Saber-Toothed Cats Had Bad Backs and Worse Luck

A spinal nerve tumor is already one of the rarest diagnoses in modern medicine, and most doctors will go their entire careers without seeing one. It causes pain first, then slowly robs function from whatever limb the affected nerve controls. In humans, researchers estimate it shows up in just 0.22 to 0.38 cases per 100,000 people.

Researchers examining thousands of bones from the La Brea Tar Pits in California found signs of that same tumor in three Smilodon fatalis, the saber-toothed cat, sitting inside a broader pattern of skeletal abnormalities that may point to inbreeding as the species approached extinction.

The team identified 3,722 vertebrae representing at least 849 adults and examined them for pathological changes. They found 32 vertebrae with incompletely developed arches, 48 fused "block" vertebrae and 226 "transitional" vertebrae where the bone formed incorrectly.

Most strikingly, three vertebrae showed widened foramina, the holes that allow nerves to pass through the spine, a signature of nerve tumor growth eroding bone from the inside. Within the La Brea sample, estimated prevalence reached 353 cases per 100,000, more than 900 times the human rate.

Researchers think the spinal problems may be a consequence of inbreeding. As the saber-toothed cat population shrank and became more isolated, harmful genetic variants may have accumulated, producing the unusually high rate of skeletal abnormalities found in the La Brea sample.

The nerve tumors could have caused chronic pain and impaired movement, and researchers suspect that made trapped prey especially tempting to a predator already struggling to hunt normally. Lead author Hugo Schmökel has described the finding as evidence that Smilodon wasn't just a formidable hunter but an animal with real physical limitations.

The saber-toothed cat looked like a perfect killing machine. Its skeleton tells a different story.

Read the full story at Discover Magazine, July 2026

Hot Take: Anyone who's ever hurt their back knows the temptation: don't bend that way, don't lift that thing, don't do anything stupid. Now imagine being a saber-toothed cat with chronic spinal pain and seeing an easy meal stuck in a tar pit.