Cyrtodactylus (Geckoella) relictus, Agarwal & Thackeray & Khandekar, 2023

Agarwal, Ishan, Thackeray, Tejas & Khandekar, Akshay, 2023, Two new spotted species of the Cyrtodactylus (Geckoella) collegalensis (Beddome, 1870) complex from the south-eastern coast of India (Reptilia: Squamata), Vertebrate Zoology 73, pp. 475-498 : 475

Cyrtodactylus (Geckoella) relictus sp. nov.

Figs 10 , 11 , 12 , 13 , 14 , 15

Holotype.

NRC-AA-1274 (CES09/1472), adult male, from near Ubbalamadagu waterfalls, Kambakkam Durg (13.6100°N, 79.8431°E; ca. 120 m asl.), Tirupati District, Andhra Pradesh, India, collected by Ishan Agarwal and team on 18th March 2014.

Paratypes.

NRC-AA-1275 (CES09/1470), NRC-AA--12-76 (CES09/1471), adult females, from near Pencha-lakona (14.3266°N, 79.4219°E; ca. 170 m asl.), Nellore District, Andhra Pradesh, India, collected by Ishan Agarwal and team on 17th March 2014.

Etymology.

The specific epithet is from the Latin relictus; which refers to an organism or species that has survived from an earlier period with different environmental conditions. Peninsular India was covered by wet forests and has gradually become more arid since at least the Miocene ( Morley 2007; Patnaik et al. 2012; Pound et al. 2012). This is apt for the new species as it is known only from small areas of relatively cool, closed canopy habitats in a matrix of otherwise warm and open habitats.

Suggested common name.

Relict Geckoella .

Diagnosis.

A small-sized Cyrtodactylus (Geckoella) , snout to vent length up to 53 mm (n = 3); 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 rounded than those on body dorsum, scales on flank slightly larger than those on dorsum; ventral scales much larger than scales on dorsum, smooth, subcircular, subimbricate, subequal from chest to vent; absence of femoral and precloacal pores; absence of enlarged precloacal or femoral scales, no precloacal groove; four pairs of dark rounded spots from occiput to hindlimb insertions, spots rarely just in contact along mid-vertebral line; post-occipital collar broken into a pair of spots (1/3) or forming a U-shaped band (2/3).

Comparison with members of the Cyrtodactylus collegalensis complex.

The diagnostic characters listed above for Cyrtodactylus (Geckoella) relictus sp. nov. easily differentiate the new species from all other Cyrtodactylus and Cyrtodactylus (Geckoella) apart from members of the Cyrtodactylus collegalensis complex. Cyrtodactylus (Geckoella) relictus sp. nov. can be differentiated from the other members of the Cyrtodactylus collegalensis complex by its dorsal colour pattern of four pairs of dark spots from behind occiput to hindlimb insertions (first pair fused with postocular streak on either side, spots may be just in contact centrally) 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 , Cyrtodactylus (Geckoella) irulaorum sp. nov. and C. varadgirii (which all have 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 ), its SVL up to 52.7 mm (versus SVL up to 47.6 mm 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) relictus sp. nov. overlaps in colour pattern with C. irulaorum sp. nov. almost completely, except that the first pair of spots is fused with the postocular streak in C. relictus sp. nov. (versus postocular streak usually separated from first pair of spots in C. irulaorum sp. nov.). The two species occupy distinct positions in multivariate morphospace (Fig. 2 ) and differ significantly across a number of size-corrected morphometric variables. Additionally, Cyrtodactylus (Geckoella) relictus sp. nov. is slightly larger (maximum SVL 52.7 mm, mean 51.5 versus maximum SVL 50.5 mm, mean 43.4 mm in C. irulaorum sp. nov.) and has a significantly (p <0.05) wider body (BW/SVL mean 0.215, range 0.201-0.230 versus BW/SVL mean 0.167, range 0.141-0.188 in C. irulaorum sp. nov.) and wider head (HW/SVL mean 0.182, range 0.180-0.186 versus mean 0.175, range 0.163-0.182 in C. irulaorum sp. nov.).

