Proterozoic aeon

Từ điển WordNet v3.1 - WordNet Dictionary

noun

from 2,500 to 544 million years ago;
bacteria and fungi;
primitive multicellular organisms
• Syn:
Proterozoic, Proterozoic eon
• Derivationally related forms:
proterozoic (for: Proterozoic)
• Instance Hypernyms:
eon, aeon
• Part Holonyms:
Precambrian, Precambrian eon, Precambrian aeon, Precambrian period