Editing Monitor lizard

{{Short description|Genus of reptiles}}
{{Automatic taxobox
| name = Monitor lizard
| fossil_range = {{fossilrange|Early Miocene | Recent}}
| image = The Genus Varanus.png
| image_caption = Left: ''[[Varanus salvadorii|V. salvadorii]]'', ''[[Varanus griseus|V. griseus]]'', ''[[Varanus acanthurus|V. acanthurus]]'', ''[[Varanus olivaceus|V. olivaceus]]'' ''[[Varanus bengalensis|V. bengalensis]]'' Right: ''[[Varanus salvator|V. salvator]]'', ''[[Varanus albigularis|V. albigularis]]'', ''[[Varanus albigularis|V. albigularis]]'', ''[[Varanus spinulosus|V. spinulosus]]'', ''[[Varanus prasinus|V. prasinus]]'', ''[[Varanus jobiensis|V. jobiensis]]'' Bottom: ''[[Varanus komodoensis|V. komodoensis]]''
| taxon = Varanus
| authority = [[Blasius Merrem|Merrem]], 1820
| type_species = ''[[Varanus varius|Lacerta varia]]''{{cn|date=August 2024}}
| type_species_authority = [[George Shaw (biologist)|Shaw]], 1790
| subdivision_ranks = Subgenera
| subdivision = {{plainlist|
* ''[[Empagusia]]''
* ''[[Varanus (Euprepiosaurus)|Euprepiosaurus]]''
* ''[[Varanus (Hapturosaurus)|Hapturosaurus]]''
* ''[[Varanus (Odatria)|Odatria]]''
* ''[[Varanus (Papusaurus)|Papusaurus]]''
* ''[[Varanus (Philippinosaurus)|Philippinosaurus]]''
* ''[[Varanus (Polydaedalus)|Polydaedalus]]''
* ''[[Varanus (Psammosaurus)|Psammosaurus]]''
* ''[[Varanus (Solomonsaurus)|Solomonsaurus]]''
* ''[[Varanus (Soterosaurus)|Soterosaurus]]''
* ''[[Varanus (Varanus)|Varanus]]''
}}
For species, see [[Monitor lizard#Taxonomy|text]]
| range_map = Worldwidevaranus.PNG
| range_map_caption = Combined native range of all the monitor lizards
}}
'''Monitor lizards''' are [[lizard]]s in the [[genus]] '''''Varanus''','' the only extant genus in the family [[Varanidae]]. They are native to Africa, Asia, and [[Oceania]], and [[West African Nile monitor|one species]] is also found in south America as an [[invasive species]].<ref>{{Cite web |date=2023-05-23 |title=Monitor {{!}} lizard {{!}} Britannica |url=https://www.britannica.com/animal/monitor-lizard |access-date=2023-06-06 |website=www.britannica.com |language=en}}</ref>  About 80 species are recognized.

Monitor lizards have long necks, powerful [[tail]]s and claws, and well-developed limbs. The adult length of extant species ranges from {{convert|20|cm|in|abbr=on}} in some species such as ''[[Dampier Peninsula monitor|Varanus sparnus]]'', to over {{convert|3|m|ft|abbr=on|0}} in the case of the [[Komodo dragon]], though the extinct [[megalania]] (''Varanus priscus'') may have reached lengths of more than {{convert|7|m|ft|abbr=on|0}}. Most monitor species are [[terrestrial locomotion|terrestrial]], but many are also [[arboreal]] or semiaquatic. While most monitor lizards are [[carnivorous]], eating smaller reptiles, [[fish]], [[bird]]s, [[insect]]s, small mammals, and eggs, a few species also eat [[fruit]] and [[vegetation]].<ref name="EoR">{{cite book |editor=Cogger, H.G. |editor2=Zweifel, R.G. |author= Bauer, Aaron M. |year=1998 |title=Encyclopedia of Reptiles and Amphibians |publisher= Academic Press |location=San Diego |pages= 157–159 |isbn= 0-12-178560-2}}</ref>

==Etymology==
The [[genus|generic]] name ''Varanus'' is derived from the [[Arabic (language)|Arabic]] word {{lang|ar|ورل}} ''waral'' [Standard Arabic] / {{lang|ar|ورر}} ''warar'' [colloquially] / {{lang|ar|ورن}} ''waran'' [colloquially], from a common [[Semitic languages|Semitic]] root ''ouran'', ''waran'', ''warar'' or '' waral'', meaning "lizard beast".<ref name="Sprackland">{{cite book |author=Robert George Sprackland |title=Giant lizards |publisher=T.F.H. Publications |location=Neptune, NJ |year=1992 |pages= 61 |isbn=0-86622-634-6}}</ref>

In English, they are known as "monitors" or "monitor lizards". The earlier term "monitory lizard" became rare by about 1920.<ref>[https://books.google.com/ngrams/graph?content=monitory+lizard%2F%28monitory+lizard%2Bmonitor+lizard%29&year_start=1800&year_end=2000&corpus=15&smoothing=3&share=&direct_url=t1%3B%2C%28monitory%20lizard%20/%20%28monitory%20lizard%20%2B%20monitor%20lizard%29%29%3B%2Cc0 Google ngrams]</ref> The name may have been suggested by the occasional habit of varanids to stand on their two hind legs and to appear to "monitor",<ref name="Sprackland" /> or perhaps from their supposed habit of "warning people of the approach of venomous animals".<ref>[[Horatio Nelson]], Matthew Henry Barker, ''The Life of Nelson Revised and Illustrated. With Original Anecdotes, Notes, Etc. By the Old Sailor'', 1836 [https://books.google.com/books?id=PapWAAAAcAAJ&pg=PA35 p. 35]</ref> But all of these explanations for the name "monitor" postdate Linnaeus giving the scientific name ''Lacerta monitor'' to the [[Nile monitor]] in 1758, which may have been based on a mistaken idea by [[Carl Linnaeus|Linnaeus]] that the [[German (language)|German]] word ''Waran'' (borrowed from Arabic) was connected to ''warnen'' (to warn), leading him to incorrectly [[Latin]]ize it as ''monitor'' ('warner', 'adviser').<ref name="Zimmern">{{cite book |author=Heinrich Zimmern |title=Akkadische Fremdwörter als Beweis für babylonischen Kultureinfluss |language=German |type=Thesis |publisher=Universität Leipzig |year=1915 |pages=52 |oclc=697605207}}</ref>

[[Austronesian languages]] spoken across [[Southeast Asia]], where varanids are common, have a large number of slightly related local names for them. They are usually known as ''biawak'' ([[Malay language|Malay]], including [[Indonesian language|Indonesian]] standard variety), ''bayawak'' ([[Philippine languages|Filipino]]), ''binjawak'' or ''minjawak or nyambik'' ([[Javanese language|Javanese]]), or variations thereof.<ref>{{cite web|url=https://acd.clld.org/cognatesets/25202#4/4.56/109.28|title=*''bayawak'': monitor lizard, ''Varanus'' spp. (esp. ''V. salvator'')|last1=Blust|first1=Robert|last2=Trussel|first2=Stephen|website=Austronesian Comparative Dictionary|date=2010|publisher=Max Planck Institute for Evolutionary Anthropology|access-date=January 30, 2022}}</ref> Other names include ''hokai'' ([[Solomon Islands]]); ''bwo'', ''puo'', or ''soa'' ([[Maluku Islands|Maluku]]); ''halo'' ([[Cebu]]); ''galuf'' or ''kaluf'' ([[Micronesia]] and the [[Caroline Islands]]); ''batua'' or ''butaan'' ([[Luzon]]); ''alu'' ([[Bali]]); ''hora'' or ''ghora'' ([[Komodo (island)|Komodo]] group of islands); ''phut'' ([[Burma|Burmese]]); and ''guibang'' ([[Manobo languages|Manobo]]).<ref name="bayl">{{cite journal|author=Mark K. Bayless|year=2004|title=The local names of Pacific monitor lizards (Sauria: Varanidae) of Oceania & Indo-Malaysia, excluding Australia|journal=Micronesia|volume=37|issue=1|pages=49–55|url=http://www.uog.edu/up/micronesica/dynamicdata/assetmanager/images/vol37/49-55%20bayless%2037%281%29.pdf}}</ref><ref name="gaulk">{{cite journal|author=[[Maren Gaulke]]|year=1992|title=Taxonomy and biology of Philippine water monitors (''Varanus salvator'')|journal=The Philippine Journal of Science|volume=121|issue=4|pages=345–381|url=http://scinet.dost.gov.ph/union/UploadFiles/download.php?b=Pages%20from%20PJS%20vol%20121(4)_66870.pdf&f=../Downloads/Pages%20from%20PJS%20vol%20121(4)_66870.pdf&t=application/pdf|archive-date=2021-08-01|access-date=2013-11-16|archive-url=https://web.archive.org/web/20210801134103/http://scinet.dost.gov.ph/union/UploadFiles/download.php?b=Pages%20from%20PJS%20vol%20121(4)_66870.pdf&f=../Downloads/Pages%20from%20PJS%20vol%20121(4)_66870.pdf&t=application/pdf|url-status=dead}}</ref>

