Cyrtodactylus (Geckoella) irulaorum, Agarwal & Thackeray & Khandekar, 2023
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publication ID |
https://dx.doi.org/10.3897/vz.73.e102602 |
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publication LSID |
lsid:zoobank.org:pub:EBCD7D0E-182D-47EE-B238-7237304509F7 |
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persistent identifier |
https://treatment.plazi.org/id/972542B9-EF36-4D70-922B-499C49370E18 |
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taxon LSID |
lsid:zoobank.org:act:972542B9-EF36-4D70-922B-499C49370E18 |
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treatment provided by |
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scientific name |
Cyrtodactylus (Geckoella) irulaorum |
| status |
sp. nov. |
Cyrtodactylus (Geckoella) irulaorum sp. nov.
Figs 3 View Figure 3 , 4 View Figure 4 , 5 View Figure 5 , 6 View Figure 6 , 7 View Figure 7 , 8 View Figure 8
Holotype.
NRC-AA-1266 (CES09/1438), adult male, from a farm near Vallam Reserve Forest (12.6920°N, 80.0263°E; ca. 55 m asl.), Kancheepuram District, Tamil Nadu, India, collected by Ishan Agarwal on 10th April 2013.
Paratypes.
NRC-AA-1267 (CES09/1437), NRC-AA-12-68 (CES09/1439), NRC-AA-1269 (CES09/1440), NRC--AA--1270 (CES09/1441), adult males, same collection data as holotype; NRC-AA-1272 (AK 105), NRC-AA-1273 (AK 106), adult females, same collection data as holotype except collected by Ishan Agarwal, Akshay Khandekar, R. Chaitanya and Caleb Daniel on 11th November 2017; NRC-AA-1271 (IAG 193), adult female, from Thervoy Kandigai (13.3713°N, 79.9791°E; ca. 30 m asl.), Tiruvallur District, Tamil Nadu, India, collected by R. Chaitanya on date 14th December 2015.
Etymology.
The specific epithet is a patronym in honour of the Irula tribe, an indigenous Dravidian group who are expert snake trackers and catchers. Romulus Whitaker, whose farm the type series was collected at, has worked closely with the Irulas for decades and helped them set up a venom extraction cooperative in 1978. The Irula Snake Catchers’ Industrial Cooperative Society is the largest contributor to antivenom production in India.
Suggested common name.
Irula Geckoella .
Diagnosis.
A small-sized Cyrtodactylus (Geckoella) , snout to vent length up to 51 mm (n = 8); tail shorter than SVL. Dorsal pholidosis on trunk homogeneous; covered with smooth, subcircular, weakly conical granular scales; scales on occiput and nape slightly smaller and more rounded than those on body dorsum, scales on flank slightly larger than those on dorsum; ventral scales much larger than dorsal scales, smooth, somewhat elongate, subimbricate, subequal from chest to vent; femoral and precloacal pores absent; enlarged precloacal or femoral scales absent, no precloacal groove; four pairs of dark rounded spots from behind occiput to hindlimb insertions, spots occasionally fused along mid-vertebral line forming horizontal figure 8-shaped marking; post-occipital collar broken into a pair of spots.
Comparison with members of the Cyrtodactylus collegalensis complex.
