Galliformes


Galliformes, also known as gallinaceous birds or landfowl, is an order of heavy-bodied terrestrial birds that contains about 290 species. The order is divided into five families: Phasianidae, Odontophoridae, Numididae, Cracidae, and Megapodiidae. Galliformes and the semi-aquatic order Anseriformes are collectively called fowl.
Galliform birds have adapted to most environments except innermost deserts and perpetually icy regions, inhabiting every continent except Antarctica. They are important in their ecosystems as seed dispersers and insectivores/vermivores, and many are skilled ground-dwellers that escape predators by running rather than flying. They are sexually dimorphic, and males of most species are more colorful than the females, with often elaborate courtship behaviors that include strutting, fluffing of tail or head feathers, and vocal sounds. They are mainly non-migratory.
The name galliformes derives from the type genus Gallus, Latin for "rooster". Several galliform species have been farmed by humans as poultry for their meat and eggs, and the wild species are hunted as upland game birds, where they are known as gamefowl.

Systematics and evolution

The living Galliformes were once divided into seven or more families. Despite their distinctive appearance, grouse and turkeys probably do not warrant separation as families due to their recent origin from partridge- or pheasant-like birds. The turkeys became larger after their ancestors colonized temperate and subtropical North America, where pheasant-sized competitors were absent. The ancestors of grouse, though, adapted to harsh climates and could thereby colonize subarctic regions. Consequently, the Phasianidae are expanded in current taxonomy to include the former Tetraonidae and Meleagrididae as subfamilies.
The Anseriformes and the Galliformes together make up the Galloanserae. They are basal among the living neognathous birds, and normally follow the Paleognathae in modern bird classification systems. This was first proposed in the Sibley-Ahlquist taxonomy and has been the one major change of that proposed scheme that was almost universally adopted. However, the Galliformes as they were traditionally delimited are called Gallomorphae in the Sibley-Ahlquist taxonomy, which splits the Cracidae and Megapodiidae as an order "Craciformes". This is not a natural group, however, but rather an erroneous result of the now-obsolete phenetic methodology employed in the Sibley-Ahlquist taxonomy. Phenetic studies do not distinguish between plesiomorphic and apomorphic characters, which leads to basal lineages appearing as monophyletic groups.
Historically, the buttonquails, mesites and the hoatzin were placed in the Galliformes, too. The former are now known to be shorebirds adapted to an inland lifestyle, whereas the mesites are probably closely related to pigeons and doves. The relationships of the hoatzin are entirely obscure, and it is usually treated as a monotypic order Opisthocomiformes to signify this.
The fossil record for the Galliformes is incomplete.

Evolution

-like birds were one of the main survivors of the K-T Event, that killed off the rest of the dinosaurs. The dominant birds of the dinosaur era were the enantiornithes, toothed birds that dominated the trees and skies. Unlike those enantiornithes, the ancestors of the galliformes were a niche group that were toothless and ground-dwelling. When the asteroid impact killed off all non-avian dinosaurs, and the dominant birds, it destroyed all creatures that lived in trees and on open ground. The enantiornithes were wiped out, but the ancestors of galliformes were small and lived in the ground which protected them from the blast and destruction.
Fossils of these galliform-like birds originate in the Late Cretaceous, most notably those of Austinornis lentus. Its partial left tarsometatarsus was found in the Austin Chalk near McKinney, Texas, dating to about 85 million years ago. This bird was quite certainly closely related to Galliformes, but whether it was a part of these or belongs elsewhere in the little-known galliform branch of Galloanserae is not clear. However, in 2004, Clarke classified it as a member of the larger group Pangalliformes, more closely related to chickens than to ducks, but not a member of the crown group that includes all modern galliformes. Another specimen, PVPH 237, from the Late Cretaceous Portezuelo Formation in the Sierra de Portezuelo has also been suggested to be an early galliform relative. This is a partial coracoid of a neornithine bird, which in its general shape and particularly the wide and deep attachment for the muscle joining the coracoid and the humerus bone resembles the more basal lineages of galliforms.
Additional galliform-like pangalliformes are represented by extinct families from the Paleogene, namely the Gallinuloididae, Paraortygidae and Quercymegapodiidae. In the early Cenozoic, some additional birds may or may not be early Galliformes, though even if they are, they are unlikely to belong to extant families:
  • †Argillipes
  • †Coturnipes
  • †Palaeophasianus
  • †Percolinus
  • †Amitabha – phasianid?
  • †"Palaeorallus" alienus
  • †Anisolornis
From the mid-Eocene onwards – about 45 Mya or so, true galliforms are known, and these completely replace their older relatives in the early Neogene. Since the earliest representatives of living galliform families apparently belong to the Phasianidae – the youngest family of galliforms, the other families of Galliformes must be at least of Early Eocene origin but might even be as old as the Late Cretaceous. The ichnotaxon Tristraguloolithus cracioides is based on fossil eggshell fragments from the Late Cretaceous Oldman Formation of southern Alberta, Canada, which are similar to chachalaca eggs, but in the absence of bone material, their relationships cannot be determined except that they are apparently avian in origin.
Modern genera of phasianids start appearing around the Oligocene-Miocene boundary, roughly 25–20 Mya. It is not well known whether the living genera of the other, older, galliform families originated around the same time or earlier, though at least in the New World quail, pre-Neogene forms seem to belong to genera that became entirely extinct later on.
A number of Paleogene to mid-Neogene fossils are quite certainly Galliformes, but their exact relationships in the order cannot be determined:
  • †Galliformes gen. et sp. indet. – formerly in Gallinuloides; phasianid?
  • †Palaealectoris – tetraonine?