Description of holotype.

Adult male in good state of preservation except a 4.7 mm vertical incision in the sternal region for liver tissue collection (Fig. 10A, B ). SVL 49.1 mm, head short (HL/SVL 0.25), wide (HW/HL 0.71), not strongly depressed (HD/HL 0.45), slightly narrower than body (HW/BW ratio 0.78), and distinct from neck (Fig. 11A-C ). Loreal region slightly inflated, canthus rostralis not prominent. Snout marginally less than half the head length (ES/HL 0.45), slightly longer than eye diameter (ED/ES 0.52); 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. 11A, C ). Eye small (ED/HL 0.24); pupil vertical, dilated with indistinct crenate margins; supraciliaries short, larger anteriorly, not elongate; interorbital scale rows across narrowest point of frontal 15; 42 scale rows between left and right supraciliaries at mid-orbit (Fig. 11A, C ). Ear-opening oval, small (EL/HL 0.08); eye to ear distance slightly more than eye diameter (EE/ED 1.26). Rostral almost twice wider (2.5 mm) than deep (1.4 mm), incompletely divided dorsally by weakly developed rostral groove for half of its height; a single enlarged supranasal on each side, much larger than postnasals, separated from each other by two enlarged internasals on the snout; three subequal postnasals, much smaller than supranasals; rostral in contact with nostril, supralabial I, supranasals, and internasals on either side; nostrils oval, 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. 11C ). Mental enlarged, triangular, wider (2.0 mm) than long (1.3 mm); two pairs of postmentals; inner pair in strong contact with each other, roughly pentangular and slightly longer than mental (1.2 mm) as mental; bordered by mental, infralabial I, outer postmental and two enlarged chin shields on either side; outer postmentals separated from each other by inner pair, roughly rectangular and half the size (0.8 mm) of inner pair; bordered by inner postmentals, infralabial I and II on either side and three enlarged chin shields on left and four on right 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. 11B ). Ten supralabials up to angle of jaw and seven at midorbital position on each side; eight infralabials up to angle of jaw, and six infralabials at midorbital position on both sides (Fig. 11C ).

Body somewhat slender (BW/AGL 0.56), trunk less than half of SVL (AGL/SVL 0.40) without ventrolateral folds. Dorsal pholidosis on trunk homogeneous; covered with smooth, subcircular, weakly conical granular scales; 17 dorsal midbody scale rows across trunk contained within one eye diameter (Fig. 12A ). Granular scales on occiput and nape slightly smaller 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, subcircular, subimbricate, subequal from chest to vent; 15 ventral midbody scale rows across belly contained within one eye diameter (Fig. 12B ). Scales on throat slightly smaller than those on belly; gular region with much smaller granular scales, those on chin bordering postmentals, enlarged, juxtaposed and flattened (Fig. 11B ). No enlarged precloacal or femoral scales, no precloacal or femoral pores; no precloacal groove (Fig. 10B ). Scales on palm and soles granular, smooth, rounded to oval; scales on dorsal aspects of limbs heterogeneous in shape and size; mixture of small, granules similar to dorsum and many smooth flattened and subimbricate 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. 10A, B ).

Fore-limbs and hind-limbs slightly 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 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: (4-5-6-6-6 right manus, Fig. 13A ; 4 - 6 - 7 - 9 - 7 right pes, Fig. 13B ), (5-5-6-6-6 left manus; 4-6-7-10-7 left pes); distal lamellae series: (8-7-8-6-7 right manus, Fig. 13A ; 8-8 - 9-9-9 right pes, Fig. 13B ), (8-7-8-6-7 left manus; 8-8-9-8-10 left pes).Relative length of digits (measurements in mm in parentheses): III (3.5)> IV (3.2)> II (3.0)> V (2.7)> I (2.2) (right manus); III (4.4)> IV (3.9)> V (3.7) = II (3.7)> I (2.2) (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 0.71). Scales on dorsal aspect of tail base similar to body dorsum except marginally larger; scales on dorsal aspect of tail large flat, subcircular, smooth, and imbricate, becoming slightly larger towards lateral aspect, largest on ventral side, but not forming median row of transversely enlarged subcaudal scales. Three small, smooth, subequal, conical postcloacal spurs on each side of tail base; prominent hemipenal swelling, flap of skin covering cloacal aperture. Tail slightly constricted at the base (Fig. 10A, B ).

