Proterozoic
adjective
- latest eon of the Precambrian super-eon; eon preceding the Phanerozoic
Wiktionary
Pronunciation: /ˌpɹoʊt(ə)ɹrəˈzoʊɪk/ / /ˌpɹoʊt(ə)ɹoʊˈzoʊɪk/ / /ˌpɹɒt(ə)ɹəˈzəʊɪk/
adj
Etymology: From protero- + -zoic.
- Of or relating to the geologic eon from 2,500 Ma to 541.0±1.0 Ma.
name
Etymology: From protero- + -zoic.
- The eon from 2,500 Ma to 541.0±1.0 Ma, the beginning of the Phanerozoic, marked by the build up of oxygen in the atmosphere and the emergence of primitive multicellular life.