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ZOOTAXA
ISSN 1175-5326 (print edition)
ISSN 1175-5334 (online edition)
Accepted by A. Datta-Roy: 1 Jul. 2024; published: 24 Jul. 2024 129
Zootaxa 5486 (1): 129–141
https://www.mapress.com/zt/
Copyright © 2024 Magnolia Press Article
https://doi.org/10.11646/zootaxa.5486.1.6
http://zoobank.org/urn:lsid:zoobank.org:pub:844C10B1-309E-4D22-9D3B-7A8DC716E51B
A New Species of the Genus Tropidophorus Duméril, Bibron, 1839 (Reptilia:
Squamata: Scincidae) from China-Vietnam Border Region in Southeastern
Yunnan Province, China
KAI WANG1,2,5#, LING LI1,6#, HAO-NAN MU1,3,7, SHENG-JING XU4,8 & JING CHE1,2,9*
1Key Laboratory of Genetic Evolution and Animal Models, and Yunnan Key Laboratory of Biodiversity and Ecological Conservation of
Gaoligong Mountain, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, 650223, China
2Southeast Asia Biodiversity Research Institute, Chinese Academy of Sciences, Yezin, Nay Pyi Taw, 05282, Myanmar
3Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming 650204, China
4College of Forestry, Southwest Forestry University, Kunming 650224, China
5
�
wangkai@mail.kiz.ac.cn; https://orcid.org/0000-0002-6736-3346
6
�
liling8514@163.com; https://orcid.org/0000-0002-7650-2280
7
�
muhaonan@mail.kiz.ac.cn; https://orcid.org/0009-0003-4081-3380
8
�
chengqingyan070@163.com; https://orcid.org/0009-0005-6703-535X
9
�
chej@mail.kiz.ac.cn; https://orcid.org/0000-0003-4246-6514
#Authors contributed equally
*Corresponding author.
Abstract
Based on morphological and genetic data, we describe a new species of Tropidophorus from the tropical karst landscape
in southeastern Yunnan Province, China, close to the Vietnam border. Phylogenetically, the new species forms a clade
with T. baviensis, T. murphyi, and T. hainanus, with p-distances ranging from 4.7–5.1% for the 16S gene and 3.9–6.8%
for 12S gene. Morphologically, the new species shares the karst morphotype of Tropidophorus, particularly similar as
T. murphyi and T. baviensis, in which all having a dorsally compressed head and body, smooth dorsal head scales, and
distinctively keeled body scales. However, the new species can be distinguished from these similar species by numbers
of supralabial scales, ventral scales, scales around the tail at the10th subcaudal, and a larger body size. We emphasize the
urgency of conservation for the tropical karst landscape in northern Indochina.
Key words: cryptic species, conservation, Sphenomorphinae, Vietnam, water skink
Introduction
Water Skinks of the genus Tropidophorus are a diverse group of semi-aquatic skinks that inhabit tropical and
subtropical regions in Indochina and Southeast Asia, with 29 species currently recognized (Pui et al. 2017; Uetz
et al. 2024). While the majority of the recognized diversity occurs in southern Indochina, eight species have been
reported in northern Indochina and southern China, including four species from China [T. berdmorei (Blyth, 1853),
T. guangxiensis Wen, 1992, T. hainanus Smith, 1923, and T. sinicus Boettger, 1886] (Zhao et al. 1999; Guo et
al. 2021), three from Laos [T. baviensis Bourret, 1939, T. microlepis Günther, 1861 and T. laotus Smith, 1929]
(Chuaynkern et al. 2005; Okabe et al. 2020), and six from northern Vietnam (T. baviensis, T. berdmorei, T. hainanus,
T. microlepis, T. murphyi Hikida, Orlov, Nabhitabhata, Ota, 2002, and T. sinicus) (Truong et al. 2010).
While Northern Vietnam is a hot spot for Tropidophorus diversity, with many karst specialists that are nearly
sympatric and share a distinctive morphology (Hikida et al. 2002; Truong et al. 2010), only a single species, T.
berdmorei, has been previously reported from the bordering southeastern Yunnan Province of China (Wang et al.,
2022). As karst habitat is continuous and extensive from southeastern Yunnan to northern Vietnam, the diversity of
the genus in southeastern Yunnan near the Vietnam border is likely underestimated.
