proterozoic_aeon | ||
1. | [ noun ] (geology) from 2,500 to 544 million years ago; bacteria and fungi; primitive multicellular organisms | |
Synonyms: | Preoterozoic_era proterozoic_eon Proterozoic | |
Related terms: | eon era Precambrian | |
Similar spelling: |
proterozoic_eon Preoterozoic_era |