It Was Dangerous Being a Saber-Toothed Cat in Los Angeles 12,000 Years Ago

Like modern gray wolves, dire wolves — which “are not made-up beasts for ‘Game of Thrones,’” Brown said — were predators that caught and killed prey with their jaws. By contrast, saber-toothed cats (Smilodon fatalis), a species without close modern descendants, are thought to have ambushed large prey using powerful back and forelimb muscles to pull down and position the animals for killing bites. Saber-toothed cats were heavier than dire wolves, and are believed to have used their large forelimbs to pin down their prey.

“Consequently, we expected injuries in saber-toothed cats would likely be concentrated in the shoulder, anterior ribcage and spine, while those of dire wolves were likely to be more evenly distributed across all four limbs,” said senior author Blaire Van Valkenburgh, a UCLA professor of ecology and evolutionary biology. “In addition, head injuries were likely to be more common in the dire wolves because they were at risk of being kicked while biting the hind¬quarters during a chase. Caitlin and Mairin’s analyses supported these conclusions.”

While previous studies of these animals have demonstrated that injuries likely occurred during fierce battles, the UCLA biologists are the first scientists to study enough bones to determine how frequently the injuries occurred.

The finding that saber-toothed cats sustained more frequent injuries than dire wolves suggests that the cats faced a much greater risk of injury over their lifetimes. It is thought that this is because the cats killed relatively larger prey and may have done so alone, rather than as part of a group. Instead of exhaust¬ing their prey through a long pursuit, the cats ambushed prey at a short distance and immobilized them using their massive forelimbs before killing the prey with precisely positioned bites, the researchers said.

“Dire wolves hunted in packs, which were essentially a running set of jaws,” Van Valkenburgh said. “They had to do everything with their mouths. So we expected to see injuries where they were kicked in the head, and maybe injuries in the limbs, either by being kicked or by tripping during a hunt.”

Saber-toothed cats are not tigers, Balisi noted, and are only distantly related to modern cats.

The biologists studied only trauma, injuries that likely resulted from hunting. This trauma included fractures that had healed, severe or chronic muscle strain, and osteoarthritis.