Eurypygimorphae or Phaethontimorphae is a clade of birds that contains the orders

Phaethontiformes The Phaethontiformes are an order of birds. They contain one extant family, the tropicbirds (Phaethontidae), and one extinct family Prophaethontidae from the early Cenozoic. Several fossil genera have been described. The tropicbirds were tradit ...

(tropicbirds) and

Eurypygiformes Eurypygiformes is an order formed by the kagus, comprising two species in the family Rhynochetidae endemic to New Caledonia, and the sunbittern (''Eurypyga helias'') from the tropical regions of the Americas. Its closest relatives appear to b ...

(

kagu The kagu or cagou (''Rhynochetos jubatus'') 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, alt ...

and

sunbittern The sunbittern (''Eurypyga helias'') is a bittern-like bird of tropical regions of the Americas, and the sole member of the family Eurypygidae (sometimes spelled Eurypigidae) and genus ''Eurypyga''. It is found in Central and South America, and ...

) recovered by genome analysis. The relationship was first identified in 2013 based on their nuclear genes. Historically these birds were placed at different parts of the tree, with tropicbirds in

Pelecaniformes The Pelecaniformes are an order of medium-sized and large waterbirds found worldwide. As traditionally—but erroneously—defined, they encompass all birds that have feet with all four toes webbed. Hence, they were formerly also known by such n ...

and the kagu and sunbittern in

Gruiformes The Gruiformes are an order containing a considerable number of living and extinct bird families, with a widespread geographical diversity. Gruiform means "crane-like". Traditionally, a number of wading and terrestrial bird families that did ...

. Some genetic analyses have placed the eurypygimorph taxa in the controversial and obsolete clade

Metaves Metaves ("other birds") is a controversial group proposed by Fain & Houde (2004) and later rescued on the studies of Ericson ''et al.'' (2006)Ericson, P.G.P. ''et al.'' (2006Diversification of Neoaves: integration of molecular sequence data and f ...

, with uncertain placement within that group. More recent molecular studies support their grouping together in Eurypygimorphae, which is usually recovered as the sister taxon to Aequornithes within Ardeae.Prum, R.O. ''et al''. (2015
A comprehensive phylogeny of birds (Aves) using targeted next-generation DNA sequencing
Nature 526, 569–573.

References

Neognathae {{bird-stub