Content uploaded by Nikolay Poyarkov
Author content
All content in this area was uploaded by Nikolay Poyarkov on Jul 01, 2024
Content may be subject to copyright.
ZOOTAXA
ISSN 1175-5326 (print edition)
ISSN 1175-5334 (online edition)
Accepted by V. Deepak: 4 Jun. 2024; published: 1 Jul. 2024 375
Zootaxa 5474 (4): 375–411
https://www.mapress.com/zt/
Copyright © 2024 Magnolia Press Article
https://doi.org/10.11646/zootaxa.5474.4.3
http://zoobank.org/urn:lsid:zoobank.org:pub:4F341940-B3FA-42A4-A0F5-7EF88FD5ECB9
A new species of green pitviper of the Trimeresurus macrops complex (Reptilia:
Serpentes: Viperidae) from South Central Coastal Region of Vietnam
SABIRA S. IDIIATULLINA1, TAN VAN NGUYEN2,3,*, ANDREY M. BRAGIN1,4, PARINYA
PAWANGKHANANT5,6, DAC XUAN LE4, GERNOT VOGEL7,
PATRICK DAVID8, NIKOLAY A. POYARKOV1,4,*
1Department of Vertebrate Zoology, Lomonosov Moscow State University, Leninskiye Gory, GSP–1, Moscow 119991, Russia.
https://orcid.org/0000-0003-1647-7754
https://orcid.org/0000-0002-3621-9763
2Institute for Research and Training in Medicine, Biology and Pharmacy, Duy Tan University, Da Nang, 550000, Vietnam.
3College of Medicine and Pharmacy, Duy Tan University, 120 Hoang Minh Thao, Lien Chieu, Da Nang, 550000, Vietnam.
4Joint Vietnam – Russia Tropical Science and Technology Research Center, Nghia Do, Cau Giay, Hanoi, Vietnam.
https://orcid.org/0000-0003-4586-6214
5Rabbit in the Moon foundation, Suanphueng, Ratchaburi 70180, Thailand.
6Division of Fishery, School of Agriculture and Natural Resources, University of Phayao, Phayao, Thailand.
https://orcid.org/0000-0002-0947-5729
7Society for South East Asian Herpetology, Im Sand-3, D-69115 Heidelberg, Germany.
https://orcid.org/0000-0002-4542-518X
8Reptiles & Amphibiens, UMR 7205 OSEB, Département évolution et Systématique, CP 30, Muséum National d’Histoire Naturelle. 57
rue Cuvier, F-75231 Paris Cedex 05, France.
https://orcid.org/0000-0001-7562-684X
Corresponding authors:
�
tan.sifasv@gmail.com; https://orcid.org/0000-0001-5413-968X;
�
n.poyarkov@gmail.com;
https://orcid.org/0000-0002-7576-2283
Abstract
We describe a new species of green pitviper from southern and central parts of coastal Vietnam based on morphological
and molecular (2406 bp from cyt b, ND4, and 16S rRNA mitochondrial DNA genes) lines of evidence. Trimeresurus
cyanolabris sp. nov. is distinguished from its congeners by the combination of the following morphological characters:
small size, maximum known SVL of 638 mm; dorsal scales in 21 (rarely 23)–21–15 rows, moderately keeled except the
outermost rows; ventral scales 166–178; subcaudal scales 52–75, all paired; hemipenis forked, calyculate, reaching the
8th subcaudal; eye bright yellow in both sexes; dorsal surface deep green lacking cross-bands; postocular white stripe
missing in both sexes; ventrolateral stripe faintly present on the first few dorsal scale rows in males, absent in females;
throat, chin, and lower labials in shades of blue. The new species forms a distinct clade on the phylogenetic tree of the
genus Trimeresurus and differs from the morphologically similar T. rubeus by a significant divergence in cytochrome b
mitochondrial DNA gene sequences (p = 6.0%). The new species is currently known from low- to mid-elevations (ca.
90–400 m a.s.l.) in tropical forests of central-southern Vietnam. This discovery further underlines the importance of this
area as a local center of herpetofaunal diversity and endemism, which is under great threat of deforestation.
Key words: Trimeresurus cyanolabris sp. nov., Vietnam, new species, morphology, molecular phylogeny, systematics
Introduction
The Asian pitviper genus Trimeresurus Lacépède, 1804, comprises terrestrial to arboreal species that are widely
distributed across South and Southeast Asia (Gumprecht et al. 2004). Trimeresurus represents one of the most
complex and species-rich genera of venomous snakes and currently includes 49 recognized species (Uetz et al.
2024). However, the morphological conservativeness of the green species in this genus makes it difficult to study
its taxonomy, hindering our understanding of its true diversity. Recently, both morphological and phylogenetic
analyses have helped to resolve some particularly problematic taxonomic issues among such complexes of cryptic
IDIIATULLINA ET AL.
376 · Zootaxa 5474 (4) © 2024 Magnolia Press
pitvipers as the T. albolabris complex (eg. Vogel et al. 2023); T. kanburiensis complex (eg., Idiiatullina et al. 2023;
2024a); T. popeiorum complex (eg., Idiiatullina et al. 2024b); and T. stejnegeri complex (eg., Rathee et al. 2022).
Another example is the Trimeresurus macrops species complex, which is widely distributed across Thailand,
Laos, Cambodia, and Vietnam (Gumprecht et al. 2004; Nguyen et al. 2009; Mrinalini et al. 2015). It belongs to the
subgenus Trimeresurus that differs from other members of the genus Trimeresurus by the combination of a long
papillose or calyculate hemipenis and a partially fused first supralabial and nasal scales (Malhotra & Thorpe 2004
[as genus Cryptelytrops]; Sumontha et al. 2021). For a long time, this complex was considered monotypic until
recently, when Mrinalini et al. (2015), based on mitochondrial (12S and 16S rRNA, NADH4) and nuclear loci (298
AFLP markers), divided it into three distinct species, namely T. macrops Kramer that inhabits Thailand, southern
and central Laos, and northeastern Cambodia; T. cardamomensis (Malhotra, Thorpe, Mrinalini & Stuart) - from
southeastern Thailand and the Cardamom mountains of southwestern Cambodia; and T. rubeus (Malhotra, Thorpe,
Mrinalini & Stuart) found in the southern lowlands of Vietnam and eastern Cambodia.
Populations of green pitvipers from the southern and central coastal regions of Vietnam with the first supralabial
partially or completely fused with the nasal were traditionally identified as Trimeresurus albolabris Gray or T.
macrops (eg., Nguyen et al. 2009). However, the taxonomic status of these populations has never been studied in
detail. During our recent surveys in the tropical forests of the southern and central coastal regions of Vietnam, a
series of green pitvipers superficially resembling T. macrops were collected from Ninh Thuan, Binh Dinh, and Khanh
Hoa provinces. A closer morphological examination of their scalation, color, and morphometric characteristics
demonstrated clear morphological differences from the members of the T. macrops species complex as well as from
other congeners. Consequently, phylogenetic analyses of three mtDNA genes (cyt b, ND4, and 16S) confirmed the
placement of the Ninh Thuan population within the subgenus Trimeresurus as a sister species of T. rubeus with
strong support. Combining morphological and molecular data, we describe these specimens of green pitvipers from
lowland forests in the southern and central coastal regions of Vietnam as a new species.
Material and Methods
Sampling. Fieldwork was carried out in Vietnam in Nui Chua and Phuoc Binh National Parks (hearafter NP) in
Ninh Thuan Province by N.A. Poyarkov and A.M. Bragin in February and March 2023; in Cam Lam, Diem Khanh,
and Ninh Hoa districts in Khanh Hoa Province in May 2023 by T.V. Phan, T.D. Nguyen, and T.V. Nguyen; in
Quy Nhon City and Van Canh District in Binh Dinh Province by T.V. Phan and T.D. Nguyen in August 2023 (Fig.
