Psittacopasserae

Psittacopasserae is a taxon of birds consisting of the Passeriformes (passerines, a large group of perching birds) and Psittaciformes (parrots). Per Ericson and colleagues, in analysing genomic DNA, revealed a lineage comprising Passerines, Psittaciformes and Falconiformes.[1] The group was proposed following an alignment of nuclear intron sequences by Shannon Hackett et al. in 2008,[2] it was formally named in a 2011 Nature Communications article by Alexander Suh and other authors working with Jürgen Schmitz's group,[3] based on genetic analysis of the insertion of retroposons into the genomes of key avian lineages over the course of evolution during the Mesozoic Era.

The (possible) alternative names for this group are Psittacimorphae (Huxley, 1867) and/or Passerimorphae (Sibley et al., 1988) though more likely the former would be correct as the latter incorporated other avian orders that are now discarded to be close relatives to songbirds.

Psittacopasserans
Temporal range: Paleocene - Holocene
House Sparrow mar08
House sparrow, Passer domesticus
Psittacus erithacus -perching on tray-8d
Grey parrot, Psittacus erithacus
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Clade: Eufalconimorphae
Clade: Psittacopasserae
Suh et al., 2011
Orders

Zygodactylidae
Psittacopedidae?
Eofringillirostrum
Passeriformes
Psittaciformes

Technical considerations

Analysis of retroposon insertions offers a higher degree of confidence because retroposon insertion is "virtually homoplasy-free", as retroposons insert at random positions throughout the genome, whereas point mutations in DNA cycle between only four possible options. This makes it less likely that random coincidence or convergent evolution creates illusory similarities between unrelated groups. However, the technique requires very extensive genomic data - in the 2011 paper, approximately 200,000 retroposon-containing loci were examined to identify 51 individual retroposition events which are present in some birds but not others.

Significance in the evolution of birdsong

Passerines are renowned as songbirds, and parrots share a capacity for vocal learning. Thus it is possible that vocal learning, and the corresponding variety of song, was present in a psittacopasseran ancestor.[3]

References

  1. ^ Ericson, P. G. P.; Anderson, C. L.; Britton, T.; Elzanowski, A.; Johansson, U. S.; Källersjö, M.; Ohlson, J. I.; Parsons, T. J.; Zuccon, D.; Mayr, G. (2006). "Diversification of Neoaves: integration of molecular sequence data and fossils". Biology Letters. 2 (4): 543–547. doi:10.1098/rsbl.2006.0523. PMC 1834003. PMID 17148284.
  2. ^ Shannon J. Hackett; et al. (2008-06-07). "A Phylogenomic Study of Birds Reveals Their Evolutionary History". Science. 320 (5884): 1763–1768. doi:10.1126/science.1157704. PMID 18583609.
  3. ^ a b Alexander Suh; et al. (2011-08-23). "Mesozoic retroposons reveal parrots as the closest living relatives of passerine birds". Nature Communications. 2 (8). doi:10.1038/ncomms1448. PMC 3265382. PMID 21863010.
Australaves

Australaves is a recently defined clade of birds, consisting of the Eufalconimorphae (passerines, parrots and falcons) as well as the Cariamiformes (including seriemas and the extinct "terror birds"). 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 lead other lifestyles. Basal parrots and falcons are at any rate vaguely crow-like and probably omnivorous.

Cladogram of Telluraves relationships based on Prum, R.O. et al. (2015).

Bird

Birds, also known as Aves or avian dinosaurs, are a group of endothermic vertebrates, characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweight skeleton. Birds live worldwide and range in size from the 5 cm (2 in) bee hummingbird to the 2.75 m (9 ft) ostrich. They rank as the world's most numerically-successful class of tetrapods, with approximately ten thousand living species, more than half of these being passerines, sometimes known as perching birds. Birds have wings which are more or less developed depending on the species; the only known groups without wings are the extinct moa and elephant birds. Wings, which evolved from forelimbs, gave birds the ability to fly, although further evolution has led to the loss of flight in flightless birds, including ratites, penguins, and diverse endemic island species of birds. The digestive and respiratory systems of birds are also uniquely adapted for flight. Some bird species of aquatic environments, particularly seabirds and some waterbirds, have further evolved for swimming.

The fossil record demonstrates that birds are modern feathered dinosaurs, having evolved from earlier feathered dinosaurs within the theropod group, which are traditionally placed within the saurischian dinosaurs. The closest living relatives of birds are the crocodilians. Primitive bird-like dinosaurs that lie outside class Aves proper, in the broader group Avialae, have been found dating back to the mid-Jurassic period, around 170 million years ago. Many of these early "stem-birds", such as Archaeopteryx, retained primitive characteristics such as teeth and long bony tails. DNA-based evidence finds that birds diversified dramatically around the time of the Cretaceous–Palaeogene extinction event 66 million years ago, which killed off the pterosaurs and all the non-avian dinosaur lineages. But birds, especially those in the southern continents, survived this event and then migrated to other parts of the world while diversifying during periods of global cooling. This makes them the sole surviving dinosaurs according to cladistics.

