The saber-toothed “tiger” (Smilodon) had long, saber-like teeth — as did a couple other saber-toothed species — and those saber-like teeth seem to come with massive arms:
Back in 2010, Meachen-Samuels placed Smilodon fossils in an X-ray machine, and showed that it has extra-thick, reinforced bone in its upper arms, with large attachment points for its large muscles. It was a particularly butch cat.
The study confirmed the idea that Smilodon used its huge teeth in a very different way to its modern relatives. Living cats use their jaws to close the throat or nose of their prey, choking them to death. Their conical canines are well-suited to the task, able to withstand forces in all directions. Sabre-teeth, while they look formidable, were actually quite fragile. They were long and flattened, rather than short and conical. If the cat’s prey struggled, its teeth would have shattered. If the teeth hit bone during a bite, they would have shattered.
So Smilodon used the sabres like an assassin’s dagger rather than a swordsman’s blade, dispatching victims with quick stabs. Its big arms helped it to restrain its prey for the killing blow. Meachen-Samuels wondered if other sabre-toothed predators shared the same adaptations.
She compared the skeletons of 15 species of living cats with fossils from 8 species of sabre-toothed ones, 5 nimravids and 1 barbourofelid. Across the groups, Meachen-Samuels found that the species with the most exaggerated canines also had the most robust front legs and the widest paws. Based on the dimensions of these limbs, you could predict whether one of these animals had sabre teeth with almost perfect accuracy.