Eurypygimorphae or Phaethontimorphae is a
clade
A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...
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 trad ...
(tropicbirds) and
Eurypygiformes (
kagu 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 ...
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, 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
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