1). Geographic coordinates and elevations were recorded using a Garmin GPSMAP 60CSx GPS receiver (USA)
in datum WGS 84. Specimens were collected by means of snake hooks in the field, photographed in life, and
euthanized using MS-222 solution within 24 h after capture. Specimens were fixated in 4% buffered formalin for
24 h and later stored in 70% ethanol. Specimens were subsequently deposited in the herpetological collections of
the Zoological Museum of Duy Tan University (DTU, Da Nang, Vietnam) and the Zoological Museum of Moscow
State University (ZMMU, Moscow, Russia). Tissues for genetic analyses were taken from the liver or heart prior to
specimen preservation and stored in ethanol at 96%.
Specimen collection and animal use protocols were approved by the Institutional Ethical Committee of the Joint
Vietnam - Russia Tropical Science and Technology Research Centre (VRTC). Field work in Nui Chua NP. and Phuoc
Binh NP., including the collection of animals in the field and specimen exportation, was authorized by the People’s
Committee of Ninh Thuan Province, Vietnam (#317/UBND-VXNV of 03.02.2023) and granted to VRTC.
DNA isolation and sequencing. Total genomic DNA was extracted from ethanol-preserved muscle or liver
tissues using standard phenol-chloroform extraction procedures (Sambrook et al. 1989), followed by isopropanol
precipitation. We used polymerase chain reaction (PCR) to amplify three mitochondrial DNA (hereafter mtDNA)
fragments: complete sequences of cytochrome b (cyt b), NADH dehydrogenase subunit 4 gene (ND4), and fragments
of 16S rRNA. Primers used for both PCR and sequencing are summarized in Table 1.
For cytochrome b sequences, we used the modified PCR protocol of Dahn et al. (2018) with the touchdown: (1) initial
denaturation step at 94°C for 5 min; (2) 10 cycles of denaturation at 94°C for 1 min, annealing for 1 min with temperature
decreasing from 50°C to 45°C (with cool-down at 0.5°C per each cycle) and extension at 72°C for 1 min; (3) 24 cycles
of denaturation at 94°C for 1 min, annealing at 45°C for 1 min and extension at 72°C for 1 min; (4) final extension at
72°C for 10 min; and (5) cooling step at 4°C for storage. For ND4, we followed the protocol from Salvi et al. (2013): (1)
TRIMERESURUS CYANOLABRIS S P. NOV. Zootaxa 5474 (4) © 2024 Magnolia Press · 377
initial denaturation step at 92°C for 3 minutes, followed by 16 touchdown cycles with 30 seconds at 92°C; (2) annealing
temperature decreasing 0.5°C per cycle from 60°C to 52°C (30 seconds); and (3) extension for 1 minute at 72°C. Then 20
more cycles similar to these, but with annealing temperatures stable at 52°C, followed. A final extension was carried out at
72°C for 15 minutes. For 16S rRNA, we used the PCR protocol that followed Green et al. (2010): (1) initial denaturation
step at 94°C for 5 min; (2) 35 cycles of denaturation at 94°C for 1 min, annealing at 55°C for 1 min, and extension at 72°C
for 1 min; (3) final extension at 72°C for 10 min; and (4) cooling step at 4°C for storage.
FIGURE 1. Distribution of the green-colored members of the Trimeresurus macrops species complex in Indochina. Colors of
icons and locality numbers correspond to those of Fig. 2 and Appendix III. Stars indicate the type localities; circles indicate the
localities of specimens that were used in phylogenetic analysis; (for the Trimeresurus cyanolabris sp. nov. specimens from the
type locality were included in the phylogenetic analysis) and triangles indicate distribution records (see Appendix III).
All amplifications were run using an iCycler Thermal Cycler (Bio-Rad). PCR products were loaded onto 1%
agarose gels in the presence of ethidium bromide and visualized by electrophoresis. The successful targeted PCR
products were purified by the Diatom DNA PCR Clean-Up kit and outsourced to Evrogen® (Moscow, Russia) for
sequencing; sequence data collection and visualization were performed on an ABI 3730xl Automated Sequencer
(Applied Biosystems).
IDIIATULLINA ET AL.
378 · Zootaxa 5474 (4) © 2024 Magnolia Press
TABLE 1. Primers used in this study. F – forward primer, R – reverse primer.
Gene Primer name Sequence Reference
cyt bH14910 (F) 5’-GACCTGTGATMTGAAAAACCAYCGTT-3’ Dahn et al.
(2018)
THRSN2 (R) 5’-CTTTGGTTTACAAGAACAATGCTTTA-3’
ND4 Trim-ND4F (F) 5’-CACCTATGACTACCAAAAGCTCATGTAGAAGC-3’ Salvi et al. (2013)
Trim-ND4LEUR (R) 5’-CATTACTTTTACTTGGATTTGCACCA-3’
16S
rRNA
16S1LM (F) 5’-CCGACTGTTGACCAAAAACAT-3’ Green et al.
(2010)
16SH1 (R) 5’-TCCGGTCTGAACTCAGATCACGTAGG-3’
FIGURE 2. Maximum Likelihood (ML) phylogenetic tree of Trimeresurus derived from the analysis of 2406 bp of cyt b,
ND4, and 16S rRNA mitochondrial DNA gene sequences. For voucher specimen information and GenBank accession numbers,
see Table 2. Numbers at the nodes correspond to ML UFBS/BI PP support values, respectively. Colors of clades and locality
numbers correspond to those on the map in Figure 1. Photograph by A. M. Bragin.
Molecular phylogeny. To estimate the phylogenetic relationships of the genus Trimeresurus, we used the
newly obtained cyt b, ND4, and 16S sequences together with previously published sequences of T. cardamomensis,
T. macrops, and T. rubeus (36 sequences in total), as well as representative sequences of 30 species of Trimeresurus.
Azemiops feae Boulenger was used to root the tree (Table 2).
We initially aligned the nucleotide sequences in MAFFT online (Katoh et al. 2019) with default parameters
and subsequently checked them by eye in BioEdit 7.0.5.2 (Hall 1999) and adjusted when required. The mean
uncorrected genetic p-distances between sequences were calculated with MEGA 6.0 with pairwise deletion option
(Tamura et al. 2013) based on cyt b sequences of pitvipers of the subgenus Trimeresurus. The best-fit substitution
models for the data set were selected for genes and codon positions using Partitionfinder 2.1.1 (Lanfear et al. 2012)
with Akaike information criterion (AIC), which selected GTR+I+G for 16S, the first codon position of cyt b, and the
TRIMERESURUS CYANOLABRIS S P. NOV. Zootaxa 5474 (4) © 2024 Magnolia Press · 379
first and third codon positions of ND4; GTR+I for the second codon position of cyt b; GTR+G for the third codon
position of cyt b; and GTR for the second codon position of ND4. When the same model was proposed for different
codon partitions of a given gene, they were treated as a single partition; this resulted in four partitions in total; the
data on substation models and other parameters for each genes are summarized in Appendix I.
Phylogenetic trees were estimated for the combined mitochondrial DNA fragments (cyt b, ND4, and 16S) data
set. We inferred the matrilineal genealogy of Trimeresurus using Bayesian inference (BI) and maximum likelihood
(ML) approaches. We used the IQ-TREE online server (Nguyen et al. 2015) to generate the ML tree and assessed
the confidence in tree topology by 1000 bootstrap replications (BS). We conducted BI in the terminal version of
MrBayes 3.1.2 (Huelsenbeck & Ronquist 2001). Metropolis-coupled Markov chain Monte Carlo (MCMCMC)
analyses were run with one cold chain and three heated chains for 40 million generations and sampled every 40,000
generations. The run was checked to ensure the effective sample sizes (ESS) were all above 200 by exploring the
likelihood plots using TRACER v. 1.7 (Rambaut et al. 2018). We discarded the initial 1000 trees as burn-in. We
assessed the confidence in tree topology by the posterior probability (PP) of the nodes (Huelsenbeck & Ronquist
2001). We a priori regard nodes with UFBS values of 95% or higher and PP values over 0.95 as strongly supported;
UFBS values between 95% and 90% and PP values between 0.95 and 0.90 were regarded as well-supported, and
lower values were regarded as a lack of node support (Minh et al. 2013).
