Concealed weapons: A revised reconstruction of the facial anatomy and life appearance of the sabre-toothed cat Homotherium latidens (Felidae, Machairodontinae)

Abstract

Homotherium is one of the sabre-toothed felid genera with a more extensive overlap in space and time with species of our own genus Homo, who must have been familiar with the animal, but now we only have its fossil remains to infer its life appearance. A revised reconstruction of the soft tissue and life appearance of Homotherium latidens is proposed here on the basis of new observations on the anatomy of extant carnivorans and a re-evaluation of the fairly preserved skull and mandible from the classical Late Pliocene site of Perrier (France). This fossil specimen provides some of the best information available about the morphology of the skull and mandible. Like other large early specimens of Homotherium, it has enormous upper canines relative to skull size and high-crowned enough to protrude beyond the lips in the living animal. On the other hand, observations of facial expressions in living big cats and dissected specimens show that, contrary to previous conclusions, the soft tissue around the mouth and the lower lip in particular can cover the upper canines of large felids, even when those are considerably high-crowned. Such observations lead us to propose a revised hypothesis about the life appearance of Homotherium and other sabre-toothed carnivorans, where the upper canines may have been covered in life when the mouth was completely closed.