Some birds, especially corvids and parrots, are among the most intelligent animals; several bird species make and use tools, and many social species pass on knowledge across generations, which is considered a form of culture. Many species annually migrate great distances. Birds are social, communicating with visual signals, calls, and bird songs, and participating in such social behaviours as cooperative breeding and hunting, flocking, and mobbing of predators. The vast majority of bird species are socially monogamous (referring to social living arrangement, distinct from genetic monogamy), usually for one breeding season at a time, sometimes for years, but rarely for life. Other species have breeding systems that are polygynous (arrangement of one male with many females) or, rarely, polyandrous (arrangement of one female with many males). Birds produce offspring by laying eggs which are fertilised through sexual reproduction. They are usually laid in a nest and incubated by the parents. Most birds have an extended period of parental care after hatching. Some birds, such as hens, lay eggs even when not fertilised, though unfertilised eggs do not produce offspring.

Many species of birds are economically important as food for human consumption and raw material in manufacturing, with domesticated and undomesticated birds (poultry and game) being important sources of eggs, meat, and feathers. Songbirds, parrots, and other species are popular as pets. Guano (bird excrement) is harvested for use as a fertiliser. Birds prominently figure throughout human culture. About 120–130 species have become extinct due to human activity since the 17th century, and hundreds more before then. Human activity threatens about 1,200 bird species with extinction, though efforts are underway to protect them. Recreational birdwatching is an important part of the ecotourism industry.

Bird of prey

Birds of prey, or raptors, include species of bird that primarily hunt and feed on vertebrates that are large relative to the hunter. Additionally, they have keen eyesight for detecting food at a distance or during flight, strong feet equipped with talons for grasping or killing prey, and powerful, curved beaks for tearing flesh. The term raptor is derived from the Latin word rapio, meaning to seize or take by force. In addition to hunting live prey, most also eat carrion, at least occasionally, and vultures and condors eat carrion as their main food source.Although the term bird of prey could theoretically be taken to include all birds that primarily consume animals, ornithologists typically use the narrower definition followed in this page. Examples of animal-eating birds not encompassed by the ornithological definition include storks, herons, gulls, skuas, penguins, kookaburras, and shrikes, as well as the many songbirds that are primarily insectivorous.

Eufalconimorphae

Eufalconimorphae is a proposed clade of birds, consisting of passerines, parrots, falcons, caracaras, and forest falcons (but not other raptors). It has whole-genome DNA support.

List of birds

This page lists living orders and families of birds. The links below should then lead to family accounts and hence to individual species.

The passerines (perching birds) alone account for well over 5000 species. In total there are about 10,000 species of birds described worldwide, though one estimate of the real number places it at almost twice that.

Taxonomy is very fluid in the age of DNA analysis, so comments are made where appropriate, and all numbers are approximate. In particular see Sibley-Ahlquist taxonomy for a very different classification.

Neoaves

Neoaves is a clade that consists of all modern birds (Neornithes or Aves) with the exception of Paleognathae (ratites and kin) and Galloanserae (ducks, chickens and kin). Almost 95% of the roughly 10,000 known species of modern birds belong to the Neoaves.

The early diversification of the various neoavian groups occurred very rapidly around the Cretaceous–Paleogene extinction event, and attempts to resolve their relationships with each other have resulted initially in much controversy.

Neognathae

Neognaths (Neognathae) (from Ancient Greek neo- "new" + gnáthos “jaw”) are birds within the subclass Neornithes of the class Aves. The Neognathae include virtually all living birds; exceptions being their sister taxon (Palaeognathae), which contains the tinamous and the flightless ratites.

There are nearly 10,000 species of neognaths. The earliest fossils are known from the very end of the Cretaceous but molecular clocks suggest that neognaths originated sometime in the first half of the Late Cretaceous about 90 million year ago. Since then, they have undergone adaptive radiation producing the diversity of form, function, and behavior that we see today. It includes the order Passeriformes (perching birds), the largest clade of land vertebrates, containing some 60% of living birds and being more than twice as speciose as rodents and about five times as speciose as Chiroptera (bats), which are the largest clades of mammals. There are also some very small orders, usually birds of very unclear relationships like the puzzling hoatzin.

The neognaths have fused metacarpals, an elongate third finger, and 13 or fewer vertebrae. They differ from the Palaeognathae in features like the structure of their jawbones. "Neognathae" means "new jaws", but it seems that the supposedly "more ancient" paleognath jaws are among the few apomorphic (more derived) features of the Palaeognaths, meaning that the respective jaw structure of these groups is not informative in terms of comparative evolution.

New Zealand parrot

The New Zealand parrot superfamily, Strigopoidea, consists of three genera of parrots – Nestor, Strigops, and the fossil Nelepsittacus. The genus Nestor consists of the kea, kaka, Norfolk Island kaka and Chatham Island kaka, while the genus Strigops contains the iconic kakapo. All extant species are endemic to New Zealand. The species of the genus Nelepsittacus were endemics of the main islands, while the two extinct species of the genus Nestor were found at the nearby oceanic islands such as Chatham Island of New Zealand, and Norfolk Island and adjacent Phillip Island.

