''Ristella'' is a

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 ...

skinks Skinks are a type of lizard 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 liz ...

lizards Lizard is the common name used for all squamate reptiles other than snakes (and to a lesser extent amphisbaenians), encompassing over 7,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The ...

in the

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. The genus is

endemic Endemism is the state of a species being found only 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 foun ...

to the Western Ghats of southwestern

India India, officially the Republic of India, is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area; the List of countries by population (United Nations), most populous country since ...

. Member

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

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 colouration, with paler undersides. This poorly known group of lizards is diurnal,

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

terrestrial Terrestrial refers to things related to land or the planet Earth, as opposed to extraterrestrial. 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 o ...

to semi-

fossorial A fossorial animal () is one that is adapted to digging and which lives primarily (but not solely) underground. Examples of fossorial vertebrates are Mole (animal), moles, badgers, naked mole-rats, meerkats, armadillos, wombats, and mole salamand ...

in habits. They inhabit deep leaf-litter and

grassland A grassland is an area where the vegetation is dominance (ecology), dominated by grasses (Poaceae). However, sedge (Cyperaceae) and rush (Juncaceae) can also be found along with variable proportions of legumes such as clover, and other Herbaceo ...

s 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 forests characterized by a closed and continuous tree Canopy (biology), canopy, moisture-dependent vegetation, the presence of epiphytes and lianas and the absence of wildfire. Rainforests can be generally classified as tropi ...

Description

Lizards of the genus ''Ristella'' share the following characters. The palatine and pterygoid bones are in contact on the median line of the palate, which is toothless. The palatine notch is small, far behind, corresponding to the posterior notch of the tongue. The teeth are conical. The eyelids are well developed, and are scaly. The ear-opening is distinct. The nostril is pierced in a single nasal scale. There are no supranasals. The prefrontals are small or coalesced. The frontoparietals and the interparietal are distinct. The limbs are well developed. The anterior limbs have four digits, and the posterior have five. The claws are completely retractile, each 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 the genus ''Ristella'' 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 the southernmost States and union territories of India, state of India. 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 Indi ...

Kerala Kerala ( , ) is a States and union territories of India, 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 ...

and

Karnataka Karnataka ( ) is a States and union territories of India, state in the southwestern region of India. It was Unification of Karnataka, formed as Mysore State on 1 November 1956, with the passage of the States Reorganisation Act, 1956, States Re ...

states. Hill ranges such as

Travancore The kingdom of Travancore (), also known as the kingdom of Thiruvithamkoor () or later as Travancore State, was a kingdom that lasted from until 1949. It was ruled by the Travancore Royal Family from Padmanabhapuram, and later Thiruvanan ...

hills, High Ranges,

Anaimalai Anaimalai is a Town Panchayat 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 ...

, Nilgiris,

Palni Hills The Palani Hills are a mountain range in the southern Indian states of Tamil Nadu and Kerala. 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 with ...

Coorg Kodagu district () (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 ...

Canara Kanara or Canara, also known as Karāvali, is the historically significant stretch of land situated by the southwestern Konkan coast of India, alongside the Arabian Sea in the present-day Indian state of Karnataka. The subregion comprises thr ...

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 bound by 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

are recognized as being valid: www.reptile-database.org. *'' Ristella beddomii'' Boulenger, 1887 – Beddome's cat skink *'' Ristella guentheri'' Boulenger, 1887 – Günther's ristella *'' Ristella rurkii''

Gray Grey (more frequent in British English) or gray (more frequent in American English) is an intermediate color between black and white. It is a neutral or achromatic color, meaning that it has no chroma. It is the color of a cloud-covered s ...

, 1839 – Rurk's ristella *'' Ristella travancorica'' ( Beddome, 1870) – Travancore cat skink, Travancore ristella ''

Nota bene ( ; plural: ) is the Latin language, Latin phrase meaning ''note well''. In manuscripts, ''nota bene'' is abbreviated in upper-case as NB and N.B., and in lower-case as n.b. and nb; the editorial usages of ''nota bene'' and ''notate bene'' fi ...

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

References

External links