Proterozoic

1 definition found

From WordNet (r) 2.0 [wn]:

  proterozoic
       adj : formed in the later of two divisions of the Precambrian era;
             "proterozoic life forms"
       n : from 2,500 to 544 million years ago; bacteria and fungi;
           primitive multicellular organisms [syn: {Proterozoic eon},
            {Proterozoic aeon}]