''Ristella'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

skinks 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. Ski ...

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to the Western Ghats of southwestern

India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...

. They are commonly known as cat skinks because of their retractile claws. This genus can be instantly identified by the presence of only four fingers in forelimbs in all the species (instead of the usual five). All the members look more or less similar and are drab dark brown to blackish in complexion with paler undersides. This poorly known groups of lizards are diurnal,

insectivorous A robber fly eating a hoverfly An insectivore is a carnivorous animal or plant that eats insects. An alternative term is entomophage, which can also refer to the human practice of eating insects. The first vertebrate insectivores were ...

terrestrial Terrestrial refers to things related to land or the planet Earth. Terrestrial may also refer to: * Terrestrial animal, an animal that lives on land opposed to living in water, or sometimes an animal that lives on or near the ground, as opposed to ...

to semi

fossorial A fossorial () animal is one adapted to digging which lives primarily, but not solely, underground. Some examples are badgers, naked mole-rats, clams, meerkats, and mole salamanders, as well as many beetles, wasps, and bees. Prehistoric eviden ...

in habits. They inhabit deep leaf-litter and grasslands in

montane forests Montane ecosystems are found on the slopes of mountains. The alpine climate in these regions strongly affects the ecosystem because temperatures fall as elevation increases, causing the ecosystem to stratify. This stratification is a crucial f ...

and

rainforests Rainforests are characterized by a closed and continuous tree canopy, moisture-dependent vegetation, the presence of epiphytes and lianas and the absence of wildfire. Rainforest can be classified as tropical rainforest or temperate rainforest ...

Description

Palatine and pterygoid bones in contact on the median line of the palate, which is toothless;palatine notch small, far behind, corresponding to the posterior notch of the tongue. Teeth conical. Eyelids well developed, scaly. Ear-opening distinct. Nostril pierced in a single nasal; no supranasals; prefrontals small or coalesced; frontoparietals and interparietal distinct. Limbs well developed, anterior with 4, posterior with 5 digits; claws completely retractile into a large compressed sheath formed of one large scale cleft beneath. Boulenger GA. 1890. ''The Fauna of British India, Including Ceylon and Burma. Reptilia and Batrachia.'' London: Secretary of State for India in Council. (Taylor and Francis, printers). xviii + 541 pp. (Genus ''Ristella'', p. 214).

Geographic range

All species in this genus are endemic to the Western Ghats hill-tracts of southwestern India. Currently these skinks have been recorded from the southern and central Western Ghats of

Tamil Nadu Tamil Nadu (; , TN) is a States and union territories of India, state in southern India. It is the List of states and union territories of India by area, tenth largest Indian state by area and the List of states and union territories of India ...

Kerala Kerala ( ; ) is a state on the Malabar Coast of India. It was formed on 1 November 1956, following the passage of the States Reorganisation Act, by combining Malayalam-speaking regions of the erstwhile regions of Cochin, Malabar, South ...

and

Karnataka Karnataka (; ISO: , , also known as Karunāḍu) is a state in the southwestern region of India. It was formed on 1 November 1956, with the passage of the States Reorganisation Act. Originally known as Mysore State , it was renamed ''Karnat ...

states. Hill ranges such as

Travancore The Kingdom of Travancore ( /ˈtrævənkɔːr/), also known as the Kingdom of Thiruvithamkoor, was an Indian kingdom from c. 1729 until 1949. It was ruled by the Travancore Royal Family from Padmanabhapuram, and later Thiruvananthapuram. At ...

hills,

High Ranges High may refer to: Science and technology * Height * High (atmospheric), a high-pressure area * High (computability), a quality of a Turing degree, in computability theory * High (tectonics), in geology an area where relative tectonic uplift to ...

Anaimalai Anaimalai is a taluk in Coimbatore district in the Indian state of Tamil Nadu. Agricultural day work is the main occupation. Paddy, banana, sugarcane and other crops are grown in the area. Anaimalai is a pilgrimage spot, due to the worship o ...

