Biggest mass extinction caused by global warming leaving ocean animals gasping for breath
Fossils in ancient seafloor rocks display a thriving and diverse marine ecosystem, then a swath of corpses. Some 96 percent of marine species were wiped out during the "Great Dying", followed by millions of years when life had to multiply and diversify once more. What has been debated until now is exactly what made the oceans inhospitable to life -- the high acidity of the water, metal and sulfide poisoning, a complete lack of oxygen, or simply higher temperatures.
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