During herpetological surveys of southeastern Yunnan Province in 2023, two specimens of Tropidophorus were
collected from Maguan County, Wenshan Prefecture, Yunnan Province, near the Vietnam border. Morphological
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130 · Zootaxa 5486 (1) © 2024 Magnolia Press
comparison shows that this Chinese population resembles species of the large karst-form of the genus, but it differs
from those and all remaining recognized species by a suite of morphological characters as well as considerable
genetic divergence. Therefore, we describe the Chinese population from Wenshan as a new species.
Materials and methods
Sampling. A total of two specimens of Tropidophorus were collected from Gulinqing Provincial Nature Reserve in
Maguan County, Wenshan Prefecture, southeastern Yunnan Province, China (Fig. 1). Liver tissues were taken and
fixed in 95% ethanol after euthanasia, and specimens were fixed in 10% formalin and transferred to 75% ethanol for
long-term storage. Both newly collected specimens were deposited at the Zoological Museum of Kunming Institute
of Zoology, Chinese Academy of Sciences (KIZ). Morphological data for congeners were taken from the literature
(Zhao et al. 1999; Hikida et al. 2002, 2003; Chuaynkern et al. 2005; Hartmann et al. 2009; Truong et al. 2010;
Nguyen et al. 2010; Guo et al. 2021) and through examination of additional specimens (Appendix I).
FIGURE 1. Type localities of Tropidophorus near China-Vietnam border region. Red star: Tropidophorus vongx sp. nov.;
yellow circle: T. baviensis; blue circle: T. murphyi; and purple circle: T. hainanus.
Morphological data. Morphometric characters were measured with a digital caliper to a precision of 0.1mm,
while scalation characters were examined under a dissection microscope. Morphometric characters were: snout–vent
length (SVL), from tip of snout to posterior edge of precloacal plate; tail length (TAL), posterior edge of precloacal
plate to tip of tail; head length (HL), tip of snout to posterior end of parietal scale; head width (HW), as linear distance
TROPIDOPHORUS VONGX SP. N OV. Zootaxa 5486 (1) © 2024 Magnolia Press · 131
perpendicular to midline across widest point of head; head depth (HD), perpendicular distance between dorsal and
ventral surfaces of head at deepest point; snout-tympanum distance (STD), tip of snout and medial-anterior most
edge of the tympanum; snout-eye distance (SEL), tip of snout and anterior corner of eye; internarial distance (IN),
dorsally between dorsomedial margins of nares; vertical tympanum diameter (VTD), greatest vertical diameter of
tympanum; horizontal tympanum diameter (HTD), greatest horizontal diameter of tympanum; eye diameter (ED),
horizontal diameter of eye at level of palpebral margin; eye-tympanum distance (ETD), posterior corner of eye and
anterosuperior corner of tympanum; anterior interorbital distance (IODA), dorsally between anterior corners of
eyes; posterior interorbital distance (IODP), dorsally between posterior corners of eyes; snout–limb distance (SnL),
tip of snout along midline to level of anterior edge of forelimb with limbs at right angles to body; forearm length
(FAL), tip of finger IV (excluding claw) to extensor side of elbow when forelimb was bent; brachium length (BL),
extensor side of elbow to posterior side of forelimb insertion point with limb held at a right angle to the body wall;
forelimb length (FLL), sum of FAL and BL; tibia–foot length (TFL), knee to tip of toe IV (excluding claw) when
foot straightened; femur length (FL), anterior hind limb insertion point to the patella-tibia joint when limb held at
a right angle to the body wall; hind limb length (HLL), sum of TFL and FL; trunk length (TRL), between axilla
(posterior insertion point of forelimb to the body wall) and groin (anterior insertion point of hind limb to the body
wall) when limbs held at right angel; pectoral width (PCW), dorsally between axillae; pelvis width (PLW), dorsally
between groins; mid-trunk body width (MTBW), dorsally, perpendicular to the vertebral line at midpoint of trunk;
mid-trunk body depth (MTBD), perpendicularly between dorsal ventral surfaces of body at midpoint of trunk; tail
depth (TALD), perpendicularly between dorsal and ventral surfaces of tail at level of vent. All paired measurements
were taken on the left side of the body.
