Most books skip the early beginnings—the Precambrian period—and start with the Cambrian Explosion, but this resource explores the Precambrian, which makes up about 90% of Earth’s history.This printable poster/ coloring page shows the geological time scale with a focus on the Precambrian time, the longest part of Earth’s history. It features a clear, easy-to-understand timeline of early Earth, highlighting important events such as the formation of the planet, appearance of oceans, atmosphere,