Morphological analysis. For this study, a total of 90 preserved specimens of species from the Trimeresurus
macrops species complex were examined for their morphological characters by four co-authors (G. Vogel, T.V.
Nguyen, P. David, and P. Pawangkhanant) (Appendix II). Altogether, 45 morphological characters, including the
structure of the hemipenes (see Table 3), were considered, either as raw values or derived from these raw values. Not
all these characters were useful to distinguish between species in this study, but all of them were compared because
they may be of use for further taxonomic studies and geographical variation.
Measurements were taken with a slide-caliper to the nearest 0.1 mm, except body and tail lengths, which
were measured to the nearest 1 mm with a measuring tape. The number of ventral scales was counted according to
Dowling (1951); half-ventral plates were counted as one plate. The enlarged wide (i.e., notably wider than long)
plate(s) anterior to the first ventral plate were regarded as preventral(s); other plates anterior to the first preventral
were regarded as gulars. The first scale under the tail meeting its opposite was considered the first subcaudal scale,
and the unpaired terminal scute was not included in the number of subcaudals. The number of dorsal scale rows
was counted at one head length behind the head, at midbody, at half SVL, and at one head length before the vent.
Infralabials were defined as those shields that were completely below a supralabial and bordering the mouth gap.
Values for paired head characters were recorded on both sides of the head and reported in a left/right order. Eye size
was measured horizontally (ED), the greatest diameter; see below and in Table 3 for abbreviations); the eye-nostril
distance (EN) was measured from the anterior margin of the eye to the posterior margin of the nostril; the distance
from the eye to the lip (DEL) was measured between the lower margin of the eye and the edge of the upper lip; the
head length (HL) was measured from the snout tip to the angle of the jaws; and the head width (HW) was measured
at the widest part of the head on the posterior side. Sex was determined by dissection of the ventral tail base in
preserved specimens and with a probe in live individuals.
For comparison with other taxa, we relied on previously published data, for example: Kramer (1977), Regenass
& Kramer (1981), Gumprecht et al. (2004), Malhotra et al. (2011), Vogel et al. (2023), Idiiatullina et al. (2023), and
Idiiatullina et al. (2024a, b); we also personally examined specimens of all currently recognized species of genus
Trimeresurus.
Abbreviations. Morphology and morphometry. CLP: condition of the cloacal plate; DSR: dorsal scale rows; G:
pair of gular scales; IL: infralabials; IN: internasals; PV: preventrals; SbS: number of scales between supraoculars;
SC: number of subcaudals excluding terminal scute; SL: number of supralabials; SO: supraocular(s); SVL: snout
ventral length from snout to last ventral scale; TaL: tail length from anal to tail tip; TL: total length from the tip
of the snout to the end of the tail; TL/TaL: ratio of total length to tail length; VEN: number of ventrals. Other
abbreviations. Mt.: Mountain; NP.: National Park; NR.: Nature Reserve; Isl.: Island.
Museum abbreviations. AUP: School of Agriculture and Natural Resources, University of Phayao, Phayao,
Thailand; CAS: California Academy of Sciences Museum, California, USA; DTU: Duy Tan University, Da Nang,
Vietnam; LSUHC: La Sierra University Herpetological Collection, California, USA; MHNG: Muséum d’Histoire
Naturelle, Ville de Genève, Switzerland; MNHN: Muséum national d’Histoire naturelle, Paris, France; NHMW
(formerly NMW): Natural History Museum Vienna, Vienna, Austria; QSMI: Queen Saovabha Memorial Institute,
IDIIATULLINA ET AL.
380 · Zootaxa 5474 (4) © 2024 Magnolia Press
Bangkok, Thailand; SYS: Sun Yat-sen University, Guangdong, China; ZFMK: Zoologisches Forschungsinstitut und
Museum Alexander Koenig, Bonn, Germany; ZMMU: Zoological Museum of Moscow State University, Moscow,
Russia.
Results
Sequence variation. A total of 2406 (1091 bp from cyt b, 800 bp from ND4, and 515 bp from 16S) aligned base
pairs were obtained from the three mtDNA fragments, respectively. Protein-coding sequences were translated into
amino acids to confirm that no pseudogenes had been amplified. We deposited the newly obtained sequences in
GenBank under the accession numbers PP766216–22, PP779472–78, and PP792705 (Table 2).
Phylogenetic relationships. The ML and BI analyses recovered trees with very similar topologies; the nodes that
are reconstructed differently mostly refer to deeper phylogenetic relationships among the subgenera of Trimeresurus,
which are not important in this analysis because in this study we only focus on the analysis of relationships within
the T. macops species group (Fig. 2). According to our phylogenetic tree, genus Trimeresurus is monophyletic
(100/1.0; hereafter node support values are given for ML UFBS/BI PP, respectively), but intrageneric topology
is unclear. Subgenus Popeia Malhotra & Thorpe and Parias Gray is monophyletic in both ML and BI analyses
(100/1.0), while Himalayophis Malhotra & Thorpe and Viridovipera Malhotra & Thorpe is strongly monophyletic
only in the BI analysis and moderately in the ML analysis (87/0.97 and 88/0.99, respectively). The monophyly of
the subgenus Trimeresurus is not supported (40/-) in either analysis. It consists of two strongly supported subclades
(100/1.0): the first includes species from the T. albolabris complex, and the second contains species from the T.
macrops and T. kanburiensis complexes. Inside this latter clade, the relationships between species are generally well
resolved. The subgenera themselves form an unresoved polytomy.
Trimeresurus ciliaris is sister to all other species of the second subclade with high support (95/0.97) but an
extremely short branch length. T. rubeus (from eastern Cambodia and southern Vietnam) and the population of
Trimeresurus sp. from Ninh Thuan are monophyletic (99/1.0 and 100/1.0, respectively) and sister species (100/1.0)
and compose the sister lineage of the remaining species in the subclade with high support (97/1.0). Among the
remaining species, T. kanburiensis Smith is monophyletic (100/1.0) and the sister of the remaining species of the
subclade with high support (100/1.0). Trimeresurus cardamomensis (from western Cambodia and southeastern
Thailand, 94/1.0) and T. venustus Vogel are sister species (100/1.0), composing the sister lineage to a monophyletic
group that includes T. macrops, T. honsonensis (Grismer, Ngo & Grismer), T. kuiburi Sumontha, Suntrarachun,
Pauwels, Pawangkhanant, Chomngam, Iamwiriyakul & Chanhome, and T. kraensis (99/1.0). Within this lineage, T.
kraensis forms a sister taxon to the clade which includes the three remaining species (albeit with strong support in
ML analysis and no support in BI analysis: 95/0.5), while T. macrops (from Thailand, Laos, and northern Cambodia,
100/1.0) and T. honsonensis are grouped together with high node support (96/1.0). Based on our phylogenetic tree,
we can propose with confidence that Trimeresurus sp. from Ninh Thuan Province represents a new highly divergent
and previously unknown lineage of pitvipers, which does not fall into the radiation of T. macrops but is recovered
as the sister species to T. rubeus.
Genetic distances. The uncorrected p-distances for the cyt b gene fragment among the Trimeresurus species
examined here are presented in Table 4. Interspecific distances varied from p = 2.0% (between T. erythrurus Cantor
and T. ayeyarwadyensis Chan, Anuar, Sankar, Law, Law, Shivaram, Christian, Mulcahy & Malhotra) to p = 16.0%
(between Trimeresurus sp. from Ninh Thuan and T. albolabris). The new lineage from southern Vietnam differs
from T. rubeus by 6.0%, from T. cardamomensis by 8.0%, and from T. macrops by 8.5% in the cyt b gene.
