Read Edit View history 元古宙 Yuángǔzhòu Proterozoic Origin Definitions Defs Strokes Stroke Words Sentences Sents created sense approved 元古宙 · Yuángǔzhòu · Proterozoic 2026/03/04 元古宙 Yuángǔzhòu Proterozoic Proterozoic eon (geological eon from 2500 to 645 million years ago) 元古宙时期，地球上开始出现最早的多细胞生物。 noun created sense Mar 4, 2026, 02:25 AM