Apodiformes

Life-forms

Superregnum: Eukaryota
Regnum: Animalia
Subregnum: Eumetazoa
Cladus: Bilateria
Cladus: Nephrozoa
Superphylum: Deuterostomia
Phylum: Chordata
Cladus: Craniata
Subphylum: Vertebrata
Infraphylum: Gnathostomata
Superclassis: Tetrapoda
Cladus: Reptiliomorpha
Cladus: Amniota
Classis: Reptilia
Cladus: Eureptilia
Cladus: Romeriida
Subclassis: Diapsida
Cladus: Sauria
Infraclassis: Archosauromorpha
Cladus: Crurotarsi
Divisio: Archosauria
Subsectio: Ornithodira
Subtaxon: Dinosauromorpha
Cladus: Dinosauria
Ordo: Saurischia
Cladus: Theropoda
Cladus: Neotheropoda
Infraclassis: Aves
Cladus: Euavialae
Cladus: Avebrevicauda
Cladus: Pygostylia
Cladus: Ornithothoraces
Cladus: Euornithes
Cladus: Ornithuromorpha
Cladus: Ornithurae
Cladus: Carinatae
Parvclassis: Neornithes
Cohors: Neognathae
Ordo: Apodiformes
Familia: Apodidae - Hemiprocnidae - Trochilidae
Name

Apodiformes Peters, 1840
Note:

Some taxonomic authorities do not include the family Trochilidae (Hummingbirds) within this order.
References

Sangster, G. 2005: A name for the clade formed by owlet-nightjars, swifts and hummingbirds (Aves). Zootaxa, 799: 1–6. PDF

Vernacular names
Deutsch: Seglervögel
English: Alpine Swift
Esperanto: Apodoformaj
suomi: Kiitäjälinnut, kirskulinnut
Nordfriisk: Siilfögler
hrvatski: Srpokrilke
italiano: Apodiformi
日本語: アマツバメ目
lietuvių: Čiurliniaipaukščiai
македонски: Пиштарковидни
Nederlands: Grootvleugeligen
polski: Krótkonogie
slovenščina: Hudourniki
svenska: Seglarfåglar
Türkçe: Ebabiller (Sağanlar)
українська: Стрижеподібні
中文: 雨燕目

Traditionally, the bird order Apodiformes /ˈæpədɪfɔːrmiːz/ contained three living families: the swifts (Apodidae), the treeswifts (Hemiprocnidae), and the hummingbirds (Trochilidae). In the Sibley-Ahlquist taxonomy, this order is raised to a superorder Apodimorphae in which hummingbirds are separated as a new order, Trochiliformes. With nearly 450 species identified to date, they are the most diverse order of birds after the passerines.

Description

As their name ("footless" in Greek) suggests, their legs are small and have limited function aside from perching. The feet are covered with bare skin rather than the scales (scutes) that other birds have. Another shared characteristic is long wings with short, stout humerus bones.[1] The evolution of these wing characteristics has provided the hummingbird with ideal wings for hovering.[2]

The hummingbirds, swifts, and crested swifts share other anatomical similarities with one another, as well as similarities (notably as to the skull) with their probable closest living relatives, the owlet-nightjars.[3] The owlet-nightjars are apparently convergent with the closely related Caprimulgiformes, which form a clade Cypselomorphae with the Apodiformes.[2]
Evolution

The Apodiformes evolved in the Northern Hemisphere. Eocypselus, a primitive genus known from the Late Paleocene or Early Eocene of north-central Europe, is somewhat difficult to assign; it is considered a primitive hemiprocnid.[4] This would suggest that the major apodiform lineages diverged shortly after the Cretaceous–Paleogene boundary. However, the perching adaptation of the foot of Eocypselus on which this theory rests may just as well be a symplesiomorphy. Most researchers believe that presently this genus cannot be unequivocally assigned to either the Apodiformes or the Caprimulgiformes.

The Early Eocene Primapus, found in England, is similar to both a primitive swift and the aegialornithids, which are in some aspects intermediate between swifts and owlet-nightjars. Fossil evidence demonstrates the existence of swifts during that period in Europe. At that time, most of Europe had a humid, subtropical climate, possibly comparable to modern-day southern China. For a map of Early–Middle Eocene Earth, see the Paleomap project;[5] here note that both the Caucasus mountains and the Alps did not exist yet and aegialornithids were possibly present in North America.[6] By the late Eocene (around 35 MYA), primitive hummingbirds started to diverge from the related jungornithids; the Middle Eocene Parargornis (Messel, Germany) and the Late Eocene Argornis, found in today's southernmost Russia, belong to this lineage. Cypselavus (Late Eocene – Early Oligocene of Quercy, France) was either a primitive hemiprocnid or an aegialornithid.

The placement of the Aegialornithidae is not quite clear. Various analyses place them sufficiently close to the Apodiformes to be included here, or into the unique owlet-nightjar lineage in the Cypselomorphae.
Taxonomy
Phylogeny of Apodiformes[7]
 
 

†Aegialornithidae

Apodi

†Laputavis

Hemiprocnidae

	†Scaniacypselus

	Apodidae

Trochili

†Cypselavidae

	†Jungornithidae

	Trochilidae

ORDER APODIFORMES

Family †Aegialornithidae Lydekker 1891 [Primapinae Harrison 1984c]

Genus †Primapus Harrison & Walker 1975
Genus †Aegialornis Lydekker 1891

Suborder Apodi

Genus †Procypseloides Harrison 1984c
Genus †Laputavis Dyke 2001b
Genus †Scaniacypselus Harrison 1984
Family †Eocypselidae Harrison 1984
- Genus †Eocypselus Harrison 1984

- Parargornis messelensis fossil
Family Hemiprocnidae Oberholser 1906 (treeswifts)
Family Apodidae Olphe-Galliard 1887 (swifts)

Suborder Trochili

Genus †Palescyvus Karchu 1988
Family †Cypselavidae Mourer-Chauviré 2006
- Genus †Argornis Karchu 1999
- Genus †Cypselavus Gaillard 1908
- Genus †Parargornis Mayr 2003
Family †Jungornithidae Karchu 1988
- Genus †Jungornis Karchu 1988
Family Trochilidae Vigors 1825 (hummingbirds)