National Geographic

The Ultimate Cold Case

Around 252 million years ago, as many as 96 percent of all species on Earth became extinct. For my new “Matter” column in the New York Times, I write about the scientists who are trying to solve this great murder mystery, and what their work may tell us about how the planet may respond to our own disruptions. Check it out.

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  1. David Bump
    February 21, 2014

    Fascinating. Am I correct in understanding that an estimate of 60Ky with “a margin of error of 48″Ky means the period could be as short as 12Ky or as long as 108Ky? Even the longer period would be only about half the time that, just a few years ago, seemed strikingly fast — the error margin at that time allowed for an event of less than 100Ky, which to a palaeontologist seems like overnight. The 12Ky end may sound like just a statistical curiosity, but, for a smaller but more recent comparison, consider how fast the North American Megafauna of 13Kya disappeared.
    The Ammonite fossils and the Demogorgon here raise some head-scratchers, too, in comparison with the 65Mya dino extinction. As with Demogorgon and other large mammal-like reptiles, the extinction seemed to hit the most successful kinds of animals up to that point the hardest. The dino-killer also knocked out the ammonites, which had survived the much worse P/T event, but avian dinosaurs (“birds”), crocodilians, and snakes survived (and produced giant descendants).

    Then there’s the second greatest extinction event, almost twice as far back (443Mya, the Ordovician), for which there seems to be no volcanic or astrobleme-marked catastrophe, but there was an ice age, which has been blamed on a gamma ray burst.

    Poor little late-Triassic extinction, just 30My after the great P/T, doesn’t seem to get much press, but like the dino-killer, it knocked out an estimated 50% of the species and ushered in the Age of the Dinosaurs, right?

    How about the Ediacaran fauna? Too little known, from too few sites (just Australia and China?), to put “global extinction” in its epitaph?

  2. Wilson
    February 22, 2014

    A mass extinction that took place over about 60,000 years, probably caused by a sudden – in geological terms – surge of carbon dioxide?

    This story makes me wonder how much fossil (and artifactual) evidence there will be of humanity’s existence, 250 million years from now.

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