The diagnostic characters listed above for Cyrtodactylus (Geckoella) irulaorum sp. nov. easily differentiate the new species from all other Cyrtodactylus and Cyrtodactylus (Geckoella) apart from members of the Cyrtodactylus collegalensis complex. Cyrtodactylus (Geckoella) irulaorum sp. nov. can be differentiated from the other members of the complex by its dorsal colour pattern of four pairs of dark spots from behind occiput to hindlimb insertions (spots may be fused centrally forming horizontal figure 8-shaped markings) from C. aravindi (a single dark broad band and one or two single dark spots on dorsum), C. collegalensis (three pairs of dark spots that may be fused forming horizontal figure 8-shaped markings), C. rishivalleyensis (two broad dark bands on dorsum), C. srilekhae (three rows of irregular dark blotches), C. speciosus (two broad dark bands on dorsum) and the Sri Lankan species C. yakhuna (one or two broad dark bands or spots on dorsum in both subspecies). The new species is most similar in colour pattern to C. chengodumalaensis and C. varadgirii (4-6 pairs of dark spots on dorsum) but can be distinguished by the absence of a few, enlarged dorsal tubercles on the dorsum (versus the presence of these tubercles in C. chengodumalaensis ) and by the absence of a patch of enlarged roughly hexagonal scales on the canthus rostralis and beneath the angle of the lower jaw (versus the presence of these enlarged scales in C. varadgirii ). Cyrtodactylus (Geckoella) irulaorum sp. nov. is closely allied to Cyrtodactylus (Geckoella) relictus sp. nov. and is diagnosed as part of the species description below.
Description of holotype.
Adult male in good state of preservation except head slightly bent towards left and tail significantly bent towards right side, and a 5.7 mm vertical incision in the sternal region for liver tissue collection (Fig. 3A, B View Figure 3 ). SVL 41.5 mm, head short (HL/SVL 0.24), wide (HW/HL 0.70), not strongly depressed (HD/HL 0.46), almost as broad as body (HW/BW ratio 0.96), and distinct from neck (Fig. 4A-C View Figure 4 ). Loreal region slightly inflated, canthus rostralis not prominent. Snout marginally less than half the head length (ES/HL 0.44), slightly longer than eye diameter (ED/ES 0.61); scales on snout, canthus rostralis, and loreal region large, subcircular, smooth and, flattened; much larger than granular scales on forehead and interorbital region; occipital and temporal region with much smaller, smooth granules (Fig. 4A, C View Figure 4 ). Eye small (ED/HL 0.27); pupil, dilated, vertical with crenate margins; supraciliaries short, larger anteriorly, not elongate; 12 interorbital scale rows across narrowest point of frontal; 37 scale rows between left and right supraciliaries at mid-orbit (Fig. 4A, C View Figure 4 ). Ear-opening oval, small (EL/HL 0.12); eye to ear distance almost same as eye diameter (EE/ED 1.07). Rostral twice wider (2.1 mm) than deep (1.1 mm), incompletely divided dorsally by weakly developed rostral groove for half of its height; a single enlarged supranasal on each side, more than twice the size of the postnasals, separated from each other by a single enlarged internasal on the snout; three subequal postnasals, much smaller than supranasals; rostral in contact with nostril, supralabial I, supranasals, and internasals on either side; nostrils rounded, directed outwards, covering most of the nasal scale; surrounded on either side by supralabial I, rostral, supranasals, and postnasals; a single row of smaller scales separate the orbit from the supralabials (Fig. 4A, C View Figure 4 ). Mental enlarged, triangular, wider (1.6 mm) than long (1.2 mm); two pairs of postmentals; inner pair in strong contact with each other, roughly pentangular and same length (1.2 mm) as mental; bordered by mental, infralabial I, outer postmental and two enlarged chin shields on left and a single on right side; outer postmentals separated from each other by left inner postmental and an enlarged chin scale, roughly rectangular and half the size (0.6 mm) of inner pair; bordered by inner postmentals and five enlarged chin shields on either side; chin shields bordering postmentals and infralabials flat, smooth, smaller than outermost postmentals, rest flattened, small, smooth; two or three rows of enlarged elongated scales separating gular scales from infralabials (Fig. 4B View Figure 4 ). Twelve supralabials up to angle of jaw on left and 10 on right side, and eight at midorbital position on left and seven on right side; nine infralabials up to angle of jaw on either side, and six infralabials at midorbital position on both sides (Fig. 4C View Figure 4 ).
