COMPARISONS OF HINDLIMB MUSCLE MAPS OF SMILODON FATALIS WITH THOSE OF NEOFELIS NEBULOSA, AND FELIS CATUS

Smilodon fatalis is a Rancho La Brean saber-toothed cat with robust extremities and a short tail, and is believed to be an ambush predator. In this study, select pelvic, femoral, and tibial muscle attachment sites were determined for Smilodon fatalis based on osteological muscle scars and comparisons with muscle attachment site maps developed for Neofelis nebulosa (clouded leopard) and Felis catus (domesticated cat). Careful dissection of two specimens of the clouded leopard and three domestic cats demonstrated that the muscle attachment locations, relative muscle scar surface areas and proportional muscle weights were remarkably similar. Comparison of Smilodon muscle scar locations and relative surface areas with those of the clouded leopard and domestic cat showed that it was also quite similar. Our analytical methods appear valid because muscle analysis parameters of the three felid species were different from those of a non-felid species, the black-footed ferret (Mustela nigripes). As these comparisons are made between two similar extant species and the extinct Smilodon, we are confident that our estimation of the muscle attachment sites in Smilodon is reasonably accurate. In addition, we found that the attachment sites of several muscles in Smilodon showed increased levels of rugosity compared to the clouded leopard and domestic cat, supporting the concept that this animal may have been an ambush predator that required more robust muscles to leap at and grapple with prey.