Egernia

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Egernia
Egernia stokesii.jpg
Stokes's skink, (Egernia stokesii), a small species of Egernia sensu stricto
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Family: Scincidae
Subfamily: Egerniinae
Genus: Egernia
Gray, 1832
Species

See text

Synonyms

Contundo Wells & Wellington, 1984
SilubosaurusGray, 1845
SivascincusWells & Wellington, 1985
StorrisaurusWells & Wellington, 1985
Tropidolopisma A.M.C. Duméril & Bibron, 1839
and see text

Contents

Egernia is a genus of skinks (family Scincidae) that occurs in Australia. These skinks are ecologically diverse omnivores that inhabit a wide range of habitats. However, in the loose delimitation (which incorporates about 30 species) the genus is not monophyletic but an evolutionary grade, as has long been suspected due to its lack of characteristic apomorphies. [1]

Some of the skinks traditionally placed in Egernia appear to be among the most intelligent squamates. They have been shown to be able to distinguish between relatives and unrelated conspecifics, and can recognize relatives individually. Several species form monogamous pair-bonds. For instance, the black rock skink is a species who can perform kin discrimination based on scent and form monogamous pair-bonds and a nuclear family structure. [2] Most of these species belong to Egernia sensu stricto , and similar behaviour is also known in the related Solomon Islands skink (Corucia zebrata). The latter means that the high intelligence and social skills are probably plesiomorphic for the Egernia genus-group as a whole, and that the solitary species appear to have evolved towards being less intelligent and social again. It may still be, however, that the intelligent behaviour is a homoplasy that evolved several times in the Egernia genus-group; the fact that Corucia is a monotypic and rather distinct genus makes it impossible to decide at present. [1] [3]

Systematics, taxonomy and evolution

It is the namesake genus of the Egernia genus-group, which also includes the Solomon Islands skink (Corucia), Cyclodomorphus and the blue-tongued skinks (Tiliqua). In some older works, it is considered closely related to Mabuya , but even among the subfamily Lygosominae this genus does not seem to be particularly closely related and would—were the genus-groups treated at the rarely used rank of infrafamily—certainly constitute an infrafamily of its own. On the other hand, the enigmatic crocodile skinks (Tribolonotus) might be a very basal member of the Egernia genus-group. [3]

The genus Egernia proper, as well as the other lineages, appear to be of Miocene—probably Early Miocene—origin, meaning they radiated at least 15, maybe 20 million years ago (mya). There are fossils of Egernia-like Lygosominae from around the Oligocene-Miocene boundary 23 mya, but these cannot be assigned to the present genus with certainty. Rather, they appear to be basal members of the Egernia genus-group, still very plesiomorphic Lygosominae with a habitus similar to Mabuya . [1]

Species

Stokes's skink (E. stokesii) is a large species of the "typical" clade Silubosaurus Stokesii (Discoveries in Australia).jpg
Stokes's skink ( E. stokesii) is a large species of the "typical" clade

Mid-sized to large skinks (adult snout-vent length 100–240 mm) with a bulky, usually somewhat flattened body and small eyes. 24–46 rows of midbody scales; dorsal scales smooth, ridged, keeled or spiny (the tail is often notably spiny). The nasal scale has a postnarial groove; the subocular scale row is incomplete. Eyelids similar in colour to the adjacent scales. [1]

ImageScientific NameCommon NameDistribution
Egernia cunninghami.jpg Egernia cunninghami (Gray, 1832)Cunningham's spiny-tailed skinksoutheastern Australia.
Egernia cygnitos Doughty, Kealley & Donnellan, 2011Western Pilbara spiny-tailed skinknorthwestern Australia
PygmySpinyTailedSkink2.jpg Egernia depressa (Günther, 1875)pygmy spiny-tailed skinkWestern Australia, the Northern Territory and South Australia.
Egernia douglasi Glauert, 1956Kimberley crevice-skinkWestern Australia.
Egernia eos Doughty, Kealley & Donnellan, 2011central pygmy spiny-tailed skinkwestern Australia
Egernia epsisolus Doughty, Kealley & Donnellan, 2011Eastern Pilbara spiny-tailed skinknorthwestern Australia
Egernia formosa Fry, 1914Goldfield's crevice-skinknorthwestern Australia
Egernia hosmeri Kinghorn, 1955Hosmer's spiny-tailed skinkQueensland and the Northern Territory.
Egernia hosmeri.jpg Egernia kingii (Gray, 1838)King's skinknorthwestern Australia
Egernia mcpheei Wells & Wellington, 1984eastern crevice-skink, McPhee's egerniaAustralia.
23 mars (20) Egernia napoleonis.JPG Egernia napoleonis (Gray, 1838)southwestern crevice-skinkwestern Australia.
Egernia pilbarensis.jpg Egernia pilbarensis Storr, 1978Pilbara crevice-skinkwestern Australia.
Egernia richardi (W. Peters, 1869)bright crevice-skink, dark spiny-tailed skinkSouth Australia and Western Australia.
Egernia roomi, around 2019, 3.jpg Egernia roomi (Wells and Wellington, 1985)New South Wales.
Egernia rugosa De Vis, 1888Yakka skink [4] Queensland in eastern Australia
Egernia saxatilis black rock skink.jpg Egernia saxatilis Cogger, 1960Black rock skink, black crevice-skinkEastern and Southern Australia from central New South Wales to Grampians National Park in Victoria
Gidgee Skink, Egernia stokesii, Alice Springs.JPG Egernia stokesii (Gray, 1845)gidgee spiny-tailed skink, gidgee skink, Stokes's skinkAustralia
Egernia striolata 247332717.jpg Egernia striolata (W. Peters, 1870)tree crevice-skink, "tree skink"Victoria, the Northern Territory, Queensland, New South Wales and South Australia.

