The researchers did this with a new technique called "dental microwear texture analysis." It uses a high-powered microscope to produce three-dimensional images of tooth surfaces. These images reveal tooth wear patterns that suggest how, and what, the animals often ate.
Chowing down on red meat, for example, produces small parallel scratches, while chomping on bones adds larger, deeper pits.
DeSantis and others previously found that the dental wear patterns of the extinct American lions closely resembled those of modern cheetahs, which are extremely finicky eaters that mostly consume tender meat and rarely gnaw on bones.
Saber-tooth cats were instead similar to African lions that chewed on both flesh and bone.
Some variation existed among the La Brea cougars, but many showed wear patterns closer to those of modern hyenas, which consume almost the entire body of their prey, bones and all.
Do Some Animals Get a Taste for Human Blood?
"This suggests that the Pleistocene cougars had a 'more generalized' dietary behavior," DeSantis said. "Specifically, they likely killed and often fully consumed their prey, more so than the large cats that went extinct."