Six new Cyrtodactylus (Squamata: Gekkonidae) from northeast India
Author
Agarwal, Ishan
Author
Mahony, Stephen
Author
Giri, Varad B.
Author
Chaitanya, R.
Author
Bauer, Aaron M.
text
Zootaxa
2018
2018-11-26
4524
5
501
535
journal article
27911
10.11646/zootaxa.4524.5.1
e3c8fdb6-8f18-470c-8f72-43bcf2effe2a
1175-5326
2610704
B8D8C69B-D05A-4C0F-96D0-46325EC93543
Cyrtodactylus kazirangaensis
sp. nov.
Figs. 6–9
.
Holotype
.
Adult
male (
BNHS 2148
, field number CES09/1137) collected from near
Hatikhuli Tea Estate
,
Golaghat district
,
Assam
state,
India
(
26.57810°N
,
93.40701°E
,
100 m
asl
.) by
Ishan Agarwal
on
11 November 2009
.
Paratypes
.
Adult males (
BNHS 2147
,
BNHS 2149
) bear the same collection data as the holotype
.
Etymology.
The specific epithet is a toponym for Kaziranga National Park, which is adjacent to the
type
locality. Kaziranga, a World Heritage Site, is best known for having most of the world’s surviving Indian onehorned rhinoceros, though it has high biodiversity across taxonomic groups.
Diagnosis.
Cyrtodactylus kazirangaensis
sp. nov.
can be distinguished from all congeners by its moderate body size (SVL to at least 80.0 mm); 11 or 12 supralabials; 9–11 infralabials; 22 or 23 longitudinal rows of rounded, feebly keeled dorsal tubercles; tubercles not extending beyond first segment of tail; 36–38 paravertebral tubercles; 37–43 ventral scales between ventrolateral folds; no precloacal groove; 10 or 11 precloacal pores and no femoral pores in males; 14–19 total subdigital lamellae beneath toe IV of pes; subcaudal scalation of original tail without enlarged plates; dorsal pattern composed of six or seven irregular light and dark crossbars; tail with alternating dark and light bands.
FIGURE 6.
Cyrtodactylus kazirangaensis
sp. nov.
in life (adult male paratype BNHS 2149).
Description of
holotype
.
Holotype
in good preservation condition: tail curved toward left and tail tip removed as tissue voucher, fourth digit of right pes broken at inflection, constriction just anterior to hind limb insertion due to overzealous tag tying. Adult male, SVL 79.0 mm. Head long (HL/SVL 0.27; HW/HL 0.69), somewhat depressed (HD/HW 0.55), distinct from neck; loreal region somewhat inflated, interorbital region flat, canthus rostralis not prominent; snout short (SE/HL 0.45), twice as long as orbital diameter (ED/SE 0.49); scales on snout and canthus rostralis granular, juxtaposed, homogenous in shape, with scales on snout being slightly larger; scales on interorbital region, dorsal surface of eyelids, forehead and occipital region slightly smaller, granular, juxtaposed, with those on forehead and interorbital region interspersed with slightly larger tubercles that are rounded, smooth and two to three times the size of adjacent granules; enlarged tubercles sparse on forehead and dense on occipital region. Eye small (ED/HL 0.22); pupil vertical with crenulated margins; supraciliaries large, decreasing in size towards posterior and anterior ends of orbit, largest about one-third the way from anterior edge of orbit; dorsal surface of eyelids covered with granular scales, row of tubercles bordering supraciliaries absent. Ear opening oval, obliquely oriented, large; eye to ear distance slightly more than eye diameter (ED/EE 0.73). Rostral much wider (
3.2 mm
) than deep (
1.4 mm
), partially divided dorsally by weakly developed rostral groove; single much enlarged supranasal on either side, separated by one slightly smaller, circular internasal, which is twice the size of enlarged scales on snout; rostral in contact with supralabial I, nostrils, supranasals and internasals; nostrils oval, laterally oriented, posterior half covered by a nasal pad, each in broad contact with rostral and surrounded by supranasal, supralabial I, and four smaller, granular postnasal scales; seven rows of granular scales between midorbital position and supralabials; mental wider (
2.8 mm
) than deep (2.0 mm), triangular, two well-developed postmentals on either side, inner pair in broad contact (
1.5 mm
) behind mental, larger (
2.2 mm
) than and separating outer pair (
1.3 mm
); each inner postmental bordered by mental, infralabial I, outer postmental and two enlarged gular scales; outer postmentals bordered by inner postmentals, infralabials I and II, a large, roughly hexagonal scale posteriorly and four gular scales; eight supralabials to midorbital position and 12 to angle of jaw on each side, bordered by a row of flat, somewhat elongated scales, slightly larger than their adjacent granules; 10 infralabials on each side.
