The sunbittern is a bittern-like bird of tropical regions of the Americas, and the sole member of the family Eurypygidae and genus Eurypyga. It is found in Central and South America, and has three subspecies. The sunbittern shows both morphological and molecular similarities with the kagu of New Caledonia, indicating a gondwanic origin, both species being placed in the clade Eurypygiformes.

The kagu or cagou is a crested, long-legged, and bluish-grey bird endemic to the dense mountain forests of New Caledonia. It is the only surviving member of the genus Rhynochetos and the family Rhynochetidae, although a second species has been described from the fossil record.