Blue-tongued skinks comprise the

Australasia Australasia is a subregion of Oceania, comprising Australia, New Zealand (overlapping with Polynesia), and sometimes including New Guinea and surrounding islands (overlapping with Melanesia). The term is used in a number of different context ...

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

''Tiliqua'', which contains some of the largest members of the

skink Skinks are a type of lizard belonging to the family (biology), family Scincidae, a family in the Taxonomic rank, infraorder Scincomorpha. With more than 1,500 described species across 100 different taxonomic genera, the family Scincidae is one o ...

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

(Scincidae). They are commonly called blue-tongued lizards or simply blue-tongues or blueys in

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

or panana in

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania, between the Indian Ocean, Indian and Pacific Ocean, Pacific oceans. Comprising over List of islands of Indonesia, 17,000 islands, including Sumatra, ...

. As suggested by these common names, a prominent characteristic of the genus is a large blue tongue that can be bared as bluff-warning to potential enemies. Their tongue can also deform itself and produce a thick

mucus Mucus (, ) is a slippery aqueous secretion produced by, and covering, mucous membranes. It is typically produced from cells found in mucous glands, although it may also originate from mixed glands, which contain both Serous fluid, serous and muc ...

in order to catch prey. They are relatively shy in comparison with other lizards, and also significantly slower due to their shorter legs.

Systematics and distribution

Blue-tongued skinks are closely related to the

genera Genus (; : genera ) is a taxonomic rank above species and below family as used in the biological classification of living and fossil organisms as well as viruses. In binomial nomenclature, the genus name forms the first part of the binomial s ...

'' Cyclodomorphus'' and '' Hemisphaeriodon''. All species are found on mainland

with the exception of ''Tiliqua gigas'', which occurs in

New Guinea New Guinea (; Hiri Motu: ''Niu Gini''; , fossilized , also known as Papua or historically ) is the List of islands by area, world's second-largest island, with an area of . Located in Melanesia in the southwestern Pacific Ocean, the island is ...

and various islands of

. The Tanimbar blue-tongued skink, a

subspecies In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...

of ''Tiliqua scincoides'', is also found on several small Indonesian islands between Australia and

. ''Tiliqua nigrolutea'', the blotched blue-tongued skink, is the only species present in

Tasmania Tasmania (; palawa kani: ''Lutruwita'') is an island States and territories of Australia, state of Australia. It is located to the south of the Mainland Australia, Australian mainland, and is separated from it by the Bass Strait. The sta ...

Ecology

Most species are diurnal, ground-foraging

omnivores An omnivore () is an animal that regularly consumes significant quantities of both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize t ...

, feeding on a wide variety of

insects Insects (from Latin ') are hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (head, thorax and abdomen), three pairs of jointed ...

gastropods Gastropods (), commonly known as slugs and snails, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, freshwater, and from the land. Ther ...

, flowers, fruits, and berries. The pygmy blue-tongue is again the exception, being primarily an

ambush predator Ambush predators or sit-and-wait predators are carnivorous animals that capture their prey via stealth, luring or by (typically instinctive) strategies utilizing an element of surprise. Unlike pursuit predators, who chase to capture prey u ...

of terrestrial

arthropods Arthropods ( ) are invertebrates in the phylum Arthropoda. They possess an arthropod exoskeleton, exoskeleton with a cuticle made of chitin, often Mineralization (biology), mineralised with calcium carbonate, a body with differentiated (Metam ...

. All are

ovoviviparous Ovoviviparity, ovovivipary, ovivipary, or aplacental viviparity is a "bridging" form of reproduction between egg-laying oviparity, oviparous and live-bearing viviparity, viviparous reproduction. Ovoviviparous animals possess embryos that develo ...

, with litter sizes ranging from 1-4 in the pygmy blue-tongue and shingleback to 5-24 in the eastern and northern blue-tongues.

Species

Extinct species

Multiple extinct species have been proposed. '' T. frangens'', the largest known species of the genus, lived during the

Pliocene The Pliocene ( ; also Pleiocene) is the epoch (geology), epoch in the geologic time scale that extends from 5.33 to 2.58Pleistocene The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fin ...

epoch around the Wellington Caves of

New South Wales New South Wales (commonly abbreviated as NSW) is a States and territories of Australia, state on the Eastern states of Australia, east coast of :Australia. It borders Queensland to the north, Victoria (state), Victoria to the south, and South ...

. Another extinct species ''T. laticephala'' may represent the same taxon as ''T. frangens''. Its nearest relative is the extant '' T. rugosa'', which is half the size and lacks the bony plates of ''T. frangens''.Supplementary Information
/ref>Extinct lizard was a bizarrely supersized version of modern skinks
Alice Klein,

New Scientist ''New Scientist'' is a popular science magazine covering all aspects of science and technology. Based in London, it publishes weekly English-language editions in the United Kingdom, the United States and Australia. An editorially separate organ ...

, 2023-06-14Meet the biggest and most bizarre skink ever found in Australia. It became extinct 47,000 years ago
2023-06-14 Another extinct species ''T. wilkinsonorum'' also lived during the

Pliocene The Pliocene ( ; also Pleiocene) is the epoch (geology), epoch in the geologic time scale that extends from 5.33 to 2.58T. pusilla'' from the middle

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

, but researchers question whether this species belong to the genus ''Tiliqua'' due to its uncertain phylogenetic position that causes

paraphyly Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic ''with respect to'' the excluded subgroups. In co ...

In captivity

Some species of this genus are kept as household pets. They are on average very friendly when raised in captivity, and are often called 'the dogs of reptiles'. Captive specimens can live 20 years or longer.

Notes

References

* (2006). Using ancient and recent DNA to explore relationships of extinct and endangered ''Leiolopisma'' skinks (Reptilia: Scincidae) in the Mascarene islands. ''Molecular Phylogenetics and Evolution'' 39(2): 503–511. (HTML abstract) * (1988). Mate fidelity in an Australian lizard ''Trachydosaurus rugosus'' (Scincidae). ''

Copeia ''Ichthyology & Herpetology'' (formerly ''Copeia'') is a quarterly peer-reviewed scientific journal covering research in ichthyology and herpetology that was originally named after Edward Drinker Cope, a prominent American researcher in these fi ...

'' 1987(3): 749-757. * (1990). Comparison of displaced and retained partners in a monogamous lizard ''Tiliqua rugosa''. ''Australian Wildlife Research'' 17: 135-140. * (1996). A prey record of the Eastern Blue-tongue ''Tiliqua scincoides'' for the common brown snake ''Pseudonaja textilis''.
Monitor
' 8(3): 155.

External links

{{DEFAULTSORT:Blue-Tongued Skink Skinks of Australia Reptiles of Indonesia Skinks of New Guinea Tiliqua Skink, Blue-tongued Articles containing video clips Taxa named by John Edward Gray Reptiles as pets