Eutropis dawsoni ( Annandale, 1909 )

Ganesh, S. R., Deuti, Kaushik, Achyuthan, N. S., Campbell, Patrick, Raha, Sujoy, Bag, Probhat & Debnath, Sudipta, 2021, Taxonomic reassessment of Eutropis macularia (Blyth, 1853) complex in the Western Ghats of India: Resurrection of Eutropis brevis (Günther, 1875), Eutropis dawsoni (Annandale, 1909) and synonymisation of Eutropis gansi (Das, 1991) (Reptilia: Squamata: Scincidae), Records of the Zoological Survey of India 121 (3), pp. 363-374 : 367-372

Eutropis dawsoni ( Annandale, 1909)

Lygosoma (Keneuxia) dawsoni Annandale, 1909

Mabuya gansi Das, 1991

Eutropis gansi – Mausfeld et al., 2002; Das et al., 2008

Lectotype: ZSI 16170 and paralectotypes ZSI 16140 , 16171 of Lygosoma dawsoni Annandale, 1909 from Maddathorai, Shashthamcottah and Tenmalai , Kerala.

Referred Material: Holotype ZSI 24826 and paratype ZSI 24828 of Mabuya gansi Das, 1991 from 2 km north-west of Muthalar Road Cross off Sengaltheri-Thalayani road (towards Moolakasam), Kalakkad-Mundanthurai Range, and Tirunelveli District, Tamil Nadu, coll. Indraneil Das on 30.viii.1990. onym Eutropis gansi ). Measurements in mm (R: regenerated tail)

Etymology: Patronym, honouring Lieut.-Col. F.W. Dawson, the then Director of Trivandrum Museum, with whom Annandale conducted the expedition on which he found this species.

Type locality: Madathorai (= Madathara, Kerala, India), after lectotype designation by Das et al. (1998) .

Diagnosis: A relatively larger species of Eutropis (adult SVL 61 mm) from the Southern Western Ghats, characterised by: a fairly robust and cylindrical body with well-developed limbs; dorsal scales with 5-6 strong keels with 3 pointed spurs projecting behind; post-nasal absent; supra-nasals and pre-frontals separated; fronto-parietals are in contact with each other; inter-parietal completely separating parietals; one pair of broad nuchals; temporal scales with 3-4 keels; ear-hole as large as lateral scale with 3-4 short, pointed anterior lobules; lower eyelids scaly with a series of opaque scales; mid-ventrals: 39-45; 4th toe subdigital lamellae: 14-16; dorsum dark grey-brown without any spots; dark grey-brown lateral stripe extending from posterior corner of eye to a little behind hind limbs.

Description and Variation: A fairly robust skink with an elongated and cylindrical body. Head indistinct from neck. Snout not depressed but obtusely pointed. Snout length exceeding eye-tympanum distance. Limbs well-developed. Fore and hind limbs touch each other. Dorsal, lateral and ventral scales almost equal in size. Dorsal scales with 5-6 strong keels with 3 pointed spurs projecting behind. Lateral scales with 5-6 strong keels with 3 pointed spurs projecting behind. Ventral scales hexagonal with 3 weak keels. Paravertebrals: 32-34. Ventrals: 39-45. Midbody scale rows: 27-30. Nostril in posterior part of nasal. Postnasal absent. Rostral more than twice as high as wide, curving up onto the dorsal surface of head, its posterior margin semicircular. Rostral is in contact with first supralabial, nasal, supranasal and frontonasal. Supranasals small and widely separated. Supranasal is in contact with rostral, nasal, frontonasal and anterior loreal. Frontonasal as wide as long and forming a broad margin with rostral anteriorly and with frontal posteriorly. Frontonasal in contact with rostral, supranasal, anterior loreal, prefrontal and frontal. Prefrontals not in contact with each other. Prefrontal in contact with frontonasal, both loreal (anterior and posterior), frontal, first supraocular (broadly) and first supraciliary (narrowly). Frontal large and arrow-shaped, posteriorly rounded. Frontal larger than frontoparietal and interparietal together, in contact with frontonasal, prefrontal, 2 nd supraocular and frontoparietal. Frontoparietals in contact with each other, larger than interparietal. Frontoparietal in contact with frontal, 2 nd supraocular narrowly, 3 rd and 4 th supraocular broadly, parietal and interparietal. Interparietal longer than wide, completely separating parietals. Parietal in contact with frontoparietal, 4 th supraocular, temporal, nuchal and interparietal. One pair of broad nuchals. 8-9 keels on each nuchal. 4 supraoculars, 2 nd the largest. Anterior loreal higher than wide but much higher than the posterior. Posterior loreal is 2.5 times wider than anterior. Anterior loreal in contact with 1 st supralabial slightly, 2 nd supralabial broadly, supranasal, frontonasal, prefrontal and posterior loreal. Posterior loreal in contact with 2 nd, 3 rd and 4 th supralabial, anterior loreal, prefrontal, 1st supraciliary and preocular. One preocular and one presubocular. 3 postoculars. 5-6 supraciliaries, 1st the largest but 3 rd the longest. Temporal scales with 3-4 keels. 6 supralabials, the 5 th is the largest and situated below eye. Earhole is round, as large as lateral scale and tympanum is deeply sunk, with 3-4 short, pointed anterior lobules. Eyelids well-developed and movable. Lower eyelids scaly with a series of opaque scales. 6 infralabials. Mental wider than long. Postmental is wider than long. Post-mental is in contact with 1st and 2 nd infralabials. First chin shields divided by a single row of ventral scales. First chin shield in contact with 2nd and 3rd infralabials; 2 nd chin shields divided by a single row of ventral scales, in contact with 3rd and 4th infralabials; 3rd chin shields divided by 3-4 rows of ventral scales, in contact with 4 th and 5 th infralabials. Forelimbs long, dorsally covered with 2-3 keels, ventrally smooth. Relative length of fingers IV>III>II>V>I. Hind limbs are long. Scales on dorsal surface of hind limbs with 2-3 keels. Scales on ventral surface of hind limbs are smooth. Scales on palm and sole rounded. Relative length of toes IV>III>V>II>I. Number of lamellae under 4th toe: 14-16. Precloacal scales not enlarged. Tail thick but gradually becomes pointed at the tip. Tail slightly longer than the body. Subcaudals not enlarged.

