is this the event they think they found a possible impact crater for which is now split between antarctica and australia (connected at the time of the event?
I guess this will have to be changed now, but here you go:
The PermianTriassic (PTr) extinction event, informally known as the Great Dying, was an extinction event that occurred 251.4 million years ago,[1][2] forming the boundary between the Permian and Triassic geologic periods. It was the Earth’s most severe extinction event, with up to 96 percent of all marine species[3] and 70 percent of terrestrial vertebrate species becoming extinct; it is the only known mass extinction of insects.[4][5] 57% of all families and 83% of all genera were killed off. Because so much biodiversity was lost, the recovery of life on earth took significantly longer than after other extinction events.[3] This event has been described as the “mother of all mass extinctions”.[6] The pattern of extinction is still disputed,[7] as different studies suggest one[1] to three[8] different pulses. There are several proposed mechanisms for the extinctions; the earlier peak was likely due to gradualistic environmental change, while the later was probably due to a catastrophic event. Possible mechanisms for the latter include large or multiple bolide impact events, increased volcanism, or sudden release of methane hydrates from the sea floor; gradual changes include sea-level change, anoxia, increasing aridity,[9] and a shift in ocean circulation driven by climate change.
http://en.wikipedia.org/wiki/Permian%E2%80%93Triassic_extinction_event