原生代

Yuánshēngdài

the Proterozoic eon

Wiktionary

Entry Composition

1 原生 yuánshēng
  1. original
  2. primary
  3. native
  4. indigenous
  5. proto-
  6. stock (firmware)
2 代 dài
  1. to be a substitute for; to act on behalf of; to replace; to substitute
  2. generation; dynasty; age; period; (historical) era; (geological) eon