Dravidoseps pruthi Sharma, 1977

Agarwal, Ishan, Thackeray, Tejas & Khandekar, Akshay, 2024, A non-adaptive radiation of viviparous skinks from the seasonal tropics of India: Systematics of Subdoluseps (Squamata: Scincidae), with description of a new genus and five cryptic new species, Vertebrate Zoology 74, pp. 23-83 : 23

Dravidoseps pruthi Sharma, 1977 comb. nov.

Figures 9A , 10

Chresonymy.

Riopa pruthi - Sharma (1977)

Lygosoma pruthi - Das (1996, 2003)

Subdoluseps pruthi - Freitas et al. (2019), Ganesh et al. (2021)

Holotype.

ZSI 22393, unsexed adult, "Chitteri range, lat. 11°50′N, long. 78°25′E, Salem District, Tamil Nadu, India [= Sitteri, Dharmapuri District, Tamil Nadu, India; ~ 11.833°N, 78.417°E] ", collected by Dr. H. S. Pruthi in 1929 ( Sharma 1977). Considered lost ( Das et al. 1998; Ganesh and Aengals 2018; Ganesh et al. 2021; Pratyush Mohapatra pers. comm).

Paratypes.

Two unsexed specimens in ZSI (museum numbers unavailable), same data and status as holotype.

Neotype.

(designated herein) NRC-AA-1291 (AK-R 2222). Adult female, from Sitteri Hills (11.90208°N, 78.51800°E; elevation ca. 880 m asl.), Dharmapuri District, Tamil Nadu State, India, collected by Akshay Khandekar, Ishan Agarwal, Swapnil Pawar and team on 29th May 2022.

Additional material (n = 9).

NRC-AA-1292 (AK 803), NRC-AA-1293 (AK 804), and NRC-AA-1294 (AK 805), subadults, from Forest Department campus, Sitteri Hills (11.89152°N, 78.50747°E; elevation ca. 950 m asl.), Dharmapuri District, collected by Akshay Khandekar, Ishan Agarwal, Swapnil Pawar, Tejas Thackeray and team on 1st June 2019 ; BNHS 2525 (AK-R 2197), BNHS 2557 (AK-R 2198), BNHS 2558 (AK-R 2200), adult males, from Palamalai Hills (11.70744°N, 77.73598°E; elevation ca. 1000 m asl.) ; ZSI-R-28600 (AK-R 2201), subadult, from Palamalai Hills (11.73335°N, 77.73156°E; elevation ca. 600 m asl.), Salem District, same collectors as neotype, collected on 28th May 2022 ; ZSI-R-28601 (AK-R 2716), adult male, from Vanavasi Reserve Forest (11.75203°N, 77.84129° E; elevation ca. 520 m asl.), Salem District, same collectors as neotype, collected on 11th October 2022 ; ZSI-R-28602 (AK-R 2750), adult female, from north of Yercaud (11.90822°N, 78.18878° E; elevation ca. 650 m asl.), in Shevaroy Hills, Salem District, same collectors as neotype, collected on 15th October 2022 .

Referred material (n = 1).

AK-R-2213, from Sitteri Hills (11.92978°N, 78.51765°E), Dharmapuri District , Tamil Nadu .

Etymology.

Named for the collector of the holotype, H.S. Pruthi.

Suggested common name.

Pruthi’s leaf-litter skink.

Diagnosis.

A medium-sized skink, snout to vent length up to 56 mm (n = 10). Seven supralabials and six (rarely seven, n = 1/10) infralabials up to angle of mouth; fifth supralabial elongate and below eye; a single post-supralabial; 6-8 supraciliaries; a single slightly elongated nuchal on either side, separated by two or three scales behind parietal; 64-69 scales in paravertebral rows; 30 scales around mid-body; 64-70 ventral scales (rarely 76, n = 1/10); 10 enlarged precloacal scales; scales on lateral sides of tail base smooth, 21-23 scales around the tail. Subdigital lamellae unpaired, smooth to weakly keeled; five or six lamellae under digit I of manus and 4-7 under digit I of pes; 10 or 11 lamellae under digit IV of manus; and 14-17 under digit IV of pes (rarely 18, n = 1/10). Dorsum dull sand; thick grey stripe from rostrum to tail speckled with light spots; supralabials with a white streak; males with yellow on lower parts of forebody and flanks; venter glossy grey-white with some darker markings.

