Cousteauvia kustovia: A Diving Duck from the Late Eocene of Kazakhstan.
Waterfowl (order Anseriformes) are characteristic elements of modern Avian faunas and are among the most common Birds in the late Cainozoic fossil record. The group comprises three commonly recognized living families, which may be classified within two suborders Anhimae (with one family Anhimidae, Screamers) and Anseres (with families Anseranatidae, Magpie Geese, and Anatidae, all other Ducks, Geese, and Swans). The early (pre-Late Oligocene) fossil record of the Anseriformes is rather scanty, and thus the early diversity and disparity of the group remains poorly known. Most early-diverged Palaeocene to early Eocene Anseriforms (Presbyornis isoni, Anatalavis oxfordi, Conflicto antarcticus, Naranbulagornis khun) were relatively large-bodied Birds, and the exceptionally well-studied smaller Presbyornithidae are characterized by highly mosaic and apparently somewhat aberrant postcranial morphology, in which they rather resemble Waders and Flamingoes.