LEIPZIG, Germany, April 1 (UPI) -- A team of German, Russian, Austrian and South African scientists says the Earth's largest mass land extinction might have been caused by giant salt lakes.

The scientists posit such lakes might have produced halogenated gases emissions, changing the planets atmospheric composition so dramatically that vegetation was irretrievably damaged.


Approximately 250 million years ago about 90 percent of the planet's animal and plant species ashore became extinct, the researchers said. Several theories have been offered as to what caused those extinctions, including volcanic eruptions, the impacts of asteroids or methane hydrate.

The scientists' new theory is based on a comparison of today's biochemical and atmospheric chemical processes.

"Our calculations show that airborne pollutants from giant salt lakes like the Zechstein Sea must have had catastrophic effects at that time", said study co-author Ludwig Weibflog of Germany's Helmholtz-Center for Environmental Research.

"The question as to whether the halogenated gases from the giant salt lakes alone were responsible for it or whether it was a combination of various factors with volcanic eruptions, the impact of asteroids or methane hydrate equally playing their role still remains unanswered," said Weibflog, who added, however, the effects of salt seas were previously underestimated.

The study led by Weibflog and Karsten Kotte of the University of Heidelberg appears in the Proceedings of the Russian Academy of Sciences.