Nota bene : A binomial authority in parentheses indicates that the species was originally described in a genus other than Egernia.

Fossils

Splitting Egernia in four

Cladistic analysis of NADH dehydrogenase subunit 4, 12S rRNA, c-mos and β-fibrinogen intron 7 DNA sequence data delimits 3 clades, Bellatorias , Liopholis , and Lissolepis in Egernia sensu lato , which are best regarded as separate genera — as had already been often proposed in former times, as early as the 19th century. [1]

Related Research Articles

<span class="mw-page-title-main">Skink</span> Family of reptiles

Skinks are lizards belonging to the family Scincidae, a family in the infraorder Scincomorpha. With more than 1,500 described species across 100 different taxonomic genera, the family Scincidae is one of the most diverse families of lizards. Skinks are characterized by their smaller legs in comparison to typical lizards and are found in different habitats except arctic and subarctic regions.

<i>Carinascincus</i> Genus of lizards

Carinascincus is a genus of skinks, commonly called snow skinks or cool-skinks and residing mainly in Tasmania or Victoria, Australia. Then recognised as the genus Niveoscincus, it was found to belong to a clade with the genera Carlia, Lampropholis and others of the Eugongylus group within Lygosominae. Cogger has rejected the use of the junior name Niveoscincus and recognizes the valid senior generic name Carinascincus for the group. For similar skinks see genera Pseudemoia, Lampropholis, and Bassiana. These skinks have adapted to the cooler weather of southern Australia and particularly Tasmania, hence the common names.

<span class="mw-page-title-main">Blue-tongued skink</span> Genus of lizards

Blue-tongued skinks comprise the Australasian genus Tiliqua, which contains some of the largest members of the skink family (Scincidae). They are commonly called blue-tongued lizards or simply blue-tongues or blueys in Australia or panana in Indonesia. 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. The type of predator/threat that is near will determine the intensity of colour present in the tongue. The tongue can also deform itself and produce a thick mucus in order to catch prey. They are relatively shy in comparison with other lizards, and also significantly slower due to their shorter legs.

Eutropis dawsoni, also known commonly as Gans's grass skink and Gans's mabuya, is a species of lizard in the family Scincidae. The species is endemic to the southern Western Ghats, India.

<i>Eutropis multifasciata</i> Species of lizard

Eutropis multifasciata, commonly known as the East Indian brown mabuya, many-lined sun skink, many-striped skink, common sun skink or (ambiguously) as golden skink, is a species of skink.

<span class="mw-page-title-main">Lygosominae</span> Subfamily of lizards

Lygosominae is the largest subfamily of skinks in the family Scincidae. The subfamily can be divided into a number of genus groups. If the rarely used taxonomic rank of infrafamily is employed, the genus groups would be designated as such, but such a move would require a formal description according to the ICZN standards.

<i>Chioninia</i> Genus of lizards

Chioninia is a genus of skinks, lizards in the subfamily Lygosominae. For long, this genus was included in the "wastebin taxon" Mabuya. The genus Chioninia contains the Cape Verde mabuyas.

<span class="mw-page-title-main">Noronha skink</span> Species of skink

The Noronha skink is a species of skink from the island of Fernando de Noronha off northeastern Brazil. It is covered with dark and light spots on the upperparts and is usually about 7 to 10 cm in length. The tail is long and muscular, but breaks off easily. Very common throughout Fernando de Noronha, it is an opportunistic feeder, eating both insects and plant material, including nectar from the Erythrina velutina tree, as well as other material ranging from cookie crumbs to eggs of its own species. Introduced predators such as feral cats prey on it and several parasitic worms infect it.

<i>Liopholis</i> Genus of lizards

Liopholis is a genus of skinks, lizards in the family Scincidae. Species of the genus are found in the Australian region. They were previously placed in the genus Egernia.

<i>Concinnia</i> Genus of lizards

Concinnia is a genus of skinks in the subfamily Lygosominae.

