1) Archaeozoic 2) Early 3) Era 1) Archaeozoic 2) Early 
The archeozoic period was the first geological period. It was characterised by an absence of animal life and extensive volcanic activity.
[adj] - (geology) formed in the earlier of two divisions of the Precambrian era
Archaeozoic, Archeozoic 1. Living in the earliest geological era. 2. The time from 3,800 million years to 2,500 million years ago; earth's crust formed; unicellular organisms were the earliest forms of life. 3. Formed in the earlier of two divisions of the Precambrian era. 4. Noting or pertaining to the earlier half of the Precambrian Era, from ...
archaeozoic adjective formed in the earlier of two divisions of the Precambrian era; `archeozoic life forms`