Tropidophorus vongx, Wang & Li & Mu & Xu & Che, 2024

Wang, Kai, Li, Ling, Mu, Hao-Nan, Xu, Sheng-Jing & Che, Jing, 2024, A New Species of the Genus Tropidophorus Duméril, Bibron, 1839 (Reptilia: Squamata: Scincidae) from China-Vietnam Border Region in Southeastern Yunnan Province, China, Zootaxa 5486 (1), pp. 129-141 : 134-139

Tropidophorus vongx sp. nov.

Figs. 3 and 4 ; Table 3 .

Chresonyms

Tropidophorus berdmorei Wang et al. 2022 : Appendix I.

Holotype. KIZ 54236 , adult male from Gulinqing, Maguan County, Wenshan Zhuang and Miao Autonomous Prefecture , Yunnan Province, China (103.990306ºE, 22.738171ºN, elevation 810m). Collected by Kai Wang, Hao-Nan Mu, Sheng-Jing Xu, Zhi-Ying Wang, and Dan-Yang Zhou on 11 August, 2023.

Paratype. KIZ 55737 , adult female from the same locality as the holotype. Collected by Xiang-Jin Liu on 4 November 2023.

Diagnosis. The new species can be diagnosed from congeners by a combination of the following characters: (1) SVL 90.9–102.8mm in adults; (2) head triangular, distinctively swollen at jaw, HW 90.7% HL; (3) head, body, and tail distinctively compressed, HD 67.2% HW, BD 9–10% SVL, TALD 9% SVL; (4) head scales smooth dorsally and anterolaterally, weakly keeled posterolaterally; (5) supralabials 7, infralabials 5–6, each bearing a single lateral keel; (6) frontonasal divided; (7) paravertebral scales smooth or only feebly keeled, not widen, 56–59; (8) dorsolateral and lateral body scales distinctively keeled; (9) midbody scale rows 28; (10) ventrals 48–49; (11) lamellae under fourth finger 13–15, lamellae under fourth toe 19–21; (12) scale rows at 10 th subcaudal 11–12; (13) in male, dorsal background Raw Umber (Color 280), with Cinnamon (Color 255) to Light Orange Yellow (Color 77) transverse streaks and spots, ventral surface Light Orange Yellow (Color 77); and in female, dorsal color uniformly Vandyke Brown (Color 281) without pattern, ventral surface uniform Smoky White (Color 261).

Comparisons. The new species T. vongx sp. nov. is morphologically most similar to, geographically closest to, and phylogenetically close to T. murphyi , but differs from T. murphyi by having a larger body size (SVL 90.9mm vs. 62.4–85.1mm in males; 102.8 mm vs. 79.3–95.6mm in females), frontonasal divided (vs. undivided), more supralabial scales (SL 7 vs. 6), fewer scale rows at midbody (SRMB 28 vs. 30–32), and fewer ventral scale rows (VEN 48 or 49 vs. 56–59).

Of the other two species in the same clade, T. vongx sp. nov. is most similar to T. baviensis , as both species have a wide head and dorsoventrally compressed body form; however, the new species differs from T. baviensis by having a larger body size (SVL 90.9mm vs. 55.7–71.5mm in males; 102.8mm vs. 83.2–84.9mm in females), more supralabial scales (SL 7 vs. 6), and frontonasal divided (vs. undivided), and a different ventral coloration in males (Light Orange Yellow [Color 77] vs. cream white). Tropidophorus vongx sp. nov. differs from T. hainanus by having a larger body size (SVL 90.9mm vs. 39.1–44.3mm in males; 102.8mm vs. 43.9–55.7mm in females), head distinctively swollen at jaw (vs. not swollen), scales on head dorsum smooth (vs. keeled), frontonasal divided (vs. undivided), and a different ventral coloration in males (Light Orange Yellow [Color 77] vs. cream white).

Among other species that are distributed in proximity in southwestern China and northern Vietnam, T. vongx sp. nov. differs from T. berdmorei by having a larger body size (SVL≥ 90.9 mm vs. ≤ 83.2 mm), much flatter body shape (vs. only slightly compressed dorsally), and distinctively keeled scales on lateral body and around the tail (vs. smooth or only feebly keeled); from T. microlepis and T. sinicus , by having a larger body size (in males, SVL 90.9mm vs. 63.8–68.5mm in T. microlepis , 54.3–60.4mm in T. sinicus ; in females, 102.8mm vs. 66.8–67mm in T. microlepis , 55.2–66.8mm in T. sinicus ), fewer scale rows at the 10 th subcaudal scale (11–12 vs. 13–15), and smooth scales on the head dorsum (vs. keeled).