In [[South Asia]], they are known as {{transliteration|mni|hangkok}} in [[Meitei language|Meitei]], mwpou in Boro, {{transliteration|mr|ghorpad}} घोरपड in [[Marathi language|Marathi]], {{transliteration|ta|uḍumbu}} உடும்பு in [[Tamil language|Tamil]] and ''udumbu'' ഉടുമ്പ്  in [[Malayalam language|Malayalam]], {{transliteration|bho|bilgoh}} in [[Bhojpuri Language|Bhojpuri]], ''gohi'' (गोहि) in [[Maithili language|Maithili]], in [[Sinhala language|Sinhala]] as තලගොයා / කබරගොයා ({{transliteration|si|talagoya [land monitor] / kabaragoya [water monitor where kabara means vitiligo] }}), in [[Telugu language|Telugu]] as ''uḍumu'' (ఉడుము), in [[Kannada language|Kannada]] as {{transliteration|mni|uḍa}} (ಉಡ), in [[Punjabi language|Punjabi]] and [[Magahi]]  as गोह (''goh''), in [[Assamese language|Assamese]] as ''gui xaap'', in [[Odia language|Odia]] as ଗୋଧି (''godhi''), and in [[Bengali language|Bengali]] as গোসাপ ({{transliteration|bn|goshaap}}) or গুইসাপ ({{transliteration|bn|guishaap}}), and गोह (''goh'') in [[Hindi language|Hindi]] and गोधा (''godhā'') in [[Sanskrit]].<ref>{{Cite book |last1=Turner |first1=Ralph Lilley |url=https://dsal.uchicago.edu/cgi-bin/app/soas_query.py?qs=g%C5%8Ddh%C4%81%CC%81&searchhws=yes&matchtype=exact |title=A comparative dictionary of the Indo-Aryan languages |last2=Turner |first2=Dorothy Rivers |date=1966 |publisher=Oxford university press |isbn=978-0-19-713550-1 |location=London |chapter=#4286}}</ref>

The [[West African Nile monitor]] is known by several names in [[Yoruba language|Yoruba]], including {{transliteration|yo|awọ́nríwọ́n}}, {{transliteration|yo|awọ̀n}}, and {{transliteration|yo|àlégbà}}. In [[Serer language|Serer]]<ref name="Kasteel" /><ref name="Kastee2">Kesteloot, Lilyan, ''Dieux d'eau du Sahel: Voyage à travers les mythes de Seth à Tyamaba.'' Editions L'Harmattan, 2007, p. 11, {{ISBN|9782296185067}} [https://books.google.co.uk/books?id=WLqP6YqEVZoC&pg=PA11#v=onepage&q&f=false] (accessed 27 March 2025)</ref> and amongst the [[Wolofization|Wolofized]]-[[Serer people|Serers]]<ref name="Kastee2" /> of [[Kaolack]],  it is known as ''mbossé'' (or ''mboose'' in Serer<ref name="Kasteel" />)<ref name="Kasteel" /><ref name="Kastee2" /> or ''bar'' in [[Wolof language|Wolof]] (pronounced ''barrr'' with a long "R").<ref name="Kasteel" /> Mbossé is the [[Tutelary deity|tutelary]] and traditional [[totem]] of the city of Kaolack, (formerly part of the Serer precolionial [[Kingdom of Saloum]],  now part of modern-day [[Senegal]]).<ref name="Kasteel">{{cite book| last1 = Kesteloot| first1 = Lilyan | last2 = Veirman| first2 = Anja| author-link = | date = 1999| title = Histoire d'Afrique : les enjeux de mémoire|chapter = Un lieu de mémoire sans stèle et sans visite guidée : le culte du Mboose à Kaolack (Sénégal)| chapter-url = https://archive.org/details/histoiredafrique0000unse/page/83/mode/1up| location = Paris| publisher = Karthala| page = 83-91| isbn = 9782865379040 |language = French}}</ref> The mbossé is also one of the totems of the noble [[Joof family]] born of [[Guelwar|Guelwar matrilineage]],<ref name="C.Diop Ant">[[Cheikh Anta Diop|Diop, Cheikh Anta]], ''The Cultural Unity of Black Africa: The Domains of Patriarchy and of Matriarchy in Classical Antiquity.'' Third World Press, 1978, p. 190, {{ISBN|9780883780497}}</ref> which is one of the many [[Serer maternal clans]]. The mbossé or ''mbosseh'' (in [[Gambian English]]) is one of the [[Serer religion#Holy ceremonies and festivals|Serer religious festivals]],<ref>{{in lang|fr}} Niang, Mor Sadio, [in] ''Ethiopiques'' numéro 31" - révue socialiste de culture négro-africaine 3e trimestre, [[Institut Fondamental d'Afrique Noire|IFAN]], (1982) [http://ethiopiques.refer.sn/spip.php?article905] {{Webarchive|url=https://web.archive.org/web/20131224154807/http://ethiopiques.refer.sn/spip.php?article905|date=24 December 2013}}.</ref> and should not be confused with the mythical and sacred tree [[Serer creation myth#Mbos|mbos]]―enshrined in [[Serer religion]] and [[Serer creation myth|Serer cosmogony]]―where the mbossé (the lizard) takes its name. 

Due to confusion with the large New World lizards of the family [[Iguanidae]], the lizards became known as "[[goannas]]" in Australia. Similarly, in [[South African English]], they are referred to as ''leguaans'', or ''likkewaans'', from the [[Dutch language|Dutch]] term for the Iguanidae, ''leguanen''.

==Distribution==
The various species [[Range (biology)|cover]] a vast area, occurring through Africa, the [[Indian subcontinent]], to [[China]], the [[Ryukyu Islands]] in southern [[Japan]], south to [[Southeast Asia]] to [[Thailand]], [[Malaysia]], [[Brunei]], [[Indonesia]], the [[Philippines]], [[New Guinea]], [[Australia]], and islands of the [[Indian Ocean]] and the [[South China Sea]]. They have also been introduced outside of their natural range, for instance, the [[West African Nile monitor]] is now found in [[South Florida]].<ref>{{cite magazine |last=Yong |first= Ed |date= 20 April 2016 |title= Florida's Dragon Problem |url= https://www.theatlantic.com/science/archive/2016/04/the-past-and-future-of-floridas-dragon-problem/478905/ |magazine= The Atlantic |access-date=<!-- original access date unknown -->}}</ref> Monitor lizards also occurred widely in Europe in the [[Neogene]], with the last known remains in the region dating to the [[Middle Pleistocene]].<ref>{{Cite journal|last1=L|first1=Georgalis Georgios|last2=Andrea|first2=Villa|last3=Massimo|first3=Delfino|date=4 March 2017|title=The last European varanid: demise and extinction of monitor lizards (Squamata, Varanidae) from Europe|url=https://doi.org/10.1080/02724634.2017.1301946|journal=Journal of Vertebrate Paleontology|volume=37|issue=2|pages=e1301946|doi=10.1080/02724634.2017.1301946|bibcode=2017JVPal..37E1946G |issn=0272-4634|hdl=2318/1635702|s2cid=90865661|hdl-access=free}}</ref>

==Habits and diet==
Most monitor lizards are almost entirely carnivorous,<ref>{{cite book|last1=Pianka|first1=Eric R.|last2=King|first2=Dennis R|last3=King|first3=Ruth Allen|title=Varanoid Lizards of the World|date=2004|publisher=Indiana University Press|location=Bloomington, Indiana}}</ref> consuming prey as varied as insects, [[crustacean]]s, [[arachnid]]s, [[myriapod]]s, [[mollusc]]s, fish, [[amphibian]]s, reptiles, birds, and mammals. Most species feed on invertebrates as juveniles and shift to feeding on vertebrates as adults. Deer make up about 50% of the diet of adult Komodo dragons, the largest monitor species.<ref>{{cite book|last1=Auffenberg|first1=Walter|title=The Behavioral Ecology of the Komodo Monitor|date=1981|publisher=University Press of Florida}}</ref> In contrast, three [[arboreal]] species from the Philippines, ''[[Varanus bitatawa]]'', ''[[Varanus mabitang|mabitang]]'', and ''[[Varanus olivaceus|olivaceus]]'', are primarily [[frugivore|fruit eaters]].<ref name="Greene">{{cite book | last = Greene | first = Harry W. | title = Diet and Arboreality in the Emerald Monitor, Varanus Prasinus, with Comments on the Study of Adaptation | publisher = Field Museum of Natural History | location=Chicago | date = 1986 | oclc = 14915452 | ol = 7155983M }}</ref><ref name="Welton2010">{{cite journal |last1=Welton |first1=L. J. |last2=Siler |first2=C. D. |last3=Bennett |first3=D. |last4=Diesmos |first4=A. |last5=Duya |first5=M. R. |last6=Dugay|first6=R.|last7=Rico|first7=E. L. B. |last8=Van Weerd |first8=M. |last9=Brown|first9=R. M.|title=A spectacular new Philippine monitor lizard reveals a hidden biogeographic boundary and a novel flagship species for conservation |journal=Biology Letters |volume=6 |issue=5 |year=2010 |pages=654–658  |doi=10.1098/rsbl.2010.0119 |pmid=20375042 |pmc=2936141}}</ref><ref>{{cite journal|last1=Struck|first1=U|last2=Altenbach|first2=AV|last3=Gaulke|first3=M|last4=F|first4=Glaw|title=Tracing the diet of the monitor lizard Varanus mabitang by stable isotope analyses (d15N, d13C)|journal=Naturwissenschaften|date=2002|volume=89|issue=10|pages=470–473|doi=10.1007/s00114-002-0361-8|pmid=12384723|s2cid=12091969}}</ref>

