Riopa deccanensis, Bhupathi & Ray & Karuthapandi & Jaiswal & Deepak & Mohapatra, 2025
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publication ID |
https://doi.org/10.11646/zootaxa.5647.2.2 |
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publication LSID |
lsid:zoobank.org:pub:633B1EB7-D20B-4023-8D76-33270CE79C73 |
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DOI |
https://doi.org/10.5281/zenodo.15851764 |
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persistent identifier |
https://treatment.plazi.org/id/03A33867-FFF3-FFFC-72F6-FCA4FB20466C |
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treatment provided by |
Plazi |
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scientific name |
Riopa deccanensis |
| status |
sp. nov. |
Riopa deccanensis sp. nov.
urn:lsid:zoobank.org:act:B7DF0313-5468-4FEC-9850-DAAC999DB726
( Figures 3–4 View FIGURE 3 View FIGURE 4 ; Table 3 View TABLE 3 )
Holotype. FBRC /ZSI/15, adult female, from Seshachalam Biosphere Reserve (13.7066N, 79.3644 E; ca. 881 m a.s.l), Tirupati District, Andhra Pradesh, India, collected by Karuthapandi, M. and Bharath, B. on 23 May 2023. GoogleMaps
Paratypes. ZSI-R-28811, adult female, same collection details as holotype ; FBRC /ZSI/16, adult male from Domalpenta Grassland , Amrabad Tiger Reserve (16.1868 N, 78.8271 E; ca. 700 m a.s.l), Nagarkurnool district, Telangana, India, collected by Deepa, J and Bharath, B. on 23 December 2021 GoogleMaps .
Etymology. The specific epithet is a toponym for the area in which it occurs, the Deccan Peninsula Biogeographic Zone (Zone 6), as per the Rodgers and Panwar (1988) classification of Biogeographic Zones of India. This biogeographic zone comprises 42% of the total geographic landmass of India, surrounded by the Western Ghats (Zone 5) on the western side, Semi-arid (Zone 4) towards the northwest, Gangetic plain (Zone 7) on the northern side and East Coast (Zone 8) on the eastern side. This Zone 6 is further divided into five Biogeographic Provinces, namely Central Highlands (6A), Chhota-Nagpur Plateau (6B), Eastern Highlands (6C), Central Plateau (6D) and Deccan South (6E), of which Riopa deccanensis sp. nov. is distributed in the 6C and 6D biogeographic provinces of India.
Suggested English Name: Deccan Gracile Skink or Deccan slender-bodied skink.
Diagnosis
A slender and elongated skink of the genus Riopa with adult body size measuring 51.5–63.3 mm SVL. Dorsum with 16 distinct longitudinal lines. Limbs short and weakly developed with five fingers and five toes. Frontal smaller than single, large, shield-like fronto-parietal. Nuchals absent. Tympanum covered by scales. Eyes very small with a semi-transparent disk in the lower eyelid.
Description of the holotype
An adult female, in a good state of preservation, with a broken tail at the 9 th subcaudal and part of the regenerated tail tip; medium-sized and slender skink (SVL 63.3 mm; axilla-groin length 48.5 mm); trunk elongated (AGD 76.6% of SVL). The specimen has an open jaw and is preserved linearly. Head small (HL 7.5 mm), not distinct from the neck; snout obtusely pointed; rostral wider than long, visible from above, in broad contact with supranasals; supranasals just touching one another behind the rostral, in contact with rostral, nasal, fronto-nasal and anterior loreal; prefrontals relatively small, widely separated on midline, in contact with fronto-nasal, both the anterior and posterior loreal, frontal, 1 st supraocular and 1 st supraciliary; frontal elongate, widest anteriorly, in contact with fronto-nasal, prefrontal, first two supraoculars and fronto-parietal; four supraoculars, first smallest; a single large shield-like fronto-parietal, larger than frontal, contacting second, third, and fourth supraoculars anterolaterally and parietals and interparietal posteriorly; interparietal diamond shaped, large, slightly projecting posteriorly; postinterparietal absent; parietals elongated, in medial contact posterior to interparietal, contacting fourth supraocular anteriorly; nuchals absent; one primary temporal; two secondary temporals; nasals small, widely separated, contacting rostral anteriorly, supranasal dorsally, anterior loreal posteriorly, first supralabial ventrally; nostril in center of nasal; anterior loreal longer than wide; posterior loreal wider than long; upper and lower preoculars present; five superciliaries, posterior superciliary elongate; seven supralabials, fourth and fifth touching the eye; sixth supralabial largest; lower eyelid with a semi-transparent disk; six infralabials; mental wider than long; single, large postmental contacting first and second infralabials; three enlarged pairs of chinshields posterior to postmental, first pair just touching each other, contacting second and third infralabials; second pair separated by a single scale, contacting third and fourth infralabials; third pair separated by five rows of ventral scales, contacting fourth and fifth infralabials; ear opening is small and covered by scales.