From two other species that are morphologically similar (e.g., having a distinctively swollen jaw and relatively large body size) but distantly related phylogenetically, T. vongx sp. nov. differs from T. matsuii by having a more flattened body shape (extremely compressed vs. moderately compressed), a paravertebral scales not wider than adjacent rows (vs. wider), fewer scale rows at midbody (28 vs. 34), and fewer paravertebral scale rows (56–59 vs. 65); and from T. latiscutatus by having a more flattened body shape (extremely compressed vs. moderately compressed), frontonasal scale divided (vs. undivided), and a paravertebral scales not wider than adjacent rows (vs. widen).

Description of holotype.––Body size large, SVL 90.9mm, strongly compressed dorsally; tail complete, only broken after capture toward posterior tip, slightly longer than body, TAL 112.0% SVL, compressed dorsally at base; head dorsally compressed, HD 61.1% HL, triangular, distinctively swollen at jaw, longer than wide, HW 91.0% HL. Rostral rectangular, slightly visible dorsally, longer than wide; nasal diamond shaped, larger than first supralabial, nare situated centrally; loreals smooth, anterior loreal two, stacked vertically, both bordering nasal anteriorly, upper anterior loreal bordering frontonasal dorsally, lower anterior loreal bordering second supralabial ventrally; posterior loreal larger, four times larger than anterior loreals combined, bordering prefrontal dorsally, first supraocular posterodorsally, second and third supralabials ventrally; suboculars two, arranged longitudinally, anterior subocular bordering posterior loreal; posterior subocular bordering anteroventral margin of eye; shallow groove along loreal-supralabial border, extending to posterior subocular; eye moderate, lower eyelid with eight somewhat rectangular, semitransparent scales; supraciliary narrow rectangular shape, six or seven; supralabials seven, first smallest, fourth largest, first six bearing a single lateral keel, fourth and fifth entering orbit; remaining lateral head scales moderately keeled. Dorsal head scales smooth; frontonasal divided by a transverse suture, posterior half pentagonal with posterior tip; prefrontals near pentagonal, not in contact medially; frontal spear-shaped, anterior angle obtuse, posterior extension long, bordering anterior two supraoculars and frontoparietals; supraoculars four, together forming tear-drop shaped convex area, third widest,largest and bordering frontoparietal, last bordering parietal; frontoparietals rectangular, narrow, aligned obliquely to form an inverted V shape; interparietal spear-shaped, tip pointing posteriorly direction longer than anterior projection; parietals large, somewhat rectangular, separated from each other by interparietal.A single pair of enlarged nuchals; remaining dorsal body scales juxtaposed, mostly homogeneous in size, near rhombus-shaped; each dorsal bearing a single weak lateral keel, four medial paravertebral rows smooth or feebly keeled; paravertebral scale count 56; lateral body scales smaller than dorsals, slightly imbricate, more strongly keeled, each bearing single lateral keel and somewhat aligned in lateral rows, raised posteriorly and conical, giving spiky appearance,, fan-shaped; scale rows around midbody 28. Forelimb scales strongly keeled all around, keels aligned in longitudinal rows; hindlimb scales strongly keeled dorsally only, smooth or feebly keeled ventrally; dorsal scales of crus raised toward posterior tip; limbs pentadactyl, subdigital lamellae transversely expanded, smooth or feebly keeled.

Mental rectangular, four times wider than long; postmental single, large, near-pentagonal, tip pointing posteriorly; two pairs of enlarged chin shield; remaining gulars smooth or feebly straite; posteroventral head with a diagonal wound. Ventral body scales smooth or slightly straite, larger than gulars and lateral body scales, similar size to dorsals, ventrals 48; precloacal scale flat, large, about four times larger than ventrals, divided; subcaudals in a singular row, expanded transversely, each with keels bilaterally, larger than dorsal and lateral caudal scales.

