Sprawling moss, towering trees, flying insects, limbed amphibians: Early species vied for domination as the land went from hostile to hospitable.

After Earth's third mass extinction, mammals' surviving ancestors ruled the supercontinent Pangea. But lizards soon ushered in the age of reptiles.

The formation of continents with varied environments allowed for an explosion of biodiversity — and turbo-charged the evolution of mighty dinosaurs.