A chomped chimp: New evidence of tooth marks on an adult chimpanzee (Pan troglodytes verus)

Objectives To describe and interpret previously unreported marks on the dry cranium of an adult chimpanzee (Pan troglodytes verus) from Cote d'Ivoire at the Smithsonian's National Museum of Natural History (USNM 450071). Materials and Methods All marks on the cranium were documented and assessed through physical examination of the specimen, photography, micro-computed tomography (micro-CT), and 3D laser scanning. Pits and punctures were measured with digital calipers for comparison with published carnivore tooth mark measurements. Results The cranium shows perimortem or postmortem damage to the temporal, occipital, and maxillary regions that is not recent. Size and color variation in the marks suggest two damage events, possibly involving chewing by different animals, at least one of which was a large-bodied mammal. The 22 tooth pits and punctures (0.89-8.75 mm in maximum length and 0.88-6.63 mm in breadth) overlap in size with those inflicted by wild leopards, the most significant predators of common chimpanzees due to their largely overlapping ecological distributions. Conclusions Based on qualitative and quantitative evidence, we conclude that leopards are the most likely cause of the most prominent marks on the cranium. However, we cannot rule out the additional possibility of other chimpanzees, although there are no published studies of chimpanzee tooth marks for direct comparison. This study is the most extensive documentation to date of a modern adult chimpanzee skull exhibiting tooth marks by a large mammal, thus providing new evidence to help identify and interpret other events of predation and scavenging of large-bodied apes in the modern and fossil records.