Dravidoseps nilgiriensis Ganesh et al., 2021

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 nilgiriensis Ganesh et al., 2021 comb. nov.

Figure 9C

Chresonymy.

Subdoluseps nilgiriensis - Ganesh et al. (2021)

Holotype.

BNHS 2642, unsexed adult, Anaikatti hills (11.110°N, 76.769°E; 600 m asl.) Coimbatore District, Tamil Nadu State, India, collected by Avrajjal Ghosh, SR Ganesh and NS Achyuthan on September 2019.

Paratypes (n = 2).

BNHS 2643 and BNHS 2644, unsexed adults, same collection information as the holotype.

Additional material (n = 22).

NRC-AA-1295 (AK R 1854), adult male from near Mangalamkombu (10.31831°N, 77.65654°E; elevation ca. 1400 m asl.) and NRC-AA-1296 (AK-R 1877), adult male from near Mangalamkombu (10.303667°N, 77.640251°E; elevation ca. 1400 m asl.), Palani Hills , Dindigul District, Tamil Nadu, India, collected by Akshay Khandekar, Ishan Agarwal, Swapnil Pawar and team on 13th May 2022 ; NRC-AA-1297 (AK-R 2022), NRC-AA-1298 (AK-R 2023), subadults, from Aliyar Reserve Forest (10.48438°N, 76.92303° E; elevation ca. 400 m asl.), Anaimalai Tiger Reserve, Coimbatore District, same collectors as above except collected on 20th May 2022 ; NRC-AA-1299 (AK-R 2080), adult female, NRC-AA-1300 (AK-R 2081), subadult, from near Kattanchi view point (11.19985°N, 76.90867°E; elevation ca. 520 m asl.), close to Mettupalayam , Coimbatore District, same collectors as above except collected on 23th May 2022 ; NRC-AA-1301 (AK-R 2172), subadult, from Thamarakarai Forest Guesthouse campus (11.76779°N, 77.55715°E; elevation ca. 1000 m asl.), Erode District, same collectors as above except collected on 26th May 2022 ; BNHS 2559 (AK-R 2539), BNHS 2561 (AK-R 2541), adult females, BNHS 2560 (AK-R 2540), adult male, from near Kutladampatti Falls (10.12995°N, 78.01784°E; elevation ca. 280 m asl.), and BNHS 2562 (AK-R 2542), BNHS 2563 (AK-R 2543), subadults, from near Viralipatti (10.11638°N, 77.98282°E; elevation ca. 240 m asl.), Sirumalai Hills, Madurai District, same collectors as above except collected on 29th September 2022 ; BNHS 2564 (AK-R 2585), BNHS 2565 (AK-R 2586), ZSI-R-28603 (AK-R 2587), adult females, from Karanthamalai Hills (10.33737°N, 78.15939°E; elevation ca. 420 m asl.), Dindigul District , same collectors as above except collected on 3rd October 2022 ; ZSI-R-28604 (AK-R 2667), ZSI-R-28605 (AK-R 2668), adult males, ZSI-R-28606 (AK-R 2669), subadult, from Perunguntru trekking route (10.43080°N, 76.88132°E; elevation ca. 900 m asl.), and ZSI-R-28607 (AK-R 2671), ZSI-R-28608 (AK-R 2672), ZSI-R-28609 (AK-R 2673) subadults, from near Varagaliyar elephant camp (10.41913°N, 76.86747°E; elevation ca. 620 m asl.), Anaimalai Tiger Reserve , Coimbatore District, same collectors as above except collected on 9rd October 2022 ; ZSI-R-28694 (AK-R 2726), subadult, from Selur Reserve Forest , Kolli Hills (11.19463°N, 78.37537°E; elevation ca. 390 m asl.), Namakkal District, same collection data as above except on 12th October 2022 .

Referred material (n = 1).

AK-R-2173, same collection data as NRC-AA-1301 (AK-R 2172).

Etymology.

Named for its type locality, the Nilgiri Hills.

Suggested common name.

Nilgiri leaf-litter skink.

Diagnosis.

A medium-sized skink snout to vent length up to 58 mm (n = 22). Seven supralabials and six (rarely seven, n = 4/22) infralabials up to angle of mouth; fifth supralabial elongate and below eye; two post-supralabials; seven or eight supraciliaries (rarely nine on one side, n = 1/19); a single slightly elongated nuchal on either side (rarely two on one side, n = 1/22), in contact with each other behind parietal (rarely separated by a single scale, n = 5/22); 62-70 scales in paravertebral rows; 26-30 scales around mid-body; 61-71 ventral scales; 8-10 enlarged precloacal scales; scales on lateral sides of tail base smooth, 19-21 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 (rarely four and seven, n = 1/22), and 5-7 under digit I of pes; 9-11 lamellae under digit IV of manus (rarely 12, n = 1/22); and 13-15 under digit IV of pes (rarely 16, n = 1/22). Dorsum brown with black markings; thick black stripe from rostrum to tail speckled with light spots, males with yellow on lower parts of forebody and flanks extending onto belly; supralabials with white streak; venter glossy grey-white with some darker markings.