Our results are further corroborated by morphological analyses (see below), which uncovered stable differences
between the population of Trimeresurus sp. from Ninh Thuan, Vietnam, and other congeners. These results support
our hypothesis that this recently discovered lineage of Trimeresurus represents an undescribed species, which we
describe below.
TRIMERESURUS CYANOLABRIS S P. NOV. Zootaxa 5474 (4) © 2024 Magnolia Press · 381
Systematics
Family Viperidae Oppel, 1811
Subfamily Crotalinae Oppel, 1811
Genus Trimeresurus Lacépède, 1804
Trimeresurus cyanolabris sp. nov. (Fig. 3–4; Tables 2, 4–6)
Chresonymy:
Trimeresurus albolabris (non Trimeresurus albolabris Gray, 1842) — Nemes et al. (2013: 320); Nguyen et al. (2019: 40, in
part).
Trimeresurus macrops (non Trimeresurus macrops Kramer, 1977) — Hoang et al. (2019: 90).
Trimeresurus (Trimeresurus) macrops — Poyarkov et al. (2023: 391, in part).
Trimeresurus stejnegeri (non Trimeresurus stejnegeri Schmidt, 1925) — Hoang et al. (2019: 91).
Holotype. ZMMU Re-17679 (field ID NAP-13705), adult male, from Nui Chua National Park in Thai An Village, Vinh Hai
Commune, Ninh Hai District, Ninh Thuan Province, Vietnam (11.77757°N, 109.17603°E; altitude 155 m a.s.l.) collected
by N.A. Poyarkov and A.M. Bragin from the ground on the bank of a mountain stream on March 8, 2023.
Paratypes (n = 9). ZMMU Re-17678 (field ID NAP-13704), adult male, collected on March 8, 2023, from the same
location as the holotype; ZMMU Re-17680–81 (field ID NAP-13229–30), two adult females, collected by N.A. Poyarkov
and D. X. Le on January 6, 2023, from the valley of Nuoc Ngot River (11.778°N, 109.176°E; altitude 280 m a.s.l.), ca. 3
km south-west from Nuoc Ngot Beach, on the territory of Nui Chua N.P., Thai An Village, Vinh Hai Commune, Ninh Hai
District, Ninh Thuan Province, southern Vietnam; ZMMU Re-17682 (field ID NAP-13643), adult female, collected from
Nui Chua N.P. in Thai An Village, Vinh Hai Commune, Ninh Hai District, Ninh Thuan Province, Vietnam (11.72343°N,
109.13656°E; altitude 730 m a.s.l.) by N.A. Poyarkov and A.M. Bragin on March 4, 2023; ZMMU Re-17683–84 (field ID
NAP-13365–66), two adult females, collected from Phuoc Binh N.P., Phuoc Binh Commune, Bac Ai District, Ninh Thuan
Province, Vietnam (11.99353°N, 108.74379°E; altitude 400 m a.s.l.) by N.A. Poyarkov and A.M. Bragin on February 25,
2023; DTU 605 (adult female) from a secondary forest near Hon Ba NR, Suoi Cat Commune, Cam Lam District, Khanh
Hoa Province, Vietnam (12.134169°N, 109.034452°E; altitude 130 m a.s.l.) collected by T.V. Phan, T.D. Nguyen and T.V.
Nguyen on May 15, 2023; DTU 606 (adult female) from An Chua Area, Diem Khanh Distrist, Khanh Hoa Province, Vietnam
(12.327065°N, 109.098045°E; altitude 90 m a.s.l.) collected by T.V. Phan, T.D. Nguyen, and T.V. Nguyen on May 20, 2023;
DTU 650 (adult female) collected by T.V. Phan, T.D. Nguyen, and T.V. Nguyen from Hon Heo Island, Ninh Da Commune,
Ninh Hoa District, Khanh Hoa Province, Vietnam (12.397168°N, 109.294047°E; altitude 45 m a.s.l.) on May 19, 2023.
Additional materials (n = 3). ZFMK 94670 (adult male) from Ba To District, Quang Ngai Province, Vietnam (ca.
14.707444°N, 108.997215°E; altitude 140 m a.s.l.). DTU 653 (adult female, released) from Suoi Mo Area, Bui Thi Xuan
Town, Quy Nhon City, Binh Dinh Province, Vietnam (13.695361°N, 109.170546°E; altitude 280 m a.s.l.) collected by T.V.
Phan and T.D. Nguyen on August 03, 2023; DTU 636 (adult female, released) from Hiep Ha Commune, Van Canh District,
Binh Dinh Province, Vietnam (13.664300°N, 108.972583°E; altitude 250 m a.s.l.) collected by T.V. Phan and T.D. Nguyen
on August 10, 2023.
Etymology. The specific name “cyanolabris” is formed of the Latin adjective “cyaneus,” derived from a Latizined
form of the classical Greek adjective κυανος (kyanos), meaning “dark blue” or “deep blue,” and of the Latin noun “labrum”
(-i), the lip. This specific name means “deep blue-lipped,” and refers to the distinctive blue color found on the throat, chin,
and infralabials of the new species. Though traditionally it is recommended that the Greek and Latin words not be combined
in one species nomen, we would like to underline that the adjective “cyaneus” is common in Latin texts and can be regarded
as a proper Latin adjective. We suggest the following common English name: “Blue-lipped Green Pitviper”, Russian name:
“Golubogubaya bambukovaya kufiya”, and Vietnamese name: “Rắn lục mép xanh dương”.
Diagnosis. The new species is assigned to the subgenus Trimeresurus based on the following morphological
attributes: a long calyculate hemipenis and a partially fused first supralabial and nasal scales (Malhotra & Thorpe 2004
[as Cryptelytrops]; David et al. 2011). The new species, Trimeresurus cyanolabris sp. nov., differs from other members of
the subgenus Trimeresurus by the combination of the following morphological characters: small size, maximum known
IDIIATULLINA ET AL.
382 · Zootaxa 5474 (4) © 2024 Magnolia Press
SVL of 638 mm; dorsal scales in 21 (rarely 23)–21–15 rows, moderately keeled except the outermost rows; ventral scales
166–178; subcaudal scales 52–75, all paired; hemipenis forked, calyculate, reaching the 8th subcaudal; eye bright yellow in
both sexes; dorsal surfaces deep green lacking cross-bands; postocular streak white in both sexes; ventrolateral stripe, faint,
present on the first few dorsal scale rows in males, absent in females; throat, chin, and lower labials blue color.
FIGURE 3. The holotype of Trimeresurus cyanolabris sp. nov. in preservative (ZMMU Re-17679, adult male) from Nui Chua
NP, Ninh Thuan Province, Vietnam. A dorsolateral and B ventral view of body; C head in dorsal, D in ventral, E in lateral right,
and F in lateral left aspects. Scale bar equals 1 cm. Photographs by S.S. Idiiatullina.
TRIMERESURUS CYANOLABRIS S P. NOV. Zootaxa 5474 (4) © 2024 Magnolia Press · 383
FIGURE 4. Type specimens of Trimeresurus cyanolabris sp. nov. in life from Nui Chua NP, Ninh Thuan Province, Vietnam:
A holotype ZMMU Re-17679, adult male; B paratype ZMMU Re-17681, adult female. Photographs by A.M. Bragin (A) and
N.A. Poyarkov (B).
IDIIATULLINA ET AL.
