I like to use a meter stick and be very intentional with my spacing to model time as a scale. I also avoid using the far right of the space to infer ... preserved in the rock record of the Earth that ...
Prehistoric time line, geologic time scale, photos, facts ... formed and oxygen levels rose in the foundational years of the Precambrian. The productive Paleozoic era gave rise to hard-shelled ...
What Was Happening on Earth at This Time The Precambrian is the earliest of the geologic ages, which are marked by different layers of sedimentary rock. Laid down over millions of years ...