Dravidoseps kalakadensis, Agarwal & Thackeray & Khandekar, 2024

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 kalakadensis sp. nov.

Figures 8C-E , 9F , 15

Holotype.

NRC-AA-8275 (AK-R 984), adult male, from near Wood House, Talayanai road, (8.52200°N, 77.50403°E; elevation ca. 200 m asl.), Kalakadu Reserve Forest, Kalakad-Mundanthurai Tiger Reserve (KMTR), Tirunelveli District, Tamil Nadu State, India, collected by Akshay Khandekar, Ishan Agarwal, Swapnil Pawar and team, on 30th March 2022.

Paratypes (n = 9).

ZSI-R-28614 (AK-R 982), adult male, ZSI-R-28615 (AK-R 983) adult female, same data as holotype; NRC-AA-8278 (AK-R 666), adult male, BNHS 2829 (AK-R 667), ZSI-R-28613 (AK-R 981), adult females, from below Sengaltheri (8.52824°N, 77.47968°E; elevation ca. 400 m asl.), collected by Akshay Khandekar, Swapnil Pawar and team on 4th May 2021; NRC-AA-8276 (AK-R 605), adult male, NRC-AA-8277 (AK-R 606), subadult, from Therku Viravallanur Reserve Forest (8.57553°N, 77.53916°E; elevation ca. 400 m asl.) collected by Akshay Khandekar, Swapnil Pawar and team on 5th May 2021; BNHS 2830 (AK-R 700), BNHS 2831 (AK-R 701), adult males from near Kodumudiyaru dam (8.43122°N, 77.52425°E; elevation ca. 400 m asl.), Thirukkurungudi Reserve Forest, collected by Akshay Khandekar, Swapnil Pawar and team on 8th May 2021; all from KMTR, Tirunelveli District, Tamil Nadu State, India.

Etymology.

The specific epithet is a toponym for Kalakad in Kalakad-Mundanthurai Tiger Reserve (KMTR), Tirunelveli District of Tamil Nadu State, the type locality of the new species.

Suggested common name.

KMTR leaf-litter skink.

Diagnosis.

A medium-sized skink snout to vent length up to 55.7 mm (n = 10). Six or seven supralabials and six infralabials up to angle of mouth; fourth supralabial elongate and below eye (rarely fifth on both sides, n = 1/10 or and fifth only on one side, n = 3/10); two post-supralabials (rarely single on one side, n = 2/10); seven supraciliaries; one elongated nuchal on either side (rarely two on one side, n = 2/10), in contact with each other behind parietal; 63-66 scales in paravertebral rows; 28 scales around mid-body; 64-71 ventral scales; eight enlarged precloacal scales; scales on lateral sides of tail base smooth, 18 or 19 scales around the tail. Subdigital lamellae unpaired, smooth on manus and smooth to weakly keeled on pes; five lamellae under digit I of manus (rarely four on one of the side, n = 1/10); five or six under digit I of pes; 10 or 11 lamellae under digit IV of manus (rarely nine on one of the side, n = 1/10); and 14-16 under digit IV of pes. Dorsum coconut brown with black markings; thick brown stripe from rostrum to tail speckled with light spots; supralabials with white streak; males with yellow on lower parts of forebody and flanks extending onto belly; venter glossy grey-white without darker markings.

Comparisons.

