Last updated

Temporal range: Late Paleocene to present
Bee hummingbird (Mellisuga helenae) immature male.jpg
Bee hummingbird (Mellisuga helenae), the smallest bird in the World
Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Clade: Daedalornithes
Order: Apodiformes
Peters, 1940
Swift range.png
Range of the swifts and hummingbirds.
  • Trochiliformes Wagler 1830

Traditionally, the bird order Apodiformes /ˈæpədɪfɔːrmz/ 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.



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] [4] The owlet-nightjars are apparently convergent with the closely related Caprimulgiformes, which form a clade Cypselomorphae with the Apodiformes. [2]


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. [5] 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; [6] here note that both the Caucasus mountains and the Alps did not exist yet and aegialornithids were possibly present in North America. [7] 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.



See also

Related Research Articles

"Near passerines" and "higher land-bird assemblage" are terms of traditional, pre-cladistic taxonomy that have often been given to tree-dwelling birds or those most often believed to be related to the true passerines owing to morphological and ecological similarities; the group corresponds to some extent with the Anomalogonatae of Alfred Henry Garrod.

The Sibley–Ahlquist taxonomy is a bird taxonomy proposed by Charles Sibley and Jon E. Ahlquist. It is based on DNA–DNA hybridization studies conducted in the late 1970s and throughout the 1980s.

Caprimulgiformes Order of birds

The Caprimulgiformes is an order of birds that includes a number of birds with global distribution. They are generally insectivorous and nocturnal. The order gets its name from the Latin for "goat-milker", an old name based on an erroneous view of the European nightjar's feeding habits.

Swift Family of birds

The swifts are a family, Apodidae, of highly aerial birds. They are superficially similar to swallows, but are not closely related to any passerine species. Swifts are placed in the order Apodiformes with hummingbirds. The treeswifts are closely related to the true swifts, but form a separate family, the Hemiprocnidae.

Owlet-nightjar Genus of birds

Owlet-nightjars are small crepuscular birds related to the nightjars and frogmouths. Most are native to New Guinea, but some species extend to Australia, the Moluccas, and New Caledonia. A flightless species from New Zealand is extinct. There is a single monotypic family Aegothelidae with the genus Aegotheles.

Sulidae Family of birds

The bird family Sulidae comprises the gannets and boobies. Collectively called sulids, they are medium-large coastal seabirds that plunge-dive for fish and similar prey. The 10 species in this family are often considered congeneric in older sources, placing all in the genus Sula. However, Sula and Morus (gannets) can be readily distinguished by morphological, behavioral, and DNA sequence characters. Abbott's booby (Papasula) is given its own genus, as it stands apart from both in these respects. It appears to be a distinct and ancient lineage, maybe closer to the gannets than to the true boobies.


The mousebirds are birds in the order Coliiformes. They are the sister group to the clade Eucavitaves, which includes the Leptosomiformes, Trogoniformes (trogons), Bucerotiformes, Piciformes and Coraciformes. This group is now confined to sub-Saharan Africa, and it is the only bird order confined entirely to that continent, with the possible exception of turacos which are considered by some as the distinct Order Musophagiformes, and the cuckoo roller, which is the only member of the order Leptosomiformes. Mousebirds had a wider range in the Paleogene, with a widespread distribution in Europe and North America during the Paleocene.

Aegialornis is a genus of prehistoric apodiform birds. It formed a distinct family, the Aegialornithidae, and was in some ways intermediate between modern swifts and owlet-nightjars, lacking the more extreme adaptations to an aerial lifestyle that swifts show today, but already having sickle-shaped wings like them. They do not appear to be a direct ancestor of modern swifts, however, but rather a group that retained an overall basal morphology. Altogether, they were not too dissimilar from modern treeswifts.

Trochilinae Subfamily of hummingbirds

Trochilinae is a subfamily of the hummingbird family (Trochilidae). Members of the subfamily Trochilinae are sometimes called typical hummingbirds. They typically display iridescent plumage in metallic reds, oranges, greens and/or blues. Strong sexual dimorphism in plumage and size is evident in many species.

Scarce swift Species of bird

The scarce swift is a species of swift in the family Apodidae. It has a disjunct range of presence throughout the Afromontane : Cameroon line, Albertine Rift montane forests, Kenya, Tanzania, Malawi and Mozambique.

