Cayaoa bruneti

† Cayaoa bruneti is an extinct diving duck from the Miocene of Chubut Province, Patagonia, Argentina. This member of the family Anatidae was a specialized herbivorous diving bird adapted to feeding on aquatic vegetation in deep water, analogous to modern pochards or scoters. Its discovery documents the early Cenozoic diversification of anatid waterfowl in South America, a continent that became isolated during much of the Cenozoic and evolved a distinctive endemic avifauna.