In life, dorsal and lateral background Raw Umber (Color 280), nine Cinnamon (Color 255) to Clay Color (Color 18) transverse streaks on dorsum from neck to cloaca, some irregular shaped, disconnected medially; three pairs Cinnamon (Color 255) to Clay Color (Color 18) spots on each side of dorsolateral body between neck and posterior side of axilla. Single Light Chrome Orange (Color 76) to Light Orange Yellow (Color 77) spot on second and fourth supralabials, single Sayal Brown (Color 41) spot on fifth supralabial; last supralabial and two scales above it Light Orange Yellow (Color 77) to Sayal Brown (Color 41); scale clusters anterior and posterior to tympanum and on lateral neck Light Orange Yellow (Color 77). Limbs dorsally striped or spotted, Light Orange Yellow (Color 77) to Sayal Brown (Color 41), ventrally Buff (Color 15). Ventral background Light Orange Yellow (Color 77), gulars with Pale Buff (Color 1) speckles or short streaks and Raw Umber (Color 280) edges, ventral body scales with irregular Raw Umber (Color 280) edges, particularly along anterior medial line. Tail venter speckled, anteriorly Light Orange Yellow (Color 77), transitioning posteriorly to Sayal Brown (Color 41) and eventually Raw Umber (Color 280).

Variation. Morphometric and scalation variation is given in Table 3 . The female paratype is larger than the male holotype, and sexual dichromatism is evident: the dorsal coloration of the female is uniformly Vandyke Brown (Color 281) without pattern, and the ventral surface is uniformly Smoky White (Color 261).

Etymology. The new species name, vongx , is derived from the local language of the Miao People, which is one of the main ethnic minority groups at the type locality of the new species, and it means “dragon”. We name the new species using this word in the Miao language not only because the new species resembles a miniature dragon, but also because the dragon is an important mythological figure in local Miao culture: Yangl Vongx, meaning “Calling for Dragon”, is a major festival for Miao People celebrated every 12 years, where they sacrifice livestock and set fireworks to worship dragons, in the hope that dragons will visit them in the coming years and bring proper rains for the crops. We suggest “ ḄỆ棱# ” (Pinyin: Zhao Long Leng Xi) as its Chinese common name, and Dragon Water Skink as its English Common name.

Distribution and natural history. The new species inhabits tropical karst forest. The holotype was found in a narrow rock crevice at night where the individual anchored itself deep inside ( Fig.4 ), and the rock was in close proximity to small streams. The paratype was found on the forest floor at night. Acanthosaura lepidogaster , Cyrtodactylus gulingqingensis , Calotes emma , Cuora mouhtii were found sympatric with the new species at the type locality. Currently it is known from the type locality and the adjacent Hekou County in Honghe Prefecture, southeastern Yunnan Province, China (personal communication with Mr. Miao Benfu), and it is very likely to inhabit the border region in Lao Cai Province of northwestern Vietnam as well.

Figures

FIGURE 3. Holotype (KIZ 54236) and paratype (KIZ 55737) of Tropidophorus vongx sp. nov. in life. Photos by KW.

FIGURE 4. Detailed closeup views of the holotype (KIZ 54236, A–C) and paratype (KIZ 55737, D–F) of Tropidophorus vongx sp. nov. in life, showing lateral head, dorsal head, and lateral body. Photos by KW.

Tables

TABLE 3. Detailed morphometric and pholidosis characters of the type series of Tropidophorus vongx sp. nov.. Morphometric characters are listed in bold. Abbreviations see Materials and method in text.

Voucher number	KIZ 54236	KIZ 55737	Voucher number	KIZ 54236	KIZ 55737
Type status	Holotype	Paratype	Type status	Holotype	Paratype
Sex	M	F	Sex	M	F
SVL	90.9	102.8	FL	13.5	13.4
TAL	101.8	116.8	HLL	41.0	41.8
HL1	15.8	16.3	TRL	52.8	48.0
HL2	19.5	18.5	PCW	14.4	13.5
STL	17.8	18.4	PLW	14.3	14.0
HW	14.4	16.1	MTBW	23.2	19.8
HD	9.7	10.0	MTBD	9.7	9.4
IODA	6.4	6.8	TALD	9.4	8.6
IODP	9.6	10.2	SL	7/7	7/7
SEL	6.7	6.5	IL	6/6	5/5
IN	2.8	2.8	LOR	1/1	1/1
TDH	1.8	1.5	PNS	2/2	2/2
TDV	2.9	2.1	SUO	4/4	4/4
ED	5.1	6.1	SUC	7/7	6/7
EH	1.7	2.0	NU	1	1
ETD	6.8	7.9	CS	3	3
SnL	31.1	35.2	SRMB	28	28
FAL	21.06	20.48	PVS	56	59
BL	9.59	9.55	VEN	48	49
FLL	30.65	30.03	SCR10	11	12
TFL	28.38	27.55	F4S	15/13	15/15
			T4S	21/21	19/19