Search Result：proterozoic aeon
proterozoic aeon 
(TTS Sound)
(TTS Sound)Overview of noun proterozoic_aeon
The noun proterozoic aeon has 1 sense
- Proterozoic, Proterozoic eon, Proterozoic aeon -- (from 2,500 to 544 million years ago; bacteria and fungi; primitive multicellular organisms)