First Old World record of the poorly known, swan-sized anseriform bird Paranyroca from the late Oligocene/early Miocene of France

摘要

A tarsometatarsus of a large anseriform bird from the late Oligocene/early Miocene of the Saint-Gerand-le-Puy area in France is assigned to the distinctive taxon Paranyroca, which was before only known from the early Miocene of North America. Paranyroca may be a stem group representative of Anatidae and its tarsometatarsus exhibits a peculiar character mosaic, with an Anhimidae-like hypotarsus and an Anatidae-like distal end. With regard to these features, the bone resembles the tarsometatarsus of another anseriform bird from Saint-Gerand-le-Puy, which was described as Cygnopterus alphonsi but has not yet been compared with Paranyroca in the original description. C. alphonsi was originally identified as a swan, but this classification has subsequently been contested and here it is proposed that the species is more closely related to Paranyroca.