Dravidoseps kalakadensis sp. nov. can be diagnosed from known congeners based on the following characters: 28.0 ± 0.00 (28) RBS (versus 30.0 ± 0.00 (30) in D. pruthi comb. nov., and 31.0 ± 1.41 (30-32) in D. gingeeensis sp. nov. and in D. jawadhuensis sp. nov.); 8.0 ± 0.00 (8) SPCLR (versus 12.0 ± 0.00 (12) in D. gingeeensis sp. nov., 12.5 ± 0.71 (12-13) in D. jawadhuensis sp. nov., 9.2 ± 0.60 (8-10) in D. nilgiriensis comb. nov., 10.0 ± 0.00 (10) SPCLR in D. pruthi comb. nov., and 8.3 ± 0.76 (8-10) in D. goaensis comb. nov.); 18.7 ± 0.52 (18-19) RTS (versus 21.0 ± 0.00 (21) in D. gingeeensis sp. nov., 22.5 ± 0.71 (22-23) in D. jawadhuensis sp. nov., 20.1 ± 1.07 (19-22) in D. nilgiriensis comb. nov., and 21.4 ± 0.89 (21-23) in D. pruthi comb. nov.); six SL (rarely seven on just one specimen on both sides and on three specimens on one side) (versus seven SL in D. pruthi comb. nov., D. nilgiriensis comb. nov., D. gingeeensis sp. nov., and D. jawadhuensis sp. nov.); SL IV elongate and below eye (rarely SL V elongate and below eye, on just one specimen on either side and on three specimens on one side) (versus SL V elongate and below eye in D. pruthi comb. nov., D. nilgiriensis comb. nov., D. gingeeensis sp. nov., D. jawadhuensis sp. nov., and in D. goaensis comb. nov. (SL IV elongate and below eye only on two specimens on one side)); a single (rarely two on one side) Nu on either side and Sb Nu absent (versus a single Nu on either side and two or three Sb Nu present in D. pruthi comb. nov., and a single Nu on either side and three Sb Nu in D. gingeeensis sp. nov.); presence of unkeeled scales on tail base (versus keeled scales on tail base in D. goaensis comb. nov.). Dravidoseps kalakadensis sp. nov. is diagnosed against the new species described below as part of their respective descriptions.

Description of the holotype.

Adult male (SVL 45.7 mm) in good state of preservation except body and tail tip slightly bent towards left side, tail slightly detached at its half-length from ventral side, and hemipenis everted partially on left and entirely on right (Fig. 15A, B ). Head short (HL/SVL 0.16), wide (HW/HL 0.72), not strongly depressed (HH/HL 0.53), indistinct from neck. Loreal region not inflated, canthus rostralis indistinct. Snout almost half head length (ES/HL 0.41), slightly less than twice eye diameter (ES/ED 1.88). Rostral more than twice as wide (1.7 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, in contact with frontonasal anteriorly, frontal, first supraocular and first supraciliary posteriorly, anterior and posterior loreals laterally. 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 posteriorly, first secondary temporal laterally; a single enlarged, elongate, nuchal scale on either side in median contact posterior to parietals (Fig. 15C ). 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 (0.6 mm) than wide (0.5 mm); posterior loreal slightly larger than anterior loreal and slightly wider (0.8 mm) than tall (0.7 mm); a single small supra-preocular, an upper and lower preocular, and a single sub-preocular present only on either side (Fig. 15E ). Eye small (ED/ HL 0.22) with round pupil; lower eyelid with enlarged, transparent central window; seven supraciliaries on either side, 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; six supralabials, fourth and fifth below eye; fourth supralabial elongate, in broad contact with pre-subocular, last post-subocular and four small scales on lower eyelid below eye on either side; two post-supralabials on either side; six infralabials on either side; two scales separating post-supralabial and external ear opening; external ear opening small (EL/HL 0.09), oval, bearing a single anterior lobule on either side; tympanum deep (Fig. 15E ). Mental slightly more than twice as wide (1.9 mm) as long (0.8 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 posterior pair of chin shields, four gular scales on either side, and third and fourth infralabials on left and only third infralabial on right side; posterior pair smallest (0.9 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. 15D ).

Body relatively slender (BW/AGL 0.26), elongate (AGL/SVL = 0.57); dorsal scales on body smooth, cycloid, imbricate; ventrals similar to dorsals except subequal from chest to vent, marginally larger on pectoral and precloacal region; 63 scales in paravertebral rows; 28 scales around mid-body; 66 ventral scales; eight enlarged precloacal scales (Fig. 15A, B ). Limbs, robust, short (FL/SVL = 0.05; CL/SVL = 0.08), widely separated when adpressed; dorsal scales wider and 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 on manus and smooth to weakly keeled on pes; lamellae series: 4-6-9-10-7 left manus (Fig. 15F ), 6-9-14-16-10 left pes (Fig. 15G ), 5-8-9-10-7 right manus, 6-9-16-16-11 right pes. Relative length of digits (measurements in mm in parentheses): IV (1.7)> III (1.6)> II (1.3)> V (1.0)> I (0.9) (left manus); IV (4.9)> III (3.1)> V (2.5)> II (2.1)> I (1.0) (left pes).

Tail original, entire, cylindrical, slightly longer than snout-vent length (TL/SVL 1.14); dorsal and ventral scales cycloid, imbricate, similar to those on body dorsum except for median dorsal and median subcaudal scale rows somewhat larger than surrounding scales on tail; scales on lateral sides of the base tail base smooth, 19 scales around the tail counted (Fig. 15A, B )).