Pholidosis characters included the numbers of: supralabial scales (SL), from first scale posterior to rostral to last
enlarged scale along upper lip; infralabial scales (IL), from first scale posterior to mental to last enlarged scale along
lower lip; loreal scales (LOR), vertical scales between nasal and presubocular; supraocular scales (SUO), enlarged
supraocular scales bordering frontal, frontoparietal and parietal; supraciliary scales (SUC), small rectangular scales
inferior to and bordering supraoculars; nuchal scales (NU), enlarged scales posterior to parietals; chin shields (CS),
pairs of enlarged scales posterior to postmental scale; scale rows at mid body (SRMB), transverse scale rows
around body at level of mid-trunk; paravertebral scales (PVS), from first nuchal to the scale above level of vent
along dorsal midline; ventral scales (VEN), along ventral midline from and including the postmental scale to the
last scale anterior to precloacal plate; scale rows at 10th subcaudal (SCR10), scale rows around tail at the level of
10th subcaudal scale, including subcaudals; subdigital lamellae under finger IV (F4S), from base of finger to tip,
excluding claw; and subdigital lamellae under toe IV (T4S), from base of the toe to tip, excluding claw. Color names
and codes for coloration followed Köhler (2012).
Phylogenetic analyses
Molecular data and phylogenetic analysis. Total genomic DNA was extracted from their liver tissues using
TSINGKE Animal DNA Extraction Kit (Universal). Fragments of mitochondrial (mt) DNA loci, 12S and 16S, were
amplified using published universal primers and PCR conditions for vertebrate species (Kocher et al. 1989). All the
DNA extractions, PCR amplifications and sequencing steps were taken by Beijing Tsingke Biotech Company.
In addition to the two new sequences produced in this study, matching gene sequences of recognized congeners
were downloaded from Genbank. The outgroup selection, which included a single species of Lygosoma (Appendix
1), followed Guo et al. (2021). All sequences were aligned using MAFFT v. 7.310 (Katoh et al. 2013) with a “auto”
argument on Linux system, with additional manual edition. Uncorrected genetic pairwise distances (p-distance)
were calculated using MEGA v. 7.0.26 (Kumar et al. 2016). The final alignment matrix contained 27 sequences of
1298bp, representing 25 species.
Both Bayesian inference (BI) and Maximum Likelihood (ML) analyses were performed using a non-partitioned
strategy. For the Bayesian inference, the best scheme of substitution models was firstly estimated according to
Bayesian Information Criterion (BIC) using PartitionFinder v. 2.1.1 (Lanfear et al. 2017), and the BI tree was
estimated using MrBayes v. 3.2.7a (Ronquist et al. 2012), using the following settings: two independent Markov
Chain Monte Carlo analyses with default parameters, each with four Metropolis-coupled chains; for each run, 10
million generations of analysis were conducted and were sampled every 1000 generations. The final 25% samples
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132 · Zootaxa 5486 (1) © 2024 Magnolia Press
from the beginning were discarded as burnin. Both runs were checked for convergence using Tracer v. 7.1.1 (Rambaut
& Drummond 2003) by the criterion of ESS>200 and the similarity of posteriori distributions of two runs.
TABLE 1. Genbank accession numbers of samples used in this present study. New sequences are indicated in bold, and
“-” indicates missing data.
Species voucher ID 12S rRNA 16S rRNA Sample localities Reference
Tropidophorus vongx
sp. nov.
