Via PhysOrg:
... researchers at MIT have determined that the end-Permian extinction occurred over 60,000 years, give or take 48,000 years—practically instantaneous, from a geologic perspective. The new timescale is based on more precise dating techniques,
Read more at: http://phys.org/news/2014-02-end-permian-extinction-yearsmuch-faster-earlier.html#jCp