Editing Galliformes (section)

== Flightlessness ==

While most Galliformes are rather reluctant flyers, truly [[flightless bird|flightless]] forms are unknown among the extant members of the order. Though they are often mischaracterised as weak-flying, Galliformes are actually highly specialised for their particular flight style, bearing extremely powerful flight muscles, and some species are even migratory.<ref>Gary W. Kaiser, The Inner Bird: Anatomy and Evolution Paperback – 1 Feb 2008</ref> Adult [[snowcock]]s are, however, flightless, requiring gravity to launch, although juveniles can still fly relatively well.<ref>Madge, Steve; McGowan, J. K.; Kirwan, Guy M. (2002). Pheasants, Partridges and Grouse: A Guide to the Pheasants, Partridges, Quail, Grouse, Guineafowl, Buttonquail and Sandgrouse of the World. A.C. Black. pp. 174–180. {{ISBN|9780713639667}}.</ref>

Nonetheless, a few birds [[Pangalliformes|outside the Galliformes crown-group]] did produce flightlessness.

The genus ''[[Sylviornis]]'', a huge [[prehistoric]]ally [[extinct]] species of [[New Caledonia]], was flightless, but as opposed to most other flightless birds like [[ratite]]s or island [[rail (bird)|rails]] which become flightless due to [[neoteny|arrested development]] of their flight apparatus and subsequently [[evolution|evolve]] to larger size, ''Sylviornis'' seems to have become flightless simply due to its bulk, with the wing reduction following consequently, not being the reason for its flightlessness.

The gigantic Australian [[mihirungs]], which may be closer to Galliformes than to [[Anseriformes]] as traditionally expected,<ref>Worthy, T., Mitri, M., Handley, W., Lee, M., Anderson, A., Sand, C. 2016. Osteology supports a steam-galliform affinity for the giant extinct flightless birds Sylviornis neocaledoniae (Sylviornithidae, Galloanseres). PLOS ONE. doi: 10.1371/journal.pone.0150871</ref> achieved flightlessness more traditionally, strongly reducing their wings and keel. They were massive herbivorous birds, among the largest avian dinosaurs of all time.

By contrast, the stem-galliform ''[[Scopelortyx]]'' appears to have been more aerial than modern fowl, with a flight style more suited for gliding and soaring.<ref>{{cite journal | last1 = Mourer-Chauviré | first1 = C. | last2 = Pickford | first2 = M. | year = 2015 | title = Stemp group galliform and stemp group psittaciform birds (Aves, Galliformes, Paraortygidae, and Psittaciformes, family incertae sedis) from the Middle Eocene of Namibia | journal = Journal of Ornithology | volume = 156 | issue = 1| pages = 275–286 | doi = 10.1007/s10336-014-1124-y | s2cid = 16336177 }}</ref>