==Biology==
{{Multiple image
| image1            = Bell's phase lace monitor (Varanus varius) cropped.jpg
| image2            = Bell's phase lace monitor (Varanus varius) 2 cropped.jpg
| total_width       = 250
| caption1          = 
| caption2          = 
| align             = right
| footer            = A Bell's phase [[lace monitor]] in a tree
}}
[[File:Varanoid skulls.png|thumb|Skulls of various varanoids]]
Monitor lizards are considered unique among animals in that its members are relatively morphologically conservative, yet show a very large size range.<ref name=pianka1995>{{cite journal|author=Pianka, E.R. |title= Evolution of Body Size: Varanid Lizards as a Model System|journal= The American Naturalist|volume= 146|issue= 3|pages= 398–414|doi=10.1086/285806|url=http://www.zo.utexas.edu/courses/THOC/BodySize.pdf|year= 1995|bibcode= 1995ANat..146..398P|s2cid= 85237692}}</ref> However, finer morphological features such as the shape of the skull and limbs do vary, and are strongly related to the ecology of each species.<ref>{{cite journal|doi=    10.1371/journal.pone.0130625
|pmid=    26106889
|title=    The Relationship between Cranial Structure, Biomechanical Performance and Ecological Diversity in Varanoid Lizards
|journal=    PLOS ONE
|volume=    10
|issue=    6
|pages=    e0130625
|year=    2015
|last1=    McCurry
|first1=    Matthew R.
|last2=    Mahony
|first2=    Michael
|last3=    Clausen
|first3=    Phillip D.
|last4=    Quayle
|first4=    Michelle R.
|last5=    Walmsley
|first5=    Christopher W.
|last6=    Jessop
|first6=    Tim S.
|last7=    Wroe
|first7=    Stephen
|last8=    Richards
|first8=    Heather
|last9=    McHenry
|first9=    Colin R.
|pmc=4479569
|bibcode= 2015PLoSO..1030625M
|doi-access= free
}}</ref><ref>{{cite journal|doi=10.1111/j.1469-7998.2009.00559.x|title=Evolutionary relationships of sprint speed in Australian varanid lizards|journal=Journal of Zoology|volume=278|issue=4|pages=270–280|year=2009|last1=Clemente|first1=C. J.|last2=Thompson|first2=G. G.|last3=Withers|first3=P. C.|doi-access=free}}</ref>

Like snakes, monitor lizards have highly forked tongues that act as part of the "smell" sense, where the tips of the tongue carry molecules from the environment to the a sensory organ in the skull called the [[Vomeronasal organ|Jacobson's organ]]. The forked apparatus allows for these lizards to sense boundaries in the molecules they collect, almost smelling in "stereo".<ref>{{Cite journal |last=Sack |first=Jeffrey D. |date=2022-08-01 |title=True Facts: Snake and Lizard Tongues |url=https://online.ucpress.edu/abt/article/84/6/378/189894/True-Facts-Snake-and-Lizard-Tongues |journal=The American Biology Teacher |language=en |volume=84 |issue=6 |pages=378 |doi=10.1525/abt.2022.84.6.378 |s2cid=251407423 |issn=0002-7685 |doi-access=free}}</ref><ref>{{Cite journal |last1=Srichairat |first1=Nattawut |last2=Taksintum |first2=Wut |last3=Chumnanpuen |first3=Pramote |date=2017-07-11 |title=Gross Morphological Structure of Digestive System in Water Monitor Lizard Varanus salvator (Squamata: Varanidae) |url=http://wjst.wu.ac.th/index.php/wjst/article/view/3356 |journal=Walailak Journal of Science and Technology |volume=15 |issue=3 |pages=245–253 |doi=10.48048/wjst.2018.3356 |issn=2228-835X|doi-access=free }}</ref> While most reptiles possess [[Taste bud|taste buds]], monitor lizards and likely snakes as well completely lack taste buds.<ref>{{Cite journal |last=Young |first=Bruce A. |date=1997 |title=On the Absence of Taste Buds in Monitor Lizards (Varanus) and Snakes |url=https://www.jstor.org/stable/1565343 |journal=Journal of Herpetology |volume=31 |issue=1 |pages=130–137 |doi=10.2307/1565343 |jstor=1565343 |issn=0022-1511}}</ref> [[Mertens' water monitor|Merten's water monitor]], the most aquatically adapted monitor species, is uniquely capable of using its sense of smell underwater to locate and capture prey.<ref>{{Cite journal |last1=Mayes |first1=P. J. |last2=Thompson |first2=G. G. |last3=Withers |first3=P. C. |date=2005 |title=Diet and foraging behaviour of the semi-aquatic Varanus mertensi (Reptilia:Varanidae) |url=http://www.publish.csiro.au/?paper=WR04040 |journal=Wildlife Research |language=en |volume=32 |issue=1 |pages=67 |doi=10.1071/WR04040 |bibcode=2005WildR..32...67M |issn=1035-3712}}</ref>

Monitor lizards are [[oviparous]],<ref name="piankavitt2003" /> laying from seven to 38 [[Egg (biology)|eggs]],<ref>https://indonesiaindonesia.com/f/37477-sejarah-pulau-komodo/ (in [[Indonesian language|Indonesian]])</ref> which they often cover with soil or protect in a hollow tree stump. Some species, including the Komodo dragon, are capable of [[parthenogenesis]].<ref>{{cite journal |last=Smith |first=Kerri |year=2006 |title=Dragon virgin births startle zoo keepers |url=http://www.nature.com/news/2006/061218/full/061218-7.html |journal=Nature |doi=10.1038/news061218-7 |s2cid=191590714 |access-date=2006-12-20 |doi-access=free}}</ref>

=== Venom ===
Anatomical and molecular studies indicate that most if not all [[Varanidae|varanids]] are [[venom]]ous.<ref name="Fry2009">
{{cite journal |vauthors=Fry BG, Wroe S, Teeuwisse W, van Osch JP, Moreno K, Ingle J, McHenry C, Ferrara T, Clausen P, Scheib H, Winter KL, Greisman L, Roelants K, van der Weerd L, Clemente CJ, Giannakis E, Hodgson WC, Luz S, Martelli P, Krishnasamy K, Kochva E, Kwok HF, Scanlon D, Karas J, Citron DM, Goldstein EJ, Mcnaughtan JE, Norman JA |date=June 2009 |title= A central role for venom in predation by ''Varanus komodoensis'' (Komodo dragon) and the extinct giant ''Varanus (Megalania) priscus''. |journal= PNAS |volume= 106 |pages= 8969–8974 |doi = 10.1073/pnas.0810883106 |pmid = 19451641 |issue = 22 |pmc = 2690028|bibcode=2009PNAS..106.8969F |doi-access=free }}</ref><ref name="Fry2006">
{{cite journal |vauthors=Fry BG, Vidal N, Norman JA, Vonk FJ, Scheib H, Ramjan SF, Kuruppu S, Fung K, Hedges B, Richardson MK, Hodgson WC, Ignjatovic V, Summerhays R, Kochva E |date=February 2006 |title= Early evolution of the venom system in lizards and snakes |journal= Nature |volume= 439 |pages= 584–588 |doi = 10.1038/nature04328 |pmid = 16292255 |issue = 7076|bibcode=2006Natur.439..584F |s2cid=4386245 }}</ref> Unlike snakes, monitor lizard venom glands are situated in their lower jaw.<ref>{{Cite journal |last1=Fry |first1=Bryan G. |last2=Wroe |first2=Stephen |last3=Teeuwisse |first3=Wouter |last4=van Osch |first4=Matthias J. P. |last5=Moreno |first5=Karen |last6=Ingle |first6=Janette |last7=McHenry |first7=Colin |last8=Ferrara |first8=Toni |last9=Clausen |first9=Phillip |last10=Scheib |first10=Holger |last11=Winter |first11=Kelly L. |last12=Greisman |first12=Laura |last13=Roelants |first13=Kim |last14=van der Weerd |first14=Louise |last15=Clemente |first15=Christofer J. |date=2009-06-02 |title=A central role for venom in predation by Varanus komodoensis (Komodo Dragon) and the extinct giant Varanus ( Megalania ) priscus |journal=Proceedings of the National Academy of Sciences |language=en |volume=106 |issue=22 |pages=8969–8974 |doi=10.1073/pnas.0810883106 |issn=0027-8424 |pmc=2690028 |pmid=19451641 |bibcode=2009PNAS..106.8969F |doi-access=free }}</ref> The venom of monitor lizards is diverse and complex, as a result of the diverse ecological niches monitor lizards occupy.<ref>{{Cite journal|last1=Dobson|first1=James S.|last2=Zdenek|first2=Christina N.|last3=Hay|first3=Chris|last4=Violette|first4=Aude|last5=Fourmy|first5=Rudy|last6=Cochran|first6=Chip|last7=Fry|first7=Bryan G.|date=May 2019|title=Varanid Lizard Venoms Disrupt the Clotting Ability of Human Fibrinogen through Destructive Cleavage|journal=Toxins|language=en|volume=11|issue=5|pages=255|doi=10.3390/toxins11050255|pmid=31067768|pmc=6563220|doi-access=free}}</ref> 

