SEATTLE, Nov. 6 (UPI) -- Hydrogen sulfide may have been responsible for the largest mass extinction in Earth's history some 251 million years ago, a Penn State research team says.
A team of scientists headed by Lee R. Kump of Penn State University told the annual meeting of the Geological Society of America carbon dioxide is not a likely agent for the mass extinction, Science Daily reported Thursday.
Produced in the oceans through sulfate decomposition by sulfur bacteria, hydrogen sulfide can easily kill both terrestrial and oceanic plants and animals.
At the end-Permian era 251 million years ago, as the levels of atmospheric oxygen fell and the levels of hydrogen sulfide and carbon dioxide rose, the upper levels of the oceans could have become rich in hydrogen sulfide.
This would kill most of the oceanic plants and animals. The hydrogen sulfide dispersing in the atmosphere would kill most terrestrial life, Kump said.