Colouration in life (Fig. 9F).

Dorsal ground colouration of body, head and tail dull coconut brown; head with scattered dark markings; head with a large dark blotch on the frontonasal; dorsal scales of body and tail finely outlined by dark brown, centre of scales with dark markings forming indistinct stripes, more prominent on tail; limbs darker than body dorsum and with light spots; a thick dark brown stripe running from rostrum through orbit and onto flank and tail with scattered light spots; supralabials with a white streak; yellow markings below dark stripe from throat to hindlimb insertions extending onto belly; ventral regions glossy grey-white.

Variation and additional information.

Mensural and meristic data for the paratype series are given in Table 9 . There are six adult males, three adult females and a single subadult. All specimens resemble the holotype male (NRC-AA-8275) in overall morphology and head scalation except for the following variation: three PoSbO on either side in ZSI-R-28613, three on left and four on right side in BNHS 2830 and ZSI-R-28615, four on left and three on right side in NRC-AA-8278; middle postmental bordered by IL III and IV, posterior pair of CS, and four gular scales on either side in all paratypes. NRC-AA-8276 with complete and original tail, slightly longer than body (TL/SVL 1.13 mm); ZSI-R-28615 without tail; rest of the paratypes with either fully or partially regenerated tails, shorter than body. BNHS 2830 and ZSI-R-28614 with partial or fully everted hemipenis on either side. NRC-AA-8276-8278 and BNHS 2829-2831 with small incision in sternum region for liver tissue collection. Three gravid females - BNHS 2829, ZSI-R-28613, and ZSI-R-28615 with longitudinal incision on ventral mid-body (17.5, 29.0, and 21.2 mm, respectively) to check for eggs/ developing embryos. NRC-AA-8278 (adult male) was dissected (12.4 mm long incision on ventral mid-body) to confirm the sex.

Distribution and natural history.

Dravidoseps kalakadensis sp. nov. is known only from a few closely spaced localities (<20 km in aerial distance) on the eastern slopes of the southern Western Ghats in Kalakad-Mundanthurai Tiger Reserve (Fig. 1 ). All localities are dry and moist deciduous forests at elevations between 200-400 m asl. (Fig. 11F ). At Kalakad, D. kalakadensis sp. nov. was observed moving in dry leaf-litter at night (1900-2100 hrs) after being disturbed. Dravidoseps kalakadensis sp. nov. was observed moving in leaf-litter and also found under rocks during the day (0730-1030 hrs) at Therku Viravallanur and Thirukkurungudi Reserve forests. Sympatric lizards encountered were Hemidactylus acanthopholis Mirza & Sanap, H. frenatus , H. leschenaultii , H. whitakeri , Cnemaspis azhagu Khandekar, Thackeray & Agarwal, Cn. mundanthuraiensis Khandekar, Thackeray & Agarwal, Eutropis carinata , E. macularia , Riopa albopunctata , Calotes calotes , Ca. versicolor , and Psammophilus dorsalis .

Reproduction.

Viviparous, litter size two or three. ZSI-R-28613, three embryos in late stages of development; ZSI-R-28615, two embryos in late stages of development; and BNHS 2829, two embryos in early stages of development (Fig. 8C-E ).

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 8. Embryos of Dravidoseps gen. nov. at different development stages: A two pairs in D. goaensis comb. nov. in early developmental stages (neotype, BNHS 2567); B two pairs in D. gingeeensis sp. nov. in early developmental stages (holotype, NRC-AA- 8273); C - E various development stages of D. kalakadensis sp. nov. (paratypes, BNHS 2829, ZSI-R- 28613, and ZSI-R- 28615 respectively); F - N various development stages of D. srivilliputhurensis sp. nov. (paratypes, BNHS 2832, BNHS 2834, BNHS 2835, BNHS 2837 - 2839, NRC-AA- 8284, NRC-AA- 8285, ZSI-R- 28618); O two almost completely developed in D. tamilnaduensis sp. nov. (paratype, BNHS 2859). Scale bars = 5 mm; photos by Akshay Khandekar.

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 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).

Figure 15. Dravidoseps kalakadensis sp. nov. (holotype, NRC-AA- 8275): A dorsal view of body, B ventral view of body, C dorsal view of head, D ventral view of head, E lateral right 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.