384 · Zootaxa 5474 (4) © 2024 Magnolia Press
Description of the holotype. Adult male (Fig. 3), specimen in a good state of preservation. Body cylindrical,
long, and thin (SVL 464 mm, TaL 106 mm, TL 570 mm, TaL/TL 0.186) (Fig. 3A–B). Head triangular in dorsal view
(Fig. 3C), elongate, clearly distinct from the neck (HL 21.2 mm; HW 13.0 mm; HW/HL ratio 0.61). Snout elongate,
flattened, and rounded in dorsal view (Fig. 3C), rather rectangular in lateral view (Fig. 3E–F), with a very distinct
and sharp canthus rostralis. Eyes large (ED 3.5 mm; EN 5.2 mm; ED/EN ratio 0.67). Rostral slightly visible in dorsal
aspect, triangular (Fig. 3C). Pupil vertically elliptical, loreal pit present, triangular in shape (Fig. 3E–F). Nostril
completely enclosed in nasal scale; nasal scale partially fused with first supralabial (Fig. 3E–F). Shield bordering
the anterior edge of the loreal pit fused with second supralabial, which is tall. Anterior subocular long, thin, crescent-
like, separated from the 4th and 5th supralabials by one row of scales; posterior subocular ovoid, separated from the
6th supralabial by 2/1 scales (Fig. 3E–F). Three preoculars on each side of the head; two upper preoculars located
above the loreal pit, elongate, in contact with the single loreal, which separates them from the nasal; lower preocular
forming the lower margin of the loreal pit, lower preocular in contact with third supralabial (Fig. 3E–F). A small
scale between nasal and second supralabial; 2/2 postoculars; 10/10 supralabials, third the largest (Fig. 3E–F); 12/12
infralabials, those of the first pair in contact with each other behind the mental; the first three pairs of infralabials in
contact with the single pair of chin shields (Fig. 3E–F). Six pairs of gulars aligned between the chin shields and the
first preventral (Fig. 3D). One large pair of enlarged internasals, separated by three small scales. One supraocular,
large (Fig. 3C). Scales on snout and in the interorbital region smooth, irregular, subimbricate; temporal and occipital
scales feebly keeled (Fig. 3E-F). Dorsal scales in 21–21–15 rows, moderately keeled, except the first row, which is
smooth (Fig. 3A). One preventral and 175 ventrals. Anal plate single; 72 subcaudals, all divided. Hemipenes long,
papillose, and deeply forked with small, soft basal spines, reaching the 8th subcaudal (Fig. 3B).
Coloration. In life (Fig. 4A), the body is uniformly bright grass-green above and on the upper part of the sides
and gradually turns yellow on the lower sides, without a ventrolateral stripe. Tail dull brick red, dorsally extending
as far as vent, with a faint margin on lateral side of tail. Venter light greenish-yellow, paler in its anterior part, and
light green in its posterior part. The dorsal surface of the head and the temporal region are green without a postocular
streak; supralabial, infralabial, chin and throat regions are blue. Iris bright yellow. In preservative (Fig. 3), the
background dorsal color faded to a light gray; the ventral color became white.
Variation (for detailed information, see Table 5). The longest known specimen is 743 mm long (SVL 638 mm,
TaL 105 mm; female, DTU 635); the longest known male is 607 mm long (SVL 478 mm, TaL 129 mm; ZFMK
94670). Ratio TaL/TL: 0.129–0.213 (males: 0.181–0.213, females: 0.129–0.154).
Body scalation. 21 (rarely 23 in the ZMMU Re-176 Paratype)–21–15 DSR; 166–178 VEN, without sexual
dimorphism; 52–75 SC (males: 71–75, females: 52–62); total number of VEN+SC: 223–247 (males: 241–247,
females: 223–237).
Head scalation. InSep: none, internasals in contact in all known specimens; Cep: 9–10; SL: 10 (exceptionally
9 or 11); IL: 10–13.
Main characters of the pattern. The postocular streak is always absent in both sexes; ventrolateral stripe present,
white, faint, and thin in males; absent in females. Eyes bright yellow in both sexes.
Comparisons. The new species is phylogenetically placed within the subgenus Trimeresurus (Malhotra &
Thorpe 2004 [as Cryptelytrops]; David et al. 2011) and is morphologically most similar to other green pitviper
species from the T. macrops complex, including T. rubeus, T. cardamomensis, and T. macrops; therefore, the
comparisons with these three species appear to be the most pertinent. The main diagnostic characters separating
Trimeresurus cyanolabris sp. nov. from these three species are summarized in Table 6.
Trimeresurus cyanolabris sp. nov. is distinguished from T. rubeus (restricted to southern Vietnam and eastern
Cambodia) by having: (1) lower max SVL in males (478 mm vs. 586 mm), but higher max SVL in females (638 mm
vs. 503 mm); (2) slightly lower ratio TaL/TL in both sexes (0.18–0.21 [ X = 0.19] in males, 0.13–0.15 [ X = 0.14]
in females vs. 0.21–0.22 [ X = 0.22] in males, 0.15–0.19 [ X = 0.17] in females); (3) slightly higher ratio HW/HL
in both sexes (0.55–0.68 [ X = 0.61] in males, 0.65–0.70 [ X = 0.66] in females vs. 0.53–0.60 [ X = 0.56] in males,
0.46–0.72 [ X = 0.61] in females); (4) slightly higher ratio ED/EN in males (0.67–0.78 [ X = 0.74] vs. 0.66–0.74 [ X =
0.70], but lower ratio ED/EN in females (0.62–0.88 [ X = 0.71] vs. 0.79–0.95 [ X = 0.85]; (5) slightly higher number
VEN in both sexes (166–175 [ X = 171.0] in males, 169–178 [ X = 174.1] in females vs. 164–171 [ X = 167.5] in
males, 158–163 [ X = 159.8] in females); (6) slightly lower number SC in males (71–75 [ x =72.7] in males, 52–62
[ X = 57.7] in females vs. 78–80 [ X = 79.0] in males, 52–69 [ X = 61.6] in females; (7) slightly lower total number
of VEN+SC in females (223–237 [ X = 231.8] vs. 214–228 [ X = 221.4]; (8) without postocular white stripe in males
TRIMERESURUS CYANOLABRIS S P. NOV. Zootaxa 5474 (4) © 2024 Magnolia Press · 385
(vs. present); (9) ventrolateral body stripe present, faint, poorly contrasted in males (vs. well developed, highly
contrasted with reddish and white); (10) ventral surface of body greenish-blue (vs. greenish-yellow); (11) eye color
bright yellow in both sexes (vs. bright red, blood-red or deep reddish–orange in both sexes).
Trimeresurus cyanolabris sp. nov. further differs from T. cardamomensis (restricted to southwestern Cambodia,
southeastern Thailand, and the southermost part of Vietnam) by having: (1) lower max SVL in males (478 mm vs.
535 mm), but higher max SVL in females (638 mm vs. 536 mm); (2) slightly lower ratio ED/EN in both sexes
(0.67–0.78 [ X = 0.74] in males, 0.62–0.88 [ X = 0.71] in females vs. 0.66–0.91 [ X = 0.78] in males, 0.51–0.97 [ X
= 0.74] in females); (3) slightly higher number of SC in males (71–75 [ X = 72.7] vs. 60–75 [ X = 67.0]); (4) higher
total number of VEN+SC in males (241–247 [ X = 243.7] vs. 226–243 [ X = 234.0]); (5) postocular stripe absent in
males (vs. present, white or blue); (6) ventrolateral body stripe present, faint, poorly contrasted in male (vs. well
developed, highly contrasted, white); (7) ventral surface of body greenish-blue (vs. greenish-yellow); (8) head
shape more elongate-oval (vs. more triangular); (9) small size scales on head behind internasal scales (vs. lager).
Furthermore, T. cyanolabris sp. nov. is widely separated from T. cardamomensis on a geographical basis, as the
latter species inhabits only southeastern Thailand, southerwestern Cambodia, and southernmost Vietnam (Phu Quoc
Isl.). Moreover, T. rubeus separates the ranges of both species..
