Causes and Consequences of Pleistocene Megafaunal Extinctions as Revealed from Rancho La Brea Mammals

The authors applied dental microwear texture analysis to carnivores from Rancho La Brea, comparing microscopic wear surfaces on the teeth of Smilodon fatalis and other predators across the deposit's chronology. Microwear records the physical properties of food consumed shortly before death, distinguishing flesh-dominated diets from heavy bone processing. Contrary to the food-stress narrative, the sabertooth microwear resembled that of modern cats that avoid extensive bone consumption, suggesting Smilodon was not desperately scraping carcasses clean in its final millennia. The findings complicated simple resource-depletion models of megafaunal extinction and showed that diet proxies can yield contradictory signals, underscoring the value of combining microwear, isotopes, and breakage data when reconstructing fossil felid ecology.