Inside the Painful End of the Saber-Toothed Cat

Saber-toothed cats may have been limping toward extinction long before they vanished. A new study of more than 3,700 vertebrae from Smilodon fatalis found at Los Angeles' La Brea Tar Pits documents high rates of congenital spinal deformities and a few rare nerve tumors—conditions researchers link to sustained inbreeding as populations shrank near the end of the last ice age, Science reports. The abnormalities likely made movement painful and hunting difficult, pushing the giant predators to rely on easy meals like animals already mired in tar, according to the study published in Frontiers in Veterinary Science.

Tumors on spinal nerves are rare in modern humans, with an occurrence of 0.38 per 100,000 individuals. The rate was 1,000 times higher in the saber-toothed cat sample at 353 per 100,000 individuals, per Science News, which notes that two of the three fossils bearing evidence of tumors date to 12,000 and 13,000 years ago, not long before the species went extinct. While it's unclear whether these abnormalities affected saber-toothed cats more broadly, experts say the study offers a rare window into the health effects of population decline—an ancient warning that today's embattled big carnivores could face a similar genetic squeeze.