Comparisons.

Dravidoseps pruthi comb. nov. is diagnosed against D. goaensis comb. nov., D. nilgiriensis comb. nov. and the new species described below as part of their respective descriptions.

Description of the neotype.

Adult female (SVL 54.9 mm) in good state of preservation except body slightly bent towards right at forearm insertion, tail towards left posterior to base, a 3.4 mm long incision in the sternal region for liver tissue collection, and 15.5 mm long incision (made after taking morphological data and photos) at ventral mid-body to check for eggs/ embryos (Fig. 10A, B ). Head short (HL/SVL 0.14), wide (HW/HL 0.71), not strongly depressed (HH/HL 0.52), indistinct from neck. Loreal region not inflated, canthus rostralis indistinct. Snout almost half head length (ES/HL 0.46), more than twice eye diameter (ES/ED 2.23). Rostral almost twice as wide (1.5 mm) as long (0.8 mm), in broad contact with supranasals posteriorly and supralabial I and nasals on either side; supranasals in contact with each other medially, frontonasal posteriorly, nasals and anterior loreals laterally; frontonasal much wider (1.8 mm) than long (1.1 mm), in contact with supranasals anteriorly, prefrontals and frontal posteriorly, anterior loreals laterally; prefrontals relatively small, widely separated on midline, anteriorly in contact with frontonasal, posteriorly with frontal, first supraocular and first supraciliary, laterally with anterior and posterior loreals. Frontal elongate, roughly bell-shaped, widest anteriorly at the point where prefrontals and first supraciliary connect; in contact with frontonasal anteriorly, frontoparietals posteriorly, prefrontals and first two supraoculars on either side; four supraoculars and one small post-supraocular and postocular on either side; frontoparietals in medial contact posterior to frontal, in contact with second, third, and fourth supraoculars anterolaterally and parietals and interparietal posteriorly. Interparietal large, roughly diamond-shaped, slightly projecting posteriorly, eyespot in posterior projection; postinterparietal absent; parietals large, in medial contact posterior to interparietal, in contact with frontoparietals, fourth supraocular, and post-supraocular anteriorly, two nuchal scales and three dorsal scales posteriorly, first secondary temporal laterally; a single enlarged nuchal scale on either side separated from each other by three dorsal scales (Fig. 10C ). Nasals small, trapezoidal, widely separated, in contact with rostral anteriorly, supranasal dorsally, anterior loreal posteriorly, first supralabial ventrally; nostril in center of nasal; anterior loreal marginally taller (0.7 mm) than wide (0.6 mm); posterior loreal slightly larger than anterior loreal and slightly wider (0.8 mm) than tall (0.6 mm); a single small supra-preocular, an upper and lower preocular, and a single sub-preocular present on either side (Fig. 10E ). Eye small (ED/ HL 0.20) with round pupil; lower eyelid with enlarged, transparent central window; eight supraciliaries on left and seven on right, anterior supraciliary largest, bordered by prefrontal anteriorly, first supraocular dorsally, and pre-supraocular, upper preocular and posterior loreal laterally; posterior superciliary elongate and projecting dorsomedially, bordered by fourth supraocular dorsally, post-supraocular posteriorly, and first post-subocular laterally; four post-suboculars on either side; a single primary temporal, two secondary temporals, and three tertiary temporals on either side; seven supralabials, fifth and sixth below eye; fifth supralabial elongate, in broad contact with four or five small scales on lower eyelid below eye on either side; a single post-supralabial on either side; six infralabials on either side; two scales separating post-supralabial and external ear opening; external ear opening small (EL/HL 0.07), oval, bearing two anterior lobules on either side; tympanum deep (Fig. 10E ). Mental almost twice as wide (1.8 mm) as long (1.0 mm); a single large postmental in contact with first and second infralabials on either side; three enlarged pairs of chin shields posterior to postmental; anterior pair large (1.4 mm), roughly rectangular, in medial contact with each other below postmental and bordered by second and third infralabials, middle pair of chin shields, and by a single median gular scale on either side; middle pair largest (1.7 mm), roughly rectangular, separated from each other by two longitudinally arranged gular scales, bordered by third and fourth infralabials, posterior pair of chin shields, and four gular scales on either side; posterior pair smallest (0.8 mm), roughly square, separated from each other by five transversely arranged gular scales, bordered by fourth and fifth infralabials and three gular scales on either side; rest of the gular scales much smaller than postmentals, cycloid and imbricate, two or three rows bordering infralabials slightly smaller and elongate (Fig. 10D ).

