Initially, presbyornithids were believed to present a mix of characters shown by waterbirds,
shorebirds and
flamingos and were used to argue for an evolutionary relationship between these groups,[5] but they are now generally accepted to be
waterfowl closely related to modern ducks, geese, and
screamers.[6] They were generally long-legged, long-necked birds, standing around one meter high, with the body of a duck, feet similar to a
wader but
webbed, and a flat duck-like bill adapted for
filter feeding. At least some species were social birds that lived in large flocks and nested in colonies, while others like Wilaru were terrestrial and territorial.[6]
Specimens of presbyornithids have also been discovered from the
Lance Formation of
Wyoming.[7] Other possible
Eocene presbyornithids include Presbyornis mongoliensis from
Mongolia, Proherodius oweni and Headonornis hantoniensis from
England with the partial right
scapulaBMNH PAL 4989, but P. oweni is now considered as
Avesincertae sedis,[8] and the two other taxa are now referred to as stem group representatives of the
Phoenicopteriformes.[9][10]
^Hope, S. (2002). "The Mesozoic radiation of Neornithes". In Chiappe, L.M.; Witmer, L.W. (eds.). Mesozoic Birds: Above the Heads of Dinosaurs. Berkeley: University of California Press. pp. 339–388.
ISBN978-0520200944.