Colouration in Life (Fig. 14A).

Dorsal ground colour faded light tan, four pairs of dark brown spots from behind occiput to hindlimb insertions. All spots separated except those forming first pair fused with postocular streak on either side; edged by black on the outer 1-5 rows of scales, finest along flanks; anterior two pairs of spots largest. Flank with 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 eight indistinct black edged brown crossbars reducing in size toward tail-tip. Dorsum of limbs and digits similar in colour to trunk with scattered black spots. Post-occipital collar formed of two brown spots edged with black and a finer light border. Spots on post-occipital collar smaller than the smallest dorsal blotches. Crown slightly darker than 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 longer than two interorbital spots and 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 extends from posterior edge of eye through tympanum and fuses with first pair of spots on the neck, separated from dorsolateral markings of collar; preocular streak extends till nostril. All head markings separated from each other except post-occipital and parietal spots fused on right. Labials with dark streaks, a few unmarked scales finely spotted with black. A fine dark streak extends from angle of jaw onto start of forearm, discontinuous until below anterior edge of ear opening. Ventral aspects dirty white with scattered spots on the lateral edge of the belly and numerous grey streaks and spots on infralabials and gular region; ventral aspect of tail many-coloured with indistinct dark reticulations.

Variation and additional information from paratypes (Figs 14B, C 15A, B).

Mensural and meristic data for the type series is given in Table 3 . There are two adult female specimens, both having same SVL (52.7 mm). All specimens resemble the holotype male (NRC-AA-1274) except for the following variations: single internasal between supranasals behind rostral in both the female paratypes. Inner postmental bordered by mental, infralabial I, outer postmental on either side and bordered by two enlarged chin scales on left and four on right side in NRC-AA-1276. Outer postmental bordered by inner pair, infralabial I and II and three enlarged chin scales on either side in NRC-AA-1275; outer postmental bordered by inner pair, infralabial I and II and two enlarged chin scales on either side in NRC-AA-1276. Both female paratypes with complete but fully regenerated tail, slightly shorter than body (TL/SVL 0.42 in both). Ground colour varies from light khaki to yellowish and brown, dorsal pairs of spots may be fused mid-vertebrally but individual spots from adjacent pairs do not fuse; collar fused in paratypes, post-orbital streak fused with first pair of spots; few dark spots on the flanks; regenerated tail similar to ground colouration with a few spots.

Distribution and Natural History.

Cyrtodactylus (Geckoella) relictus sp. nov. is known from only two localities about 90 km apart and at elevations of 120 m and 170 m (Fig. 1 ). The type locality is at the base of Kambakkam, an isolated massif that reaches a maximum elevation of just over 820 m from a base elevation of 30 m to the east (Fig. 16 ). The paratypes were collected from the eastern slopes at the base of the Velikonda Range that reaches a maximum elevation of over 1100 m from a base elevation of ~150 m in the east. Both collection localities are along streams with riparian gallery forest which cuts through open, arid and scrubby habitats at the type locality and dry evergreen forest at the paratype locality. The holotype was collected in about an hour of search in leaf litter along the stream while the paratypes were collected in about an hour and a half of search with one found in riparian habitat and the other in a patch of dry evergreen forest. The new species is sympatric with the endemic Cnemaspis avasabinae Agarwal, Bauer & Khandekar, 2020 at the paratype locality and an undescribed species of Cnemaspis at the type locality ( Agarwal et al. 2020; Agarwal unpublished data).

