View source for Ristella

{{Short description|Genus of lizards}}
{{Italic title}}
{{Automatic taxobox
| name = ''Ristella''
| image = Cat skink.jpg 
| image_caption =''[[Ristella travancorica]]'' from the [[Western Ghats]].
| taxon = Ristella
| authority = [[John Edward Gray|Gray]], 1839<ref>Genus ''Ristella''. ''Dahms Tierleben''. www.dahmstierleben.de.</ref>
}}

'''''Ristella''''' is a [[genus]] of [[skinks]], [[lizards]] in the [[Family (biology)|family]] [[Scincidae]]. The genus is [[Endemism|endemic]] to the [[Western Ghats]] of southwestern [[India]]. Member [[species]] 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 cycle|diurnal]], [[insectivorous]], [[terrestrial animal|terrestrial]] to semi-[[fossorial]] in habits. They inhabit deep leaf-litter and [[grassland]]s in [[montane forests]] and [[rainforests]].

[[File:Ristella sp.jpg|thumb|right|A ''Ristella'' from Dandeli in the [[Western Ghats]].]]

==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.<ref name="Blgr1890">[[George Albert Boulenger|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).</ref>

==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]], [[Kerala]] and [[Karnataka]] states. Hill ranges such as [[Travancore]] hills, [[High Ranges]], [[Anaimalai]], [[Nilgiris]], [[Palni Hills]], [[Coorg]], [[Kanara|Canara]] and [[Goa]] Ghats have been known to harbour these lizards.<ref name="Blgr1890"/>

==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'' <ref name="Blgr1890"/>

[[File:Ristella rurkii gab fbi.png|thumb|The retractile claws which give ''Ristella'' the common name of cat skinks.]]

==Species==
The following four [[species]] are recognized as being valid:<ref>{{EMBL genus|genus=Ristella}} www.reptile-database.org.</ref>

*''[[Ristella beddomii]]'' <small>[[George Albert Boulenger|Boulenger]], 1887</small> – Beddome's cat skink
*''[[Ristella guentheri]]'' <small>Boulenger, 1887</small> – Günther's ristella
*''[[Ristella rurkii]]'' <small>[[John Edward Gray|Gray]], 1839</small> – Rurk's ristella
*''[[Ristella travancorica]]'' <small>([[Richard Henry Beddome|Beddome]], 1870)</small> – Travancore cat skink, Travancore ristella

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

==References==
{{Reflist}}

==Further reading==
* [[John Edward Gray|Gray JE]] (1839). "Catalogue of the Slender-tongued Saurians, with Descriptions of many new Genera and Species". ''Annals and Magazine of Natural History'', [''First Series'' ] '''2''': 331-337. (''Ristella'', new genus, p.&nbsp;333).

==External links==
*[[species:Sumaithangi Rajagopalan Ganesh|Ganesh SR]] (2018). "The rediscovery of Rurk's Cat Skink ''Ristella rurkii'' Gray, 1839 (Reptilia: Ristellidae) with remarks on distribution and natural history". ''Journal of Threatened Taxa'' '''10''' (10): 12376-12381. https://doi.org/10.11609/jott.3946.10.10.12376-12381


{{Taxonbar|from=Q1997970}}

[[Category:Ristella| ]]
[[Category:Lizard genera]]
[[Category:Taxa named by John Edward Gray]]