KIZ 54236 PP883960 PP883962 Gulingqing, Wenshan
Prefecture, Yunnan Province,
China
Present study
KIZ 55737 PP883961 PP883961
T. apulus - AY308473 AY308322 - Schmitz 2003
T. baconi KUZR 38805 AB222937 AB222953 Sulawesi Honda et al.
2006
T. baviensis ROM 25552–3 AB222942 AB222958 Ha Tay, Vietnam
T. beccarii KUZR 35005 AB222935 AB222951 Sarawak, Borneo,
T. berdmorei - AB028811 AB028823 Phu Luang, Thailand, Honda et al.
2000
T. boehmei - - GU550104 Mt. Hoang Lien, Lao Cai,
northern Vietnam
Nguyen et al.
2000
T. brookei KUZR 19008 AB222933 AB222949 Sarawak, Borneo Honda et al.
2006
T. cocincinensis ROM 32129 AB222943 AB222959 Gia Lai, Vietnam
T. grayi KUZR 51147 AB222941 -Philippines
T. guangxiensis GKJ2019009 MW413385 MW411360 Mt. Daming, Zhejiang, China Guo et al.
2021
T. hainanus - AB222944 AB222960 Philippines
Honda et al.
2006
T. latiscutatus KUZR 40256 AB222934 AB222950 Phu Wua, Thailand
T. matsuii KUZR 40540 AB222936 AB222952 Phu Pa Namtip, Thailand
T. microlepis - AB222947 AB222963 Indochina
T. micropus P1168 KY488452 KY488456
Putai, upper Sungei Baleh,
Kapit District, Sarawak,
Malaysia
Pui et al. 2017
T. misaminius KUZR 59084 AB222948 AB222964 Mindanao, Philippines Honda et al.
2006
T. murphyi ROM 41223-4 AB222945 AB222961 Cao Bang, Vietnam
T. noggei - - EF611186 - Ziegler et al.
2007
T. partelloi KUZR 60096 AB222946 AB222962 Mindanao, Philippines Honda et al.
2006
T. robinsoni MNHN 1999–7694 AB222939 AB222955 Phang-Nga, Thailand
T. sebi P1166 KY488450 KY488454
Putai, upper Baleh, Kapit
district,Sarawak, East
Malaysia
Pui et al. 2017
T. sinicus KUZR 37673 AB222938 AB222954 Hong Kong, China Honda et al.
2006
T. thai KUZR 27510 AB222940 AB222956 Doi Suthep, Thailand
Lygosoma koratense - AY308421 AY308269 - Schmitz 2003
Lygosoma koratense - AB028805 AB028817 Thailand Honda et al.
2000
IQTREE v. 2.2.0.3 (Minh et al. 2020) were used to calculate the ML tree. The best substitution model for the
whole alignment was chosen using ModelFinder according to Bayesian Information Criterion (Kalyaanamoorthy et
al. 2017). To measure the reliability of each phylogenetic node in the ML tree, the ultrafast bootstrap (UFBoot) and
SH-aLRT test were performed (Minh et al. 2013; Anisimova et al. 2011), both of which performed 1000 iterations,
to generate two values of nodal support. A node is considered robust if SH-aLRT≥ 80% and UFBoot≥ 95%.
TROPIDOPHORUS VONGX SP. N OV. Zootaxa 5486 (1) © 2024 Magnolia Press · 133
FIGURE 2. Mitochondrial geneology of the genus Tropidophorus inferred from 12S and 16S genes using both Bayesian (BI)
and Maximum Likelihood (ML) methods. Bayesian posterior probabilities (BPP) are mapped on the ML topology. For each
node, three nodal support values are given, which are Bayesian posterior probabilities/ultrafast bootstrap/SH-aLRT. Lygosoma
koratense was used as the outgroup to root the tree.
