Until about 10,000 years ago, the saber-tooth cat Smilodon fatalis was a fearsome predator in what is now the American West.
More than 3,000 fossilized cats have been pulled from the acrid ooze of the La Brea tar pits in California, and researchers studying them have long pictured Smilodon as a lion-like hunter, chasing bison and horses out on open grasslands.