Proterozoic

High Quality Content by WIKIPEDIA articles! The Proterozoic ( /ˌproʊtərɵˈzoʊ.ɨk/) is a geological eon representing a period before the first abundant complex life on Earth. The name Proterozoic comes from the Greek earlier life. The Proterozoic Eon extended from 2,500 Ma to 542.0 1.0 Ma (million years ago), and is the most recent part of the old, informally named 'Precambrian' time.