Results
Phylogenetically, the two individuals of Tropidophorus from southeastern Yunnan Province form a clade with respect
to other recognized species (posterior probability 1.0/UFBoot 100/SH-aLRT 100/, given in this order subsequently),
and the two individuals are nearly identical in terms of genetic divergence (0% for 16S, 0.8% for 12S). This clade
is basal to the clade containing T. hainanus and T. baviensis (0.99/88.8/95), and together they form a clade with
T. murphyi (1.00/100/100). The uncorrected genetic distance between the southeastern Yunnan population and
recognized species ranges between 3.9–9.2% for 12S and 4.7–9.8% for 16S, with the shortest distance being with
T. murphyi (Table 2).
Morphologically, the two individuals from southeastern Yunnan Province are nearly identical in terms of
external morphology, resembling the karst-dwelling form of the genus Tropidophorus: having a large body size,
extremely dorsoventrally compressed body, smooth dorsal head scales, and distinctively keeled dorsal and lateral
body scales (Figs. 3 and 4). The only exception is that they have different coloration (details see variation section
below). In comparison to congeners of the same karst morphotype from nearby regions in northern Indochina, these
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134 · Zootaxa 5486 (1) © 2024 Magnolia Press
two individuals from southeastern Yunnan Province differ by having a larger body size and differential pholidosis
characters (details see comparison section below).
Therefore, considering its phylogenetic position, considerable genetic divergence to closest relatives, as well as
distinct morphology, we describe the southeastern Yunnan population as a new species.
TABLE 2. Uncorrected genetic distances based on and 817bp of 16S (top) and 420 bp of 12S (bottom) genes between
Tropidophorus vongx sp. nov. and closely related congeners. “-” indicate missing data for 12S gene.
1 2 3 4 5 6 7 8
1Tropidophorus vongx
sp.nov.
0
0.008
2T. baviensis 0.051
0.065–0.068
3T. berdmorei 0.096
0.089–0.92
0.094
0.084
4T. boehmei 0.086
-
0.066
-
0.090
-
5T. hainanus 0.047
0.052–0.055
0.043
0.039
0.084
-
0.074
0.076
6T. latiscutatus 0.105
0.086–0.089
0.094
0.084
0.094
-
0.074
0.073
0.098
0.076
7T. matsuii 0.098
0.089–0.092
0.090
0.086
0.090
-
0.066
0.086
0.096
0.084
0.039
0.052
8T. murphyi 0.047
0.039–0.042
0.051
0.037
0.088
-
0.076
0.073
0.041
0.039
0.090
0.073
0.086
0.081
9T. noggei 0.088
-
0.080
-
0.098
-
0.070
-
0.084
-
0.047
-
0.049
-
0.080
-
Taxonomic account
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
TROPIDOPHORUS VONGX SP. N OV. Zootaxa 5486 (1) © 2024 Magnolia Press · 135
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 10th 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).
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.
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136 · Zootaxa 5486 (1) © 2024 Magnolia Press
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
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 10th subcaudal scale (11–12 vs. 13–15), and smooth
scales on the head dorsum (vs. keeled).
TROPIDOPHORUS VONGX SP. N OV. Zootaxa 5486 (1) © 2024 Magnolia Press · 137
FIGURE 5. Macro- (A) and micro-habitat (B) of Tropidophorus vongx sp. nov. in Gulingqing, Maguan County, Wenshan
Prefecture, China.
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
WANG ET AL.
138 · Zootaxa 5486 (1) © 2024 Magnolia Press
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.
TABLE 4. Morphological comparison between Tropidophorus vongx sp. nov. and closely related congeners from northern
Indochina. M: male; F: female. “-” indicates missing data. Morphological data of congeners were taken from literature.
Species Tropidophorus
vongx sp. nov
T. baviensis
(Nguyen et al.
2010; Okabe et al.
2020)
T. latiscutatus
(Hikida et al.
2002; Nguyen et
al. 2010)
T. matsuii
(Hikida et al.
2002; Nguyen et
al. 2010)
T. murphyi
(Hikida et al.
