Aythya
Aythya is a genus of diving ducks. It has twelve described species. The name Aythya comes from the Ancient Greek word αυθυια, which may have referred to a sea-dwelling duck or an auklet.
Aythya shihuibas was described from the Late Miocene of China. Zelenkov transferred the species Anas denesi Kessler, known from the late Miocene of Hungary, to the genus Aythya. An undescribed prehistoric species is known only from Early Pleistocene fossil remains found at Dursunlu, Turkey; it might however be referrable to a paleosubspecies of an extant species considering its age.
The Miocene "Aythya" arvernensis is now placed in Mionetta, while "Aythya" chauvirae seems to contain the remains of two species, at least one of which does not seem to be a diving duck.
The genus Aythya was introduced in 1822 by the German zoologist Friedrich Boie. The type species is the greater scaup.''Aythya'' species
Phylogeny
Based on the Taxonomy in Flux from John Boyd's website.