Osteomyelitis in the manus of Smilodon populator (Felidae, Machairodontinae) from the Late Pleistocene of South America

The knowledge of the paleopathologies that affected large mammals during the Pleistocene of South America has increased in the last years, but most of the reported cases belong to the endemic clade Xenarthra. On the contrary, almost no case of diseases is known among representatives of other clades, such as Carnivora. Here we present and describe an inflammatory lesion in a left metacarpal IV assigned to the saber tooth Smilodon populator (Felidae) from the Late Pleistocene (ca. 100 ka; MIS 5) of Northeastern Argentina. The macroscopic and radiologic analyses reveal features consistent with chronic osteomyelitis, which in turn represents the first accurate record of an infectious process in a limb of this predator. This injury presumably caused lameness and loss of toe flexion, and considerably reduced the hunting abilities of this top predator, which used its robust forelimbs, particularly wide forepaws, and powerful back muscles to catch and bring down large prey.