Precambrian time.
Precambrian
fossil record geologic time scale
fossil record geologic time scale
fossil record geologic time scale
fossil record geologic time scale
fossil record geologic time scale
fossil record geologic time scale
fossil record geologic time scale
fossil record geologic time scale
fossil record geologic time scale
fossil record geologic time scale
Yes, the geologic time scale is typically divided based on major changes in the fossil record, called biostratigraphy. These divisions are used to categorize different periods in Earth's history based on the types of organisms that lived during that time.