Body relatively slender (BW/AGL 0.23), elongate (AGL/SVL = 0.59); dorsal scales on body smooth, cycloid, imbricate; ventrals similar to dorsals except subequal from chest to vent, marginally larger on pectoral and precloacal region; 69 scales in paravertebral rows; 30 scales around mid-body; 69 ventral scales; 10 enlarged precloacal scales (Fig. 10A, B ). Limbs, robust, short (FL/SVL = 0.06; CL/SVL = 0.08), widely separated when adpressed; dorsal scales slightly larger than ventral scales; palmar scales raised; plantar scales large, raised, coarse granules; all digits short, scales on dorsal surfaces in single row, subdigital lamellae unpaired, smooth to weakly keeled; lamellae series: 6-8-9-11-7 left manus (Fig. 10F ), 6-10-14-16-11 left pes (Fig. 10G ), 6-10-10-11-8 right manus, 6-11-14-15-11 right pes. Relative length of digits (measurements in mm in parentheses): IV (2.2)> III (2.1)> II (1.7)> V (1.4)> I (0.9) (left manus); IV (4.5)> III (3.7)> V (2.9)> II (2.6)> I (1.2) (left pes).

Tail original, entire, cylindrical, slightly shorter than snout-vent length (TL/SVL 0.88); dorsal and ventral scales on tail cycloid, imbricate, similar to those on body dorsum except for posterior 1/3rd on which median dorsal and subcaudal scale rows distinctly larger than surrounding scales; tail ending in a pointed scute; scales on lateral sides of tail base smooth, 21 scales around the tail (Fig. 10A, B ).

Colouration in life (Fig. 9A).

Dorsal ground colouration of body, head and tail dull sand with a bronze tint; head with a few dark markings; dorsal scales of body and tail outlined by dark brown, centre of scales with dark markings, more prominent on hindbody and tail; limbs darker than body dorsum and with light spots; a thick grey stripe running from rostrum through orbit and onto flank and tail with scattered white spots, flanked dorsally by an indistinct, narrow, lighter stripe; supralabials with a white streak, dark band forming reticulations on lateral aspect of tail; ventral regions glossy grey-white with fine black stripes on edges of throat, neck and tail.

Variation and additional information.

Mensural and meristic data for topotypic and additional specimens are given in Table 5 . There are four subadults, four adult males and a single adult female. All specimens resemble the neotype female (NRC-AA-1291) in overall morphology and head scalation except for the following variation: four SO with an additional small scale between SO I and II on left side; six SC on either side in NRC-AA-1292, seven in BNHS 2557, six on left and seven on right side in ZSI-R-28602, and eight on either side in BNHS 2525, BNHS 2558, ZSI-R-28600, ZSI-R-28601; a single PrSbO on either side in NRC-AA-1292, NRC-AA-1293, BNHS 2525, BNHS 2558, ZSI-R-28600, ZSI-R-28601, ZSI-R-28602, and PrSbO absent on either side in BNHS 2557; 2.8 mm and 3.9 mm skin injury on right side of head between posterior postmental till ear opening in ZSI-R-28601 and ZSI-R-28602, respectively. More than half the tail of NRC-AA-1292 and NRC-AA-1293 collected as tissue for DNA sampling; ZSI-R-28601 with entire and original tail; BNHS 2525, BNHS 2557 and, BNHS 2558 with entire but partially regenerated tails; NRC-AA-1294, ZSI-R-28600, and ZSI-R-28602 with entire but partially regenerated tails which are detached from the body. BNHS 2557 with partial everted hemipenis on either side, BNHS 2525 with partially everted hemipenis only on right, and BNHS 2558 with only on left side. After collection of morphological data, ZSI-R-28601 (adult male) and ZSI-R-28602 (adult female) were dissected from the ventral region of mid-body (11.3 mm and 15.3 mm long incision respectively) to check sex and the presence of eggs/ embryos.