Colouration: Forehead, dorsum of body and tail grey-brown without any spots. A dark grey-brown lateral stripe from posterior corner of eye to a little behind the insertion of the hind limb. A pale yellow margin below the dark stripe from the upper lip passing below the ear opening and extending uptothe area above the fore-limb. A pink wash on the side of the throat. Ventrally cream ( Figures 4 and 5 ). Nuptial males with scarlet red gular wash and bright black lateral bands.

Distribution and natural history: This species is known from the far south of the Western Ghats, in the Agasthyamalai. Annandale (1909) first noted it from Maddathorai (=Madathara), Kulathupuzha, Tenmalai and Shasthamcotta near about the Sencottah Gap, on the slopes of Shendurney and Achenkovil. Subsequently, Das (1991) noted this species (as Mabuya gansi ) from much more southeastern localities – Sengaltheri- Thalayanai Road, near Moolaksam that are just north of Mahendragiri range, within the Kalakkad-Mundanthurai Hills. Judging by both their records ( Annandale, 1909; Das, 1991) it appears that E. dawsoni occurs in both the windward and leeward slopes of the Agasthyamalai Hills. Additionally, Annandale’s record from Shasthamcotta implies its potential presence in the Travancore Coastal Plains, farther than the Western Ghats foothills, and also in Punalur, Ranni-Konni ranges as well as its easterly versant the Devarmalai-Sivagiri Hills. Das (1991) reported this species as having fed on cockroaches and crickets, and that it laid two eggs measuring 12.2-12.6 x

7.4-7.8 mm (l x b). Probably a diurnal, leaf-litter dwelling skink, ecologically similar to E. clivicola . Natural history poorly known.

Remarks: Three of the type series of Lygosoma dawsoni were thought to have been lost in ZSI, Kolkata and hence the adult syntype from Maddathorai (ZSI 16170) was designated as the lectotype by Das et al. (1998). We subsequently located two more juvenile paralectotypes from Shashthamcottah (ZSI 16171) and Tenmalai (ZSI 16140) in the ZSI Kolkata Reptilia collections. However, the one from Kulathupuzha still remains untraced.

Comparisons: A species belonging to the E. macularia clade ( Datta-Roy et al., 2012; Barley et al., 2014), distinguished from other peninsular Indian members of the E. macularia clade as follows, only opposing character suites listed: E. brevis (smaller SVL not exceeding 37 mm; dorsal body scales with only 3-5 keels; each scale without spurs behind; tympanum smaller a lateral body scale without any anterior tympanic lobules; head length subequal to its width; fore-arm length subequal to lower arm length; shank length subequal to thigh length); E. clivicola (Smaller SVL upto 55 mm; dorsal body scales 5-7 feeble keels; each scale without projecting spurs behind; tympanum with 2-3 visible anterior tympanic lobules, a distinct half vertebral stripe on trunk; prefrontals in narrow contact with each other; interparietal in broad contact with nuchal; lower eyelid scaly with the central scale not enlarged than surrounding ones; dorsal scales feebly pentacarinate); E. allapallensis (frontoparietals fused; dorsal scale rows as low as 26); E. macularia (larger SVL upto 70 mm; dorsal body scales 5-9 keels; each scale without projecting spurs behind; tympanum larger than or at least equal to a lateral body scale with 2-3 indistinguishable anterior tympanic lobules, much lower 4th toe subdigital scale count 12–14; para-vertebrals scale count much higher: 39–41; midventral scale count much higher: upto 51). Additionally, E. dawsoni is distinct from the geographically proximate Sri Lankan members of the E. macularia clade, namely, E. madraszi , E. austini and E. greeri by: pretemporals in contact with parietal; first pair of chin shields separated by a median scale; E. tammanna : prefrontals in contact with each other.

Figures

Figure 4. Eutropis dawsoni from Meghamalai (Photo: Avrajjal Ghosh).

Figure 5. Eutropis dawsoni from Srivilliputhur (Photo: S.R. Ganesh).