Passerae
Encyclopedia
The "Passerae" were a proposed "parvclass" of birds in the Sibley-Ahlquist taxonomy
. This taxon
is a variation on the theme of "near passerine
s", birds that were - and often still are - believed to be close relatives of the passerine
s (perching birds, which include the songbird
s). This proposed taxon
was roundly rejected by subsequent cladistic analyses.
According to Sibley and Ahlquist, they include the following superorders and order
s:
Notable orders traditionally considered "near passerines" but not placed in the Passerae of the Sibley-Ahlquist taxonomy are Coliiformes, Coraciiformes
, Piciformes
and Trogoniformes (see below for why this is significant).
While the Sibley-Ahlquist taxonomy certainly represents a monumental endeavour and has some strong points (namely the recognition of the Galloanserae), basically everything about this "parvclass" is today regarded as utter fiction, brought about by the methodological and analytical problems of the phenetic DNA-DNA hybridization analysis. The "Passerae" are one of the most seriously flawed systematic proposals in modern ornithology
, perhaps rivalled only by the suggestion (based as it was on early cladistic analyses) that Hesperornithes
, Gaviiformes
and Podicipediformes form a monophyletic group. In sheer scope of their falseness, however, the "Passerae" are in post-Linne
an ornithology matched only by the ecomorphology
-based "taxa" of Charles Lucien Jules Laurent Bonaparte's mid-19th century Conspectus Generum Avium.
, about whose evolution
ary history next to nothing is known as of 2007, all the "Passerimorphae" are universally considered to be about as far from the Passeriformes as a neoavian can possibly be. The all-encompassing "Ciconiiformes
" are rejected by modern science, as is the grouping of owl
s and nightjar
s to the exclusion of swift
s and hummingbird
s, which moreover are not so distantly related to justify treatment as distinct orders. The close relationship of Musophagiformes and owls, while neither of the two groups is firmly placed in avian systematics, is also highly suspect.
At present, the closest living relatives of passerines are held to be the Piciformes
, followed by the Coraciiformes
. Neither of these two was included in the "Passerae". The Coliiformes and Trogoniformes, while of unclear relationships among the "higher landbirds", are also candidates for inclusion in a "near passerine" superorder. Insofar, it is actually hard to be less correct regarding the relationships of the perching birds than the Sibley-Ahlquist taxonomy.
Parvclasses are generally not used at all in modern ornithological systematics, as the understanding of neoavian relationship has not progressed to a point where use of such a taxonomic rank would seem sensible.
Sibley-Ahlquist taxonomy
The Sibley-Ahlquist taxonomy is a bird taxonomy proposed by Charles Sibley and Jon Edward Ahlquist. It is based on DNA-DNA hybridization studies conducted in the late 1970s and throughout the 1980s....
. This taxon
Taxon
|thumb|270px|[[African elephants]] form a widely-accepted taxon, the [[genus]] LoxodontaA taxon is a group of organisms, which a taxonomist adjudges to be a unit. Usually a taxon is given a name and a rank, although neither is a requirement...
is a variation on the theme of "near passerine
Near passerine
Near passerine or higher land-bird assemblage are terms often given to arboreal birds or those most often believed to be related to the true passerines due to ecological similarities; the group corresponds to some extent with the Anomalogonatae of Garrod All near passerines are land birds...
s", birds that were - and often still are - believed to be close relatives of the passerine
Passerine
A passerine is a bird of the order Passeriformes, which includes more than half of all bird species. Sometimes known as perching birds or, less accurately, as songbirds, the passerines form one of the most diverse terrestrial vertebrate orders: with over 5,000 identified species, it has roughly...
s (perching birds, which include the songbird
Songbird
A songbird is a bird belonging to the suborder Passeri of the perching birds . Another name that is sometimes seen as scientific or vernacular name is Oscines, from Latin oscen, "a songbird"...
s). This proposed taxon
Taxon
|thumb|270px|[[African elephants]] form a widely-accepted taxon, the [[genus]] LoxodontaA taxon is a group of organisms, which a taxonomist adjudges to be a unit. Usually a taxon is given a name and a rank, although neither is a requirement...
was roundly rejected by subsequent cladistic analyses.
