The Dawn of the Forests Brought Waves of Death to the Oceans
Nikk Ogasa, Contributor ( Inside Science ) -- Lub-dub. Lub-dub. Lub-dub. Like the pulse of a throbbing heart, death beat down upon the seas around 376 million to 360 million years ago. During this time over 70% of animal species disappeared, most of which lived in the ocean. These creatures perished in waves of extinction as oxygen levels in the water oscillated and the downward swings repeatedly suffocated the seas. It was the most devastating period of the Late Devonian Mass Extinction -- one of the five largest extinctions to ever plague the planet. But what triggered these pulses of death...
Source: insidescience.org