2002; Nguyen et
al. 2010)
Snout-vent length
(mm)
M: 90.9
F: 102.8
M: 55.7–71.5
F: 83.2–84.9
(also combined
and given as 80-91
by Ngo et al. 200)
M: 82.1–94.3
F: 93.8–102.0 M: 94.1 M: 62.4–85.1
F: 92.2–96.3
Body compression Extreme Slight Moderate Moderate Extreme
Midbody scale rows 28 28–30 28–30 34 30–32
Frontonasal divided undivided undivided divided undivided
Paravertebrals
widened No No Yes No No
Paravertebrals 56–59 47–53 58–63 65 59–67
Supralabials 7 6 6 6 6
Male ventral color Light Orange
Yellow Cream Yellowish ivory Yellowish ivory Yellowish ivory
Female ventral
color Smoky White Cream Yellowish ivory - Yellowish ivory
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
TROPIDOPHORUS VONGX SP. N OV. Zootaxa 5486 (1) © 2024 Magnolia Press · 139
the crops. We suggest “招龙棱蜥” (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.
Discussion
The tropical karst forests in northern Indochina, particularly at mid to low elevations, have been shown to serve as
the key habitat for many micro-endemic species (Schneider et al. 2014; Luu et al. 2016; Sitthivong et al. 2023).
Although several natural reserves were established in the region, many nearby regions are still vulnerable to human
deconstruction. In Yunnan Province, rubber-tree plantations have been a major cause of deforestation. Future
conservation focus should be directed toward these vulnerable regions outside of the reserves to better conserve the
unique karst biodiversity.
Our discovery hints at underestimated diversity of the genus Tropidophorus in northern Indochina, with many
species having very limited distributions. However, two taxa, T. berdmorei and T. laotus, have wide distribution
ranges across Indochina, but only limited data on their phylogenetic structure are available. Future studies should
focus on assessing variation in these two species to ensure that they do not contain additional cryptic species.
Acknowledgment
Collection of all animals used for this present study abides by the Wildlife Protection Act of P.R. China. Research
approvals were issued by the Kunming Institute of Zoology, Chinese Academy of Sciences (2019QZKK05010104).
We followed protocols of the Animal Care and Ethics Committee of the KIZ for the proper treatments of
animals in the field. This project is supported by grants from National Key R&D Program of China (Grant No.
2022YFC2602500), the Yunnan Revitalization Talent Support Program Yunling Scholar Project, and the Animal
Branch of the Germplasm Bank of Wild Species, Chinese Academy of Sciences (the Large Research Infrastructure
Funding) to J.C.; and Yunnan Revitalization Talent Support Program Young Talent Project, CAS Special Research
Assistant (SRA) Program, and the Program of Yunnan Forestry and Grassland Administration (2022GF258D-10)
to K.W.. We thank Mr. Dan-Yang Zhou and Xiang-Jin Liu, Ms. Zhi-Ying Wang, and staff at Maguan Gulinqing
Provincial Natural Reserve for their supports during fieldwork.
References
Chuaynkern, Y., Nabhitabhata, J., Inthara, C., Kamsook, M. & Somsri, K. (2005) A new species of the water skink Tropidophorus
(Reptilia: Squamata: Scincidae) from northeastern Thailand. Thailand Natural History Museum Journal, 1, 165–176.
Guo, K.J., Shu, F., Wu, N.F., Chen, S.D., Hou, M., Shi, S.C. & Deng, X.J. (2021) Neotype designation and redescription of
Tropidophorus guangxiensis Wen, 1992 (Squamata: Sauria: Scincidae), with description of a new subspecies from central
South China. Zoological Research, 42 (5), 606–613.
https://doi.org/10.24272/j.issn.2095-8137.2020.363
Hartmann, T., Chipich, H., Handschuh, M., Nguyen, Q.T. & Böhme, W. (2009) First record of Tropidophorus cocincinensis
Duméril and Bibron, 1839 from Cambodia. Herpetology Notes, 2, 87–89.
