On the true affinities of Chenornis graculoides Portis, 1884, and Anas lignitifila Portis, 1884—an albatross and an unusual duck from the Miocene of Italy

Abstract

ABSTRACTWe revise two avian fossils from the Miocene of Italy, which were described as anseriform birds by Alessandro Portis in 1884. One of these, the holotype of Chenornis graculoides, from the early Miocene of Ceva (Piemonte, northwestern Italy), is found to be a stem group representative of Diomedeidae (albatrosses), and is here classified as Plotornis graculoides, comb. nov. The fossil allows the recognition of previously unknown osteological details of Plotornis and is the first record of an albatross from the Mediterranean Sea. The second specimen, from the late Miocene of Montebamboli (Toscana, central Italy), was described as Anas lignitifila and is here recognized as a highly unusual anseriform that is transferred to the new taxon Bambolinetta. The species belongs to Anatinae but is outside a clade including Anatini, Mergini, and Aythyini. It is distinguished from all extant Anseriformes by unusually robust wing bones, and the ulna and radius appear to have been very short. The Montebamboli site was part of the Tusco-Sardinian Island in the late Miocene, and we consider it likely that Bambolinetta lignitifila was an insular species with reduced flight capabilities, possibly specialized for wing-propelled diving.