FIGURE 7.
Dorsal view (A), ventral view (B), and details of dorsal pholidosis (C) of adult male holotype (BNHS 2148) of
Cyrtodactylus kazirangaensis
sp. nov.
Scale bars 10 mm.
Body slender (BW/TRL 0.42), short (TRL/SVL 0.44); dorsal scales heterogeneous, mostly rounded granules, intermixed with irregularly arranged enlarged tubercles that are rounded and feebly keeled, flatter and more strongly keeled towards vertebral region; tubercles extend from forehead posteriorly onto base of tail; tubercles on nape smaller than those of dorsum; 22 dorsal tubercles across mid dorsum; 36–38 paravertebral tubercles; ventrolateral folds covered by scattered enlarged, smooth scales; ventral scales much larger than dorsals, smooth, rounded, juxtaposed; smaller under thighs; two rows of enlarged subimbricate scales along posterior border of precloacal pores; 39 or 40 ventral scales between ventrolateral folds; gular region with much smaller granular scales throughout, except two rows of larger, flat, juxtaposed scales originating from the posterior margin of the outer postmentals and bordering infralabials. Eleven precloacal pores in a continuous series; femoral pores absent; no precloacal groove; hemipenal bulge distinct.
Fore and hind limbs slender; forearm (FL/SVL 0.15) and tibia (CL/SVL 0.17) short; digits short, strongly inflected at each joint, all bearing robust recurved claws; five subdigital lamellae in basal series and
10 in
distal series with four non-lamellar granules at inflection (digit IV, right manus); eight basal and 11 distal lamellae with four non-lamellar granules at inflection (digit IV, right pes); inter-digital webbing absent on manus, rudimentary between toes I to IV; relative length of digits: I <II <V <III <IV (left manus) and I <II <V <III <IV (left pes); scales on palms and soles smooth, flat, juxtaposed; scales on fore limbs heterogeneous, composed of rounded, granular, juxtaposed scales on upper arms, those on forearms heterogeneous, granular, becoming flat, smooth and subimbricate anteriorly, sparsely interspersed with slightly enlarged rounded tubercles; ventral portion covered mostly with flat, granular, juxtaposed scales; scales on hind limbs heterogeneous, dorsal part of thighs and shanks, with small, slightly pointed granular scales, intermixed with scattered, enlarged, rounded tubercles; ventral aspect of hind limbs with enlarged, smooth, subimbricate scales.
FIGURE 8.
Head of
Cyrtodactylus kazirangaensis
sp. nov.
(adult male holotype, BNHS 2148), dorsal (A), lateral (B), and ventral (C) view. Scale bars 10 mm.
Tail original, tip missing, somewhat rounded, slender, tapering, divided into indistinct segments; six or seven rows of enlarged, flat, weakly pointed, feebly keeled, tubercles on base and first segment of tail only, remaining dorsal caudal scales smooth, rounded, subimbricate, similar in size dorsally but becoming larger on lateral aspect; subcaudal scales larger, smooth, imbricate; with no distinct mid-ventral series of paired scales. Five enlarged, smooth post cloacal spurs on each side.
Colouration in life (for
paratype
BNHS 2149,
Fig. 6
).
