Two Old World vultures from the middle Pleistocene of northeastern China and their implications for interspecific competition and biogeography of Aegypiinae

ABSTRACT

Two new fossil crania of Old World vultures (Accipitridae, Aegypiinae), from the middle Pleistocene Jinniushan site of Liaoning Province, northeastern China, were studied. A new species of Aegypius, A. jinniushanensis, is erected and characterized by possessing a less developed processus zygomaticus and processus suprameaticus, as well as a relatively larger condylus occipitalis, compared with A. monachus. Another specimen, assigned to Torgos, is the first record of this genus from outside Africa. The presence of two large vultures, apparently in the same feeding group, in the Jinniushan faunal assemblage suggests that there were more opportunities for interspecific competition among scavengers in the middle Pleistocene of northeastern China than at present. By analogy with phylogenetically related modern vultures, we suggest that niche differentiation between the two extinct species may have reduced the degree of competition between them. The disappearance of the genus Torgos from northeast China might be the result of the Pleistocene extinction of a suite of large mammalian herbivores, and the loss of grassland and savannah from this region.

ACKNOWLEDGMENTS

We are grateful to personnel of the field group from the School of Archaeology and Museology at Peking University and the Cultural Relics and Archaeology Institute of Liaoning Province for discovering the specimens, H. Meijer and M. Spitzer for discussion, S. Emslie, F. Hertel, and T. Worthy for valuable comments. This work was supported partly by the National Natural Science Foundation of China (30870263, 31071877), and performed during a residency in the Division of Birds, National Museum of Natural History, Smithsonian Institution, Washington, D.C.

Handling editor: Trevor Worthy