Screamer
The screamers are a small family of birds, the Anhimidae. For a long time they were thought to be related to the Galliformes because of similar bills, but they are truly related to ducks (family Anatidae), most closely to the Magpie Goose (which some DNA evidence suggests are closer to screamers than to ducks). The family is exceptional within the living birds in lacking uncinate processes of ribs.
Read more about Screamer: Distribution and Habitat, Behaviour and Ecology, Status, Species