In particular, Trimeresurus cyanolabris sp. nov. is distinguished from T. macrops by having: (1) lower max SVL
in males (478 mm vs. 557 mm), but higher max SVL in females (638 mm vs. 629 mm); (2) slightly lower ratio HW/
HL in males (0.55–0.68 [ X = 0.61] vs. 0.56–0.82 [ X = 0.68]); (3) lower ratio ED/EN in both sexes (0.67–0.78 [ X =
0.74] in males, 0.62–0.88 [ X = 0.71] in females vs. 0.62–1.12 [ X = 0.89] in males, 0.64–0.97 [ X = 0.83] in females);
(4) slightly higher number VEN in both sexes (166–175 [ X = 171.0] in males, 169–178 [ X = 174.1] in females vs.
158–173 [ X = 165.0] in males, 159–173 [ X = 166.4] in females); (5) higher total number of VEN+SC in both sexes
(241–247 [ X = 243.7] in males, 223–237 [ X = 231.8] in females vs. 225–240 [ X = 233.0] in males, 214–235 [ X
= 222.1] in females); (6) postocular stripe absent in males (vs. present); (7) ventrolateral body stripe present, faint,
poorly contrasted in male (vs. well developed, highly contrasted); (8) ventral surface of body greenish-blue (vs.
greenish-yellow).
Among the other species in the subgenus Trimeresurus, the new species can be readily distinguished from:
T. ciliaris Idiiatullina, Pawangkhanant, Tawan, Worranuch, Dechochai, Suwannapoom, Nguyen, Chanhome &
Poyarkov, T. fasciatus (Boulenger), T. labialis Fitzinger in Steindachner, T. mutabilis Stoliczka, T. honsonensis,
T. kraensis Idiiatullina, Pawangkhanant, Suwannapoom, Chanhome, Nguyen, David, Vogel & Poyarkov, T.
kanburiensis, T. kuiburi, and T. venustus by coloration and pattern (uniform green vs. reddish-brown or purple or
dark olive-brown bands on emerald-green or olive-greyish background).
Trimeresurus cyanolabris sp. nov. can be distinguished from Trimeresurus andersoni Theobald, T.
ayeyarwadyensis, T. cantori (Blyth), T. erythrurus, and T. purpureomaculatus (Gray) by the lower number of
midbody dorsal scale rows (21 vs. 23–25 in T. andersoni and T. ayeyarwadyensis, 25–29 in T. cantori, 23 (rarely
24, 25) in T. erythrurus, 25 (rarely 27, 29) in T. purpureomaculatus). The new species can be distinguished from: T.
caudornatus Chen, Ding, Vogel & Shi; T. davidi Chandramouli, Campbell & Vogel; T. guoi Chen, Shi, Vogel & Ding;
T. insularis Kramer; T. salazar Mirza, Bhosale, Phansalkar, Sawant, Gowande & Patel; T. septentrionalis Kramer, T.
uetzi Vogel, Nguyen & David by having: body size smaller (max SVL 638 mm vs. 804 mm in T. caudornatus, 835
mm in T. davidi, 804 mm in T. guoi, 735 mm in T. insularis, 819 mm in T. septentrionalis, 689 mm in T. uetzi); in
contrast, body size larger (max SVL 638 mm vs. 565 mm in T. salazar); throat, chin, and lower labials in shades of
blue (vs. creamy or white); relatively larger size of the eye (most obvious in adults); relatively wider supraoculars;
the shape of the head (widens quite abruptly behind the eyes vs. more elongate or oval).
Lastly, Trimeresurus cyanolabris sp. nov. was previously misidentified with T. albolabris and T. stejnegeri
Schmidt (see Nguyen et al. 2009; Hoang et al. 2019). The new species can be distinguished from T. albolabris by:
body size smaller (max SVL 638 mm vs. 749 mm); relatively larger size of the eye, the relatively wider supraoculars,
and the shape of the head (widens quite abruptly behind vs. more elongate or oval); it is distinguished from T.
stejnegeri by the 1st supralabial fused with nasal (vs. entirely separated by a suture); body size smaller (max SVL
638 mm vs. 720 mm); no postocular stripe in males (vs. present); eye color bright yellow in both sexes (vs. in shades
of red in both sexes).
Distribution. Currently, Trimeresurus cyanolabris sp. nov. is known from the southern and central parts of
coastal Vietnam (from Ba To District in Quang Ngai Province; from Quy Nhon City and Van Canh District in Binh
Dinh Province; from Diem Khanh District, Ninh Hoa Town, and Hon Ba NR in Cam Lam District in Khanh Hoa
IDIIATULLINA ET AL.
386 · Zootaxa 5474 (4) © 2024 Magnolia Press
Province; from Nui Chua NP in Ninh Hai District and Phuoc Binh NP., Bac Ai District in Ninh Thuan Province)
(Fig. 1, Appendix III). The occurrence of the new species in the Dak Lak and Phu Yen provinces of Vietnam is
strongly anticipated. The actual extent of its distribution is still unknown.
Natural history. Trimeresurus cyanolabris sp. nov. was recorded from relatively low- to mid-elevations (ca.
90–400 m a.s.l.) in tropical dry forests of the central southern region of Vietnam (Poyarkov et al. 2023). The male
holotype ZMMU Re-17679 was collected from the ground near a small mountain stream; the male paratype ZMMU
Re-17678 while perching on a bush ca. 40 cm above the ground; two female paratypes ZMMU Re-17680–81 were
collected on the ground (large flat stones) on the bank of a small river (see Fig. 5); the female paratype ZMMU
Re-17682 was collected while perching on a tree branch ca. 1 m above the ground, while female paratypes ZMMU
Re-17683–84 were collected from the ground in the tropical montane forests on the leaf litter; all specimens were
recorded between 1700 h and 2300 h. Therefore, the new species is semi-arboreal with crepuscular and nocturnal
activity. During the day, it often perches on the branches or in the hollows of trees 0.5–1.5 m high near streams. In
Khanh Hoa Province, it is common in the beginning (August) and at the end of the rainy season (October), often
in the lower layers of trees or on dry branches under the trees, in contrast to T. albolabris which usually occurs at
higher tree levels. There may be an ecological stratification between these two species in the Khanh Hoa population
(T.V. Phan pers. comm.). The new species feeds on small frogs and small lizards (such as Gekko sp.) (T.V. Nguyen
pers. obser.). Nothing is known about its reproduction cycle.
FIGURE 5. Habitat of Trimeresurus cyanolabris sp. nov. in Nui Chua NP, Ninh Thuan Province, Vietnam. Photograph by A.
M. Bragin.
Conservation status. Further research is required to clarify the extent of the distribution, population size,
trends, and conservation status of the new species. Trimeresurus cyanolabris sp. nov. is distributed over a large area,
including several protected zones. Across its range, the new species seems to be quite common, especially in Khanh
Hoa Province, where many local people and tourists have observed and reported it through the social networking
TRIMERESURUS CYANOLABRIS S P. NOV. Zootaxa 5474 (4) © 2024 Magnolia Press · 387
group “Snake Identification and First Aid for Snakebites in Vietnam” (SIFASV, Vietnam, T.V. Nguyen pers. obser.)
Thus, we tentatively suggest that Trimeresurus cyanolabris sp. nov. should be considered a Least Concern (LC)
following the IUCN‘s Red List categories (IUCN Standards and Petitions Committee 2019).
