Vertebrate extinction across Permian-Triassic boundary in Karoo Basin,South Africa:Discussion

摘要

The Permian-Triassic boundary was a time of lowered atmospheric oxygen and raised carbon dioxide pressure and massive vertebrate extinction.The levels of oxygen (12 vol%) and carbon dioxide (approx2000 ppmV) are typically tolerated by modern vertebrates and are not abnormal enough to have contributed significantly to the extinction.