Brief communication: Plio-Pleistocene eagle predation on fossil cercopithecids from the Humpata Plateau, southern...

Recent studies suggest a large raptor such as the crowned eagle (Stephanaoetus coronatus) was responsible for collecting at least a portion of the primate fauna from the South African fossil site of Taung, including its lone hominin specimen. This taphonomic signature at Taung is currently regarded as a unique and, most likely, isolated case in primate and human evolution. However, the activities of large, carnivorous birds should also be detectable at other primate fossil localities in Africa if raptors have been a strong selective force throughout primate evolution. Over the last 60 years, a collection of extinct cercopithecids has been assembled from several cave breccias on the Humpata Plateau in southern Angola. The material, dated near the Plio-Pleistocene boundary, includes an assortment of craniodental and postcranial remains variably assigned to Papio (Dinopithecus) cf. quadratirostris, Parapapio, Cercopithecoides, and Theropithecus. We compare the Angolan and Taung material to remains of extant primates killed by crowned eagles in the Ivory Coast's Tai National Park. Our analysis indicates that the size distribution and composition of fauna from the localities is quite similar and that there are striking consistencies in damage to the crania from each site. The absence of large bodied (>20 kg) primates and other mammalian taxa at the Taung hominin locality and Tai, and their rarity in Angola, combined with the strong likelihood that raptor nests were positioned near fissure openings at both fossil localities, provides additional support for eagle involvement. On the basis of this evidence, we conclude that at least some of the Angolan cercopithecids were most likely raptor prey and hypothesize that raptor predation has been a strong and perhaps underappreciated selective force during the course of primate evolution.