Neogene geese and ducks (Aves: Anatidae) from localities of the Great Lakes Depression, western Mongolia

Abstract

New material of ducks and geese from Late Miocene-Early Pliocene localities of the Great Lakes Depression in western Mongolia is described and the previously described material is revised. This study confirms the presence of four goose species, four dabbling ducks, and three diving ducks. A large goose previously described as Heterochen vicinus is assigned to a separate genus, Heteroanser. Bonibernicla ponderosa is transferred to Anserinae, and North American Branta woolfendeni is regarded as a junior synonym of Bonibernicla ponderosa. The validity of two goose species, Anser devjatkini and A. liskunae, is confirmed and both are assigned here to the subgenus Chen. It is also shown that the holotype of Anas molesta actually belongs to a diving duck of the genus Aythya. The presence of Anas soporata in the Hyargas Nuur Formation is not confirmed.