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 (chicken and junglefowls, Old World quails, partridges, pheasants, turkeys, peafowl and grouse), Odontophoridae (New World quails), Numididae (guinea fowl), Cracidae (including chachalacas and curassows), and Megapodiidae (incubator birds like malleefowl and brushturkeys). Galliformes and the semi-aquatic order Anseriformes (waterfowl) 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 (most notably the red junglefowl, which have been domesticated into the chicken) 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.Kimball et al. (1999), Dyke et al. (2003), Smith et al. (2005), Crowe et al. (2006a,b)
The Anseriformes (waterfowl) and the Galliformes together make up the Galloanserae. They are basal among the living neognathous birds, and normally follow the Paleognathae (ratites and tinamous) 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.Smith et al. (2005), Crowe et al. (2006a,b) Phenetic studies do not distinguish between plesiomorphic and apomorphic characters, which leads to basal lineages appearing as monophyletic groups.
Historically, the buttonquails (Turnicidae), mesites (Mesitornithidae) and the hoatzin (Opisthocomus hoazin) 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 Galloanserae-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 (unlike water for Anseriformes) which protected them from the blast and destruction.Quaillike creatures were the only birds to survive the dinosaur-killing asteroid impact
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 (Mya). 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.Clarke (2004) Another specimen, PVPH 237, from the Late Cretaceous Portezuelo Formation (Turonian-Coniacian, about 90 Mya) in the Sierra de Portezuelo (Argentina) 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.Agnolin et al. (2006)
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 (London Clay Early Eocene of England) †Coturnipes (Early Eocene of England, and Virginia, USA?) †Palaeophasianus (Willwood Early Eocene of Bighorn County, USA) †Percolinus (London Clay Early Eocene of England) †Amitabha (Bridger middle Eocene of Forbidden City, USA) – phasianid? †"Palaeorallus" alienus (middle Oligocene of Tatal-Gol, Mongolia) †Anisolornis (Santa Cruz Middle Miocene of Karaihen, Argentina)
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,Zelenitsky et al. (1996) 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. (Oligocene) – formerly in Gallinuloides; phasianid?Specimen MCZ 342506. A proximal humerus of a bird larger than Gallinuloides: Mayr & Weidig (2004) †Palaealectoris (Agate Fossil Beds Early Miocene of Sioux County, USA) – 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 (pheasant-like forms) and the Perdicinae (partridge-like forms). 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.Kimball et al. (1999, 2001), Crowe et al. (2006a,b)
A tentative list of the higher-level galliform taxa, listed in evolutionary sequence, is: †Archaeophasianus Lambrecht 1933 (Oligocene? – Late Miocene) †Argillipes Harrison & Walker 1977 †Austinornis Clarke 2004 [Pedioecetes Baird 1858] (Austin Chalk Late Cretaceous of Fort McKinney, USA) †Chambiortyx Mourer-Chauviré et al. 2013 †Coturnipes Harrison & Walker 1977 †Cyrtonyx tedfordi (Barstow Late Miocene of Barstow, USA) †Linquornis Yeh 1980 (middle Miocene) †Namaortyx Mourer-Chauviré, Pickford & 2011 †Palaeorallus alienus Kuročkin 1968 nomen dubium †Sobniogallus Tomek et al. 2014 †Tristraguloolithus Zelenitsky, Hills & Curri 1996 [ootaxa- cracid?] †Procrax Tordoff & Macdonald 1957 (middle Eocene? – Early Oligocene) †Paleophasianus Wetmore 1940 †Taoperdix Milne-Edwards 1869 (Late Oligocene) Family †Gastornithidae? Fürbringer, 1888 Gastornis Hébert, 1855 (vide Prévost, 1855) [Diatryma Cope, 1876] (Paleocene-Eocene) Family †Sylviornithidae? Mourer-Chauviré & Balouet, 2005 †Sylviornis Poplin, 1980 (Holocene) †Megavitiornis Worthy, 2000 (Holocene) 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 (Lini's megapode) †Ngawupodius & Ivison 1999 Brushturkey group Talegalla Lesson 1828 Leipoa Gould 1840 [Progura de Vis 1889; Chosornis de Vis 1889; Palaeopelargus de Vis 1892] (Malleefowl) Alectura Gray 1831 [Catheturus Swainson 1837] (Australian Brushturkeys) Aepypodius Oustalet 1880 Scrubfowl group Macrocephalon Müller 1846 [Megacephalon Gray 1846; Megacephalon Gray 1844 nomen nudum; Galeocephala Mathews 1926] (Maleos) Eulipoa Ogilvie-Grant 1893 (Moluccan Megapodes) Megapodius Gaimard 1823 non (sic) Mathews 1913 [Megathelia Mathews 1914; Amelous Gloger 1841] Family Cracidae – chachalacas, guans and curassows †Archaealectrornis Crowe & Short 1992 (Oligocene) †Boreortalis Brodkorb 1954 †Palaeonossax Wetmore 1956 (Brule Late Oligocene of South Dakota, USA) Penelopinae Bonaparte 1851 (Guans) Chamaepetes Wagler 1832 (black & sickle-winged guan) Penelopina Reichenbach 1861 (Highland Guans) Aburria Reichenbach 1853 [Opetioptila Sundevall 1873; Pipile Bonaparte 1856 non Pipilo Vieillot 1816; Cumana Coues 1900] Penelope Merrem 1786 [Penelopsis Bonaparte 1856] Cracinae Rafinesque 1815 Ortalis Merrem 1786 [Ganix Rafinesque 1815] {Ortalidini Donegan 2012} (Chachalacas) Oreophasis Gray 1844 {Oreophasini Bonaparte 1853} (Horned Guans) Cracini Rafinesque 1815 (Curassows) Nothocrax Burmeister 1856 (Nocturnal Curassows) Pauxi Temminck 1813 [Ourax Cuvier 1817; Lophocerus Swainson 1837 non Hemprich & Ehrenberg 1833; Urax Reichenbach 1850] Mitu Lesson 1831 (razor-billed curassows) Crax Linnaeus 1758 Suborder Phasiani Family †Gallinuloididae – tentatively placed here †Gallinuloides Eastman 1900 [Palaeobonasa Shufeldt 1915] †Paraortygoides Mayr 2000 Family Numididae – guineafowl Guttera Wagler 1832 Numida Linnaeus 1764 [Querelea Reichenbach 1852] (Helmeted Guineafowl) Acryllium Gray 1840 (Vulturine Guineafowl) 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