The geologic time scale is divided into eons ... The end of the Paleozoic and beginning of the Mesozoic 251 million years ago marks the largest mass extinction in the history of the planet, which ...

Prehistoric time line, geologic time scale, photos, facts ... Dinosaurs ruled the Earth in the mighty Mesozoic. And 64 million years after dinosaurs went extinct, modern humans emerged in the ...

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 Earth that is characteristic of a particular span of geologic ...