古元古代 [－－－－]

Jyutping gu2 jyun4 gu2 doi6
Pinyin gǔ yuán gǔ dài

Definitions (Wiktionary)
  1. name
    the Paleoproterozoic era (part of the Proterozoic eon, spanning from 2.5 to 1.6 billion years ago)