Dorsal scales smooth, imbricate; ventral scales smooth, same size as dorsal scales; 22 longitudinal scale rows around midbody; 109 paravertebral scale rows; 110 ventral scale rows; preanals not enlarged; subcaudals same size as ventrals; limbs, short, widely separated when adpressed; scales of dorsal surfaces slightly wider than those of ventral surfaces; palmar and plantar scales raised and rounded; all digits short, Relative length of digits (measurements in mm in parentheses): III (0.77)> IV (0.73)> II (0.47)> V(0.41)> I(0.25) (left manus); IV(1.78)>III(1.71)>II(0.95)> I(0.43)>V(0.41) (left pes), scales of dorsal surfaces in a single row; 6 subdigital lamellae on third finger; 9 subdigital lamellae on fourth toe.
Coloration
Dorsum golden-brown in preservative ( Figure 3 View FIGURE 3 ), slightly darker with bluish tinge in life ( Figure 4 a & b View FIGURE 4 ), with 16 clearly defined longitudinal lines formed by dark brown dots. Tail bluish in life. The dots are prominent on the dorsum and less so on the ventrum. The four middle longitudinal lines, which begin immediately behind the snout, extend to the middle of the tail. The limbs are dark brownish above and lighter below.
Variation
Mensural data for the type series is given in Table 3 View TABLE 3 . The SVL of the two paratypes ranges from 51.5 to 55.3 mm. The trunk length is 78.4% of the SVL in the female (ZSI-R-28811) and 74.4% in the male ( FBRC /ZSI/16). They both agree with the holotype in most morphological characters except the following: scales across midbody 22–24; scales on the paravertebral row 108–109; ventral scale rows 111; 8 lamellae under the 4 th toe.
Comparisons with congeners
The new species can be distinguished from congeners by the following combination of characters: lower eyelid with a semi-transparent disk (vs. lower eyelid scaly in R. albopunctata ); paravertebral rows 108–109 (vs. 63–72 in R. albopunctata ; 86–100 in R. guentheri ; 110–120 in R. lineata ; 78–84 in R. lineolata ; 62–76 in R. punctata ); 4 th toe lamellae 8–9 (vs. 12–16 in R. albopunctata ; 6–9 in R. anguina ; 11–14 in R. guentheri ; 4–9 in R. lineata ; 8–10 in R. lineolata ; 7 in R. popae ; 11–14 in R. punctata ); distinct longitudinal lines on dorsum (vs. indistinct longitudinal lines in R. lineolata ; absence of such lines in R. albopunctata , R. anguina , R. guentheri , R. punctata ). The new species most closely resembles R. lineata and R. vosmaerii . Riopa deccanensis sp. nov. differs from R. lineata by having five fingers and five toes (vs. four fingers and four toes), preanal scales not enlarged (vs. enlarged). It differs from R. vosmaerii by having five toes (vs. four), the fourth toe being the largest (vs. the third), ear opening covered by scales (vs. not covered by scales).
Natural history and distribution
The new species is currently known from two localities. The holotype was found below a large boulder in a dry deciduous forest during the early afternoon (12:30 hr) at an elevation of 800–900 m a.s.l. ( Figure 4C View FIGURE 4 ) along with one paratype (ZSI-R-28811), which was below another boulder about 20m away. The habitat was a grassland with lateritic red soil with scattered boulders of varying sizes. The soil was slightly moist due to drizzling in the morning hours. The other paratype ( FBRC /ZSI/16) was collected from a natural pasture situated in the understory of a tropical dry deciduous forest at an elevation of 600–700 m a.s.l. ( Figure 4D View FIGURE 4 ) and was observed in a similar habitat at Domalapenta grassland, Amrabad Tiger Reserve in Telangana. In the type locality Riopa deccanensis sp. nov. was found along with other sympatric reptile species such as Eutropis allapallensis , E. carinata and E. macularia of family Scincidae ; Calotes versicolor , Monilesaurus rouxii , Psammophilus blanfordanus , Sitana spinaecephalus and S. thondalu of family Agamidae ; Hemidactylus frenatus , H. giganteus , H. kushmorensis , H. leschenaultii , H. murrayi , H. parvimaculatus , H. reticulatus and H. triedrus of family Gekkonidae ; Ophisops jerdonii , O. leschenaultii and O. nictans of family Lacertidae ; and snakes such as Oligodon taeniolatus of family Colubridae and Indotyphlops braminus of family Typhlopidae . The type specimen has two developing elongated eggs in the abdomen, which suggests that the species lays eggs during summer like other Riopa spp. in India ( Deuti et al. 2020).
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