more than 96 percent of marine

species and 70 percent of land

species disappeared in a

geological instant. This event

the so-called end-Permian mass

extinction or more commonly

known as, "The Great Dying"

remains the most severe

extinction event in Earth's

history, but its direct cause

has remained a mystery.

Scientists suspect massive

volcanic activity in an area of

Russia called The Siberian Traps

may have had a role in the

Great Dying by raising the air

and sea temperatures and

releasing toxic amounts of

greenhouse gases into the

atmosphere of a very short

period of time. However, until

now, scientists could not

pinpoint when exactly the mass

extinction and eruptions happened

in relation to each other.

MIT researchers have now

determined the Siberian Traps

erupted at the right time and

for the right duration to have

been a likely trigger for the

end-Permian extinction.

By determining the age of rocks

in the region the team came up

with an exact timeline for the

start and end of the eruptions.

They found that the Siberian

Traps began to erupt around

300 thousand years before the

start of the extinction.

These initial eruptions were

followed by massive outpourings

of lava covering a region as

large as the United States. This

area likely kept erupting in

fits and starts finally petering

out about 500 thousand years

after the extinction's end.

While the Siberian Traps has

long been a suspected cause of

the end-Permian extinction the

team says its new timeline is

in essence a smoking gun,

placing the eruptions in the

right place and time to have

been the extinction's main

trigger. Next, the team hopes

to determine the exact tempo of

eruptions, to perhaps identify

a tipping point int he planet's

climate leading up to the

mass extinction.