Dravidoseps gingeeensis, 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

publication ID	https://dx.doi.org/10.3897/vz.74.e110674
publication LSID	lsid:zoobank.org:pub:335FBFDD-E543-40CA-8014-0E16A7977586
persistent identifier	https://treatment.plazi.org/id/0284690E-ED9D-4930-926A-51A36370E9F6
taxon LSID	lsid:zoobank.org:act:0284690E-ED9D-4930-926A-51A36370E9F6
treatment provided by	Vertebrate Zoology by Pensoft
scientific name	Dravidoseps gingeeensis
status	sp. nov.

Treatment

Dravidoseps gingeeensis sp. nov.

Figures 8B View Figure 8 , 9D View Figure 9 , 13 View Figure 13

Chresonymy.

Lygosoma pruthi - Ganesh et al. (2018)

Holotype.

NRC-AA-8273 (AK-R 147), adult female, from Pakkamalai Reserve Forest (12.17224°N, 79.31907°E; elevation ca. 400 m asl.), Gingee Hills, Viluppuram District, Tamil Nadu State, India, collected by Akshay Khandekar, Swapnil Pawar and team, on 3rd April 2021.

Paratype.

BNHS 2568 (AK-R 192), adult female, from near Arulmigu Sri Pachaiamman Temple, Vedal (12.37095°N, 79.47239°E; elevation ca. 140 m asl.), Tiruvannamalai

District, Tamil Nadu State, India, same data as holotype except collected on 4th April 2021.

Etymology.

The specific epithet is a toponym for the Gingee Hills in Villupuram District of Tamil Nadu State, the type locality of the new species.

Suggested common name.

Gingee leaf-litter skink.

Diagnosis.

A medium-sized skink snout to vent length up to 57 mm (n = 2). Seven supralabials and six or seven infralabials up to angle of mouth; fifth supralabial elongate and below eye; two post-supralabials; eight supraciliaries; a single slightly elongated nuchal on either side, separated by three scales behind parietal; 66 or 67 scales in paravertebral rows; 30-32 scales around mid-body; 67 ventral scales; 12 enlarged precloacal scales; scales on lateral sides of tail base smooth, 21 scales around the tail. Subdigital lamellae unpaired, smooth on manus and smooth to weakly keeled on pes; five or six lamellae under digit I of manus and six under digit I of pes; 11 or 12 lamellae under digit IV of manus and, 17 under digit IV of pes. Dorsum light brown with black markings; thick black stripe from rostrum to tail speckled with light spots; supralabials with white streak; venter glossy grey-white with some darker markings.

Comparisons.

Dravidoseps gingeeensis sp. nov. can be diagnosed from known congeners based on the following characters: 12.0 ± 0.00 (12) SPCLR (versus 9.2 ± 0.60 (8-10) in D. nilgiriensis comb. nov., 10.0 ± 0.00 (10) in D. pruthi comb. nov., and 8.3 ± 0.76 (8-10) in D. goaensis comb. nov.); 17.0 ± 0.00 (17) LAM4T (versus 14.4 ± 0.76 (13-16) in D. nilgiriensis comb. nov., 16.1 ± 1.20 (14-18) in D. pruthi comb. nov., and 13.4 ± 0.79 (13-15) in D. goaensis comb. nov.); a single Nu on either side and three Sb Nu (versus a single NU on either side and Sb NU either absent or one or two presents in D. goaensis comb. nov., and a single NU on either side and Sb NU either absent or rarely only a single present in D. nilgiriensis comb. nov.); presence of unkeeled scales on tail base (versus keeled scales on tail base in D. goaensis comb. nov.); 21 RTS (versus 18 or 19 RTS in D. goaensis comb. nov.). Dravidoseps gingeeensis sp. nov. is diagnosed against the new species described below as part of their respective descriptions.

Description of the holotype.

