Pauxi

Pauxi
Helmeted curassow, Pauxi pauxi
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	Galliformes
Family:	Cracidae
Subfamily:	Cracinae
Genus:	Pauxi Temminck, 1813
Type species
Crax pauxi Linnaeus, 1766
Species
3, see text

The genus Pauxi consists of the three species of helmeted curassows, terrestrial black fowl with ornamental casque on their heads. All are found in South America.

This genus contains 3 species

Image	Scientific name	Common Name	Distribution
	Pauxi pauxi	Helmeted curassow or northern helmeted curassow	eastern Andes of Venezuela and Colombia
	Pauxi unicornis	Horned curassow or southern helmeted curassow	Bolivia
	Pauxi koepckeae	Sira curassow	Cerros del Sira in central Peru

As indicated by analysis of mt and nDNA sequences and calibrated with geological data, this genus' ancestors probably diverged from those of Mitu, their closest living relatives, in the Tortonian (early Late Miocene), some 8–7.4 mya. How the present distribution in 4 small areas quite distant from each other came to be is not known. Given that helmeted curassows are birds of the foothills and uplands, it might be that the ancestral Pauxi population became fragmented by the uplift of the Andes, which in their area of distribution took place during the Late Miocene, around the Pauxi-Mitu divergence and some time after.(Pereira & Baker 2002, Pereira et al. 2002).

Pereira & Baker (2002) reported an interesting find: in the mtDNA phylogeny, Pauxi was paraphyletic, with P. unicornis being resolved as the sister species of Mitu tuberosa. This, of course, does not automatically imply that they are closely related or that the genera are invalid. Rather, the authors point out, given the distinct and peculiar morphology of the two genera, incomplete lineage sorting or hybridization between ancestral individuals of the two species is a more likely explanation. According to their data, there must have been some extent of gene flow between Mitu tuberosa and P. unicornis around 2 mya. Unfortunately, the authors do not provide subspecific identification of their single P. unicornis specimen. In any case, they took care to exclude captive hybridization in their choice of samples, as it is frequently known to occur in curassows and would have confounded the analysis. Altogether, what can be said with certainty is that there seems to have been some extent of hybridization between at least one population of the southern helmeted curassow and female razor-billed curassows at the end of the Pliocene.

References

• Pereira, Sérgio Luiz & Baker, Allan J. (2004): Vicariant speciation of curassows (Aves, Cracidae): a hypothesis based on mitochondrial DNA phylogeny. Auk 121(3): 682–694. [English with Spanish abstract] DOI:10.1642/0004-8038(2004)121[0682:VSOCAC]2.0.CO;2 HTML abstract HTML fulltext without images
• Pereira, Sérgio Luiz; Baker, Allan J.& Wajntal, Anita (2002): Combined nuclear and mitochondrial DNA sequences resolve generic relationships within the Cracidae (Galliformes, Aves). Systematic Biology 51(6): 946–958. doi:10.1080/10635150290102519 PMID 12554460 PDF fulltext

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Genera of landfowl and their extinct allies

• Kingdom: Animalia
• Phylum: Chordata
• Class: Aves
• Superorder: Galloanserae
• Clade: Pangalliformes

Pangalliformes
incertae sedis †Anisolornis? †Archaeophasianus? †Argillipes? †Austinornis †Chambiortyx †Coturnipes? †"Gigantibis"? †Litoripes? †Percolinus? †Tegulavis? †Gallinuloididae Gallinuloides Paraortygoides †Paraortygidae Paraortyx Pirortyx Scopelortyx Xorazmortyx †Quercymegapodiidae Ameripodius Quercymegapodius Taubacrex †Sylviornithidae Megavitiornis Sylviornis Galliformes See below ↓

Galliformes
Galliformes †Amitabha †Bumbanipodius †Bumbanortyx †Linquornis †Namaortyx †Palaeoalectoris †Procrax †Sobniogallus †Taoperdix Megapodiidae †Garrdimalga? †Mwalau †Ngawupodius Alecturini Aepypodius Alectura †Latagallina Leipoa †Progura Talegalla Megapodiini Eulipoa Macrocephalon Megapodius Cracidae †Archaealectrornis †Boreortalis †Palaeonossax †Procrax Penelopinae Aburria Chamaepetes Penelope Penelopina Pipile Cracinae Oreophasis Ortalis Cracini Crax Mitu Nothocrax Pauxi Phasianoidea See below ↓

Phasianoidea
Numididae Acryllium Agelastes Guttera Numida †Telecrex Odontophoridae †Miortyx †Nanortyx †Neortyx Ptilopachinae Ptilopachus Odontophorinae Callipepla Colinus Cyrtonyx Dactylortyx Dendrortyx Odontophorus Oreortyx Philortyx Rhynchortyx Phasianidae See below ↓

Phasianidae
Phasianidae †Bantamyx †Centuriavis †Diangallus †Eurobambusicola †Lophogallus †Megalocoturnix †Miogallus †Mioryaba †Palaeocryptonyx †Palaeortyx †Panraogallus †Pliogallus †Plioperdix †Rustaviornis †Schaubortyx †Shandongornis †Shanxiornis †Titanoperdix †Tologuica Rollulinae Arborophila Caloperdix Melanoperdix Rhizothera Rollulus Xenoperdix Pavoninae Tropicoperdix Coturnicini Alectoris Ammoperdix Coturnix Margaroperdix †?Ophrysia Perdicula Pternistis Synoicus Tetraogallus Gallini Bambusicola Campocolinus Francolinus Gallus Ortygornis Peliperdix Scleroptila Pavonini Afropavo Argusianus Pavo Rheinardia Polyplectronini Galloperdix Haematortyx Polyplectron Phasianinae †Chauvireria Ithaginis Lerwa Lophophorini Lophophorus Tetraophasis Tragopan Phasianini Catreus Chrysolophus Crossoptilon Lophura Perdix Phasianus Syrmaticus Tetraonini Bonasa Canachites Centrocercus Dendragapus Falcipennis Lagopus Lyrurus Meleagris †Palaealectoris †Proagriocharis Pucrasia †Rhegminornis Tetrao Tetrastes Tympanuchus