Distribution and natural history.

Dravidoseps pruthi comb. nov. is known from Sitteri Hills in Dharmapuri District (type locality), and the northern slopes of Yercaud in Shevaroy Hills, Vanavasi Reserve Forest, and Palamalai, all in Salem District, Tamil Nadu India. The two most distant localities (Palamalai and Sitteri Hills) are>85 km apart in aerial distance (Fig. 1 ). The locality, Teerthamalai, reported by Ganesh and Aengals (2018) is likely to represent an additional locality for D. pruthi as it is just 20 km north of the type locality and falls within the same hill complex. However, genetic and morphological data are needed to confirm this.

Diurnal, found in the day either moving in leaf litter, in soil or under rocks. The four localities we recorded the species from are at elevations of 500-1000 m asl. with a mix of scrub, deciduous and dry evergreen to semi-evergreen forest with scattered sheet rocks (Fig. 11A ). At Sitteri, three subadults were collected in the Forest Department Guesthouse campus from under rocks surrounded by dry leaf-litter during the day (1430 hrs). The adult female neotype was found <2 km from the first locality during the day (1030 hrs); sympatric lizards found at the first locality include Cyrtodactylus (Geckoella) cf. collegalensis ; Hemidactylus frenatus Duméril & Bibron; H. leschenaultii Duméril & Bibron; H. whitakeri Mirza, Gowande, Patil, Ambekar & Patel; Hemiphyllodactylus cf. jnana , and Calotes versicolor (Daudin); and at the second locality include Eutropis carinata (Schneider); E. macularia (Blyth); E. beddomei (Jerdon); Riopa albopunctata Gray; and Psammophilus dorsalis (Gray). At Yercaud, the species was found buried inside loose soil under a rock in a shaded area within a small open patch during the morning (0830 hrs). Sympatric lizards encountered were Riopa albopunctata and Calotes versicolor . At Vanavasi Reserve Forest, the species were found under a rock in an open area along the path during the day time (1030 hrs); the sympatric lizards seen were Cnemaspis cf. agarwali , Eutropis carinata , and Calotes versicolor . At Palamalai Hills, individuals were found buried in loose, moist soil under or around rocks in a large sheet rock patch surrounded by dry evergreen forest during the early evening (1530-1730 hrs). Sympatric lizards were Hemidactylus sankariensis Agarwal, Bauer Giri & Khandekar; Eutropis beddomei ; E. macularia ; Riopa albopunctata ; Ophisops leschenaultii (Milne-Edwards); and Psammophilus dorsalis .

Reproduction.

Unknown. No gravid female in the additional material examined (two non-gravid females dissected: ZSI-R-28602 and neotype, NRC-AA-1291).

Note.

Our topotypical and genetically assigned specimens match the original description provided by Sharma (1977) except for SVL (up to 56 mm, n = 10, versus 67 mm in original description); TL (up to 49 mm, n = 7; versus 72 mm); the number of nuchals (a single nuchal on either side separated by two or three scales versus two pairs of nuchals); the number of Elo (two or three on either side versus six); RBS (30 versus 32-34); and PVS (64-69 versus 50). We could not verify the counts as the type specimens are lost ( Das et al. 1998; Ganesh and Aengals 2018; Ganesh et al. 2021; Pratyush Mohapatra pers. comm.). The values for SVL and TL, and paravertebral scale count in original description are likely to be incorrect as none of the species in the genus have such high values. The RBS (32-34) count is also likely to be incorrect as all topotypical and other specimens assigned to the species have 30 RBS (n = 10). The nuchal scale count was most likely defined and counted differently and includes two paravertebral scales between a single elongated nuchal on either side instead of two pairs as can be seen in the line drawing from Sharma (1977); and Elo is most likely a combined count of left and right (three each). Subsequently, Ganesh et al. (2021) used morphological data (from Ganesh and Aengals 2018) and morphological + genetic data from a single specimen of Dravidoseps gen. nov. each from Pachaimalai Hills and Jawadhu Hills respectively to establish taxonomic and genetic conscription of D. pruthi comb. nov. in the absence of the type or topotypic specimens of the species, based on similarities in taxonomic characters and geography. However, our sampling from the type locality of D. pruthi comb. nov., the Pachaimalai Hills, and Jawadhu Hills show that topotypic samples of D. pruthi comb. nov. are morphologically and genetically divergent from samples from both other localities given by Ganesh et al. (2021), which we describe as new species below. Comments on discrepancies in certain morphological characters based on our data and that provided by Ganesh and Aengals (2018) and Ganesh et al. (2021) are listed as part of the respective descriptions of the new species.

