Neoproterozoic

The Neoproterozoic era lasted from 1,000 to 541 million years ago (mya).
In the first period, the Tonian, the global supercontinent Rodinia broke up into separate land masses.
In the second period, the Cryogenian, the Earth had two great ice ages, the Sturtian and Marinoan glaciations. These ice ages were so severe they are sometimes called Snowball Earth.
In the third period, the Ediacaran, the earliest fossils of multicellular organisms are found, the Ediacaran biota.