Ancient Ocean ‘Dead Zone’ Delayed Life After Mass Extinction
Ancient Ocean 'Dead Zone' Delayed Life After Mass Extinction By Wynne Parry, LiveScience.com1 April 2011 A flood of nutrients may have created an oxygen-starved ocean about 250 million years ago, preventing life from bouncing back for a few million years after a mass extinction wiped out 90 percent of marine species, a new study indicates. [...]