Archaeotrogonidae is a prehistoric bird family containing two genera, Hassiavis and Archaeotrogon. Its remains have been found in the Quercy Phosphorites of France, a geological formation containing Late Eocene and Early Oligocene deposits. They lived some 30-35 million years ago. Not all species described herein may be valid.

Eurotrochilus is a genus of extinct members of the stem group Trochilidae and are the closest relatives of the crown group Trochildae, which includes modern hummingbirds. Despite Eurotrochilus having looked very similar to modern hummingbirds, they still retained several primitive features and are not closely related to any specific extant hummingbird in the crown group. There are currently two discovered species of Eurotrochilus- E. inexpectatus and E. noniewiczi.


Apodimorphae is a clade of strisorean birds that include the extant families Trochilidae (hummingbirds), Hemiprocnidae (treeswifts), Apodidae (swifts), and Aegothelidae (owlet-nightjars), as well as many fossil families. This grouping of birds has been supported in a variety of recent studies. There are two higher classification schemes that have been proposed for the apodimorph families. One is all strisorean birds are classified in the order Caprimulgiformes, while the other is the strisorean birds are split into several distinct orders. In this case Apodimorphae is a subclade of Strisores that includes the orders Aegotheliformes and the Apodiformes. A similar name for the group Daedalornithes has been used for the owlet-night-apodiform clade, there is a difference between the two names with Apodimorphae defined as the total-group and Daedalornithes defined as the crowned group.

<i>Odontopteryx</i> Extinct genus of birds

Odontopteryx is a genus of the prehistoric pseudotooth birds or pelagornithids. These were probably rather close relatives of either pelicans and storks, or of waterfowl, and are here placed in the order Odontopterygiformes to account for this uncertainty.

<i>Dasornis</i> Extinct genus of birds

Dasornis is a genus of the prehistoric pseudotooth birds. These were probably rather close relatives of either pelicans and storks, or of waterfowl, and are here placed in the order Odontopterygiformes to account for this uncertainty.

Lithornithidae Extinct family of birds

Lithornithidae is an extinct, possibly paraphyletic clade of early paleognath birds. They are known from fossils dating to the Upper Paleocene through the Middle Eocene of North America and Europe, with possible Late Cretaceous representatives. All are extinct today; the youngest specimen is the currently unnamed SGPIMH MEV1 specimen from the mid-Eocene Messel Pit site.

<i>Paraprefica</i> Extinct genus of birds

Paraprefica is an extinct bird belonging to the Caprimulgiformes, from the middle Eocene. Its fossil remains have been found in the Messel pit at Messel, Germany.

Strisores Clade of birds

Strisores is a clade of birds. It includes the living families and orders Caprimulgidae, Nyctibiidae (potoos), Steatornithidae (oilbirds), Podargidae (frogmouths), Apodiformes, as well as the Aegotheliformes (owlet-nightjars) whose distinctness was only recently realized. The Apodiformes and the Aegotheliformes form the Daedalornithes.


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.


  1. Hyman, Libbie Henrietta (1992). Hyman's Comparative Vertebrate Anatomy. Chicago: University of Chicago Press, page 39. ISBN   0-226-87013-8
  2. 1 2 Mayr, Gerald (2003): Phylogeny of early tertiary swifts and hummingbirds (Aves: Apodiformes). Auk 120(1): 145–151. doi : 10.1642/0004-8038(2003)120[0145:POETSA]2.0.CO;2 PDF fulltext
  3. mayr
  4. Mayr, Gerald (2002): Osteological evidence for paraphyly of the avian order Caprimulgiformes (nightjars and allies). Journal für Ornithologie143: 82–97. PDF fulltext
  5. Dyke, Gareth J.; Waterhouse, David M. & Kristoffersen, Anette M. (October 2004). "Three new fossil landbirds from the early Paleogene of Denmark" (PDF). Bulletin of the Geological Society of Denmark. 51 (1): 77–85.
  6. Christopher R. Scotese. "During the Early Cenozoic India began to Collide with Asia". Paleomap project. Retrieved 20 September 2010.
  7. Somewhat doubtful, as this is difficult to reconcile with the other aegialornithid fossils and Primapus.
  8. Haaramo, Mikko. "Apodiformes – housemartins, hummingbirds, and relatives". Mikko's Phylogeny Archive. Retrieved 30 December 2017.