Modern Australia lacks big land predators, but until about 30,000 years ago, the continent was ruled by Thylacoleo carnifex, the marsupial "lion." Several well-preserved skeletons of the leopard-size beast have been found. Now, a newly discovered cave painting offers a glimpse of the animal's external appearance. In June 2008, Tim Willing, a naturalist and tour guide, photographed an ancient painting on a rockshelter wall near the shore of northwestern Australia. Kim Akerman, an independent anthropologist based in Tasmania, says the painting unmistakably depicts a marsupial lion. It shows the requisite catlike muzzle, large forelimbs, and heavily clawed front paws. And...
