Editing Frilled lizard (section)

==Description==
[[File:Frill anatomy.jpg|thumb|left|Anatomy of the frill of ''Chlamydosaurus kingii'']]
The frilled lizard can reach a total length of around {{convert|90|cm}} and a head-body length of {{cvt|27|cm}}, and weighs at least {{cvt|600|g|lb}}.<ref name=pepper17/><ref name=Shine1989/><ref>{{cite journal|last1=Frappell|first1=Peter B.|last2=Mortola|first2=Jacopo P.|year=1998|title=Passive body movement and gas exchange in the frilled lizard (''Chlamydosaurus kingii)'' and goanna (''Varanus gouldii)''|journal=Journal of Experimental Biology|volume=201|issue=15|pages=2307–2311|doi=10.1242/jeb.201.15.2307|pmid=9662501 |doi-access=free}}</ref> It has a particularly large and wide head; a long neck to accommodate the [[neck frill|frill]]; long legs and a tail that makes most of its total length.<ref name=Cogger>{{cite book|last=Cogger|first=Harold G.|author-link=Harold Cogger|year=2014|title=Reptiles and Amphibians of Australia|location=Clayton, Victoria, Australia|publisher=CSIRO publishing|edition=7th|pages=700–701|isbn=978-0-643-10035-0}}</ref><ref name=Shine1989/><ref name=Thompson2005>{{cite journal|last1=Thompson|first1=Graham G.|last2=Withers|first2=Philip C.|year=2005|title=Shape of Western Australian dragon lizards (Agamidae)|journal=Amphibia-Reptilia|volume=26|pages=73–85|doi=10.1163/1568538053693323 |url=https://brill.com/view/journals/amre/26/1/article-p73_11.xml?language=en|doi-access=free}}</ref> The species is [[sexual dimorphism|sexually dimorphic]], males being larger than females<ref name=pepper17/><ref name=Shine1989/> and having proportionally bigger frills, heads and jaws.<ref>{{cite journal|last1=Christian|first1=Keith|last2=Bedford|first2=Gavin|last3=Griffiths|first3=Anthony|year=1995|title=Frillneck lizard morphology: comparisons between sexes and sites|journal=Journal of Herpetology|volume=29|issue=4|pages=576–583|doi=10.2307/1564741|jstor=1564741}}</ref> The corners of the frilled lizard's eyes are pointed and the rounded nostrils face away from each other and angle downwards. Most of the lizard's [[reptile scale|scales]] are [[Keeled scales|keeled]], having a ridge down the centre. From the backbone to the sides, the scales alternate between small and large.<ref name=Cogger/>

The distinctive frill is a flap of skin that extends from the head and neck and contains several folded ridges. When fully extended, the frill is disc-shaped and can reach over four times the length of the animal's torso in diameter, or around {{convert|30|cm|in|abbr=on}} across. When not extended, the frill wraps around the body,<ref name=Montandon/><ref name=Shine90/><ref name=pepper17/> like a cape over the neck and shoulders.<ref>Wilson, S.; [[species:Gerry Swan|Swan, G.]] (2023). ''A Complete Guide to Reptiles of Australia, Sixth Edition''. Sydney: Reed New Holland. pp. 442–443. {{ISBN|978-1-92554-671-2}}.</ref> The frill is laterally symmetrical; the right and left sides are attached at the bottom in a V-shape, and cartilage-like connective tissue (Grey's cartilage) connects the top ends to each side of the head near the ear openings.<ref name=Thompson2005/><ref name=Montandon>{{cite journal|last1=Montandon|first1=Sophie A.|last2=Fofonjka|first2=Anamarija|last3=Milinkovitch|first3=Michel C.|year=2019|title=Elastic instability during branchial ectoderm development causes folding of the ''Chlamydosaurus'' erectile frill|journal=eLife|volume=8|page=e44455|doi=10.7554/eLife.44455|pmid=31234965 |pmc=6592688 |doi-access=free}}</ref> The frill is supported by rod-like [[hyoid bone]]s, and is spread out by movements of these bones, the lower jaw and Grey's cartilage.<ref name=Montandon/> This structure mainly functions as a [[deimatic behaviour|threat display]] to predators and for communication between individuals.<ref name=Shine90/> It can also act as camouflage when folded, but this is unlikely to have been a consequence of [[selection pressure]].<ref name=Shine90/> The frill may be capable of working like a [[Microphone#Unidirectional|directional microphone]], allowing them to better hear sounds directly in front of them but not around them.<ref>{{cite journal|last1=Peacock|first1=John|last2=Benson|first2=Monica A.|last3=Greene|first3=Nathaniel T.|last4=Tollin|first4=Daniel J.|last5=Young|first5=Bruce A.|year=2022|title=The acoustical effect of the neck frill of the frill-necked lizard (''Chlamydosaurus kingii'')|journal= The Journal of the Acoustical Society of America|volume=152|issue=1|page=437|doi=10.1121/10.0012221|pmid=35931550|bibcode=2022ASAJ..152..437P|s2cid=250592592}}</ref> There is no evidence for other suggested functions, such as food storage, gliding or temperature regulation.<ref name=Shine90>{{cite journal | last = Shine | first = R | title = Function and evolution of the frill of the frillneck lizard, ''Chlamydosaurus kingii'' (Sauria: Agamidae) | journal = Biological Journal of the Linnean Society | volume = 40 | issue = 1 | pages = 11–20 | year = 1990 | language = en | doi = 10.1111/j.1095-8312.1990.tb00531.x }}</ref>
[[File:Le Bugue - Aquarium du Périgord noir - Lézard à collerette - 001.jpg|thumb|right|A frilled lizard in a reptile display (frill folded)]]
Frilled lizards vary between grey, brown, orangish-brown, and black dorsally, the underside being paler white or yellow. Males have a dark belly but a lighter chest. The underside and lateral sides of the species are sprinkled with dark brown markings that merge to create bands on the tail.<ref name=Cogger/> The colours of the frills vary based on range; lizards west of the Ord River have red-coloured frills, those living between the river and the Carpentarian Gap have orange frills, and those east of the gap have yellow to white frills. New Guinean frilled lizards are yellow-frilled.<ref name=pepper17/> The more colourful frills have white patches which may add to the display.<ref name=antipredator/> Colouration is mainly created by [[carotenoid]]s and [[pteridine]] pigments; lizards with red and orange frills have more carotenoids than those with yellow and white frills, the latter two are also lacking in pteridines.<ref name=pepper17/><ref name=McLean2019/> Yellow colouration has been linked to higher steroid hormones.<ref name=McLean2019>{{cite journal|last1=McLean|first1=Claire A.|author1-link=species:Claire A. McLean|last2=Lutz|first2=Adrian|last3=Rankin|first3=Katrina J.|last4=Elliot|first4=Adam|last5=Moussalli|first5=Adnan|author5-link=species:Adnan Moussalli|last6=Stuart-Fox|first6=Devi|author6-link=species:Devi Stuart-Fox|year=2019|title=Red carotenoids and associated gene expression explain colour variation in frillneck lizards|journal=Proceedings of the Royal Society B: Biological Sciences|volume=286|issue=1907|page=20191172|doi=10.1098/rspb.2019.1172|pmid=31311479 |pmc=6661345 |doi-access=free}}</ref>