Adjective: proterozoicNoun: Proterozoic ,prow-tu-row'zow-ik
- From 2,500 to 544 million years ago; bacteria and fungi; primitive multicellular organisms
- Proterozoic eon, Proterozoic aeon
See also: early
Part of: Precambrian, Precambrian aeon, Precambrian eon, Precambrian period
Encyclopedia: Proterozoic