The Earliest Asian Duck (Anseriformes: <Emphasis Type="Italic">Romainvillia</Emphasis>) and the Origin of Anatidae

A new species of the extinct duck Romainvillia from the Upper Eocene of Kazakhstan is described. This is the earliest duck from Asia, the first record of Romainvillia beyond France and the first reliable evidence of the presence of Romainvilliinae (regarded here as family) in Asia. This occurrence shows a wide range of Romainvillia and suggests a greater similarity of Late Eocene faunas of Western Europe and Asia than it was previously thought. The origin of Romainvilliidae and their presumable descendants Anatidae may be connected with adaptation to a new biotope, the shallowing Late Eocene epicontinental Asian basins (due to a global decrease in sea level).