Figures

Figure 1. Elevation map showing sampling localities from peninsular India. Stars indicate type localities (neotype locality shown for Dravidoseps goaensis comb. nov., original type locality is close to the southernmost point), light blue D. jawadhuensis sp. nov., dark blue D. srivilliputhurensis sp. nov., light green D. kalakadensis sp. nov., dark green D. pruthi comb. nov., red D. gingeeensis sp. nov., yellow D. nilgiriensis comb. nov., pink D. tamilnaduensis sp. nov., and grey, D. sp. Kalrayan (colour scheme representing species is the same as Figs 3 - 6), black squares unsampled previously known localities. The approximate extent of the Central Western Ghats (CWG), Northern Western Ghats (NWG), and Southern Western Ghats (SWG) are shown; major hill ranges and features are marked by bold white text, within the Western Ghats: AG, Agasthyamalai; AN, Anaimalai; DV, Devarmalai; N, Nilgiris; PG, Palghat Gap; PL, Palani; and outside the Western Ghats: BR, Biligirangan; J, Jawadhu; K, Kollimalai; KR, Kalrayan; mm, Male Mahadeshwara; MP, Mysore Plateau; PC, Pachaimalai; PM, Palamalai; S, Sitteri; SR, Sirumalai; T, Tirupati; V, Velikonda; Y, Yercaud; YL, Yelagiri. Inset, global distribution of Dravidoseps gen. nov. (brown) and Subdoluseps sensu stricto (green). Dravidoseps goaensis = Riopa goaensis (see main text).

Figure 9. Dravidoseps gen. nov. species in life: A D. pruthi comb. nov. (neotype, NRC-AA- 1291); B D. goaensis comb. nov. (neotype, BNHS 2567); C D. nilgiriensis comb. nov. (ZSI-R- 28604); D D. gingeeensis sp. nov. (holotype, NRC-AA- 8273); E D. jawadhuensis sp. nov. (holotype, NRC-AA- 8274); F D. kalakadensis sp. nov. (holotype, NRC-AA- 8275); G D. srivilliputhurensis sp. nov. (holotype, NRC-AA- 8279); and H D. tamilnaduensis sp. nov. (holotype, NRC-AA- 8286). Photos by Akshay Khandekar (B-D, F-H) and Ishan Agarwal (A, E).

Figure 10. Dravidoseps pruthi comb. nov. (neotype, NRC-AA- 1291): A dorsal view of body, B ventral view of body, C dorsal view of head, D ventral view of head, E lateral left side view of head, F ventral view of left manus, and G ventral view of left pes. Scale bars: A, B = 10 mm; C-E, G = 5 mm; F = 3 mm. Photos by Akshay Khandekar.

Figure 11. General habitats of all species of Dravidoseps sp. nov.: A type locality of D. pruthi comb. nov.; B neotype locality of D. goaensis comb. nov.; C habitat photo of D. nilgiriensis comb. nov., from Thamarakarai; D type locality of D. gingeeensis sp. nov.; E type locality of D. jawadhuensis sp. nov.; F type locality of D. kalakadensis sp. nov.; G paratype locality of D. srivilliputhurensis sp. nov., near Atthi Kovil Falls; and H type locality of D. tamilnaduensis sp. nov.. Photos by Akshay Khandekar (A-C, F-H), Ishan Agarwal (D), and Vinod (E).