Presbyornis pervetus

Presbyornis is an early relative of modern waterfowl (ducks and geese) from the Paleocene and Eocene of North America. Presbyornis combined a duck-like head with long, wading legs, and is known from bone beds suggesting it lived in large flocks. While Presbyornis itself has only been recovered in the Cenozoic, other presbyornithids have been found in the Late Cretaceous, making them one of the earliest diverging groups of crown-birds.