Myrmecophagous microwear: implications for diet in the hominin fossil record

An increasing body of data supports the concept that early humans ate invertebrate prey items, especially insects, and that insects may have been a substantial protein source. Insects are ubiquitous throughout the landscape and of high nutritional value. Given that all modern apes and many human groups eat insects, it is likely that early hominins did as well. However, it is unknown how much, which type(s), and what foraging strategy was utilized to obtain invertebrate prey. Given that gross masticatory anatomy of early hominins, like modern apes, fails to reflect their insectivorous proclivities, dental microwear analysis might be a useful tool for identifying this behavior in our fossil ancestors. Dental microwear data was collected on three primarily myrmecophagous mammals and compared to the literature on other faunivorous, frugivorous, and folivorous species. Results indicate that myrmecophagous species have comparable pit frequencies with other faunivores and pit frequency generally distinguishes them from folivores but not all frugivores. Additionally, myrmecophagous mammals have unusually high feature densities, like other faunivores, and density is the microwear signal most suggestive of some sort of faunivory.