For example, many species have [[anticoagulant]] venom, disrupting clotting through a combination of [[fibrinogenolysis]] and blocking [[platelet]] aggregation. Amongst them, arboreal species, such as the [[Varanus (Hapturosaurus)|tree monitors]] and the [[Banded tree monitor|banded monitor]], have by far the strongest fibrinogenolytic venom. As a result, wounds from monitor lizard bites often bleed more than they would if they were simply lacerations. Venom may also cause [[hypotension]].<ref>{{Cite journal |last1=Dobson |first1=James S. |last2=Zdenek |first2=Christina N. |last3=Hay |first3=Chris |last4=Violette |first4=Aude |last5=Fourmy |first5=Rudy |last6=Cochran |first6=Chip |last7=Fry |first7=Bryan G. |date=2019-05-07 |title=Varanid Lizard Venoms Disrupt the Clotting Ability of Human Fibrinogen through Destructive Cleavage |journal=Toxins |language=en |volume=11 |issue=5 |pages=255 |doi=10.3390/toxins11050255 |issn=2072-6651 |pmc=6563220 |pmid=31067768 |doi-access=free }}</ref> 

In some species such as the [[Komodo dragon]] and the [[desert monitor]], venom also induces a powerful neurotoxic effect. In the latter species for instance, envenomation causes immediate paralysis in rodents (but not birds) and lesser effects of the same nature in humans.<ref>{{Cite journal |last=Zima |first=Yuliya |date=December 2019 |title=On the Toxicity of the Bite of the Caspian Gray Monitor Lizard (Varanus griseus caspius) |journal=Biawak |volume=13 |issue=2 |pages=115–118 |via=ResearchGate}}</ref>

=== Metabolism ===
Monitor lizards maintain large territories and employ active-pursuit hunting techniques that are reminiscent of similar-sized mammals.<ref name="kinggreenknight1999">King, D., Green, B., Knight, F. (1999). ''Monitors: The Biology of Varanid Lizards.'' Florida. Krieger Publishing Company.</ref> The highly active nature of monitor lizards has led to numerous studies on the metabolic capacities of these lizards. The general consensus is that monitor lizards have the highest standard metabolic rates of all [[Extant taxon|extant]] reptiles.<ref name="piankavitt2003">Pianka, E.R., Vitt, L.J. (2003). ''Lizards: Windows to the Evolution of Diversity.'' California. University of California Press.</ref>

Monitor lizards have a high aerobic scope<ref name=piankavitt2003 /><ref name=wood1978>{{cite journal|vauthors=Wood SC, Johansen K, Glass ML, ((Maloiy GMO)) |title= Aerobic Metabolism of the Lizard ''Varanus exanthematicus'': Effects of Activity, Temperature, and Size|journal= Journal of Comparative Physiology B|volume= 127|issue= 4|pages= 331–336|doi=10.1007/BF00738417|year= 1978|s2cid= 19320799}}</ref> that is afforded, in part, by their heart anatomy. Whereas most reptiles are considered to have three-chambered hearts, the hearts of monitor lizards – as with those of [[Boidae|boas]] and [[Pythonidae|pythons]] – have a well developed [[Ventricle (heart)|ventricular]] septum that completely separates the [[Lung|pulmonary]] and [[Systemic circulation|systemic]] sides of the circulatory system during [[systole]].<ref name=wang2003>{{cite journal|vauthors=Wang T, Altimiras J, Klein W, Axelsson M |title= Ventricular Haemodynamics in ''Python molurus'': Separation of Pulmonary and Systemic Pressures|journal= The Journal of Experimental Biology|volume= 206|issue= Pt 23|pages= 4241–5|pmid=14581594|year= 2003|doi=10.1242/jeb.00681 |doi-access= free|bibcode= 2003JExpB.206.4241W}}</ref> This allows monitor lizards to create mammalian-equivalent pressure differentials between the pulmonary and systemic circuits,<ref name=wang2003 /> which in turn ensure that oxygenated blood is quickly distributed to the body without also flooding the lungs with high-pressure blood.

==Intelligence==
{{See also|Animal cognition}}
[[File:Monitor lizard at Kaziranga National Park.jpg|thumb|A [[Bengal monitor]] eating a bird egg in [[Kaziranga National Park]]]]
At least some species of monitors are known to be able to count; studies feeding [[rock monitor]]s varying numbers of snails showed that they can distinguish numbers up to six.<ref name="King2">King, Dennis & Green, Brian. 1999. ''Goannas: The Biology of Varanid Lizards''. University of New South Wales Press. {{ISBN|0-86840-456-X}}, p. 43.</ref><ref name ="varanoid">Pianka, E.R.; King, D.R. and King, R.A. (2004). ''Varanoid Lizards of the World.'' Indiana University Press.</ref> [[Nile monitor]]s have been observed to cooperate when foraging; one animal lures the female crocodile away from her nest, while the other opens the nest to feed on the eggs. The decoy then returns to also feed on the eggs.<ref name="King2"/><ref name="varanoid"/> [[Komodo dragon]]s at the [[National Zoological Park (United States)|National Zoo in Washington, DC]], recognize their keepers and seem to have distinct personalities.<ref name="varanoid"/> [[Varanus macraei|Blue]] and [[Emerald tree monitor|green tree monitors]] in British zoos have been observed shredding leaves, apparently as a form of play.<ref name=Kane2019>{{ cite journal | title=Play behaviour by captive tree monitors, Varanus macraei and Varanus prasinus | last1=Kane | first1=D | last2=Davis | first2=AC | last3=Michaels |first3=C | journal=Herpetological Bulletin  | issue=149 | pages=28–31 | year=2019 |doi=10.33256/hb149.2831| doi-access=free }}</ref>

== Human uses ==

===As pets===
[[File:Dada Panchal with monitor lizard 6 x 4.JPG|thumb|right|Injured [[Bengal monitor]] being nursed at the [[Lok Biradari Prakalp]] in India]]
Monitor lizards have become a staple in the [[reptile pet]] trade. The most commonly kept monitors are the [[savannah monitor]] and [[spiny-tailed monitor|Ackie dwarf monitor]], due to their relatively small size, low cost, and relatively calm dispositions with regular handling.<ref name="Sprackland"/> Among others, [[black-throated monitor|black-throated]], [[Timor monitor|Timor]], [[Asian water monitor|Asian water]], [[Nile monitor|Nile]], [[mangrove monitor|mangrove]], [[emerald tree monitor|emerald tree]], [[black tree monitor|black tree]], [[roughneck monitor|roughneck]], [[Dumeril's monitor|Dumeril']]s, [[peach-throated monitor|peach-throated]], [[crocodile monitor|crocodile]], and [[Argus monitor|Argu]]s monitors have been kept in captivity.<ref name="Sprackland"/>

=== Traditional medicines ===
Monitor lizards are poached in some South- and Southeast Asian countries, as their organs and fat are used in some [[traditional medicine]]s, although there is no [[scientific evidence]] as to their effectiveness.<ref>{{Cite web|url=https://www.nationalgeographic.com/animals/article/wildlife-watch-india-monitor-lizard-poaching-plant-root-hatha-jodi|archive-url=https://web.archive.org/web/20210303205156/https://www.nationalgeographic.com/animals/article/wildlife-watch-india-monitor-lizard-poaching-plant-root-hatha-jodi|url-status=dead|archive-date=March 3, 2021|title=How Lizard Genitalia Became a Black Market Craze|website=[[National Geographic Society]] |date=7 July 2017}}</ref><ref>{{Cite web|url=https://www.deccanchronicle.com/lifestyle/pets-and-environment/040717/visakhapatnam-monsoon-activates-monitor-lizard-poaching.html|title = Visakhapatnam: Monsoon activates monitor lizard poaching|date = 4 July 2017}}</ref>
[[File:Road kill lizard. India - Flickr - gailhampshire.jpg|thumb|A dead monitor in India, with its hemipenes removed. Monitor hemipenes are often trafficked and illegally sold.]]
The dried and dyed [[Hemipenis|hemipenes]] of [[Bengal monitor|Bengal monitors]], and less often [[Yellow monitor|yellow]] and [[Asian water monitor|water monitors]], are frequently trafficked and illegally sold in India and online under the deceptive term 'Hatha Jodi', where it is claimed to be the root of a supposed rare Himalayan plant in order to fool buyers and retailers, and to disguise the trade from wildlife authorities. Sellers advertise 'Hatha Jodi' as having the [[Tantra|tantric]] power to bring wealth, power and contentment. A pair of hemipenes may sell at a value of up to US$250.<ref>{{Cite journal |last1=D'Cruze |first1=N. |last2=Singh |first2=B. |last3=Mookerjee |first3=A. |last4=Macdonald |first4=D.W. |last5=Hunter |first5=K. |last6=Brassey |first6=C.A. |last7=Rowntree |first7=J. |last8=Megson |first8=S. |last9=Megson |first9=D. |last10=Fox |first10=G. |last11=Louies |first11=J. |last12=Sharath |first12=R.S. |date=2018 |title=What's in a name? Wildlife traders evade authorities using code words |journal=Oryx |volume=52 |issue=1 |pages=13 |doi=10.1017/S0030605317001788 |doi-access=free}}</ref> In India, the body oil of monitor lizards is sold for thousands of [[Indian rupee|Indian rupees]] to residents in metropolitan cities as a treatment for [[rheumatism]].<ref>{{Cite journal |last1=Bhattacharya |first1=S. |last2=Koch |first2=A. |date=2018 |title=Hatha Jodi: An Illegal Trade of Misused Scientific Facts or Blindfolded Myths and Beliefs? |journal=Biawak |volume=12 |issue=2 |pages=97–99}}</ref>