Nilgiris The Nilgiri Mountains form part of the Western Ghats in northwestern Tamil Nadu, Southern Karnataka, and eastern Kerala in India. They are located at the trijunction of three states and connect the Western Ghats with the Eastern Ghats. At le ...

Palni Hills The Palani Hills are a mountain range in the southern Indian states of Kerala and Tamil Nadu. The Palani Hills are an eastward extension of the Western Ghats ranges, which run parallel to the west coast of India. The Palani Hills adjoin the hi ...

Coorg Kodagu (also known by its former name Coorg) is an administrative district in the Karnataka state of India. Before 1956, it was an administratively separate Coorg State, at which point it was merged into an enlarged Mysore State. It occupies ...

Canara Kanara, also known as Karavali is the historically significant stretch of land situated by the southwestern coast of India, alongside the Arabian Sea in the present-day Indian state of Karnataka. The region comprises three civil districts, ...

and

Goa Goa () is a state on the southwestern coast of India within the Konkan region, geographically separated from the Deccan highlands by the Western Ghats. It is located between the Indian states of Maharashtra to the north and Karnataka to the ...

Ghats have been known to harbour these lizards.

Key to species

*A. A pair of small prefrontals; frontonasal forming a suture with frontal. **a. Ear-opening much larger than nostril; dorsal scales feebly bi- or tricarinate. ***''R. rurkii'' **b. Ear-opening not, or but slightly, larger than nostril; dorsal scales sharply bicarinate. ***''R. travancorica'' *B. Two azygous shields between rostral and frontal. **a. 22 to 24 scales round middle of body; adpressed limbs not meeting. ***''R. guentheri'' **b 26 scales round body; adpressed limbs meeting or overlapping. ***''R. beddomii'' Ristella rurkii gab fbi

Species

The following four

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

are recognized:The Reptile Database. www.reptile-database.org. *''

Ristella beddomii ''Ristella beddomii'', commonly known as Beddome's cat skink and Beddome's ristella, is a species of skink, a lizard in the family Scincidae. The species is native to southwestern India. Etymology ''R. beddomii'' is named after Richard Henry Be ...

Boulenger Boulenger is a surname. Notable people with the surname include: * Benjamin Boulenger (born 1990), French footballer * Edward George Boulenger (1888–1946), British zoologist, director of aquarium at London Zoo * George Albert Boulenger (1858–1 ...

, 1887 – Beddome's cat skink *''

Ristella guentheri ''Ristella guentheri'', commonly known as Günther's ristella and Gunther's cat skink, is a species of lizard in the family Scincidae. The species is endemic to India. Etymology The specific name, ''guentheri'', is in honor of German- British ...

'' Boulenger, 1887 – Günther's ristella *''

Ristella rurkii ''Ristella rurkii'', commonly known as Rurk's ristella, is a species of skink endemic to the Western Ghats of southern India. It is a small, insectivorous, diurnal skink found in shola grasslands and rainforests of hills ranges in parts of Tam ...

Gray Grey (more common in British English) or gray (more common in American English) is an intermediate color between black and white. It is a neutral or achromatic color, meaning literally that it is "without color", because it can be composed o ...

, 1839 – Rurk's ristella *''

Ristella travancorica ''Ristella travancorica'', commonly known as the Travancore cat skink or the Travancore ristella, is a species of skink endemic to the Western Ghats in India. Description Ear-opening not or but slightly larger than the nostril; third to sixth ...

'' ( Beddome, 1870) – Travancore cat skink, Travancore ristella ''

Nota bene (, or ; plural form ) is a Latin phrase meaning "note well". It is often abbreviated as NB, n.b., or with the ligature and first appeared in English writing . In Modern English, it is used, particularly in legal papers, to draw the atten ...

'': A binomial authority in parentheses indicates that the species was originally described in a genus other than ''Ristella''.

Description

Geographic range

Key to species

Species

References

Further reading