Varaninae

The Varanidae are a family of lizards in the superfamily Varanoidea within the Anguimorpha group. The family, a group of carnivorous and frugivorous lizards, includes the living genus '' Varanus'' and a number of extinct genera more closely related to ''Varanus'' than to the earless monitor lizard (''Lanthanotus''). ''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 earless monitor lizard and chinese crocodile lizard. The oldest members of the family are known from the Late Cretaceous of Mongolia.

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. 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. 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''; 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, while Gauthier ''et al.'' (2012) classify it as a member of Varanidae.

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

Genera

:Genera marked with are extinct
Genera included in Varanidae according to Dong ''et al.'', 2022
*'' Ovoo'' Norell, Gao, & Conrad, 2008 (Mongolia, Late Cretaceous)

*''Aiolosaurus'' Gao and Norell, 2000 (Mongolia, Late Cretaceous)
*'' Cherminotus'' Borsuk-Bialynicka, 1984 (Mongolia, Late Cretaceous)

*'' Saniwides'' Borsuk-Bialynicka, 1984 (Mongolia, Late Cretaceous)
*'' Paravaranus'' Borsuk-Bialynicka, 1984 (Mongolia, Late Cretaceous)
*'' Proplatynotia'' Borsuk-Bialynicka, 1984 (Mongolia, Late Cretaceous)
*'' Telmasaurus'' Gilmore, 1943 (Mongolia, Late Cretaceous)
*'' Saniwa'' Leidy, 1870 (Europe, North America, Eocene)
*''Archaeovaranus'' Dong ''et al.'', 2022 (China, Eocene)

*'' Varanus'' Shaw, 1790

Phylogeny

Below is a cladogram from Dong et al. 2022.

Biology

Monitor lizards are reputed to be among the most intelligent lizards. Most species forage widely and have large home ranges, and many have high stamina. Although most species are carnivorous, three arboreal species in the Philippines (''Varanus olivaceus'', ''Varanus mabitang'', and ''Varanus bitatawa'') are primarily frugivores. 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.

Varanids possess unidirectional pulmonary airflow, including airsacs akin to those of birds.Unidirectional Airflow In The Lungs Of Birds, Crocs And Now Monitor Lizards
/ref>

See also

* Aigialosauridae
* Helodermatidae
* Mosasauridae
*Necrosauridae

References

External links

Varanidae

{{Authority control

Lizard families
Taxa named by Blasius Merrem
Extant Campanian first appearances