Monitor lizard meat, particularly the tongue and liver, is eaten in parts of India and Malaysia and is supposed to be an [[aphrodisiac]].<ref name="Parameswaran2006">{{cite journal | title=Case series of eosinophilic meningoencephalitis from South India | last1=Parameswaran | first1=K | journal=Annals of Indian Academy of Neurology | volume=9 | issue=4 | pages=217–222 | year=2006 |doi=10.4103/0972-2327.29203| doi-access=free }}</ref><ref>[http://themalaysianlife.blogspot.com/2009/04/eating-biawak.html Eating Biawak]. The Malaysian Life (April 2009)</ref>

Consuming raw blood and flesh of monitor lizards has been reported to cause [[eosinophil]]ic [[meningoencephalitis]], as some monitors are hosts for the parasitic nematode ''[[Angiostrongylus cantonensis]]''.<ref name="Parameswaran2006" />

=== Leather ===
"Large-scale exploitation" of monitor lizards is undertaken for their skins, which are described as being "of considerable utility" in the leather industry.{{cn|date=April 2025}} In [[Papua New Guinea]], monitor lizard leather is used for membranes in traditional drums (called ''[[Kundu (drum)|kundu]]''), and these lizards are referred to as ''kundu palai'' or "drum lizard" in [[Tok Pisin]], the main Papuan trade language. Monitor lizard skins are prized in making the resonant part of serjas (Bodo folk sarangis) and dotaras (native strummed string instruments of Assam, Bengal and other eastern states). The leather is also used in making a [[Carnatic music]] percussion instrument called the ''[[kanjira]]''.

=== Food ===
The meat of monitor lizards is eaten by some tribes in India,<ref>{{cite news |url=https://www.telegraphindia.com/1170108/jsp/7days/story_129083.jsp |archive-url=https://web.archive.org/web/20180812181533/https://www.telegraphindia.com/1170108/jsp/7days/story_129083.jsp |url-status=dead |archive-date=August 12, 2018 |title=Meats We Also Eat |newspaper=The Telegraph India |date=2017-01-08 |access-date=2018-08-12 |language=en }}</ref> Nepal,<ref>{{cite journal|vauthors=Ghimire HR, Phuyal S, Shah KB |title=Protected species outside the protected areas: People's attitude, threats and conservation of the Yellow Monitor (''Varanus flavescens'') in the Far-western Lowlands of Nepal|journal=Journal for Nature Conservation|volume=22|issue=6|pages=497–503|doi=10.1016/j.jnc.2014.08.003|year=2014|bibcode=2014JNatC..22..497G }}</ref> the Philippines, Australia, South Africa, and  West Africa as a supplemental meat source.{{citation needed |date=December 2013}} Both meat and eggs are also  eaten in Southeast Asian countries such as Vietnam and Thailand as a delicacy.<ref>{{cite web|url=https://www.youtube.com/watch?v=XOBq37xAsVc| archive-url=https://ghostarchive.org/varchive/youtube/20211107/XOBq37xAsVc| archive-date=2021-11-07 | url-status=live|title=Eating a DINOSAUR in Asia!!! RARE Mekong Delta Food you will only find here!|first=Sonny|last=Side|date=5 June 2019|via=YouTube}}{{cbignore}}</ref>

==Conservation==
According to [[IUCN Red List]] of threatened species, most of the monitor lizards species fall in the categories of least concern, but the population is decreasing globally. All but five species of monitor lizards are classified by the [[CITES|Convention on International Trade in Endangered Species of Wild Fauna and Flora]] under Appendix II, which is loosely defined as species that are not necessarily threatened with extinction but may become so unless trade in such species is subject to strict regulation to avoid use incompatible with the survival of the species in the wild. The remaining five species – the [[Bengal monitor|Bengal]], [[yellow monitor|yellow]], [[desert monitor|desert]], and [[Varanus nebulosus|clouded]] monitors and the Komodo Dragon– are classified under CITES Appendix I, which outlaws international commercial trade in the species.<ref>{{Cite web
|url=http://www.asean-wen.org/index.php?option=com_docman&Itemid=80
|title=Identification Guides for Wildlife Traded in Southeast Asia
|publisher=ASEAN-WEN
|year=2008
|access-date=2011-09-28
|archive-date=2016-04-12
|archive-url=https://web.archive.org/web/20160412165446/http://www.asean-wen.org/index.php?option=com_docman&Itemid=80
|url-status=dead
}}</ref>

The [[yellow monitor]] is protected in all countries in its range except Bhutan, Nepal, India, Pakistan, and Bangladesh.<ref>{{cite journal|vauthors=Ghimire HR, Shah KB |year=2014|title= Status and habitat ecology of the Yellow Monitor, ''Varanus flavescens'', in the Southeastern part of Kanchanpur District, Nepal|journal= Herpetological Conservation and Biology|volume= 9|issue=2|pages= 387–393|url=http://www.herpconbio.org/Volume_9/Issue_2/Ghimire_Shah_2014.pdf}}</ref>

In [[Kerala]], [[Andhra Pradesh]], [[Karnataka]], [[Telangana]] and all other parts of South India, catching or killing of monitor lizards is banned under the Protected Species Act.

==Evolution==
[[File:Varanus priscus Melbourne Museum.jpg|thumb|The giant extinct [[megalania]] (''Varanus priscus'')]]

''Varanus'' is the only living genus of the family [[Varanidae]]. Varanids last shared a common ancestor with their closest living relatives, [[Earless monitor lizard|earless "monitors"]], during the [[Late Cretaceous]]. The oldest known varanids are from the [[Late Cretaceous]] of Mongolia. During the [[Eocene]], the varanid ''[[Saniwa]]'' occurred in North America. The closest known relative of ''Varanus'' is ''[[Archaeovaranus]]'' from the Eocene of China, suggesting that the genus ''Varanus'' is of Asian origin. The oldest fossils of ''Varanus'' date to the early [[Miocene]].<ref name=":02">{{Cite journal |last1=Dong |first1=Liping |last2=Wang |first2=Yuan-Qing |last3=Zhao |first3=Qi |last4=Vasilyan |first4=Davit |last5=Wang |first5=Yuan |last6=Evans |first6=Susan E. |date=2022-03-28 |title=A new stem-varanid lizard (Reptilia, Squamata) from the early Eocene of China |journal=Philosophical Transactions of the Royal Society B: Biological Sciences |volume=377 |issue=1847 |pages=20210041 |doi=10.1098/rstb.2021.0041 |pmc=8819366 |pmid=35125002 }}</ref>

Many of the species within the various [[Subgenus|subgenera]] also form [[species complex]]es with each other:

''[[Varanus (Euprepiosaurus)|Euprepriosaurus]]''

*''V. indicus'' species complex (''[[Mangrove monitor|V. indicus]]'', ''[[Varanus cerambonensis|V. cerambonensis]]'', ''[[Varanus caerulivirens|V. caerulivirens]]'', ''[[Varanus colei|V. colei]]'', ''[[Sago monitor|V. obor]]'', ''[[Lirung monitor|V. lirugensis]]'', ''[[Varanus rainerguentheri|V. rainerguentheri]]'', ''[[Varanus zugorum|V. zugorum]]'')<ref name=":0">{{Cite web|url=http://www.cites.org/eng/notif/1997/964.shtml|title=Recommendations of the Nomenclature Committee|date=1997-03-07|url-status=dead|archive-url=https://web.archive.org/web/20080518210428/http://www.cites.org/eng/notif/1997/964.shtml|archive-date=2008-05-18}}</ref><ref name=":1">{{Cite journal|last=Böhme|first=Wolfgang|date=2019-11-23|title=The Kei Islands Monitor Lizard (Squamata: Varanidae: Varanus: Euprepiosaurus) as a Distinct Morphological, Taxonomic, and Conservation Unit|journal=Russian Journal of Herpetology|volume=26|issue=5|pages=272–280|doi=10.30906/1026-2296-2019-26-5-272-280|s2cid=213867767 }}</ref>

