Answer:the Precambrian, more than 80 Percent. 88 percent to be precise.
Step-by-step explanation:
Precambrian era existed since the creation of earth. That is, ''pre'' meaning 'before'' the Cambrian. The Cambrian period is about 541 million years ago.
All life-forms were long assumed to have originated in the Cambrian, hence, all the rocks earlier are grouped into Precambrians- completely devoid of fossils.
The Precambrian consist of the archean and the proterozoic eons which are geologic intervals that lasted for about four millions to about five-hundred and fourty-one millions years ago.
The Precambrian covers almost 90% of the entire history of the Earth. The Precambrian Era consist of all of the geologic time before six(6) million years ago(that is; like about 4.6 billion years ago).
Majority of the fossils in the Precambrian time are being stromatolites that is, they are often deeply buried.