1.5 - 1.44
1.44 - 1.38
1.38 - 1.32
1.32 - 1.26
1.26 - 1.2
300M
1.5 - 1.2
60M
6th 250 M Galactic year 1.5 - 1.25
5th Galactic year
Precambrian Time 4.5 - 543 M
Proterozoic Eon 2.5 - 540 M
Mesoproterozoic 1.6 B - 900 M