Monday January 12, 2026
Earth —
Around 445 million years ago, Earth faced a crisis that reshaped life in the oceans. A rapid climate shift caused glaciers to spread across the giant southern landmass Gondwana.
Sea levels dropped, shallow seas disappeared, and ocean chemistry changed in harmful ways. Almost 85 percent of marine species vanished.
Although devastating, the extinction event created conditions that allowed early vertebrates to change course and eventually dominate life in the seas.