According to Sibley and Ahlquist, they include the following superorders and order
Order (biology)
In scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...
s:
- Superorder Cuculimorphae
- Order CuculiformesCuculiformesThe near passerine bird order Cuculiformes traditionally included three families as below:* Musophagidae - turacos and allies* Cuculidae - cuckoos, coucals, roadrunners and anis* Opisthocomidae - Hoatzin...
- Order Cuculiformes
- Superorder Psittacimorphae
- Order Psittaciformes
- Superorder Apodimorphae
- Order ApodiformesApodiformesTraditionally, the bird order Apodiformes contained three living families: the swifts , the tree swifts , and the hummingbirds . In the Sibley-Ahlquist taxonomy, this order is raised to a superorder Apodimorphae in which hummingbirds are separated as a new order, Trochiliformes...
- Order Trochiliformes
- Order Apodiformes
- Superorder Strigimorphae
- Order Musophagiformes
- Order Strigiformes
- Superorder Passerimorphae
- Order ColumbiformesColumbiformesColumbiformes are an avian order that includes the very widespread and successful doves and pigeons, classified in the family Columbidae, and the extinct Dodo and the Rodrigues Solitaire, long classified as a second family Raphidae. 313 species, found worldwide, comprise the Columbiformes order....
- Order GruiformesGruiformesThe Gruiformes are an order containing a considerable number of living and extinct bird families, with a widespread geographical diversity. Gruiform means "crane-like"....
- Order CiconiiformesCiconiiformesTraditionally, the order Ciconiiformes has included a variety of large, long-legged wading birds with large bills: storks, herons, egrets, ibises, spoonbills, and several others. Ciconiiformes are known from the Late Eocene...
- Order Passeriformes
- Order Columbiformes
Notable orders traditionally considered "near passerines" but not placed in the Passerae of the Sibley-Ahlquist taxonomy are Coliiformes, Coraciiformes
Coraciiformes
The Coraciiformes are a group of usually colorful near passerine birds including the kingfishers, the Hoopoe, the bee-eaters, the rollers, and the hornbills...
, Piciformes
Piciformes
Nine families of largely arboreal birds make up the order Piciformes, the best-known of them being the Picidae, which includes the woodpeckers and close relatives...
and Trogoniformes (see below for why this is significant).
While the Sibley-Ahlquist taxonomy certainly represents a monumental endeavour and has some strong points (namely the recognition of the Galloanserae), basically everything about this "parvclass" is today regarded as utter fiction, brought about by the methodological and analytical problems of the phenetic DNA-DNA hybridization analysis. The "Passerae" are one of the most seriously flawed systematic proposals in modern ornithology
Ornithology
Ornithology is a branch of zoology that concerns the study of birds. Several aspects of ornithology differ from related disciplines, due partly to the high visibility and the aesthetic appeal of birds...
, perhaps rivalled only by the suggestion (based as it was on early cladistic analyses) that Hesperornithes
Hesperornithes
Hesperornithes is an extinct and highly specialized clade of Cretaceous toothed birds. Hesperornithine birds, apparently limited to former aquatic habitats in the Northern Hemisphere, include genera such as Hesperornis, Parahesperornis, Baptornis, Enaliornis, and probably Potamornis, all...