Comparisons.

Dravidoseps nilgiriensis comb. nov. can be diagnosed from known congeners based on the following characters: 28.1 ± 0.86 (26-30) RBS (versus 30.0 ± 0.00 (30) in D. pruthi comb. nov., and 29.0 ± 1.00 (28-30 in D. goaensis comb. nov.); an average of 14.4 ± 0.76 (13-16) (versus 16.1 ± 1.20 (14-18) Lam4T in D. pruthi comb. nov., and 13.4 ± 0.79 (13-15) in D. goaensis comb. nov.); two PoSL on each side (versus a single PoSL on each side in D. pruthi comb. nov.); a single NU on either side and Sb NU either absent or rarely only a single present (versus a single Nu on either side and two or three Sb Nu present in D. pruthi comb. nov.); unkeeled scales on tail base (versus keeled scales on tail base in D. goaensis comb. nov.). Dravidoseps nilgiriensis comb. nov. is diagnosed against the new species described below as part of their respective descriptions.

Distribution and natural history.

Dravidoseps nilgiriensis comb. nov. is the most widely distributed member of the genus, known from the Western Ghats (north and south of Palghat gap) and hills outside the Western Ghats, between an elevation range of 200-1400 m asl.; in Tamil Nadu State, India (Fig. 1 ). In the Western Ghats, the species is known from Anaikatti (type locality) and Mettupalayam in the Nilgiri, multiple localities in Anaimalai Tiger Reserve, and Palani Hills; and outside the Western Ghats, from Thamarakarai, Kolli Hills, Sirumalai Hills, and two localities north of Sirumalai. The aerial distance between two farthest localities is> 185 km north-west (from Thamarakarai to Sirumalai Hills) and> 180 km east-west (from Anaimalai Tiger Reserve to Kolli Hills).

At Palani Hills, individuals were collected/ observed sheltering under rocks in the afternoon (1230-1330 hrs) in a small open patch surrounded by wet evergreen forest at high elevation (1400 m asl.). Sympatric lizards recorded were Cnemaspis cf. palanica , Cyrtodactylus (Geckoella) cf. collegalensis , Dravidogecko sp., Eutropis cf. carinata , Kaestlea sp. Riopa albopunctata , Ristella sp., and Monilesaurus cf. rouxii . At Anaimalai Tiger Reserve, the species was observed in a relatively open area surrounded by evergreen forest located along the Perunguntru trekking route, near Varagaliyar Elephant Camp, and also in moist deciduous to semievergreen forest at Aliyar Reserve Forest. Specimens were observed either buried in loose soil under rocks or moving in the leaf-litter during morning hours (0930-1200 hrs). Sympatric lizards recorded were Cnemaspis cf. monticola , Cn. cf. littoralis , Eutropis carinata , E. macularia , Ristella sp., Sphenomorphus dussumieri ( Duméril & Bibron), Calotes calotes (Linnaeus), and Monilesaurus cf. rouxii . Near Mettupalayam, individuals were found under rocks in the morning (0930 hr) in thorny dry deciduous forests dominated by granite sheet rocks. Other sympatric skinks were Eutropis bibronii (Gray), and Riopa albopunctata . At Thamarakarai, a single juvenile was collected from under a rock in the forest guest house campus surrounded by deciduous forests (Fig. 11C ). At Sirumalai Hills, Karanthamalai Hills and Kolli Hills, individuals were found under rocks or in leaf-litter during morning hours (0830-1100 hrs) in dry deciduous forest patches. Sympatric lizards recorded were Cnemaspis cf. gracilis , Eutropis carinata , E. macularia , Riopa albopunctata , Calotes versicolor , and Psammophilus cf. blanfordanus .

Reproduction.

Unknown. No gravid female in the additional material examined (non-gravid females dissected: NRC-AA-1299, BNHS 2559, BNHS 2561, BNHS 2564, BNHS 2565 ranging in SVL from 42.7-52.6 mm).

Note.

We examined the type series (holotype and two paratypes) of this species housed at BNHS and found discrepancies in some mensural (SVL, TL, AGL, CL, HL, EE) and meristic (PVS, RBS, VS) characters provided in the original description by Ganesh et al. (2021) and our data (Table 7 ). Additionally, the original description has two different SVL values for the holotype in the holotype description (63.23 mm) and 'table 4 (67.23 mm)' ( Ganesh et al. 2021) versus our measurement of 57.1 mm.

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 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).