Definition of proterozoic in English English dictionary
Of, or relating to the geologic eon from about 2,500 to 570 million years ago; comprises the Paleoproterozoic, Mesoproterozoic and Neoproterozoic eras; marked by the build up of oxygen in the atmosphere and the emergence of primitive multicellular life
Geologic eon that occurred from 570 to 2500 million years ago During this time period, the first single-celled and multi-celled eukaryotic organisms evolved and developed
The final era of the Precambrian, spanning the time between 2 5 billion and 544 million years ago Fossils of both primitive single celled and more advanced multicellular organisms begin to appear in abundance in rocks from this era Its name means "early life "
Formed in the later of two divisions of the Precambrian era; from 600 million to 1 5 billion years ago; bacteria and fungi; primitive multicellular organism
from 2,500 to 544 million years ago; bacteria and fungi; primitive multicellular organisms formed in the later of two divisions of the Precambrian era; "proterozoic life forms
5 billion to 543 million years ago. Proterozoic rocks have been identified on all the continents and often constitute important sources of metallic ores, notably of iron, gold, copper, uranium, and nickel. The many small protocontinents that had formed during early Precambrian time had coalesced into one or several large landmasses by the beginning of the Proterozoic. Rocks of the Proterozoic contain many traces of primitive life forms, such as the fossil remains of bacteria and blue-green algae (see cyanobacteria)