A Strigogyps-like bird from the middle Paleocene of China with an unusual grasping foot

ABSTRACT

We describe a new avian species, Qianshanornis rapax, gen. et sp. nov., from the middle Paleocene Wanghudun Formation of the Qianshan Basin in Anhui Province, China. The holotype consists of an incomplete articulated foot and a few associated bones, mainly of the leg, wing, and pectoral girdle. Qianshanornis rapax is characterized by a derived foot morphology and may have had a hyperextendible second toe, which has so far only been reported for some Mesozoic taxa. The new species is markedly different from all other known Cenozoic birds and is here classified in the new taxon Qianshanornithidae. The leg bones, especially the distal end of the tibiotarsus, most closely resemble those of Strigogyps (Ameghinornithidae) from the Eocene, and possibly Oligocene, of Europe, but unlike the latter, the much smaller Q. rapax appears to have had well-developed flight capabilities.

ACKNOWLEDGMENTS

We thank our colleagues who participated to the Sino-Belgian paleontological expeditions in Anhui province of 2010 and 2011, including Y. Li, Q.-Q. Zhang, P. Missiaen, N. Van Hoey, and R. Smith. We thank S. Tränkner for taking the photographs and E. Brahm for access to Messel fossils. The Strigogyps dubius cast was provided by C. Mourer-Chauviré (to D. S. Peters at Senckenberg). This paper is a contribution to a Sino-Belgian bilateral research project supported by the Chinese Ministry of Science and Technology (2009DFA32210) and the Belgian Federal Science Policy Office (BL/36/C54). We thank J. Noriega and an anonymous reviewer for comments on the manuscript.

Handling editor: Trevor Worthy.