Body relatively slender (BW/AGL 0.41), trunk less than half of SVL (AGL/SVL 0.43) without ventrolateral folds. Dorsal pholidosis on trunk homogeneous; covered with smooth, subcircular, weakly conical granular scales; 20 dorsal midbody scale rows across trunk contained within one eye diameter (Fig. 5A View Figure 5 ). Granular scales on occiput and nape slightly smaller and rounded than those on body dorsum; granular scales on flank slightly larger than those on dorsum. Ventral scales much larger than granular scales on dorsum, smooth, somewhat elongate, subimbricate, subequal from chest to vent; 15 ventral midbody scale rows across belly contained within one eye diameter (Fig. 5B View Figure 5 ). Scales on throat slightly smaller than those on belly; gular region with much smaller, granular scales with those on chin bordering postmentals, enlarged, juxtaposed and flattened (Fig. 4B View Figure 4 ). No enlarged precloacal or femoral scales, no precloacal or femoral pores; no precloacal groove (Fig. 3B View Figure 3 ).
Scales on palm and soles granular, smooth, rounded; scales on dorsal aspects of limbs heterogeneous in shape and size; mixture of small, granules similar to dorsum and many smooth flattened and imbricate scales which are much larger than granules on the body dorsum, largest on anterior aspect of the hands and feet; lateral and ventral aspects of limbs with small granular scales (Fig. 3A, B View Figure 3 ). Fore-limbs and hind-limbs long, slender (LAL/SVL 0.13; CL/SVL 0.16); digits short, slender, with a strong, recurved claw, moderately inflected, distal portions laterally compressed. Series of unpaired lamellae on basal portion of digits except one or two which on some digits which are paired, separated from narrower distal lamellae by a single large lamella at the inflection, unpaired except one or two which are divided; basal lamellae series: (5-6-5-6-7 right manus, Fig. 6A View Figure 6 ; 3 View Figure 3 - 6-6 View Figure 6 - 8 View Figure 8 - 6 View Figure 6 right pes, Fig. 6B View Figure 6 ), (5-5-6-6-7 left manus; 3-5-6-7-6 left pes); distal lamellae series: (7-6-8-7-7 right manus, Fig. 6A View Figure 6 ; 7-7 View Figure 7 - 9-9-9 View Figure 9 right pes, Fig. 6B View Figure 6 ), (7-6-8-7-7 left manus; 8-7-9-8-9 left pes). Relative length of digits (measurements in mm in parentheses): IV (3.1)> III (2.9)> II (2.6)> V (2.3)> I (1.8) (right manus); IV (3.9)> III (3.4)> V (3.3)> II (3.0)> I (1.8) (right pes).
Tail original, circular in cross section with indistinct median dorsal furrow, relatively thick, tapering gradually to tip, unsegmented, slightly shorter than snout-vent length (TL/SVL ratio 0.78). Scales on dorsal aspect of tail base similar to body dorsum; scales on dorsal aspect of tail large flat, subcircular, smooth, and imbricate, becoming slightly larger towards the lateral aspect, largest on ventral side, but not forming median row of transversely enlarged subcaudal scales. Three small, smooth, subequal, conical postcloacal spurs on left side and two on right side of tail base; prominent hemipenal swelling, flap of skin covering cloacal aperture. Tail slightly constricted at the base (Fig. 3B View Figure 3 ).
Colouration in Life (Fig. 7A).
