Authentic mega-killers kept their mouths shut

Robin and the Honey Badger respond: “Fang-baring varies greatly in extant Carnivora. For example, some families, such as the bears, show no fang-baring expressions in interspecific conflict. And even within the family Felidae, certain species fang-bare extremely readily, whereas others of similar body size and canine length fang-bare in interspecific conflict extremely reluctantly if at all. In the case of sabretooth cats in the genus Smilodon, there are three main reasons to doubt that fang-baring occurred at all, let alone in warnings to other species. Firstly, it’s unlikely that the canines were used in self-defence against other predators. This is because these teeth were extremely specialised for killing large herbivores and would have been too cumbersome as well as too fragile to be used for rapid snapping or stabbing, or other methods of sparring; indeed these teeth were probably a liability rather than an asset in brawling. Secondly, the main weapons used by Smilodon, in fights with conspecifics and other Carnivora, were probably the self-sharpening claws, which were extremely large on the forefeet. And thirdly, the function of fang-baring in felids is to show the full length and sharpness of the canines. Because in sabretooth cats the upper canines projected permanently from the lips while the lower canines were diminutive, such display seems pointless whether directed intra- or interspecifically. In its bid for dramatic appeal, the usual depiction of fang-baring by Smilodon consequently risks being superfluous and pseudo-scientific. In future it would be more realistic – and ultimately no less impressive – to portray Smilodon keeping its mouth closed in aggressive and defensive postures.”