*''V. doreanus'' species complex (''[[Blue-tailed monitor|V. doreanus]]'', ''[[Finsch's monitor|V. finschi]]'', ''[[Mussau Island blue-tailed monitor|V. semotus]]'', ''[[Varanus yuwonoi|V. yuwonoi]]'')<ref name=":3" />
*''V. jobiensis'' species complex (''[[Peach-throated monitor|V. jobiensis]]'')<ref name=":3" />
''[[Varanus (Odatria)|Odatria]]''
*''V. acanthurus'' species complex (''[[Spiny-tailed monitor|V. acanthurus]]'', ''[[Black-spotted ridge-tailed monitor|V. baritji]]'', ''[[Northern blunt-spined monitor|V. primordius]]'', ''[[Varanus storri|V. storri]]'')
*''V. timorensis'' species complex (''[[Varanus timorensis|V. timorensis]]'', ''[[Peacock monitor|V. auffenbergi]]'', ''[[Banded tree monitor|V. scalaris]]'', ''[[Varanus similis|V. similis]]'', ''[[Black-headed monitor|V. tristis]])''
''[[Varanus (Varanus)|Varanus]]''
*''V. gouldii'' species complex (''[[Sand goanna|V. gouldii]]'', ''[[Rosenberg's monitor|V. rosenbergi]]'', ''[[Yellow-spotted monitor|V. panoptes]]'')
''[[Varanus (Polydaedalus)|Polydaedalus]]''
*''V. exanthematicus'' species complex (''[[Savannah monitor|V. exanthematicus]]'', ''[[Rock monitor|V. albigularis]]'', ''[[Yemen monitor|V. yemenensis]]'')
*''V. niloticus'' species complex (''[[Nile monitor|V. niloticus]]'', ''[[West African Nile monitor|V. stellatus]]'')
''[[Empagusia]]''
*''V. bengalensis'' species complex (''[[Bengal monitor|V. bengalensis]]'', ''[[Clouded monitor|V. nebulosus]]'')
''[[Varanus (Soterosaurus)|Soterosaurus]]''
*''V. salvator'' species complex (''[[Asian water monitor|V. salvator]]'', ''[[Yellow-headed water monitor|V. cumingi]]'', ''[[Large-scaled water monitor|V. nuchalis]]'', ''[[Togian water monitor|V. togianus]]'', ''[[Marbled water monitor|V. marmoratus]]'')<ref>{{Cite journal|last=BÖHME|first=WOLFGANG|date=2003|title=Checklist of the living lizards of the world (family Varanidae)|journal= Zool. Verh. Leiden |volume=341|url=http://www.repository.naturalis.nl/document/46740}}</ref><ref name=":0" /><ref name=":2">{{Cite journal|last=Koch|first=Andre|date=2010|title=Updated checklist of the living monitor lizards of the world (Squamata: Varanidae)|journal=Bonn Zoological Bulletin|volume=57|pages=127–136}}</ref><ref>{{Cite journal|last=Koch|first=Andre|date=2010-05-06|title=Unravelling The Underestimated Diversity Of Philippine Water Monitor Lizards (Squamata: Varanus Salvator Complex), With The Description Of Two New Species And A New Subspecies|journal=Zootaxa|volume=2446|pages=1–54|doi=10.11646/zootaxa.2446.1.1}}</ref><ref>{{Cite journal|last=Mendyk|first=Robert|date=2018|title=An Annotated Bibliography of Captive Reproduction in Monitor Lizards (Varanidae: Varanus). Part III. Soterosaurus|journal=Biawak|volume=12}}</ref>

The tree monitors of the ''V. prasinus'' species complex (''[[Emerald tree monitor|V. prasinus]]'', ''[[Black tree monitor|V. beccarii]]'', ''[[Golden-spotted tree monitor|V. boehmei]]'', ''[[Bogert's monitor|V. bogerti]]'', ''[[Canopy goanna|V. keithhornei]]'', ''[[Varanus kordensis|V. kordensis]]'', ''[[Varanus macraei|V. macraei]]'', ''[[Varanus reisingeri|V. reisingeri]]'', ''[[Varanus telenesetes|V. telenesetes]]'') were once in the subgenus ''Euprepriosaurus'', but as of 2016, form their own subgenus ''[[Hapturosaurus]]''.<ref name=":3">{{Cite journal|last=Weijola|first=Valter|date=2019-03-14|title=A molecular phylogeny for the Pacific monitor lizards (Varanus subgenus Euprepiosaurus) reveals a recent and rapid radiation with high levels of cryptic diversity|journal=Zoological Journal of the Linnean Society|volume=186|issue=4|pages=1053–1066|doi=10.1093/zoolinnean/zlz002}}</ref>

''[[Peach-throated monitor|V. jobiensis]]'' was once considered to be a member of the ''V. indicus'' species complex, but is now considered to represent its own species complex.<ref name=":3" />
{| class="wikitable mw-collapsible mw-collapsed"
|+
Phylogeny as of Brennan ''et al.'' 2020 <ref>{{Cite journal|last1=Brennan|first1=Ian G.|last2=Lemmon|first2=Alan R.|last3=Lemmon|first3=Emily Moriarty|last4=Portik|first4=Daniel M.|last5=Weijola|first5=Valter|last6=Welton|first6=Luke|last7=Donnellan|first7=Stephen C.|last8=Keogh|first8=J. Scott|date=2020-02-03|title=Phylogenomics of monitor lizards and the role of competition in dictating body size disparity|url=https://www.biorxiv.org/content/10.1101/2020.02.02.931188v1|journal=bioRxiv|language=en|pages=2020.02.02.931188|doi=10.1101/2020.02.02.931188|s2cid=211297088}}</ref>
|-
|[[File:Varanus phylogeny as of Brennan et al 2020 (UPDATE 5).jpg|frameless|647x647px]]
|}

==Taxonomy==
[[File:Iguana and Indian monitor lizard.jpg|alt=|thumb|[[Bengal monitor]] (''V. bengalensis'') with [[green iguana]] (''Iguana iguana'')]]
[[File:Dumeril's Monitor Lizard (Varanus dumerilii) (Photo by Xavier MALLERET) (24237560651).jpg|thumb|Dumeril's monitor (''[[Dumeril's monitor|V. dumerilii]]'')]]
'''Genus ''Varanus'''''

:<small>Species marked with {{extinct}} are [[Extinction|extinct]]</small>

* <small>''{{extinct}}''</small>''[[Varanus bolkayi|V. bolkayi]]<ref name=":5">{{Cite book |last=Molnar |first=Ralph E. |title=Varanoid Lizards of the World |publisher=Indiana University Press |year=2004 |isbn=978-0-253-34366-6 |editor-last=Pianka |editor-first=Eric R. |chapter=The Long and Honorable History of Monitors and their Kin |editor-last2=King |editor-first2=Dennis R. |editor-last3=King |editor-first3=Ruth Allen}}</ref>''
* <small>''{{extinct}}''</small>''[[Varanus darevskii|V. darevskii]]''<ref>{{Cite book |last1=Pianka |first1=Eric R. |url=https://books.google.com/books?id=0e3OuHRRoIQC |title=Varanoid Lizards of the World |last2=King |first2=Dennis |last3=King |first3=Ruth Allen |date=2004 |publisher=Indiana University Press |isbn=978-0-253-34366-6 |pages=40, 106 |language=en}}</ref><ref>{{Cite journal |last1=Villa |first1=Andrea |last2=Abella |first2=Juan |last3=Alba |first3=David M. |last4=Almécija |first4=Sergio |last5=Bolet |first5=Arnau |last6=Koufos |first6=George D. |last7=Knoll |first7=Fabien |last8=Luján |first8=Àngel H. |last9=Morales |first9=Jorge |last10=Robles |first10=Josep M. |last11=Sánchez |first11=Israel M. |date=2018-12-05 |title=Revision of Varanus marathonensis (Squamata, Varanidae) based on historical and new material: morphology, systematics, and paleobiogeography of the European monitor lizards |journal=PLOS ONE |language=en |volume=13 |issue=12 |pages=e0207719 |doi=10.1371/journal.pone.0207719 |issn=1932-6203 |pmc=6281198 |pmid=30517172|bibcode=2018PLoSO..1307719V |doi-access=free }}</ref>
* <small>''{{extinct}}''</small>''[[Varanus emeritus|V. emeritus]]'' (<small>=''V. salvadorii''?</small>)''<ref name=":5" />''
* <small>''{{extinct}}''</small>''[[Varanus hooijeri|V. hooijeri]]<ref name=":5" />''
* <small>''{{extinct}}''</small>''[[Varanus hofmanni|V. hofmanni]]<ref name=":5" />''
* <small>''{{extinct}}''</small>''[[Varanus lungui|V. lungui]]<ref name=":5" />''
* <small>''{{extinct}}''</small>''[[Varanus marathonensis|V. marathonensis]]''
* <small>''{{extinct}}''</small>''[[Varanus mokrensis|V. mokrensis]]''<ref name=":4">{{Cite journal |last1=Ivanov |first1=Martin |last2=Ruta |first2=Marcello |last3=Klembara |first3=Jozef |last4=Böhme |first4=Madelaine |date=2018-07-15 |title=A new species of Varanus (Anguimorpha: Varanidae) from the early Miocene of the Czech Republic, and its relationships and palaeoecology |url=http://eprints.lincoln.ac.uk/28635/4/28635%20Varanus_text_FINAL_MI_MR.pdf |journal=Journal of Systematic Palaeontology |volume=16 |issue=9 |pages=767–797 |doi=10.1080/14772019.2017.1355338 |bibcode=2018JSPal..16..767I |issn=1477-2019 |s2cid=73543240 |archive-date=2019-04-27 |access-date=2020-08-26 |archive-url=https://web.archive.org/web/20190427193129/http://eprints.lincoln.ac.uk/28635/4/28635%20Varanus_text_FINAL_MI_MR.pdf |url-status=dead }}</ref>
* <small>''{{extinct}}''</small>''[[Varanus pronini|V. pronini]]<ref name=":5" />''
* <small>''{{extinct}}''</small>''[[Varanus rusingensis|V. rusingensis]]<ref name=":5" />''<ref name=":4" />
* <small>''{{extinct}}''</small>''[[Varanus semjonovi|V. semjonovi]]<ref name=":5" />''
* <small>''{{extinct}}''</small>''[[Varanus sivalensis|V. sivalensis]]''
* <small>''{{extinct}}''</small>''[[Varanus tyrasiensis|V. tyrasiensis]]'' (<small>=''V. hofmanni''?</small>)''<ref name=":5" />''

Subgenus '''''[[Varanus (Empagusia)|Empagusia]]''''':
[[File:Clouded monitor 2.1.jpg|thumb|Clouded monitor (''[[Clouded monitor|V. nebulosus]]'')]]
*''[[Bengal monitor|V. bengalensis]]'', Bengal monitor
*''[[Varanus dumerilii|V. dumerilii]]'', Dumeril's monitor, brown roughneck monitor
*''[[Yellow monitor|V. flavescens]]'', golden monitor, yellow monitor, short-toed monitor
*''[[Clouded monitor|V. nebulosus]]'', clouded monitor

