The "past 550 million years" includes the Permian-Triassic Extinction, or Great Dying, of 251 million years ago. Do they refer to the million-year death zone af

The "past 550 million years" includes the Permian-Triassic Extinction, or Great Dying, of 251 million years ago. Do they refer to the million-year death zone after this event as a period when "[CO2 was] measured in thousands of parts per million"? Seems like an incomplete analysis. Wikipedia claims, "[the] trigger for these mass extinctions appears to be a warming of the ocean caused by a rise of carbon dioxide levels to about 1000 parts per million": https://en.wikipedia.org/wiki/Anoxic_event#Atmospheric_effects https://en.wikipedia.org/wiki/Anoxic_event#Atmospheric_effec... Here's the Scientific American article they cited: https://www.scientificamerican.com/article/impact-from-the-deep/ https://www.scientificamerican.com/article/impact-from-the-d...