Dorsal ground colour of body, limbs and tail brown; top of head pale brown with scattered dark brown streaks; labials darker than dorsum of head; a preorbital streak and two light yellow narrow postorbital streaks that do not extend as far as ear opening; occiput with light yellowbuff blotches; neck with light tan blotches forming indistinct wavy cross-bar flanked by a pair of dark blotches, light mid-dorsal marking extends from occiput to tail base, seven light and seven dark bands from fore limb insertion to tail base; ventral surfaces immaculate; limbs with indistinct crossbars and a few lighter blotches; regenerated tail light brown with dark spots dorsally, light grey and tan ventrally; iris green-brown with darker reticulations, pupil outlined in orange-red
Colouration in preservative (
Figs. 7
&
8
).
Dorsal ground colour of body, limbs and tail brown; top of head mottled brown; labials about as dark as dorsum of head; two indistinct light narrow postorbital streaks that do not extend as far as ear opening, preorbital streak indistinct; occiput with light blotches; neck with light tan blotches forming indistinct cross-shaped marking bar flanked by a pair of dark blotches, light mid-dorsal marking discontinuous from occiput to tail base, seven light and seven dark bands from fore limb insertion to tail base; ventral surfaces immaculate; limbs with indistinct crossbars and a few lighter blotches; regenerated tail light brown with dark spots dorsally, light grey and tan ventrally.
Variation (
Fig. 9
).
Dorsal colour pattern of six or seven irregular light and dark crossbars on types; BNHS 2147 darker in ground colouration, without clear mid-dorsal markings; crown-shaped light marking on nape; regenerated portion of tail dirty brown; ventral surfaces dirty white, subcaudals dark with some lighter, and yellow spots. Both
paratypes
have a continuous series of 10 precloacal pores (
Table 4
).
Distribution and Natural History.
Cyrtodactylus kazirangaensis
sp. nov.
is known only from its
type
locality, which lies at the northern edge of the Mikir Hills. The entrance to Kaziranga National Park is less than
5 km
away, and it is likely that this species also occurs in the park itself. The
type
series was collected together emerging from drainage holes in a concrete wall on the edge of a patch of degraded deciduous forest/plantations, facing a small stream, about an hour after sunset.
Comparisons.
Cyrtodactylus kazirangaensis
sp. nov.
is a member of the lowland clade and differs from other species by 14.7–19.7 % uncorrected genetic distance.
Cyrtodactylus kazirangaensis
sp. nov.
can be diagnosed by the presence of 10 or 11 precloacal pores and absence of femoral pores on males from
C. ayeyarwadyensis
(10–28 PcP–PcFP),
Cyrtodactylus guwahatiensis
sp. nov.
(26 PcFPs in a discontinuous series), and
C. tripuraensis
(29–37 PcFP).
Cyrtodactylus kazirangaensis
sp. nov.
can be further diagnosed by having more ventral scales (37–43 MVSR) than
C. ayeyarwadyensis
(32–37 MVSR).
Cyrtodactylus kazirangaensis
sp. nov.
is very similar morphologically to
C. khasiensis
from which it differs in the ear to eye distance being proportionately less than snout to eye distance (EE/SE 0.67–0.69
vs.
0.70–0.77), and ear to eye distance proportionately less than nostril to eye distance (EE/NE 0.81–0.88
vs.
0.90–1.01).
Cyrtodactylus kazirangaensis
sp. nov.
is diagnosed against
C. septentrionalis
sp. nov.
after its description. Major diagnostic characters for the new species and other regional congeners are summarized in
Table 3
.
Remarks.
Wood
et al
. (2012)
included a specimen of
C.
“
khasiensis
”
(MFA 50083) from “Kaziranga,
Assam
” and the ND2 sequence (
JX440543
) was found to be 99% similar to the sequence (
KM255170
) of the
paratype
of
Cyrtodactylus kazirangaensis
sp. nov.
in a BLAST search (results not shown), and thus is referable to this species. This sequence was also included in
Brennan
et al
’s (2017)
phylogenetic study as
C.
“
khasiensis
”
.