DISCUSSION
Initially, Trimeresurus macrops sensu lato was considered a widespread species due to its occurrence in Thailand, Laos,
Cambodia, and Vietnam (e.g., Gumprecht et al. 2004). It was often misidentified as T. albolabris (e.g., Nemes et al. 2013;
Zhu et al. 2016) based on their superficial morphological resemblance. Later, phylogenetic studies (Mirza et al. 2023;
Idiiatullina et al. 2023, 2024a) demonstrated that the T. macrops complex is not monophyletic and is related to members
of the T. kanburiensis complex forming the T. kanburiensis-macrops species group, which is only distantly related to the T.
albolabris species group. This indicates that limestone- or rupicolous pitvipers with blotched coloration (such as members
of the T. kanburiensis complex) and forest-dwelling pitvipers with uniformly green coloration (such as the T. macrops
complex) are closely related to each other (Idiiatullina et al. 2023, 2024a).
Several attempts have been made to review the taxonomy and distribution of the Trimeresurus macrops species
complex. Recently, a number of studies based on both morphological and molecular data showed that the T. macrops
complex consists of several cryptic or not very cryptic species, such as T. cardamomensis from Cardamom Mts.
and T. rubeus from Southern Vietnam (Malhotra et al. 2011; Mrinalini et al. 2015). However, when these taxa
were described, their authors did not assess populations across the range of T. macrops sensu lato, and as such, the
taxonomic status of many populations remained unclear. For example, the lineage of “T. macrops” from Phu Quoc
Island of Vietnam was recently re-identified as T. cardamomensis (Ziegler et al. 2018; also confirmed by the data
presented in this study), while the populations of yellow-eyed T. cf. macrops from coastal areas of southern and
central Vietnam were up-to-date and never included in any phylogenetic analyses. In this research, it is demonstrated
that these populations comprise a monophyletic lineage morphologically different from all other members of the
genus Trimeresurus, which we herein describe as a new species. It is surprising that the yellow-eyed Trimeresurus
cyanolabris sp.nov. was recovered as the sister taxon to the red-eyed species T. rubeus from southern Vietnam but
was only distantly related to the superficially similar yellow-eyed T. macrops sensu stricto from central Thailand
(see Fig. 2). Furthermore, we also observed several individuals of T. macrops in northeast Thailand (such as in Phu
Pha Man NP in Khon Kaen Province and Phu Kradung NP in Loei Province, see Fig. 6F–G, respectively) having
distinct pale yellow bands, thus differing from typical specimens of T. macrops from Central Thailand. We therefore
tentatively suggest that populations in northern Thailand should be regarded as Trimeresurus cf. macrops, pending
future integrative studies to clarify their taxonomic status.
The recorded distribution of T. macrops in Vietnam still remains controversial. Ngo et al. (2022) and Uetz et
al. (2024) provide records of this species for Vietnam without providing any voucher specimens or other evidence,
even though Malhotra et al. (2011) and Mrinalini et al. (2015) suggested that T. macrops should be removed from
the herpetofaunal list of Vietnam. Orlov et al. (2003: 237) and Nguyen et al. (2009: 418) reported this species
from Dong Nai Province (Cat Tien NP), Kien Giang Province (Phu Quoc NP), and Ca Mau Province, but also
without providing detailed morphological information. The record of T. macrops from Cat Tien NP is likely based
on a misidentification of T. rubeus (see Malhotral et al. 2011; our data), and the species was not included in the
herpetofaunal checklist of the national park (Vassilieva et al. 2016). The existing records of T. macrops from Phu
Quoc NP are based on misidentified specimens of T. cardamomensis (see Ziegler et al. 2018; our data). Finally, the
record of T. macrops from Ca Mau Province is highly likely based on a misidentification of T. albolabris, which
is the most common species in lowland and human-disturbed areas of southern Vietnam. Furthermore, some of the
published records of T. rubeus from Bien Hoa City, Tan Phuc District, Dong Nai Province, and Cu Chi District in Ho
Chi Minh City, Vietnam (Malhotra et al. 2011) could actually be based on misidentified specimens of T. albolabris,
which originate from the Cho Ray Hospital, Vietnam (TV. Nguyen pers. obser.); however, further research is needed
to confirm this assumption. In summary, we provide strong evidence for the removal of T. macrops from the snake
fauna of Vietnam. Future studies are required to elucidate the actual distribution, ecology, and toxicology of the
three morphologically similar green-colored forest-dwelling members of the T. macrops species complex found in
Vietnam, namely: Trimeresurus cyanolabris sp. nov., T. cardamomensis, and T. rubeus.
IDIIATULLINA ET AL.
388 · Zootaxa 5474 (4) © 2024 Magnolia Press
FIGURE 6. Other members of Trimeresurus macrops species complex in life. – Trimeresurus cardamomensis: A Pong Nam
Ron, Chanthaburi, Thailand (adult male); B Khao Soidao WS, Chanthaburi, Thailand (adult female) – T. macrops: C Makkasan,
Bangkok, Thailand (adult male); D Tha Luang, Lop Buri, Thailand (adult male); E Wang Nam Khiao, Nakhon Ratchasima,
Thailand (adult female) – T. macrops (Northern Thailand): F Phu Kradung NP, Loei, Thailand (adult male); G: Phu Wiang NP,
Khon Kaen, Thailand (adult male) – T. rubeus: H-I Cat Tien NP, Dong Nai, Vietnam (adult male and adult female, respectively).
Photos by: A. Khaosung (A–B, D–F), P. Pawangkhanant (C), A. Pierce (G), H. X. N. Nguyen (H), and A. M. Bragin (I).
Our phylogenetic results suggest that multiple changes in habitat preferences and dorsal coloration likely
occurred during the evolution of the subgenus Trimeresurus. Also, the presence of a distinct, previously unnoticed
species of Trimeresurus in coastal areas of southern and central Vietnam further underlines the importance of this
area as a local center of herpetofaunal diversity and endemism (Poyarkov et al. 2021, 2023). Recent studies have
reported on numerous new species of reptiles (e.g., Pauwels et al. 2018; Kliukin et al. 2023; 2024) and amphibians
(e.g., Duong et al. 2018; Gorin et al. 2023) from this region. Also, we would like to note that the remaining forest
communities in coastal areas of the southern and central coastal regions of Vietnam are under a great threat of
deforestation (Meijer 1973; De Koninck 1999; Laurance 2007; Meyfroidt & Lambin 2008; Kuznetsov & Kuznetsova
2011). The discovery of Trimeresurus cyanolabris sp. nov. further underlines the key importance of these unique
coastal tropical forests for the conservation of herpetofaunal diversity in Southeast Asia.
Our work raises the total number of species of the genus Trimeresurus to 50; Trimeresurus cyanolabris sp. nov.
represents the tenth species of Trimeresurus known from Vietnam, together with T. albolabris, T. cardamomensis, T.
gumprechti David, Vogel, Pauwels & Vidal, T. guoi, T. honsonensis, T. rubeus, T. stejnegeri, T. truongsonensis Orlov,
Ryabov, Bui & Ho, and T. vogeli David, Vidal & Pauwels. Despite recent progress on the study of Trimeresurus
species, the taxonomic status of some of the widely distributed species in Indochina (including Vietnam, Laos,
Cambodia, and Thailand) still remains comparatively less studied and controversial, such as the T. gumprechti
complex and T. stejnegeri complex. Furthermore, in Vietnam, venomous snakes of the genus Trimeresurus are
considered to be the most common in recorded cases of snakes to human conflicts such as snakebites; they are
endangered due to hunting, illegal trade, and progressing habitat loss. Recently, a number of initiatives were launched
TRIMERESURUS CYANOLABRIS S P. NOV. Zootaxa 5474 (4) © 2024 Magnolia Press · 389
to increase public awareness about snakes in Vietnam, such as “Snake Identification and First Aid for Snakebites
in Vietnam” (SIFASV), “Snakes & Wildlife Central Vietnam-Inform & Protect,” “Snakes of Vietnam,” and “Viet
Snake Rescuer” (available on social networks). Therefore, we take the opportunity in this paper to further emphasize
the need for future studies to clarify the taxonomy, distribution, ecology, and toxicology of Trimeresurus species in
Vietnam, as well as additional activities concerning conservation education in order to raise awareness of first aid
in cases of snake bite and the importance of snake conservation in Vietnam.
