The Permian extinction, which almost annihilated life on Earth more than 250 million years ago, happened over the course of 60,000 years - 10 times faster than earlier estimates, MIT scientists have found.
The largest mass extinction in the history of animal life occurred some 252 million years ago, wiping out more than 96 per cent of marine species and 70 per cent of life on land - including the largest insects known to have inhabited the Earth, researchers said.
Researchers at Massachusetts Institute of Technology (MIT) have determined that the end-Permian extinction occurred over 60,000 years - with an uncertainty of 48,000 years - practically instantaneous, from a geologic perspective.
The new timescale is based on more precise dating techniques, and indicates that the most severe extinction in history may have happened more than 10 times faster than scientists had previously thought.
"We've got the extinction nailed in absolute time and duration," said Sam Bowring, the Robert R Shrock Professor of Earth and Planetary Sciences at MIT and lead author.
In addition to establishing the extinction's duration, Bowring, graduate student Seth Burgess, and a colleague from the Nanjing Institute of Geology and Paleontology also found that, 10,000 years before the die-off, the oceans experienced a pulse of light carbon, which likely reflects a massive addition of carbon dioxide to the atmosphere.
This dramatic change may have led to widespread ocean acidification and increased sea temperatures by 10 degrees Celsius or more, killing the majority of sea life, researchers said.
The leading theory of what originally triggered the spike in carbon dioxide, among geologists and paleontologists has to do with widespread, long-lasting volcanic eruptions from the Siberian Traps, a region of Russia whose steplike hills are a result of repeated eruptions of magma.
To determine whether eruptions from the Siberian Traps triggered a massive increase in oceanic carbon dioxide, Burgess and Bowring are using similar dating techniques to establish a timescale for the Permian period's volcanic eruptions that are estimated to have covered over five million cubic kilometres.
In 2006, Bowring and his students made a trip to Meishan, China, a region whose rock formations bear evidence of the end-Permian extinction.
Bowring sampled rocks from this area, as well as from nearby alternating layers of volcanic ash beds and fossil-bearing rocks.
After analysing the rocks in the lab, his team reported in 2011 that the end-Permian likely lasted less than 200,000 years.
For the new study, Bowring and his colleagues reanalysed rock samples collected from five volcanic ash beds at the Permian-Triassic boundary.
The study was published in the journal Proceedings of the National Academy of Sciences.
