-
40,000 BCE
Archean era
is a geologic eon, 4,000 to 2,500 million years ago (4 to 2.5 billion years), -
8500 BCE
Cryogenian period
A division of the geological time scale, is the second geological period of the Neoproterozoic Era. It began about 720 million years ago and ended about 635 million years ago. -
Ediacaran
A division of the geological time scale, is the third and last geological period of the Neoproterozoic Era.