[[File:Varanidae - Varanus doreanus.JPG|thumb|Blue-tailed monitor (''[[Blue-tailed monitor|V. doreanus]]'')]][[File:Varanus macraei - Reptilium Landau 01.jpg|thumb|Blue-spotted tree monitor (''[[Varanus macraei|V. macraei]]'')]]

Subgenus '''''[[Varanus (Euprepiosaurus)|Euprepiosaurus]]''''':<ref>[[:fr:Thomas Ziegler (zoologiste)|Ziegler, Thomas]]; [[:fr:Andreas Schmitz|Schmitz, Andreas]]; Koch, Andre; [[:de:Wolfgang Böhme (Zoologe)|Böhme, Wolfgang]] (2007). "A review of the subgenus ''Euprepiosaurus'' of ''Varanus'' (Squamata: Varanidae): morphological and molecular phylogeny, distribution and zoogeography, with an identification key for the members of the ''V. indicus'' and the ''V. prasimus'' species groups". ''Zootaxa'' '''1472''': 1-28.</ref>

*''[[Varanus bennetti|V. bennetti]]'', Bennett's long-tailed monitor<ref name="ReferenceA">{{Cite journal|last1=Weijola|first1=Valter|last2=Vahtera|first2=Varpu|last3=Koch|first3=André|last4=Schmitz|first4=Andreas|last5=Kraus|first5=Fred|title=Taxonomy of Micronesian monitors (Reptilia: Squamata: Varanus): endemic status of new species argues for caution in pursuing eradication plans|journal=Royal Society Open Science|year=2020|volume=7|issue=5|pages=200092|doi=10.1098/rsos.200092|pmid=32537217|pmc=7277287|bibcode=2020RSOS....700092W|doi-access=free}}</ref>
*''[[Varanus caerulivirens|V. caerulivirens]]'', turquoise monitor
*''[[Varanus cerambonensis|V. cerambonensis]]'', Ceram monitor
*''[[Varanus colei|V. colei]]'' Kei Islands monitor<ref name=":1" />
*''[[Varanus doreanus|V. doreanus]]'', blue-tailed monitor
*''[[Varanus douarrha|V. douarrha]]'',  New Ireland monitor
*''[[Varanus finschi|V. finschi]]'', Finsch's monitor
*''[[Varanus indicus|V. indicus]]'', mangrove monitor
*''[[Varanus jobiensis|V. jobiensis]]'', peach-throated monitor
*''[[Varanus juxtindicus|V. juxtindicus]]'', Rennell Island monitor
*''[[Varanus lirungensis|V. lirungensis]]'', Talaud mangrove monitor
*''[[Varanus louisiadensis|V. louisiadensis]]'', Louisiade monitor<ref name="weikraus">{{cite journal|doi=10.1080/00222933.2023.2218574|title=Two new species of monitor lizards (Squamata: ''Varanus'') endemic to the Louisiade and Tanimbar archipelagos|journal=Journal of Natural History|volume=57|issue=13–16|pages=947–975|year=2023|last1=Weijola|first1=Valter|last2=Kraus|first2=Fred|doi-access=free}}</ref>
*''[[Varanus melinus|V. melinus]]'', quince monitor<ref>{{cite journal|url=http://www.mapress.com/zootaxa/2010/f/z02434p032f.pdf|title=A new melanistic species of monitor lizard (Reptilia: Squamata: Varanidae) from Sanana Island, Indonesia|journal=Zootaxa|volume= 2434|pages= 17–32|year=2010|author1=Weijola, Valter |author2=Sweet, Samuel |doi=10.11646/zootaxa.2434.1.2}}</ref>
*''[[Varanus obor|V. obor]]'', sago monitor
*''[[Varanus rainerguentheri|V. rainerguentheri]]'' Rainer Günther's monitor
*''[[Varanus semotus|V. semotus]]'', Mussau Island blue-tailed monitor<ref name="vwei">{{cite journal|doi=10.3897/zookeys.568.6872|pmid=27103877|pmc=4829673|title=A new blue-tailed Monitor lizard (Reptilia, Squamata, Varanus) of the Varanus indicus group from Mussau Island, Papua New Guinea|journal=ZooKeys|issue=568|pages=129–54|year=2016|last1=Weijola|first1=Valter|last2=Donnellan|first2=Stephen|last3=Lindqvist|first3=Christer|bibcode=2016ZooK..568..129W |doi-access=free}}</ref>
*''[[Varanus tanimbar|V. tanimbar]]'', Tanimbar monitor<ref name="weikraus"/>
*''[[Varanus tsukamotoi|V. tsukamotoi]]'', Mariana monitor<ref name="ReferenceA"/>
*''[[Varanus yuwonoi|V. yuwonoi]]'' black-backed mangrove monitor, tricolor monitor
*''[[Varanus zugorum|V. zugorum]]'', silver monitor, Zug's monitor

[[File:Varanus timorensis.jpg|thumb|Timor tree monitor (''[[Varanus timorensis|V. timorensis]]'')]]

Subgenus '''''[[Varanus (Hapturosaurus)|Hapturosaurus]]''''':<ref name=":3" />

*''[[Varanus beccarii|V. beccarii]]'', black tree monitor
*''[[Varanus boehmei|V. boehmei]]'', golden-spotted tree monitor
*''[[Varanus bogerti|V. bogerti]]'', Bogert's monitor
*''[[Varanus keithhornei|V. keithhornei]]'', canopy goanna, blue-nosed tree monitor, Nesbit River monitor<ref>[http://reptile-database.reptarium.cz/species?genus=Varanus&species=keithhornei&search_param=%28%28genus%3D%27Varanus%27%2Cexact%29%29 ''Varanus keithhornei''], The Reptile Database</ref>
*''[[Varanus kordensis|V. kordensis]]'', Biak tree monitor
*''[[Varanus macraei|V. macraei]]'', blue-spotted tree monitor
*''[[Varanus prasinus|V. prasinus]]'', emerald tree monitor<ref>[http://reptile-database.reptarium.cz/species?genus=Varanus&species=prasinus&search_param=%28%28genus%3D%27Varanus%27%2Cexact%29%29 ''Varanus prasinus''], The Reptile Database</ref>
*''[[Varanus reisingeri|V. reisingeri]]''<ref>Eidenmüller, Bernd; Wicker, Rudolf (2005). "''Eine weitere neue Waranart aus dem'' Varanus prasinus-''Komplex von den Insel Misol, Indonesian'' ". ''Sauria'' '''27''' (1): 3-8. (''Varanus reisingeri'', new species). (in German).</ref> yellow tree monitor
*''[[Varanus telenesetes|V. telenesetes]]'', mysterious tree monitor, Rossell tree monitor

[[File:Amneville varanus acanthurus 2708 2010.jpg|thumb|Ridge-tailed monitor (''[[Spiny-tailed monitor|V. acanthurus]]'')]]
[[File:Varanus Salvadorii Köln Zoo 31122014 2.jpg|alt=|thumb|Crocodile monitor (''[[Varanus salvadorii|V. salvadorii]]'')]][[File:Varanus bitatawa (KU 322188) from Barangay Dibuluan, San Mariano - ZooKeys-266-001-g069.jpg|thumb|Northern Sierra Madre forest monitor (''[[Northern Sierra Madre forest monitor|V. bitatawa]])'']]

Subgenus '''''[[Varanus (Odatria)|Odatria]]''''':

*''[[Spiny-tailed monitor|V. acanthurus]]'', spiny-tailed monitor, ridge-tailed monitor, Ackie's dwarf monitor
**''V. a. acanthurus'', spiny-tailed monitor
**''V. a. brachyurus'', common spiny-tailed monitor
*''[[Varanus auffenbergi|V. auffenbergi]]'', Auffenberg's monitor, peacock monitor
*''[[Varanus brevicauda|V. brevicauda]]'', short-tailed monitor
*''[[Varanus bushi|V. bushi]]'', Pilbara stripe-tailed monitor, Bush's monitor
*''[[Varanus caudolineatus|V. caudolineatus]]'', stripe-tailed monitor
*''[[Varanus citrinus|V. citrinus]]'', Gulf ridge-tailed monitor<ref name=":6">{{Cite journal |last1=Pavón-Vázquez |first1=Carlos J. |last2=Esquerré |first2=Damien |last3=Fitch |first3=Alison J. |last4=Maryan |first4=Brad |last5=Doughty |first5=Paul |last6=Donnellan |first6=Stephen C. |last7=Keogh |first7=J. Scott |date=2022-08-01 |title=Between a rock and a dry place: phylogenomics, biogeography, and systematics of ridge-tailed monitors (Squamata: Varanidae: Varanus acanthurus complex) |url=https://www.sciencedirect.com/science/article/pii/S1055790322001294 |journal=Molecular Phylogenetics and Evolution |language=en |volume=173 |pages=107516 |doi=10.1016/j.ympev.2022.107516 |pmid=35577290 |bibcode=2022MolPE.17307516P |s2cid=248807709 |issn=1055-7903}}</ref>
*''[[Varanus eremius|V. eremius]]'', rusty desert monitor, pygmy desert monitor
*''[[Varanus gilleni|V. gilleni]]'', pygmy mulga monitor
*''[[Varanus glauerti|V. glauerti]]'', Kimberley rock monitor
*''[[Varanus glebopalma|V. glebopalma]]'', twilight monitor, black-palmed rock monitor
*''[[Varanus hamersleyensis|V. hamersleyensis]]'', Hamersley Range rock monitor
*''[[Varanus insulanicus|V. insulanicus]]'', Groote Eylandt monitor<ref name=":6" />
**''[[Black-spotted ridge-tailed monitor|V. i. baritji]]'', black-spotted ridge-tailed monitor
*''[[Varanus kingorum|V. kingorum]]'', Kings' rock monitor
*''[[Varanus mitchelli|V. mitchelli]]'', Mitchell's water monitor
*''[[Varanus ocreatus|V. ocreatus]]'', Storr's monitor<ref name=":6" />
*''[[Varanus pilbarensis|V. pilbarensis]]'', Pilbara rock monitor
*''[[Varanus primordius|V. primordius]]'' northern blunt-spined monitor
*''[[Varanus scalaris|V. scalaris]]'', banded tree monitor
*''[[Varanus semiremex|V. semiremex]]'' rusty monitor
*''[[Varanus similis|V. similis]]'', Similis monitor, spotted tree monitor
*''[[Varanus sparnus|V. sparnus]]'', Dampier Peninsula monitor
*''[[Varanus storri|V. storri]]'', eastern Storr's monitor
*''[[Varanus timorensis|V. timorensis]]'', Timor monitor
*''[[Varanus tristis|V. tristis]]''
**''V. t. tristis'', black-headed monitor
**''V. t. orientalis'', freckled monitor

