Diving ducks from the Middle Miocene of western Mongolia

Medium-sized diving ducks from the Middle Miocene of the Sharga locality (western Mongolia) are described. Sharganetta mongolica gen. et sp. nov. and Nogusunna conflictoides gen. et sp. nov. are evolutionary more advanced than the thoroughly studied Early Miocene genus Mionetta, but more primitive than Anatinae and Oxyurinae. The humeral morphology gives evidence of an aberrant position of the two new genera. Another taxon, Protomelanitta gracilis gen. et sp. nov. presumably belongs to basal Mergini.