, Gaviiformes
Gaviiformes
Gaviiformes is an order of aquatic birds containing the loons or divers and their closest extinct relatives. Modern gaviiformes are found in many parts of North America and northern Eurasia , though prehistoric species were more widespread.-Classification and evolution:There are five living...
and Podicipediformes form a monophyletic group. In sheer scope of their falseness, however, the "Passerae" are in post-Linne
Carolus Linnaeus
Carl Linnaeus , also known after his ennoblement as , was a Swedish botanist, physician, and zoologist, who laid the foundations for the modern scheme of binomial nomenclature. He is known as the father of modern taxonomy, and is also considered one of the fathers of modern ecology...
an ornithology matched only by the ecomorphology
Ecomorphology
Ecomorphology or Ecological Morphology is studying relationships between morphological and ecological variation. There is modern emphasis on linking the two aspects of variation by measuring the performance of traits associated behaviors, and fitness outcomes of the relationships...
-based "taxa" of Charles Lucien Jules Laurent Bonaparte's mid-19th century Conspectus Generum Avium.
Refutation
Subsequent studies consider none of the orders contained in the "Passerae" particularly close to the passerines. And with the possible exception of the ColumbiformesColumbiformes
Columbiformes are an avian order that includes the very widespread and successful doves and pigeons, classified in the family Columbidae, and the extinct Dodo and the Rodrigues Solitaire, long classified as a second family Raphidae. 313 species, found worldwide, comprise the Columbiformes order....
, about whose evolution
Evolution
Evolution is any change across successive generations in the heritable characteristics of biological populations. Evolutionary processes give rise to diversity at every level of biological organisation, including species, individual organisms and molecules such as DNA and proteins.Life on Earth...
ary history next to nothing is known as of 2007, all the "Passerimorphae" are universally considered to be about as far from the Passeriformes as a neoavian can possibly be. The all-encompassing "Ciconiiformes
Ciconiiformes
Traditionally, the order Ciconiiformes has included a variety of large, long-legged wading birds with large bills: storks, herons, egrets, ibises, spoonbills, and several others. Ciconiiformes are known from the Late Eocene...
" are rejected by modern science, as is the grouping of owl
Owl
Owls are a group of birds that belong to the order Strigiformes, constituting 200 bird of prey species. Most are solitary and nocturnal, with some exceptions . Owls hunt mostly small mammals, insects, and other birds, although a few species specialize in hunting fish...
s and nightjar
Nightjar
Nightjars are medium-sized nocturnal or crepuscular birds with long wings, short legs and very short bills. They are sometimes referred to as goatsuckers from the mistaken belief that they suck milk from goats . Some New World species are named as nighthawks...
s to the exclusion of swift
Swift
The swifts are a family, Apodidae, of highly aerial birds. They are superficially similar to swallows, but are actually not closely related to passerine species at all; swifts are in the separate order Apodiformes, which they share with hummingbirds...
s and hummingbird
Hummingbird
Hummingbirds are birds that comprise the family Trochilidae. They are among the smallest of birds, most species measuring in the 7.5–13 cm range. Indeed, the smallest extant bird species is a hummingbird, the 5-cm Bee Hummingbird. They can hover in mid-air by rapidly flapping their wings...
s, which moreover are not so distantly related to justify treatment as distinct orders. The close relationship of Musophagiformes and owls, while neither of the two groups is firmly placed in avian systematics, is also highly suspect.
At present, the closest living relatives of passerines are held to be the Piciformes
Piciformes
Nine families of largely arboreal birds make up the order Piciformes, the best-known of them being the Picidae, which includes the woodpeckers and close relatives...
, followed by the Coraciiformes
Coraciiformes
The Coraciiformes are a group of usually colorful near passerine birds including the kingfishers, the Hoopoe, the bee-eaters, the rollers, and the hornbills...
. Neither of these two was included in the "Passerae". The Coliiformes and Trogoniformes, while of unclear relationships among the "higher landbirds", are also candidates for inclusion in a "near passerine" superorder. Insofar, it is actually hard to be less correct regarding the relationships of the perching birds than the Sibley-Ahlquist taxonomy.
Parvclasses are generally not used at all in modern ornithological systematics, as the understanding of neoavian relationship has not progressed to a point where use of such a taxonomic rank would seem sensible.