Subgenus '''''[[Varanus (Papusaurus)|Papusaurus]]'''''

* ''[[Crocodile monitor|V. salvadorii]]'', crocodile monitor

Subgenus '''''[[Varanus (Philippinosaurus)|Philippinosaurus]]''''':
*''[[Northern Sierra Madre forest monitor|V. bitatawa]]'', northern Sierra Madre forest monitor, ''butikaw'', ''bitatawa''
*''[[Panay monitor|V. mabitang]]'', Panay monitor, ''mabitang''
*''[[Gray's monitor|V. olivaceus]]'', Gray's monitor, ''butaan''

[[File:Monitor lizard in Kalahari.JPG|thumb|right|White-throated monitor (''[[White-throated monitor|V. a. albigularis]]'') on the Kalahari savannah]]
[[File:Varanus niloticus ornatus.jpg|thumb|right|"Ornate monitor", "''[[Ornate monitor|V. ornatus]]''"]]

Subgenus '''''[[Varanus (Polydaedalus)|Polydaedalus]]''''':
*''[[Varanus albigularis|V. albigularis]]'', rock monitor, white-throated monitor
**''[[Varanus albigularis albigularis|V. a. albigularis]]'', white-throated monitor
**''[[Varanus albigularis angolensis|V. a. angolensis]]'', Angolan monitor
**''[[Black-throated monitor|V. a. microstictus]]'', black-throated monitor
*''[[Varanus exanthematicus|V. exanthematicus]]'', savannah monitor, Bosc's monitor
*''[[Varanus niloticus|V. niloticus]]'', Nile monitor
*''[[Varanus stellatus|V. stellatus]]'', West African Nile monitor
*''[[Varanus ornatus|V. ornatus]]'', ornate monitor
*''[[Varanus yemenensis|V. yemenensis]]'', Yemen monitor

[[File:Varanus griseus caspius.jpg|thumb|Caspian monitor (''[[Desert monitor|V. g. caspius]]'')]]
[[File:Monitor Lizard, Sungei Buloh Wetlands Reserve, Singapore (1669835154).jpg|thumb|Water monitor ([[Asian water monitor|''V. salvator'']])]]
Subgenus '''''[[Varanus (Psammosaurus)|Psammosaurus]]''''':
*''[[desert monitor|V. griseus]]'', desert monitor
**''V. g. griseus'', desert monitor, grey monitor
**''V. g. caspius'', Caspian monitor
**''V. g. koniecznyi'', Indian desert monitor, Thar desert monitor
*''[[Nesterov's desert monito|V. nesterovi]]'', Nesterov's desert monitor

Subgenus '''''[[Varanus (Solomonsaurus)|Solomonsaurus]]''''':<ref>{{Cite journal|last=Bucklitsch|first=Yannick|date=2016-08-17|title=Scale Morphology and Micro-Structure of Monitor Lizards (Squamata: Varanidae: Varanus spp.) and their Allies: Implications for Systematics, Ecology, and Conservation|journal=Zootaxa|volume=4153|issue=1|pages=1–192|doi=10.11646/zootaxa.4153.1.1|pmid=27615821}}</ref>

* ''[[Varanus spinulosus|V. spinulosus]]'', spiny-necked mangrove monitor, Solomon Islands spiny monitor

[[File:Perentie Lizard Pair.jpg|alt=|thumb|Perentie (''[[Varanus giganteus|V. giganteus]]'')]]
Subgenus '''''[[Varanus (Soterosaurus)|Soterosaurus]]''''':
*''[[Varanus bangonorum|V. bangonorum]]'', Bangon monitor<ref name="undercover-researchers">{{cite web|url=https://news.ku.edu/2015/01/12/undercover-researchers-expose-two-new-species-lizard-sale-philippine-black-market|title=Undercover researchers expose two new species of lizard for sale on Philippine black market|author=Brendan M. Lynch|date=2015-01-12|work=KU Today|publisher=KU {{!}} The University of Kansas}}</ref>
*''[[Varanus cumingi|V. cumingi]]'', Cuming's water monitor, yellow-headed water monitor
*''[[Varanus dalubhasa|V. dalubhasa]]'', Enteng's monitor<ref name="undercover-researchers"/>
*''[[marbled water monitor|V. marmoratus]]'', marbled water monitor, Philippine water monitor
*''[[Varanus nuchalis|V. nuchalis]]'' large-scaled water monitor
*''[[Varanus palawanensis|V. palawanensis]]'', Palawan water monitor
*''[[Varanus rasmusseni|V. rasmusseni]]''<ref>Koch, André; Gaulke, Maren; Böhme, Wolfgang (2010). "Unravelling the underestimated diversity of Philippine water monitor Lizards (Squamata: ''Varanus salvator'' complex), with description of two new species and a new subspecies". ''Zootaxa'' '''2446''': 1-54. (''Varanus rasmusseni'', new species, p. 28).</ref><ref>[http://reptile-database.reptarium.cz/species?genus=Varanus&species=rasmusseni&search_param=%28%28genus%3D%27Varanus%27%29%28species%3D%27rasmusseni%27%29%29 ''Varanus rasmusseni''], The Reptile Database</ref> Rasmussen's water monitor
*''[[Varanus rudicollis|V. rudicollis]]'', black roughneck monitor
*''[[Asian water monitor|V. salvator]]'', Asian water monitor
**''V. s. salvator'', Sri Lankan water monitor
**''V. s. andamanensis'', Andaman water monitor
**''V. s. bivittatus'', two-striped water monitor, Javan water monitor
**''V. s. macromaculatus'', Southeast Asian water monitor
**''V. s. ziegleri'', Ziegler's water monitor
*''[[Varanus samarensis|V. samarensis]]'', Samar water monitor
*''[[Varanus togianus|V. togianus]]'', Togian water monitor

[[File:Komodo Dragon (15620549901).jpg|thumb|Komodo dragon (''[[Komodo dragon|V. komodoensis]])'']]
Subgenus '''''[[Varanus (Varanus)|Varanus]]''''':
*''[[Perentie|V. giganteus]]'', perentie
*''[[Sand goanna|V. gouldii]]'', Gould's monitor, sand monitor, sand goanna
*''[[Komodo dragon|V. komodoensis]]'', Komodo dragon
*''[[Mertens' water monitor|V. mertensi]]'', Mertens' monitor
*''[[Argus monitor|V. panoptes]]''
**''V. p. panoptes'', Argus monitor
**''V. p. horni'', Horn's monitor
** ''V. p. rubidus'', yellow-spotted monitor
*<small>''{{extinct}}''</small>''[[Megalania|V. priscus]]'', megalania
*''[[Varanus rosenbergi|V. rosenbergi]]'', Rosenberg's monitor, heath monitor
*''[[Varanus spenceri|V. spenceri]]'', Spencer's monitor
*''[[Lace monitor|V. varius]]'', lace monitor
{{Clear}}

==References==
{{Reflist|colwidth=30em}}

{{clear}}

==Further reading==
*[[Blasius Merrem|Merrem B]] (1820). ''Versuchs eines Systems der Amphibien: Tentamen Systematis Amphibiorum.'' Marburg: J.C. Krieger. xv + 191 pp. + one plate. (''Varanus'', new genus, p.&nbsp;58). (in German and Latin).

==External links==
*{{Wikispecies-inline}}
*{{Commons category-inline}}
*[http://www.museum.wa.gov.au/faunabase/_asp_bin/ByFamilyCommonNamecx.asp?d=Reptiles&f=Varanidae Western Australian Museum photos]
*[http://www.komodonationalpark.org/downloads/ciofi%201999.pdf Scientific American article]

{{Varanoidea}}

{{Taxonbar|from=Q81228}}
{{Authority control}}

{{DEFAULTSORT:Monitor lizard}}
[[Category:Varanus| ]]
[[Category:Extant Miocene first appearances]]
[[Category:Taxa named by Blasius Merrem]]
[[Category:Venomous lizards]]