SOME 17,000 YEARS AGO, on a wall of Lascaux cave in southwestern France, an artist made a painting of a deer with fantastically elongated antlers. To modern eyes, it looks like an exaggeration or a parody, but it was an accurate representation of an animal that early Europeans knew well. Today we call it the Irish elk, or Megaloceros giganteus.
The biggest males weighed 1,500 pounds, about the same as an Alaskan moose, and they sported the largest antlers the world has ever known—12 feet across, weighing almost 90 pounds. They were shed and regrown annually. The females were 10 to 15 percent shorter than the males, without antlers.
As a name, Irish elk is a double misnomer. The animal thrived in Ireland but was not exclusively Irish, ranging across…