Adult female (SVL 56.6 mm) in good state of preservation except head and tail tip slightly bent towards left side, and a 3.6 mm long incision at sternum region for liver tissue collection (Fig. 13A, B View Figure 13 ), and 15.5 mm long ventral incision at mid-body (made after taking morphological data and photos) to confirm eggs/developing embryos. Head short (HL/SVL 0.15), wide (HW/HL 0.72), not strongly depressed (HH/HL 0.58), indistinct from neck. Loreal region not inflated, canthus rostralis indistinct. Snout almost half head length (ES/HL 0.43), marginally more than twice eye diameter (ES/ED 2.03). Rostral twice as wide (1.8 mm) as long (0.9 mm), frontonasal much wider (1.9 mm) than long (1.3 mm), in contact with supranasals anteriorly, prefrontals and frontal posteriorly, anterior loreals laterally; prefrontals relatively small, widely separated on midline, in contact anteriorly with frontonasal, posteriorly with frontal, first supraocular and first supraciliary, anterior and laterally with 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. 13C View Figure 13 ). 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 (1.0 mm) than tall (0.7 mm); a single small supra-preocular, an upper and lower preocular, and a single sub-preocular present only on right side (Fig. 13E View Figure 13 ). Eye small (ED/ HL 0.21) with round pupil; lower eyelid with enlarged, transparent central window; eight 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; seven supralabials, fifth and sixth below eye; fifth supralabial elongate, in broad contact with pre-subocular and six 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 0.07), oval, bearing two anterior lobules on either side; tympanum deep (Fig. 13E View Figure 13 ). Mental twice as wide (2.0 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 (1.6 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 (1.8 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 (1.0 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. 13D View Figure 13 ).

Body relatively slender (BW/AGL 0.27), elongate (AGL/SVL = 0.58); dorsal scales on body smooth, cycloid, imbricate; ventrals similar to dorsals except subequal from chest to vent, marginally larger on pectoral and precloacal region; 67 scales in paravertebral rows; 32 scales around mid-body; 67 ventral scales; 12 enlarged precloacal scales (Fig. 13A, B View Figure 13 ). Limbs, robust, short (FL/SVL = 0.06; 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: 6-10-10-11-7 left manus (Fig. 13F View Figure 13 ), 6-10-14-17-13 left pes (Fig. 13G View Figure 13 ), 6-10-9-11-7 right manus, 6-11-15-17-13 right pes. Relative length of digits (measurements in mm in parentheses): IV (2.4)> III (2.3)> II (1.9)> V (1.7)> I (1.1) (left manus); IV (4.5)> III (3.7)> V (2.8)> II (2.5)> I (1.3) (left pes).

Tail half original half regenerated, cylindrical, slightly shorter than snout-vent length (TL/SVL 0.88); dorsal and ventral scales on original tail cycloid, imbricate, similar to those on body dorsum; scales on lateral sides of tail base smooth, 21 scales around the tail; dorsal and ventral scales on regenerated tail similar to those on original tail except for median dorsal and subcaudal scale rows distinctly rectangular and larger than surrounding scales (Fig. 13A, B View Figure 13 ).

Colouration in life (Fig. 9D).

Dorsal ground colouration of body, head and tail light brown with a bronze tint; head with scattered dark markings; dorsal scales of body and tail finely outlined by dark brown, centre of some scales with dark markings forming indistinct stripes; 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; ventral regions glossy, off-white with scattered black and grey markings.

Variation and additional information.

Mensural and meristic data for the adult (SVL 53.6 mm) female paratype (BNHS 2568) are given in Table 8 View Table 8 . It resemble the holotype female (NRC-AA-8273) in overall morphology, head scalation, and colouration except for the following variation: a single PrSbO on either side; three PoSbO on either side; and more than half of its tail is detached and missing.

Distribution and natural history.

Dravidoseps gingeeensis sp. nov. is known from its type locality (Pakkamalai Reserve Forest in Viluppuram District; 400 m asl.) and paratype locality (Arulmigu Sri Pachaiamman Temple, near Vedal, Tiruvannamalai District; 140 m asl.), both in north-eastern Tamil Nadu, <30 km apart from each other in aerial distance (Fig. 1 View Figure 1 ). Both localities have sparse, dry tropical evergreen forests dominated by granite boulders (Fig. 8D View Figure 8 ). Dravidoseps gingeeensis sp. nov. was encountered during a single day of fieldwork at each locality. At Pakkamalai, the female holotype was collected from under a rock in leaf-litter inside a forested patch during the day (1130 hrs). At Vedal, the female paratype was observed feeding on cockroach in the morning (0915 hrs) in dry leaf-litter among granite boulders. Sympatric species at both localities recorded were Calodactylodes aureus (Beddome), Hemidactylus frenatus Duméril & Bibron; Hemidactylus pakkamalaiensis Narayanan et al., 2023, Hemidactylus whitakeri , Eutropis carinata , and Psammophilus dorsalis .