Otidae is a clade that includes the superorders Otidimorphae and Strisores. It was identified in 2014 by genome analysis. Earlier it was thought that Strisores was closely related to birds such as pigeons, flamingos, tropicbirds, and the sunbittern and kagu in the taxon Metaves, but subsequent work has provided evidence that Metaves is polyphyletic. Although analyses of genome data provided relatively high support for monophyly of Otidae, indicating that it occupies a basal branch of the clade Passerea, other analyses of large data matrices have not recovered a clade comprising Otidimorphae and Strisores, raising questions about the monophyly of Otidae.
The mesites (Mesitornithidae) are a family of birds that are part of a clade (Columbimorphae) that include Columbiformes and Pterocliformes. They are smallish flightless or near flightless birds endemic to Madagascar. They are the only family with more than two species in which every species is threatened.
Neoaves is a clade that consists of all modern birds with the exception of Paleognathae and Galloanserae. Almost 95% of the roughly 10,000 known species of extant birds belong to the Neoaves.
Aequornithes, or core water birds, are defined as "the least inclusive clade containing Gaviidae and Phalacrocoracidae".
The order Falconiformes is represented by the extant family Falconidae and a handful of enigmatic Paleogene species. Traditionally, the other bird of prey families Cathartidae, Sagittariidae (secretarybird), Pandionidae (ospreys), Accipitridae (hawks) were classified in Falconiformes. A variety of comparative genome analysis published since 2008, however, found that falcons are part of a clade of birds called Australaves, which also includes seriemas, parrots and passerines. Within Australaves falcons are more closely related to the parrot-passerine clade (Psittacopasserae), which together they form the clade Eufalconimorphae. The hawks and vultures occupy a basal branch in the clade Afroaves in their own clade Accipitrimorphae, closer to owls and woodpeckers.
Australaves is a recently defined clade of birds, consisting of the Eufalconimorphae as well as the Cariamiformes. They appear to be the sister group of Afroaves. As in the case of Afroaves, the most basal clades have predatory extant members, suggesting this was the ancestral lifestyle; however, some researchers like Darren Naish are skeptical of this assessment, since some extinct representatives such as the herbivorous Strigogyps led other lifestyles. Basal parrots and falcons are at any rate vaguely crow-like and probably omnivorous.
Afroaves is a clade of birds, consisting of the kingfishers and kin (Coraciiformes), woodpeckers and kin (Piciformes), hornbills and kin (Bucerotiformes), trogons (Trogoniformes), cuckoo roller (Leptosomiformes), mousebirds (Coliiformes), owls (Strigiformes), raptors (Accipitriformes) and New World vultures (Cathartiformes). The most basal clades are predatory, suggesting the last common ancestor of Afroaves was also a predatory bird.
Telluraves is a recently defined clade of birds defined by their arboreality. Based on most recent genetic studies, the clade unites a variety of bird groups, including the australavians as well as the afroavians. They appear to be the sister group of the Ardeae.
Columbea is a clade suggested by genome analysis that contains Columbiformes, Pteroclidae (sandgrouse), Mesitornithidae (mesites) and Mirandornithes. Until their recent placement as the sister taxon to Passerea, in the last decade various genetic analysis found them to be in the obsolete clade Metaves.
Eurypygimorphae or Phaethontimorphae is a clade of birds that contains the orders Phaethontiformes (tropicbirds) and Eurypygiformes 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 and the kagu and sunbittern in Gruiformes. 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.
Phaethoquornithes is a clade of birds that contains Eurypygimorphae and Aequornithes, which was first recovered by genome analysis in 2014. Members of Eurypygimorphae were originally classified in the obsolete group Metaves, and Aequornithes were classified as the sister taxon to Musophagiformes or Gruiformes.
Coraciimorphae is a clade of birds that contains the order Coliiformes (mousebirds) and the clade Cavitaves. The name however was coined in the 1990s by Sibley and Ahlquist based on their DNA-DNA hybridization studies conducted in the late 1970s and throughout the 1980s. However their Coraciimorphae only contains Trogoniformes and Coraciiformes.
Eucavitaves is a clade that contains the order Trogoniformes (trogons) and the clade Picocoraciae. The name refers to the fact that the majority of them nest in cavities.
Cavitaves is a clade that contain the order Leptosomiformes and the clade Eucavitaves. The name refers to the fact that the majority of them nest in cavities.
Picocoraciae is a clade that contains the order Bucerotiformes and the clade Picodynastornithes supported by various genetic analysis and morphological studies. While these studies supported a sister grouping of Coraciiformes and Piciformes, a large scale, sparse supermatrix has suggested alternative sister relationship between Bucerotiformes and Piciformes instead.
Columbimorphae is a clade discovered by genome analysis that includes birds of the orders Columbiformes, Pterocliformes (sandgrouse), and Mesitornithiformes (mesites). Previous analyses had also recovered this grouping, although the exact relationships differed. Some studies indicated a sister relationship between sandgrouse and pigeons while other studies favored a sister grouping of mesites and sandgrouse instead.
Picodynastornithes is a clade that contains the orders Coraciiformes and Piciformes. This grouping also has current and historical support from molecular and morphological studies.
Columbaves is a clade that contains Columbimorphae and Otidimorphae discovered by genomic analysis by Prum et al. (2015). This conflicts with the Columbea and Otidae hypotheses which Mirandornithes are the sister taxon to Columbimorphae and Cypselomorphae the sister taxon to Otidimorphae, respectively, found by Jarvis et al. (2014). Neither hypothesis supports the two subdivisions of Metaves and Coronoaves as previous studies had found.
Aequorlitornithes is a clade of waterbirds recovered in a comprehensive genomic systematic study using nearly 200 species in 2015. It contains the clades Charadriiformes, Mirandornithes and Phaethoquornithes. Previous studies have found different placement for the clades in the tree.
Vanescaves is a probable clade of strisorean birds that include the clades Steatornithiformes, Nyctibiiformes, Podargiformes (frogmouths), and Apodimorphae. Some molecular studies do support the grouping of these birds, others offer conflicting positions of the non-apodimorphaean strisoreans. In 2019 the authors Chen et al. performed a combined analysis using 2289 ultra-conserved elements [UCEs], 117 morphological characters from extant and fossil taxa found support in this clade. The authors then proposed to name this group, which its meaning is Latin for "vanish birds" in reference to the disparate nature of their geographic distribution, as well as to the poem "A Route of Evanescence" by the American poet Emily Dickinson which features a hummingbird as the main subject. In 2020 Chen & Field named the two major subclades of this group, with Sedentaves and Letornithes for their crown-groups.
