Dietary ecology of Smilodon across time and space: Additional perspectives from Smilodon gracilis and Smilodon fatalis in Florida.

Abstract

Smilodon, the iconic saber-toothed cat, was a Pleistocene apex predator comprised of three morphologically distinct species: Smilodon fatalis, Smilodon gracilis, and Smilodon populator. While at Rancho La Brea (RLB) the paleobiology of S. fatalis is analogous to African lions in terms of carcass utilization, far less is known about S. fatalis outside of southern California. Further, Smilodon gracilis specimens are rare and less studied throughout most of its former range. This study expands our understanding of Smilodon's dietary ecology in North America by using dental microwear texture analysis (DMTA) to quantify carcass utilization and feeding behavior via complexity (Asfc) and anisotropy (epLsar) in populations of S. gracilis and S. fatalis from Florida, USA. Results reveal that S. fatalis populations from Florida and RLB have indistinguishable diets across climatically disparate regions during the Pleistocene. Additionally, S. fatalis and S. gracilis in Florida appear indistinguishable based on dental microwear textures, suggesting both species exhibited a generalist feeding strategy despite their temporal and morphological differences. Lastly, microwear in S. gracilis demonstrates a shift away from a tougher and potentially harder diet (epLsar and Asfc) during the glacial Inglis 1A site, as compared to the interglacial Leisey Shell Pit 1A site-similar to previously documented dietary shifts in glacial and interglacial populations of S. fatalis at RLB. Collectively, our findings are consistent with the hypothesis that the dietary behavior of S. fatalis and S. gracilis was generally consistent across space and time, with more subtle dietary differences occurring during glacial versus interglacial periods.