    List of major taxa

For a long time, the pheasants, partridges, and relatives were indiscriminately lumped in the Phasianidae, variously including or excluding turkeys, grouse, New World quail, and guineafowl, and divided into two subfamilies – the Phasianinae and the Perdicinae. This crude arrangement was long considered to be in serious need of revision, but even with modern DNA sequence analyses and cladistic methods, the phylogeny of the Phasianidae has resisted complete resolution.
File:Palaeortyx.jpg|thumb|Palaeortyx skeleton, Muséum national d'histoire naturelle, Paris
A tentative list of the higher-level galliform taxa, listed in evolutionary sequence, is:
  • †Archaeophasianus Lambrecht 1933
  • †Argillipes Harrison & Walker 1977
  • †Austinornis Clarke 2004
  • †Chambiortyx Mourer-Chauviré et al. 2013
  • †Coturnipes Harrison & Walker 1977
  • †Cyrtonyx tedfordi
  • †Linquornis Yeh 1980
  • †Namaortyx Mourer-Chauviré, Pickford & 2011
  • †Palaeorallus alienus Kuročkin 1968 nomen dubium
  • †Sobniogallus Tomek et al. 2014
  • †Tristraguloolithus Zelenitsky, Hills & Curri 1996
  • †Procrax Tordoff & Macdonald 1957
  • †Paleophasianus Wetmore 1940
  • †Taoperdix Milne-Edwards 1869
  • Family †Gastornithidae? Fürbringer, 1888
  • * Gastornis Hébert, 1855
  • Family †Sylviornithidae? Mourer-Chauviré & Balouet, 2005
  • *†Sylviornis Poplin, 1980
  • *†Megavitiornis Worthy, 2000
  • Family †Paraortygidae Mourer-Chauviré 1992
  • * †Pirortyx Brodkorb 1964
  • * †Scopelortyx Mourer-Chauviré, Pickford & Senut 2015
  • * †Paraortyx Gaillard 1908 sensu Brodkorb 1964
  • * †Xorazmortyx Zelenkov & Panteleyev 2019
  • Family †Quercymegapodiidae Mourer-Chauviré 1992
  • * †Taubacrex Alvarenga 1988
  • * †Ameripodius Alvarenga 1995
  • * †Quercymegapodius Mourer-Chauviré 1992
  • Family Megapodiidae – mound-builders and scrubfowl, or megapodes
  • * †Mwalau Worthy et al. 2015
  • * †Ngawupodius & Ivison 1999
  • * Brushturkey group
  • ** Talegalla Lesson 1828
  • ** Leipoa Gould 1840
  • ** Alectura Gray 1831
  • ** Aepypodius Oustalet 1880
  • * Scrubfowl group
  • ** Macrocephalon Müller 1846
  • ** Eulipoa Ogilvie-Grant 1893
  • ** Megapodius Gaimard 1823 non Mathews 1913
  • Family Cracidae – chachalacas, guans and curassows
  • * †Archaealectrornis Crowe & Short 1992
  • * †Boreortalis Brodkorb 1954
  • * †Palaeonossax Wetmore 1956
  • * Penelopinae Bonaparte 1851
  • ** Chamaepetes Wagler 1832
  • ** Penelopina Reichenbach 1861
  • ** Aburria Reichenbach 1853
  • ** Penelope Merrem 1786
  • * Cracinae Rafinesque 1815
  • ** Ortalis Merrem 1786
  • ** Oreophasis Gray 1844
  • ** Cracini Rafinesque 1815
  • *** Nothocrax Burmeister 1856
  • *** Pauxi Temminck 1813
  • *** Mitu Lesson 1831
  • *** Crax Linnaeus 1758
  • Suborder Phasiani
  • * Family †Gallinuloididae – tentatively placed here
  • ** †Gallinuloides Eastman 1900
  • ** †Paraortygoides Mayr 2000
  • * Family Numididae – guineafowl
  • ** Guttera Wagler 1832
  • ** Numida Linnaeus 1764
  • ** Acryllium Gray 1840
  • ** Agelastes Bonaparte 1850
  • * Family Odontophoridae – New World quail
  • ** †Miortyx Miller 1944
  • ** †Nanortyx Weigel 1963
  • ** †Neortyx Holman 1961
