Posted on 21 December 2011.
There’s no shortage of candidates for the cause of the mass extinctions of prehistory. But experts have found flaws in every one.
Asteroid impact clearly played a role in the Cretaceous-Tertiary (KT) extinction that wiped out the dinosaurs 65,000,000 years ago, though scientists differ on whether it actually caused the extinction because serious disruptions had begun 800,000 years before. Some researchers argue that giant basalt lava flows that poisoned the atmosphere and oceans played a central role in all five major extinctions. But no consensus exists on what forces triggered them.
Lurking in the background, however, is a quite plausible cause, one that certainly would have possessed the power to set off the volcanic activity, air pollution, sea level shifts, loss of oxygen in oceans, climate changes, and other phenomena associated with the extinctions. Yet this cause does not seem to have been proposed, and proving or disproving it will require a good deal of investigation. Curiously, nonetheless, a significant body of relevant research has already been carried out in a subject parallel to the extinctions. But that research languishes in a scientific limbo.
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