Editing Forelimb (section)

=== Pronation and supination ===
{{See also|Anatomical terms of motion}}
The ability to pronate the [[Manus (anatomy)|manus]] (hand) and forearm in [[Theria|therian mammals]] is achieved by a rounded head of the radius, which allows it to swivel across the ulna. Supination requires a dorsal glide of the distal radius and pronation a palmar glide in relation to the distal ulna.

[[Pronation]] has evolved multiple times, among [[mammal]]s, [[chameleon]]s, and [[Varanidae|varanids]].<ref name=":2" /> However, the more basal condition is to be unable to pronate. [[Dinosaur]]s were not capable of more than semi-pronation of the wrist,<ref>{{Cite journal|last=Hutson|first=Joel D.|date=2014|title=Quadrupedal Dinosaurs did not Evolve Fully Pronated Forearms: New Evidence from the Ulna|journal=Acta Palaeontologica Polonica|volume=60|issue=3|pages=599–610|doi=10.4202/app.00063.2014|issn=0567-7920|doi-access=free}}</ref> though bipedal origins of all quadrupedal dinosaur clades could have allowed for greater disparity in forelimb posture than often considered.<ref name=":2">{{Cite journal|last1=VanBuren|first1=Collin S.|last2=Bonnan|first2=Matthew|date=2013-09-18|title=Forearm Posture and Mobility in Quadrupedal Dinosaurs|journal=PLOS ONE|volume=8|issue=9|pages=e74842|doi=10.1371/journal.pone.0074842|issn=1932-6203|pmc=3776758|pmid=24058633|bibcode=2013PLoSO...874842V|doi-access=free}}</ref> [[Monotreme]]s have forearms that are not as dexterous as therians. Monotremes have a sprawling posture, and multiple elements in their pectoral girdles, which are ancestral traits for mammals.<ref>{{Cite book|title=Fins into limbs evolution, development, and transformation|last=Hall, Brian Keith, 1941-|date=2007|publisher=University of Chicago Press|oclc=928978489}}</ref>

In birds, the forearm muscles supinate, pronate, flex and extend the distal wing.<ref>{{Cite journal|last=Tobalske|first=Bret W.|date=2007-09-15|title=Biomechanics of bird flight|journal=Journal of Experimental Biology|language=en|volume=210|issue=18|pages=3135–3146|doi=10.1242/jeb.000273|issn=0022-0949|pmid=17766290|doi-access=free}}</ref>