Figures

Figure 1. Map showing localities sampled for phylogenetic analyses of members of the Cyrtodactylus (Geckoella) collegalensis complex in southern India and Sri Lanka (C. varadgirii is not shown), stars represent the type localities of the two new species. Light blue, C. irulaorum sp. nov.; dark blue, C. relictus sp. nov.; light green, C. aravindi; brown, C. chengodumalaensis; white fill, C. collegalensis; black, C. speciosus; dark green, C. srilekhae; yellow, C. rishivalleyensis; grey fill, C. yakhuna.

Figure 2. Maximum likelihood phylogeny of the Cyrtodactylus (Geckoella) collegalensis complex with inset showing PCA plots for the three data treatments: A allometric, B raw and C ratios. Other members of the Cyrtodactylus triedrus group are not shown. Posterior probability (≥ 0.98) / ML bootstrap support (≥ 70) for RaXML / IQTree shown at nodes. Note that sequences for CES 09 / 1363 and CES 09 / 1365 are identical to NRC-AA- 1266 and are not shown in the tree (Table 1).

Figure 4. Cyrtodactylus (Geckoella) irulaorum sp. nov. (holotype, NRC-AA- 1266): A dorsal view of head, B ventral view of head, C right side lateral view of head. Scale bars 5 mm; photos by Akshay Khandekar.

Figure 6. Cyrtodactylus (Geckoella) irulaorum sp. nov. (holotype, NRC-AA- 1266): A ventral view of right manus, B ventral view of right pes. Scale bars 5 mm; photos by Akshay Khandekar.

Figure 7. Cyrtodactylus (Geckoella) irulaorum sp. nov. in life: A holotype, NRC-AA- 1266, B paratype, NRC-AA- 1268, C paratype, NRC-AA- 1269, D paratype, NRC-AA- 1270. Photos by Ishan Agarwal.

Figure 8. Paratypes of Cyrtodactylus (Geckoella) irulaorum sp. nov. from left to right, NRC-AA- 1267 - NRC-AA- 1273: A dorsal view, B ventral view. Scale bars 10 mm; photos by Akshay Khandekar.

Figure 9. Habitat photos at type locality of Cyrtodactylus (Geckoella) irulaorum sp. nov.: A farm at base of the hill, from where the holotype and a few paratypes were collected; B a general view from the hill located behind farm, showing the tropical dry evergreen forests. Photos by Akshay Khandekar.

Figure 10. Cyrtodactylus (Geckoella) relictus sp. nov. (holotype, NRC-AA- 1274): A dorsal view of body, B ventral view of body. Scale bars 10 mm; photos by Akshay Khandekar.

Figure 11. Cyrtodactylus (Geckoella) relictus sp. nov. (holotype, NRC-AA- 1274): A dorsal view of head, B ventral view of head, C right side lateral view of head. Scale bars 5 mm; photos by Akshay Khandekar.

Figure 12. Cyrtodactylus (Geckoella) relictus sp. nov. (holotype, NRC-AA- 1274): A dorsal view of midbody, B ventral view of midbody. Scale bars 5 mm; photos by Akshay Khandekar.

Figure 13. Cyrtodactylus (Geckoella) relictus sp. nov. (holotype, NRC-AA- 1274): A ventral view of right manus, B ventral view of right pes. Scale bars 5 mm; photos by Akshay Khandekar.

Figure 14. Cyrtodactylus (Geckoella) relictus sp. nov. in life: A holotype, NRC-AA- 1274, B paratype, NRC-AA- 1275, C paratype, NRC-AA- 1276. Photos by Ishan Agarwal.

Figure 15. Paratypes of Cyrtodactylus (Geckoella) relictus sp. nov. from left to right, NRC-AA- 1275 and NRC-AA- 1276: A Dorsal view, B ventral view. Scale bars 10 mm; photos by Akshay Khandekar.

Figure 16. Habitat photos at type locality of Cyrtodactylus (Geckoella) relictus sp. nov.: A general habitat, B tropical dry evergreen riparian forests around where the new species was collected. Photos by Karanth Lab (A. Datta-Roy, A. Lajmi, V. Deepak).