Curiously, the wild climate swings of the past few million years—in and out of punishing ice ages—have caused precious few extinctions. Unlike Isotelus rex or Dunkleosteus, which perished in earlier glaciations in earth history, woolly mammoths, giant ground sloths, enormous marsupials, and armadillos the size of cars seem to have survived the many swings between ice ages and warm interglacials of recent geological history with good humor, shifting their ranges to accommodate the finicky planet.