<i>Lissolepis</i> Genus of lizards

Lissolepis is a genus of mid-sized skinks with a bulky angular body and small eyes. 20–28 rows of midbody scales; dorsal scales smooth. The nasal scale has a postnarial groove; the subocular scale row is complete. Eyelids similar in colour to the adjacent scales. They were previously placed in the genus Egernia.

<span class="mw-page-title-main">Stokes's skink</span> Species of lizard

Egernia stokesii is a gregarious species of lizard of the Scincidae family. This diurnal species is endemic to Australia, and is also known as the Gidgee skink, spiny-tailed skink, Stokes's skink and Stokes's egernia. The species forms stable, long-term social aggregations, much like the social groups seen in mammalian and avian species. This characteristic is rarely found in the Squamata order, but is widespread within the Australian subfamily of Egerniinae skinks. Populations of E. stokesii are widely distributed, but fragmented, and occur in semi-arid environments. There are three recognised subspecies. The conservation status for the species is listed as least concern, however, one subspecies is listed as endangered.

<span class="mw-page-title-main">Tree-crevice skink</span> Species of lizard

The tree-crevice skink or tree skink (Egernia striolata) is a species of skink, a lizard in the family Scincidae. The species is endemic to Australia and is found in the states of Victoria, the Northern Territory, Queensland, New South Wales and South Australia. E. striolata tend to live in crevices and cracks in hollow logs or rocks. They greatly prefer heterogeneous and structurally diverse habitats and their behavior changes depending on the habitat they live in.

<span class="mw-page-title-main">Major skink</span> Species of lizard

The major skink is a species of lizard in the family Scincidae. The species is native to part of Australia and part of Australasia.

<span class="mw-page-title-main">Black rock skink</span> Species of lizard

The black rock skink is a species of large skink native to Eastern and Southern Australia from central New South Wales to Grampians National Park in Victoria. A large, dark colored skink, up to 135 mm from snout to base of the tail, the black rock skink is the first reptile discovered to have a "nuclear family" structure where the parents form a pair and care for their offspring for more than one year. The black rock skink is a viviparous skink meaning females give birth to live offspring instead of laying eggs. They defend their home range and families against conspecifics for up to several years.

<span class="mw-page-title-main">Egerniinae</span> Subfamily of skinks

Egerniinae is the subfamily of social skinks within the family Scincidae. The genera in this subfamily were previously found to belong the Egernia group in the large subfamily Lygosominae.

<span class="mw-page-title-main">Mabuyinae</span> Subfamily of skinks

Mabuyinae is a subfamily of lizards, commonly known as skinks, within the family Scincidae. The genera in this subfamily were previously found to belong the Mabuya group in the large subfamily Lygosominae.

<span class="mw-page-title-main">Bull skink</span> Species of lizard

The bull skink, southern sand-skink or southernheath skink is a species of terrestrial skink, a lizard in the family Scincidae. It is one of eleven species within the Liopholis genus.

Slater's desert skink, also known commonly as the Centralian Floodplains desert-skink, Slater's egernia, and Slater's skink, is a species of lizard in the family Scincidae. The species is endemic to Australia. There are two recognized subspecies.

<i>Trachylepis nancycoutuae</i> Species of lizard

Trachylepis nancycoutuae, also known commonly as Nancy Coutu's mabuya and Nancy Coutu's skink, is a species of lizard in the family Scincidae. The species is endemic to Madagascar.

References

  1. 1 2 3 4 5 Gardner, Michael G.; Hugall, Andrew F.; Donnellan, Stephen C.; Hutchinson, Mark N.; Foster, Ralph (2008). "Molecular systematics of social skinks: phylogeny and taxonomy of the Egernia group (Reptilia: Scincidae)". Zoological Journal of the Linnean Society. 154 (4): 781–794. doi: 10.1111/j.1096-3642.2008.00422.x .
  2. O'Connor, D.; Shine, R. (2003). "Lizards in 'nuclear families': a novel reptilian social system in Egernia saxatilis (Scincidae)". Molecular Ecology. 12 (3): 743–752. Bibcode:2003MolEc..12..743O. doi:10.1046/j.1365-294X.2003.01777.x. PMID   12675829.
  3. 1 2 Austin, J. J.; Arnold, E. N. (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. doi:10.1016/j.ympev.2005.12.011. PMID   16473026.
  4. Curtis, Lee K. (February 2012). Queensland's Threatened Animals. Csiro. ISBN   9780643104570.
  5. Thorn, Kailah M.; Hutchinson, Mark N.; Archer, Michael; Lee, Michael S. Y. (2019). "A new scincid lizard from the Miocene of northern Australia, and the evolutionary history of social skinks (Scincidae: Egerniinae)". Journal of Vertebrate Paleontology. 39 (1): Article e1577873. Bibcode:2019JVPal..39E7873T. doi:10.1080/02724634.2019.1577873.