of animals kno, never to return. Evenabout a t species —t en masse. It isas close as otal obliteration.

    “It ruly, a mass extinction, a carnage of a magnitude t roubled tey. t icularly devastating to sea creatures.

    trilobites vanisoget. Virtually all otaggered. Altogeter, it is t t Eart 52percent of its families—t’s t of t cer)—and per of all its species. Itime—as mucy million years by one reckoning—before speciestotals recovered.

    ts need to be kept in mind. First, t informed guesses. Estimates fort toas  knoion t perisalking about t individuals. For individuals toll could be mucically total. t survived to t ptery almost certainlyoence to a few scarred and limping survivors.

    In betinctionepisodes—t so devastating to total species numbers, but often critically  certainpopulations. Grazing animals, including  in t about five million years ago. o a single species,  t for a time it teetered on tory   grazing animals.

    In nearly every case, for botinctions and more modest ones, le idea of er stripping out t notions till more t caused tinction events ts. At leasttential culprits ified as causes or prime contributors: globalionkno leaks of meteor and cometimpacts, runarophic solar flares.

    t is a particularly intriguing possibility. Nobody knoy engine and its storms are commensurately enormous. A typical solar flare—somet even notice on Eart of a billiono space a ons or so of murderous icles. tospmosp tospace or steer to it is t t an unusually