On the origins of the sabre-toothed felid model: functional anatomy of the hindlimb in Promegantereon ogygia (Felidae, Machairodontinae, Smilodontini) from the Late Miocene of Batallones-1 (Madrid, Spain)

The Spanish Late Miocene locality of Batallones-1 (Madrid, Spain) has yielded a very rich sample of large carnivorans, including hyaenids, mustelids, amphicyonids, ailurids, felines, and two species of sabre-toothed felids that represent the first radiation event of the subfamily Machairodontinae: Machairodus aphanistus and Promegantereon ogygia. The former was the size of a tiger and the top predator of the Batallones-1 community, whereas the latter was a much smaller animal, its body weight being similar to that of an extant puma. In the present paper, we study the functional anatomy of the hindlimb of P. ogygia compared to that of extant felines and pantherines of similar size. Our observations reveal that the hindlimb of this early sabre-toothed felid, unlike the relatively derived forelimb, show several primitive features also observed in the earliest felid, Proailurus lemanensis, thus highlighting the mosaic evolution of machairodontine morphology in this Late Miocene sabre-toothed felid.