The Norfolk kaka and the Chatham kaka have become extinct in recent times, while the species of the genus Nelepsittacus have been extinct for 16 million years. All extant species, the kakapo, kea, and the two subspecies of the kaka, are threatened. Human activity caused the two extinctions and the decline of the other three species. Settlers introduced invasive species, such as pigs and possums, which eat the eggs of ground-nesting birds, and additional declines have been caused by hunting for food, killing as agricultural pests, habitat loss, and introduced wasps.The superfamily diverged from the other parrots around 82 million years ago when New Zealand broke off from Gondwana, while the ancestors of the genera Nestor and Strigops diverged from each other between 60 and 80 million years ago.

Parrot

Parrots, also known as psittacines , are birds of the roughly 393 species in 92 genera that make up the order Psittaciformes, found in most tropical and subtropical regions. The order is subdivided into three superfamilies: the Psittacoidea ("true" parrots), the Cacatuoidea (cockatoos), and the Strigopoidea (New Zealand parrots). Parrots have a generally pantropical distribution with several species inhabiting temperate regions in the Southern Hemisphere, as well. The greatest diversity of parrots is in South America and Australasia.

Characteristic features of parrots include a strong, curved bill, an upright stance, strong legs, and clawed zygodactyl feet. Many parrots are vividly coloured, and some are multi-coloured. Most parrots exhibit little or no sexual dimorphism in the visual spectrum. They form the most variably sized bird order in terms of length.

The most important components of most parrots' diets are seeds, nuts, fruit, buds, and other plant material. A few species sometimes eat animals and carrion, while the lories and lorikeets are specialised for feeding on floral nectar and soft fruits. Almost all parrots nest in tree hollows (or nest boxes in captivity), and lay white eggs from which hatch altricial (helpless) young.

Parrots, along with ravens, crows, jays, and magpies, are among the most intelligent birds, and the ability of some species to imitate human voices enhances their popularity as pets. Trapping wild parrots for the pet trade, as well as hunting, habitat loss, and competition from invasive species, has diminished wild populations, with parrots being subjected to more exploitation than any other group of birds. Measures taken to conserve the habitats of some high-profile charismatic species have also protected many of the less charismatic species living in the same ecosystems.

Passerea

Passerea is a clade of neoavian birds that was proposed by Jarvis et al. (2014). Their genomic analyis recovered two major clades within Neoaves, Passerea and Columbea, and concluded that both clades appear to have many ecologically driven convergent traits.

According to Jarvis (2014), these convergences include the footpropelled diving trait of grebes in Columbea with loons and cormorants in Passerea; the wading-feeding trait of flamingos in Columbea with ibises and egrets in Passerea; and pigeons and sandgrouse in Columbea with shorebirds (killdeer) in Passerea. For Jarvis (2014), these long-known trait and morphological alliances suggest that some of the traditional nongenomic trait classifications are based on polyphyletic assemblages.

Passerea was not recovered in other studies.

Passerine

A passerine is any bird of the order Passeriformes, which includes more than half of all bird species. Sometimes known as perching birds or – less accurately – as songbirds, passerines are distinguished from other orders of birds by the arrangement of their toes (three pointing forward and one back), which facilitates perching, amongst other features specific to their evolutionary history in Australaves.

With more than 110 families and some 6,409 identified species, Passeriformes is the largest order of birds and among the most diverse orders of terrestrial vertebrates. Passerines are divided

into three clades, Acanthisitti (New Zealand wrens), Tyranni (suboscines) and Passeri (oscine).The passerines contain several groups of brood parasites such as the viduas, cuckoo-finches, and the cowbirds. Most passerines are omnivorous, while the shrikes are carnivorous.

The terms "passerine" and "Passeriformes" are derived from the scientific name of the house sparrow, Passer domesticus, and ultimately from the Latin term passer, which refers to sparrows and similar small birds.

Telluraves

Telluraves (also called land birds or core landbirds) is a recently defined clade of birds with controversial content. Based on most recent genetic studies, the clade unites a variety of bird groups, including the australavians (passerines, parrots, seriamas, and falcons) as well as the afroavians (including the Accipitrimorphae – eagles, hawks, buzzards, vultures etc. – owls and woodpeckers, among others). They appear to be the sister group of a newly defined clade centered on Aequornithes.Given that the most basal extant members of both Afroaves (Accipitrimorphae, Strigiformes) and Australaves (Cariamiformes, Falconiformes) are carnivorous, it has been suggested that the last common ancestor of all Telluraves was probably a predator. Other researchers are skeptical of this assessment, citing the herbivorous cariamiform Strigogyps as evidence to the contrary.

Cladogram of Telluraves relationships based on Prum, R.O. et al. (2015) with some clade names after Yury, T. et al. (2013) and Kimball et al. 2013.

Terrestrornithes

Terrestrornithes ("land birds") is a group of birds with controversial content. The clade was proposed in 2007 to unite the Charadriiformes (shore birds) and their possible close relatives, the Dendrornithes (most predatory and perching birds). It may also include a group known as the Mirandornithes, the flamingos and grebes, though the placement of this group is highly uncertain and they may be members of the Metaves instead.A rough consensus of current research is reproduced below, based on Naish (2012).

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