Hikida, T., Orlov, N.L., Nabhitabhata, J. & Ota, H. (2002) Three new depressed-bodied water skinks of the genus Tropidophorus
(Lacertilia: Scincidae) from Thailand and Vietnam. Current Herpetology, 21 (1), 9–23.
https://doi.org/10.5358/hsj.21.9
Hikida, T., Riyanto, A. & Ota, H. (2003) A new water skink of the genus Tropidophorus (Lacertilia: Scincidae) from Sulawesi,
Indonesia. Current Herpetology, 22 (1), 29–36.
https://doi.org/10.5358/hsj.22.29
WANG ET AL.
140 · Zootaxa 5486 (1) © 2024 Magnolia Press
Honda, M., Ota, H., Murphy, R.W. & Hikida, T. (2006) Phylogeny and biogeography of water skinks of the genus Tropidophorus
(Reptilia: Scincidae): a molecular approach. Zoologica Scripta, 35 (1), 85–95.
https://doi.org/10.1111/j.1463-6409.2005.00215.x
Katoh, K. & Standley, D.M. (2013) MAFFT multiple sequence alignment software version 7: improvements in performance and
usability. Molecular Biology and Evolution, 30 (4), 772–780.
https://doi.org/10.1093/molbev/mst010
Kalyaanamoorthy, S., Minh, B.Q., Wong, T.K., Von Haeseler, A. & Jermiin, L.S. (2017) ModelFinder: fast model selection for
accurate phylogenetic estimates. Nature Methods, 14 (6), 587–589.
https://doi.org/10.1038/nmeth.4285
Köhler, G. (2012) Color Catalogue for Field Biologists. Herpeton, Offenbach, Hesse, 49 pp.
https://doi.org/10.30906/1026-2296-2020-27-3-127-148
Kocher, T.D., Thomas, W.K., Meyer, A., Edwards, S.V., Pääbo, S., Villablanca, F.X. & Wilson, A.C. (1989) Dynamics of
mitochondrial DNA evolution in animals: amplification and sequencing with conserved primers. Proceedings of the
National Academy of Sciences, 86 (16), 6196–6200.
https://doi.org/10.1073/pnas.86.16.6196
Kumar, S., Stecher, G. & Tamura, K. (2016) MEGA7: molecular evolutionary genetics analysis version 7.0 for bigger datasets.
Molecular Biology and Evolution, 33 (7), 1870–1874.
https://doi.org/10.1093/molbev/msw054
Lanfear, R., Frandsen, P.B., Wright, A.M., Senfeld, T. & Calcott, B. (2017) PartitionFinder 2: new methods for selecting
partitioned models of evolution for molecular and morphological phylogenetic analyses. Molecular Biology and Evolution,
34 (3), 772–773.
https://doi.org/10.1093/molbev/msw260
Luu, V.Q., Bonkowski, M., Nguyen, T.Q., Le, M.D., Schneider, N., Ngo, H.T. & Ziegler, T. (2016) Evolution in karst massifs:
Cryptic diversity among bent-toed geckos along the Truong Son Range with descriptions of three new species and one new
country record from Laos. Zootaxa, 4107 (2), 101–140.
https://doi.org/10.11646/zootaxa.4107.2.1
Minh, B.Q., Nguyen, M.A.T. & Von Haeseler, A. (2013) Ultrafast approximation for phylogenetic bootstrap. Molecular Biology
and Evolution, 30 (5), 1188–1195.
https://doi.org/10.1093/molbev/mst024
Minh, B.Q., Schmidt, H.A., Chernomor, O., Schrempf, D., Woodhams, M.D., Von Haeseler, A. & Lanfear, R. (2020) IQ-TREE
2: new models and efficient methods for phylogenetic inference in the genomic era. Molecular Biology and Evolution, 37
(5), 1530–1534.
https://doi.org/10.1093/molbev/msaa015
Nguyen, T.Q., Nguyen, T.T., Schmitz, A., Orlov, N.L. & Ziegler, T. (2010) A new species of the genus Tropidophorus Duméril
& Bibron, 1839 (Squamata: Sauria: Scincidae) from Vietnam. Zootaxa, 2439 (1), 53–68.
https://doi.org/10.11646/zootaxa.2439.1.4
Okabe, S., Sanamxay, D., Truong, N.Q. & Motokawa, M. (2020) First record of Tropidophorus baviensis Bourret, 1939 (Reptilia:
Squamata: Scincidae) from Lao PDR. Herpetology Notes, 13, 675–678.