  • ** Ptilopachinae Bowie, Coehn & Crowe 2013
  • *** Ptilopachus Swainson 1837
  • ** Odontophorinae Gould 1844
  • *** Rhynchortyx Ogilvie-Grant 1893
  • *** Oreortyx Baird 1858
  • *** Dendrortyx Gould 1844
  • *** Philortyx Gould 1846 non Des Murs 1854
  • *** Colinus Goldfuss 1820
  • *** Callipepla Wagler 1832
  • *** Cyrtonyx Gould 1844
  • *** Dactylortyx Ogilvie-Grant 1893
  • *** Odontophorus Vieillot 1816
  • * Family Phasianidae – pheasants, partridges and relatives
  • ** †Alectoris" pliocaena Tugarinov 1940b
  • ** †Bantamyx Kuročkin 1982
  • ** †Centuriavis lioae Ksepka et al., 2022
  • ** †Diangallus Hou 1985
  • ** †"Gallus" beremendensis Jánossy 1976b
  • ** †"Gallus" europaeus Harrison 1978
  • ** †Lophogallus Zelenkov & Kuročkin 2010
  • ** †Megalocoturnix Sánchez Marco 2009
  • ** †Miophasianus Brodkorb 1952
  • ** †Palaeocryptonyx Depéret 1892
  • ** †Palaeortyx Milne-Edwards 1869
  • ** †Plioperdix Kretzoi 1955
  • ** †Rustaviornis Burchak-Abramovich & Meladze 1972
  • ** †Schaubortyx Brodkorb 1964
  • ** †Shandongornis Yeh 1997
  • ** †Shanxiornis Wang et al. 2006
  • ** †Tologuica Zelenkov & Kuročkin 2009
  • ** Subfamily Rollulinae Bonaparte, 1850
  • ** Subfamily Phasianinae
  • ***Tribe Lerwini von Boetticher, 1939 – snow partridge
  • ***Tribe Ithaginini Wolters 197 – blood pheasant
  • ***Tribe Lophophorini Gray, 1841 – monals, monal-partridges, and tragopans
  • ***Tribe Pucrasiini Wolters 1976 – koklass pheasant
  • ***Tribe Meleagridini – turkey
  • ***Tribe Tetraonini Leach 1820 – grouse
  • ***Tribe Rhizotherini – long-billed partridges
  • ***Tribe Phasianini Horsfield 1821 – true pheasants and partridges
  • ***
  • **Subfamily Pavoninae
  • ***Tribe Pavonini Rafinesque 1815 – peafowl, arguses, and Tropicoperdix partridges
  • ***Tribe Polyprectronini Blyth 1852 – peacock-pheasants, Asian spurfowl, and crimson-headed partridge
  • ***Tribe Gallini Brehm 1831 – junglefowl, bamboo partridges, and true francolins
  • ***Tribe Coturnicini Reichenbach, 1848 - Old World quail, snowcocks, and allies
The relationships of many pheasants and partridges were formerly very badly resolved and much confounded by adaptive radiation and convergent evolution. Thus, the bulk of the Phasianidae was alternatively treated as a single subfamily Phasianinae. The grouse, turkeys, true pheasants, etc., would then become tribes of this subfamily, similar to how the Coturnicinae are commonly split into a quail and a spurfowl tribe. In 2021, Kimball et al. found the family to comprise three distinct subfamilies, with two containing multiple genera; these results were followed by the International Ornithological Congress.
The partridge of Europe is not closely related to other partridge-like Galliformes, as already indicated by its sexually dimorphic coloration and possession of more than 14 rectrices, traits it shares with the other advanced phasianids. However, among these its relationships are obscure; it is unclear whether it is closer to the turkeys or to certain short-tailed pheasants like Ithaginis, Lophophorus, Pucrasia, and Tragopan. In 2021, Kimball et al. found it to belong to the subfamily Phasianini, alongside the true pheasants.