Varanidae

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Varanids
Temporal range:
Late Cretaceous - Holocene, 80–0 Ma
Komodo dragons (Varanus komodoensis) fighting.jpg
male Komodo dragons fighting, Indonesia
Nile monitor lizard (Varanus niloticus).jpg
Nile monitor, Kenya
Scientific classification e
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Superfamily: Varanoidea
Family: Varanidae
Merrem, 1820
Genera

See text

The Varanidae are a family of lizards in the superfamily Varanoidea within the Anguimorpha group. The family, a group of carnivorous and frugivorous lizards,[1] includes the living genus Varanus and a number of extinct genera. Varanus includes the Komodo dragon (the largest living lizard), crocodile monitor, savannah monitor, the goannas of Australia and Southeast Asia, and various other species with a similarly distinctive appearance. Their closest living relatives are the anguid and helodermatid lizards.[2]

Taxonomy[]

The Varanidae were defined (using morphological characteristics) by Estes, de Queiroz and Gauthier (1988) as the clade containing the most recent common ancestor of Lanthanotus and Varanus and all of its descendants.[3] A similar definition was formulated by Conrad et al. (2008) (also using morphological data), who defined the Varanidae as the clade containing Varanus varius, Lanthanotus borneensis, and all descendants of their last common ancestor.[4] Using one of these definitions leads to the inclusion of the earless monitor lizard (L. borneensis) in the family Varanidae.

Lee (1997) created a different definition of the Varanidae, defining them as the clade containing Varanus and all taxa more closely related to Varanus than to Lanthanotus;[5][6] this definition explicitly excludes the earless monitor lizard from the Varanidae. Whether L. borneensis is included in or excluded from the Varanidae depends on the author; for example, Vidal et al. (2012) classify the earless monitor lizard as a member of a separate family Lanthanotidae,[7] while Gauthier et al. (2012) classify it as a member of Varanidae.[8]

Taxonomic analysis based on molecular data has identified that Varanus and Lanthanotus make up Varanidae, while Shinisaurus is a sister taxon.[9][10]

Genera[]

The extinct Saniwa ensidens
Genera marked with † are extinct

Genera usually included in Varanidae (under subfamily Varaninae according to Conrad et al., 2008)):

  • † Hoffstetter, 1969 - Considered to be a junior synonym of Varanus by Delfino et al. (2013).[11]
  • †Ovoo Norell, Gao, & Conrad, 2008[12]
  • †Saniwa Leidy, 1870
  • Varanus Shaw, 1790

Genera sometimes included in the Varanidae (under subfamily Lanthanotinae according to Conrad et al., 2008), treated as under the separate family Lanthanotidae by other authors:

Basal varanoids:

  • † Borsuk-Bialynicka, 1984
  • †Telmasaurus Gilmore, 1943[12]
  • †Palaeosaniwa Gilmore, 1928 - Might actually be more closely related to helodermatids than to varanids.[4]

Formerly included in the Varanidae:

  • † Arambourg, 1952 - Moved to a separate group of varanoid squamates, , by Houssaye et al. (2011).[13]

Phylogeny[]

Below is a cladogram from Conrad et al. (2008) that shows relationships within Varanoidea:[14]

Varanoidea 
 

†Mosasaurs Prognath waipar2DB.jpg

 
 
 

†"Saniwa" feisti

 
 
 

†Necrosaurus

 
 
 
 

†

 
 

†Telmasaurus

 
 
 Varanidae 
 Lanthanotinae 
 

†Aiolosaurus

 
 
 

Lanthanotus

 
 

†Cherminotus

 
 
 
 Varaninae 
 

†Ovoo

 
 
 

†Saniwa

 
 

Varanus Zoology of Egypt (1898) (Varanus exanthematicus).png

 
 
 
 
 
 
 
 

Biology[]

Gray's monitor (Varanus olivaceus) is a tree-dwelling varanid from the Philippines that primarily feeds on fruit

Monitor lizards are reputed to be among the most intelligent lizards. Most species forage widely and have large home ranges,[15] and many have high stamina.[16] Although most species are carnivorous, three arboreal species in the Philippines (Varanus olivaceus, Varanus mabitang, and Varanus bitatawa) are primarily frugivores.[1][17] Among species of living varanids, the limbs show positive allometry, being larger in larger-bodied species, although the feet become smaller as compared with the lengths of the other limb segments.[18]

Varanids possess unidirectional pulmonary airflow, including airsacs akin to those of birds.[19]

See also[]

References[]

