Sudden Mass Extinction Event Discovery

Sleen writes: "A new study that will appear in today's issue of the journal Science reports that the mass extinction event that preceded the age of the dinosaurs was much more sudden than expected. This article has some preliminary details. The dinosaurs actually survived this event and went on to be quite successful. But the small mammal-like reptiles did not. At this point they don't know if this cataclysm was caused by an asteroid, like in the case of 65mya at the KT boundary, or if it was caused by excessive volcanism. In the case of the dinosaur extinctions, they were on their way down when the asteroid hit, perhaps being the last straw. But this earlier event that somehow wiped out up to 80% of life on earth didn't kill them off. Interesting..."