Researchers from the Massachusetts Institute of Technology (MIT) have found out that the Permian extinction, which wiped out almost 96 percent of marine and terrestrial life of that era, happened in just 60,000 years instead of 200,000 years.
The new estimate is much faster that what scientists have previously believed. The timescale, put together by modern dating techniques, suggests that the extinction happened instantaneously and it did not give the animals a chance to adapt in order to survive.
To get a more precise estimate on the duration of the extinction, researchers led by Prof. Robert R. Shrock and Sam Bowring travelled to China to look into evidences of the Permian extinction in rock formations. They gathered rock samples and analyzed it. He initially reported in 2011 and that the extinction has lasted for 200,000 years.
However, using more precise and accurate dating instruments, the team calculated new estimates after re-analyzing the rock samples that they have gathered. The researchers pulverized the rocks and then isolated the uranium isotopes from the lead isotopes to measure their ratio. The ratio of the isotopes was then used to calculate the age of the rock sample.
Results of the new analysis found out that the extinction period lasted for 60,000 years only, give or take 48,000 years.
This new timeline supports the theory that the extinction was caused by a series of chain reactions triggered by massive volcanic eruptions in the Siberian Traps. The eruptions caused an increase of carbon dioxide in the atmosphere and this, in turn, led to a worldwide acidification of the atmosphere and warmer sea temperatures.
In order to confirm if the Siberian volcanic eruptions indeed started the extinction period, Bowring and his colleague from the Nanjing Institute of Geology and Paleontology, Seth Burgess, will work on determining the exact timeline of the Siberian Traps eruptions. The timeline for the eruptions will then be compared with the timeline for the extinction to see if they will overlap.
"We've refined our approach, and now we have higher accuracy and precision," Bowring said in a press release. "You can think of it as slowly spiraling in toward the truth."
This study was published in the Feb. 10 issue of the Proceedings of the National Academy of Sciences.
