Proterozoic:
The Proterozoic /ˌproʊtərɵˈzoʊ.ɨk/ is a geological eon representing the time just before the proliferation of complex life on Earth.
en.wikipedia.org
元古宙:
元古宙（Proterozoic，符号PR），又稱元古代、原生代，是地质时代中的一個時期，开始于同位素年龄2500Ma（百万年前），结束于542.0±1.0Ma。
zh.wikipedia.org
This article uses material from the Wikipedia articles %@, which are released under the Creative Commons Attribution-Share-Alike License 3.0.
Proterozoic元古宙