Pui, Y.M., Karin, B.R., Bauer, A.M. & Das, I. (2017) A new species of Tropidophorus Duméril & Bibron, 1839 (Squamata:
Sauria: Scincidae) from Sarawak, East Malaysia (Borneo). Zootaxa, 4258 (6), 539–550.
https://doi.org/10.11646/zootaxa.4258.6.3
Rambaut, A. & Drummond, A.J. (2003) Tracer: MCMC trace analysis tool. University of Oxford, Oxford. [program]
Ronquist, F., Teslenko, M., Van Der Mark, P., Ayres, D.L., Darling, A., Höhna, S., Larget, B., Liu, L., Suchard, M.A. &
Huelsenbeck, J.P. (2012) MrBayes 3.2: efficient Bayesian phylogenetic inference and model choice across a large model
space. Systematic Biology, 61 (3), 539–542.
https://doi.org/10.1093/sysbio/sys029
Schneider, N., Nguyen, T.Q., Le, M.D., Nophaseud, L., Bonkowski, M. & Ziegler, T. (2014) A new species of Cyrtodactylus
(Squamata: Gekkonidae) from the karst forest of northern Laos. Zootaxa, 3835 (1), 80–96.
https://doi.org/10.11646/zootaxa.3835.1.4
Sitthivong, S., Brakels, P., Xayyasith, S., Maury, N., Idiiatullina, S., Pawangkhanant, P., Wang, K., Van Nguyen, T. & Poyarkov,
N.A. (2023) Hiding on jagged karst pinnacles: A new microendemic genus and species of a limestone-dwelling agamid
lizard (Squamata: Agamidae: Draconinae) from Khammouan Province, Laos. Zoological Research, 44 (6), 1039–1051.
https://doi.org/10.24272/j.issn.2095-8137.2023.062
Taylor, E.H. (1963) The lizards of Thailand. University of Kansas Science Bulletin, 44, 687–1077.
Truong, N.Q., Van Sang, N., Orlov, N., Thao, H.N., Böhme, W. & Ziegler, T. (2010) A review of the genus Tropidophorus
(Squamata, Scincidae) from Vietnam with new species records and additional data on natural history. Zoosystematics and
Evolution, 86 (1), 5–19.
https://doi.org/10.1002/zoos.200900020
Uetz, P., Freed, P., Aguilar, R., Reyes, F., Kudera, J. & Hošek, J. (2024) The Reptile Database. Available from: http://www.
reptile-database.org (accessed 1 July 2024)
TROPIDOPHORUS VONGX SP. N OV. Zootaxa 5486 (1) © 2024 Magnolia Press · 141
Wang, K., Lvu, Z., Wang, J., Qi, S. & Che, J. (2022) The updated checklist and zoogeographic division of the reptilian fauna of
Yunnan Province, China. Biodiversity Science, 30 (4), 1–31.
https://doi.org/10.17520/biods.2021326
Ziegler, T., Thanh, V.N. & Thanh, B.N. (2005) A new water skink of the genus Tropidophorus from the Phong Nha-Ke Bang
National Park, central Vietnam (Squamata: Sauria: Scincidae). Salamandra, 41 (3), 137–146.
Zhao, E. & Adler, K. (1993) Herpetology of China. SSAR, Oxford/Ohio, 522 pp.
Zhao, E.M., Zhao, K. & Zhou, K.Y. (1999) Fauna Sinica Reptilia Vol. 2 Squamata: Lacertilia. Science Press, Beijing, 394 pp.
[in Chinese]
Appendix I. Specimens examined in the present study.
Tropidophorus sinensis: KIZ 011987–011997, Guangzhou, Guangdong Province, China.
Tropidophorus berdmorei: KIZ 55477, 55755, 55754, from Yingjiang, Dehong Prefecture, Yunnan Province,
China.