  1. ^ a b Welton, L. J.; Siler, C. D.; Bennett, D.; Diesmos, A.; Duya, M. R.; Dugay, R.; Rico, E. L. B.; Van Weerd, M.; Brown, R. M. (2010). "A spectacular new Philippine monitor lizard reveals a hidden biogeographic boundary and a novel flagship species for conservation". Biology Letters. 6 (5): 654–658. doi:10.1098/rsbl.2010.0119. ISSN 1744-9561. PMC 2936141. PMID 20375042.
  2. ^ Fry, B.G.; Vidal, N; Norman, J.A.; Vonk, F.J.; Scheib, H.; Ramjan, S.F.R; Kuruppu, S.; Fung, K.; Hedges, B.; Richardson, M.K.; Hodgson; Ignjatovic, V.; Summerhays, R.; Kochva, E. (February 2006). "Early evolution of the venom system in lizards and snakes". Nature. 439 (7076): 584–588. Bibcode:2006Natur.439..584F. doi:10.1038/nature04328. PMID 16292255. S2CID 4386245.
  3. ^ de Queiroz, Kevin; Gauthier, Jacques (1988). "Phylogenetic Relationships within Squamata". In Estes, Richard J.; Pregill, Gregory K. (eds.). Phylogenetic Relationships of the Lizard Families: Essays Commemorating Charles L. Camp. Stanford University Press. p. 166. ISBN 9780804714358. OCLC 16646258.
  4. ^ a b Conrad, J. (2008). "Phylogeny and systematics of Squamata (Reptilia) based on morphology". Bulletin of the American Museum of Natural History. 310: 1–182. doi:10.1206/310.1. hdl:2246/5915. S2CID 85271610.
  5. ^ Lee, Michael S. Y. (29 January 1997). "The phylogeny of varanoid lizards and the affinities of snakes". Philos Trans R Soc Lond B Biol Sci. The Royal Society. 352 (1349): 53–91. Bibcode:1997RSPTB.352...53L. doi:10.1098/rstb.1997.0005. PMC 1691912.
  6. ^ Lee, Michael S. Y. (2005). "Molecular evidence and marine snake origins". Biology Letters. 1 (2): 227–230. doi:10.1098/rsbl.2004.0282. PMC 1626205. PMID 17148173.
  7. ^ Vidal, Nicolas; Marin, Julie; Sassi, Julia; Battistuzzi, Fabia U.; Donnellan, Steve; Fitch, Alison J.; Fry, Bryan G.; Vonk, Freek J.; Rodriguez de la Vega, Ricardo C.; Couloux, Arnaud; Hedges, S. Blair (2012). "Molecular evidence for an Asian origin of monitor lizards followed by Tertiary dispersals to Africa and Australasia". Biology Letters. 8 (5): 853–855. doi:10.1098/rsbl.2012.0460. PMC 3441001. PMID 22809723.
  8. ^ Gauthier, Jacques A.; Kearney, Maureen; Maisano, Jessica Anderson; Rieppel, Olivier; Behlke, Adam D.B. (2012). "Assembling the Squamate Tree of Life: Perspectives from the Phenotype and the Fossil Record". Bulletin of the Peabody Museum of Natural History. 53 (1): 3–308. doi:10.3374/014.053.0101. S2CID 86355757.
  9. ^ Wiens, John J.; Kuczynski, Caitlin A.; Townsend, Ted; Reeder, Tod W.; Mulcahy, Daniel G.; Sites, Jack W., Jr (2010-12-01). "Combining Phylogenomics and Fossils in Higher-Level Squamate Reptile Phylogeny: Molecular Data Change the Placement of Fossil Taxa". Systematic Biology. 59 (6): 674–688. doi:10.1093/sysbio/syq048. ISSN 1063-5157. PMID 20930035.
  10. ^ Townsend, Ted (October 2004). "Molecular physiogenetics of squamata: the position of snakes, amphisbaenians, and dibamids, and the root of the squamate tree". Systematic Biology. 53 (5): 735–757. doi:10.1080/10635150490522340. PMID 15545252.
  11. ^ Delfino, Massimo; Rage, Jean-Claude; Bolet, Arnau; Alba, David M. (2013). "Early Miocene dispersal of the lizard Varanus into Europe:Reassessment of vertebral material from Spain". Acta Palaeontologica Polonica. 58 (4): 731–735. doi:10.4202/app.2012.0025.
  12. ^ a b c Conrad, JL; Balcarcel, AM; Mehling, CM (2012). "Earliest Example of a Giant Monitor Lizard (Varanus, Varanidae, Squamata)". PLOS ONE. 7 (8): e41767. Bibcode:2012PLoSO...741767C. doi:10.1371/journal.pone.0041767. PMC 3416840. PMID 22900001.
  13. ^ Houssaye, Alexandra; Bardet, Nathalie; Rage, Jean–Claude; Suberbiola, Xabier Pereda; Bouya, Baâdi; Amaghzaz, Mbarek; Amalik, Mohamed (2011). "A review of Pachyvaranus crassispondylus Arambourg, 1952, a pachyostotic marine squamate from the latest Cretaceous phosphates of Morocco and Syria". Geological Magazine. 148 (2): 237–249. Bibcode:2011GeoM..148..237H. doi:10.1017/S0016756810000580. S2CID 128706999.
  14. ^ Conrad, Jack L.; Rieppel, Olivier; Grande, Lance (31 December 2008). "Re-assessment of varanid evolution based on new data from Saniwa ensidens Leidy, 1870 (Squamata, Reptilia)" (PDF). American Museum Novitates (3630): 1–15. doi:10.1206/596.1. hdl:2246/5939. S2CID 83550662.
  15. ^ Perry, G.; Garland, T., Jr. (2002). "Lizard home ranges revisited: effects of sex, body size, diet, habitat, and phylogeny" (PDF). Ecology. 83 (7): 1870–1885. doi:10.1890/0012-9658(2002)083[1870:LHRREO]2.0.CO;2.
  16. ^ Clemente, C.J.; Withers, P.C.; Thompson, G.G. (2009). "Metabolic rate and endurance capacity in Australian varanid lizards (Squamata; Varanidae; Varanus)". Biological Journal of the Linnean Society. 97 (3): 664–676. doi:10.1111/j.1095-8312.2009.01207.x.
  17. ^ Greene, Harry W. (1986). Diet and Arboreality in the Emerald Monitor, Varanus prasinus, with Comments on the Study of Adaptation. Chicago: Field Museum of Natural History. OCLC 14915452. OL 7155983M.
  18. ^ Christian, A.; Garland, T., Jr. (1996). "Scaling of limb proportions in monitor lizards (Squamata: Varanidae)" (PDF). Journal of Herpetology. 30 (2): 219–230. doi:10.2307/1565513. JSTOR 1565513.
  19. ^ Unidirectional Airflow In The Lungs Of Birds, Crocs And Now Monitor Lizards

External links[]

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