Simplified timescale for the Trek Through Time

This simplified geologic timescale shows the time before abundant life on Earth in black. The Phanerozoic, which began 541 million years ago, is in colored blocks, and is subdivided into the Paleozoic (colored green), Mesozoic (blue), and Cenozoic (yellow) Eras. For a more complete version of the Divisions of the Geologic Timescale, see: https://pubs.er.usgs.gov/publication/fs20183054