At the end of the _______ period, atmospheric oxygen concentrations decreased from about 30 percent to 15 percent due to plant death associated with the widespread drying of swamps.

Question

Quizplus · Accepted Answer

The Permian period ended with a mass extinction event, which led to the decline of plant life due to a widespread drying of swamps. This, in turn, caused a decrease in atmospheric oxygen concentrations from about 30 percent to 15 percent. Therefore, the best choice is C) Permian.

At the End of the _______ Period, Atmospheric Oxygen Concentrations