Indeed. I don't have any sources off hand, but I believe the extinction lasted tens of thousands of years. And was only partially set off/caused by the impact

Indeed. I don't have any sources off hand, but I believe the extinction lasted tens of thousands of years. And was only partially set off/caused by the impact. There have also been other mass extinction events, each lasting long periods of time on the "lifetime" scale, but are still just "relatively short periods of time" on a geologic scale. [edit] here's some good reading for you: http://en.wikipedia.org/wiki/Extinction_event http://en.wikipedia.org/wiki/Extinction_event and the event discussed in the article: http://en.wikipedia.org/wiki/Cretaceous%E2%80%93Paleogene_extinction_event#Alternative_hypotheses http://en.wikipedia.org/wiki/Cretaceous%E2%80%93Paleogene_ex...