
| Tonian
| 850 - 1000
| Mesoproterozoic
| Stenian
| 1000 - 1200
| Ectasian
| 1200 - 1400
| Calymmian
| 1400 - 1600
| Paleoproterozoic
| Statherian
| 1600 - 1800
| Orosirian
| 1800 - 2050
| Rhyacian
| 2050 - 2300
| Siderian
| 2300 - 2500
| Archaeic
| Neoarchaeic
| 2500 - 2800
| Mesoarchaeic
| 2800 - 3200
| Paleoarchaeic
| 3200 - 3600
| Eoarchaeic
| no lower limit - 3600
|
* Age is rounded | 