Dorsal ground colour light tan, four pairs of dark brown spots from behind occiput to hindlimb insertions and a smaller darker pair above tail base. Spots on the left side of the body in the first and second pair fused, other pairs except the fourth separated mid-vertebrally, second pair of spots slightly larger than the rest and first smallest. Spots edged by black on the outer 1-5 rows of scales, finest along flanks and absent in fused portion of fourth set of spots. Flank with only a few scattered fine black spots. Tail dorsum similar in ground colour to body dorsum except slightly suffused with yellow; a dark small pair of spots on tail base and six indistinct darker crossbars reducing in size toward tail-tip, anteriorly forming black edged brown bands. Dorsum of limbs similar in colour to trunk with a few scattered black spots, digits with indistinct mottling. Post-occipital collar formed of two fused brown spots edged with black and a finer light border forming a horizontally 8-shaped marking. Central spots on post-occipital collar roughly subequal to smallest dorsal blotches. Crown of the same shade as trunk with a few small scattered black spots, and seven dark brown markings that have a darker border flanked by a finer light border; a pre-frontal spot that is shorter than two interorbital spots which are similar in length to the longer part of the (broken) interparietal streak and two parietal spots. Brille similar in colour to light scales on crown. Postocular streak runs from posterior edge of eye to just beyond tympanum, separated from dorsolateral markings of collar and first pair of dorsal spots on neck or just meeting above tympanum (L/R); preocular streak extends till nostril. All head markings separated from each other. Labials with dark streaks, a few unmarked scales finely spotted with black. A fine dark streak from below anterior edge of ear opening extends onto start of the forearm. Ventral aspects dirty white with few spots on the lateral edge of the belly and numerous thick streaks and spots on infralabials and gular region; ventral aspect of tail many-coloured with dark with few scattered light streaks.
Variation and additional information from paratypes (Figs 7B-D; 8A, B).
Mensural and meristic data for the type series is given in Table 3 View Table 3 . There are five adult males and three adult female specimens, SVL ranging from 39.8-50.5 mm. All specimens resemble the holotype male (NRC-AA-1266) except for the following variations: two internasals between supranasals behind rostral in NRC-AA-1267. Inner postmental separated from each other below mental by single smaller chin shield in NRC-AA-1268; inner postmental bordered by mental, infralabial I, outer postmental in all paratypes; bordered by four enlarged chin scales in NRC-AA-1267, NRC-AA-1269, NRC-AA-1272, NRC-AA-1273, by three enlarged chin scales in NRC-AA-1270, by five enlarged chin scales in NRC-AA-1271, by six enlarged chin scales in NRC-AA-1268. Outer postmental bordered by inner pair, infralabial I and II and three enlarged chin scales in NRC-AA-1267, NRC-AA-1268; outer postmental bordered by inner pair, infralabial I and II and two enlarged chin scales in NRC-AA-1271; outer postmental bordered by inner pair, infralabial I and II on either side and by two enlarged chin scales on left and, three on right side in NRC-AA-1272; outer postmental bordered by inner pair, infralabial I and II on either side and four enlarged chin scales on left and two on right side in NRC-AA-1269; outer postmental bordered by inner postmental, infralabial I and II, and four enlarged chin scales on right and by inner postmental, and five enlarged chin scales on left side in NRC-AA-1270; outer postmental bordered by inner postmental, infralabial I and II, and four enlarged chin scales on right and by inner postmental, and six enlarged chin scales on left side in NRC-AA-1273. Three paratypes (NRC-AA-1270, NRC-AA-1272, and NRC-AA-1271) have an original and complete tail, slightly shorter than body (TL/SVL 0.77, 0. 72, and 0.81 respectively); NRC-AA-1273 with partially regenerated tail, NRC-AA-1268 and NRC-AA-1269 with fully regenerated tails, NRC-AA-1267 with original but incomplete tail, all having shorter tails than body. Ground colour varies from light khaki to brown; dorsal pairs of spots may be fused along mid-vertebral line and the first two pairs of spots may be fused on one or both sides; pair of spots on collar separated or just in contact; post-orbital streak sometimes fused with first pair of spots; head pattern variable; regenerated tail greyish brown or grey with or without a few scattered spots, original tail with 6-8 indistinct bands.
Distribution and Natural History.
Cyrtodactylus (Geckoella) irulaorum sp. nov. is known from only two localities 75 km apart at elevations below ~60 m (Fig. 1 View Figure 1 ). The type locality is a small farm adjacent to low hills with largely tropical dry evergreen scrub (Fig. 9A, B View Figure 9 ), while the other locality was a patch of deciduous forest. Individuals were spotted at night (from about 45 minutes to two hours after sunset) mainly by eye-shine and were found in leaf litter and on the ground. Four individuals were spotted in about half an hour by IA on 10th April 2013 and a few individuals have been spotted on multiple occasions.
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