2.4 - 2.34
2.34 - 2.28
2.28 - 2.22
2.22 - 2.16
2.16 - 2.1
300M
2.4 - 2.1
60M
10th Galactic year 2.5 - 2.25
9th Galactic year 2.25 - 2
Proterozoic Eon 2.5 - 540 M proterozoic eon
Precambrian Time 4.5 - 543 M precambrian