”Earth's surface became entirely or nearly entirely frozen, sometime earlier than 650 Mya (million years ago) during the Cryogenian period. " https://en.m.wiki

”Earth's surface became entirely or nearly entirely frozen, sometime earlier than 650 Mya (million years ago) during the Cryogenian period. " https://en.m.wikipedia.org/wiki/Snowball_Earth https://en.m.wikipedia.org/wiki/Snowball_Earth Note that animal (multicellular eukaryotes) fossils exist from that period.