TABLE 2. Sequences and voucher specimens of the genus Trimeresurus and outgroup taxa used in this study.
No. Sample ID Genbank accession number Species Country Locality References
cytb ND4 16S
1 ZMMU Re-
17680
PP766216 PP779472 PP792705 Trimeresurus
(Trimeresurus)
cyanolabris sp.
nov.
Vietnam Ninh Thuan,
Nui Chua NP
this study
2 ZMMU Re-
17681
PP766217 PP779473 — Trimeresurus
(Trimeresurus)
cyanolabris sp.
nov.
Vietnam Ninh Thuan,
Nui Chua NP
this study
3 ZMMU Re-
17855
PP766218 PP779474 — Trimeresurus
(Trimeresurus)
macrops
Thailand Nakhon
Ratchasima,
Pak Chong
this study
4 ZMMU Re-
17856
PP766219 PP779475 — Trimeresurus
(Trimeresurus)
macrops
Thailand Bangkok this study
5 ZMMU Re-
17857
PP766220 PP779476 — Trimeresurus
(Trimeresurus)
macrops
Thailand Bangkok this study
6 ZMMU Re-
17858
PP766221 PP779477 — Trimeresurus
(Trimeresurus)
macrops
Thailand Ayutthaya this study
7 TMA2 AB920253 — — Trimeresurus
(Trimeresurus)
macrops
Thailand Nong Bua
Lamphu
Supikamolseni et
al. (2015)
8 TMA7 AB920254 — — Trimeresurus
(Trimeresurus)
macrops
Thailand Bangkok Supikamolseni et
al. (2015)
9 TMA14 AB920255 — — Trimeresurus
(Trimeresurus)
macrops
Thailand Ratchaburi Supikamolseni et
al. (2015)
10 TMA19 AB920256 — — Trimeresurus
(Trimeresurus)
macrops
Thailand Ratchaburi Supikamolseni et
al. (2015)
11 TMA20 AB920257 — — Trimeresurus
(Trimeresurus)
macrops
Thailand Ratchaburi Supikamolseni et
al. (2015)
12 TMA21 AB920258 — — Trimeresurus
(Trimeresurus)
macrops
Thailand Ratchaburi Supikamolseni et
al. (2015)
......continued on the next page
IDIIATULLINA ET AL.
390 · Zootaxa 5474 (4) © 2024 Magnolia Press
TABLE 2. (continued)
No. Sample ID Genbank accession number Species Country Locality References
cytb ND4 16S
13 TMA24 AB920259 — — Trimeresurus
(Trimeresurus)
macrops
Thailand Ratchaburi Supikamolseni et
al. (2015)
14 TMA31 AB920260 — — Trimeresurus
(Trimeresurus)
macrops
Thailand Nakhon
Ratchasima
Supikamolseni et
al. (2015)
15 TMA35 AB920261 — — Trimeresurus
(Trimeresurus)
macrops
Thailand —Supikamolseni et
al. (2015)
16 TMA37 AB920263 — — Trimeresurus
(Trimeresurus)
macrops
Thailand —Supikamolseni et
al. (2015)
17 A69 — KR021052 KR021118 Trimeresurus
(Trimeresurus)
macrops
Thailand Petchabun Mrinalini et al.
(2015)
18 B27 AF517184 AF517219 AF517176 Trimeresurus
(Trimeresurus)
macrops
Thailand Bangkok Creer et al. (2003)
19 B35 — KR021050 KR021116 Trimeresurus
(Trimeresurus)
macrops
Thailand Central
Thailand
Mrinalini et al.
(2015)
20 B93 — KR021065 KR021132 Trimeresurus
(Trimeresurus)
macrops
Thailand Nakhon
Ratchasima
Mrinalini et al.
(2015)
21 ZMMU Re-
14506
OR470577 OR470543 PP032809 Trimeresurus
(Trimeresurus)
cardamomensis
Vietnam Kien Giang,
Phu Quoc NP
Idiiatullina et al.
(2023); Idiiatullina
et al. (2024b)
22 ZMMU Re-
17859
PP766222 PP779478 — Trimeresurus
(Trimeresurus)
cardamomensis
Thailand Chanthaburi,
Khitchakut,
Kra Thing
waterfall
this study
23 B442 — KR021071 KR021138 Trimeresurus
(Trimeresurus)
cardamomensis
Cambodia Koh Kong Mrinalini et al.
(2015)
24 B443 — KR021070 KR021137 Trimeresurus
(Trimeresurus)
cardamomensis
Cambodia Koh Kong Mrinalini et al.
(2015)
25 B567 — KR021080 KR021146 Trimeresurus
(Trimeresurus)
cardamomensis
Cambodia Koh Kong Mrinalini et al.
(2015)
26 B568 — KR021081 KR021147 Trimeresurus
(Trimeresurus)
cardamomensis
Cambodia Koh Kong Mrinalini et al.
(2015)
27 B66 — KR021062 KR021129 Trimeresurus
(Trimeresurus)
cardamomensis
Thailand Chanthaburi Mrinalini et al.
(2015)
......continued on the next page
TRIMERESURUS CYANOLABRIS S P. NOV. Zootaxa 5474 (4) © 2024 Magnolia Press · 391
TABLE 2. (continued)
No. Sample ID Genbank accession number Species Country Locality References
cytb ND4 16S
28 B67 — KR021061 KR021128 Trimeresurus
(Trimeresurus)
cardamomensis
Thailand Chanthaburi Mrinalini et al.
(2015)
29 LSUHC
10089
— KX660618 KX660220 Trimeresurus
(Trimeresurus)
cardamomensis
Cambodia Cardamon Mt. Figueroa et al.
(2016)
30 ZMMU
Re-14431
OR470578 OR470542 PP032808 Trimeresurus
(Trimeresurus)
rubeus
Vietnam Lam Dong,
Bao Loc
Idiiatullina et al.
(2023); Idiiatullina
et al. (2024b)
31 B523 — KR021073 — Trimeresurus
(Trimeresurus)
rubeus
Vietnam Southern
Vietnam
Mrinalini et al.
(2015)
32 B561 — KR021075 KR021141 Trimeresurus
(Trimeresurus)
rubeus
Cambodia Mondolkiri,
O’Rang
Mrinalini et al.
(2015)
33 B562 — KR021074 KR021140 Trimeresurus
(Trimeresurus)
rubeus
Cambodia Mondolkiri,
O’Rang
Mrinalini et al.
(2015)
34 B564 — KR021079 KR021145 Trimeresurus
(Trimeresurus)
rubeus
Cambodia Mondolkiri,
O’Rang
Mrinalini et al.
(2015)
35 B71 — KR021063 KR021130 Trimeresurus
(Trimeresurus)
rubeus
Vietnam Southern
Vietnam
Mrinalini et al.
(2015)
36 B72 — GQ428484 GQ428468 Trimeresurus
(Trimeresurus)
rubeus
Vietnam Southern
Vietnam
Malhotra et al.,
2010
37 B73 — KR021064 KR021131 Trimeresurus
(Trimeresurus)
rubeus
Vietnam Southern
Vietnam
Mrinalini et al.
(2015)
38 ZMMU ISS-
074 / LSUH
C8602
OR470564 KX660619 KX660222 Trimeresurus
(Trimeresurus)
honsonensis
Vietnam Kien Giang,
Hon Son Is.
Idiiatullina et al.
(2023); Figueroa et
al. (2016)
39 ZMMU Re-
17231
OR470575 OR470545 PP032807 Trimeresurus
(Trimeresurus)
kuiburi
Thailand Prachuap
Khiri Khan,
Kuiburi, Wat
Khao Daeng
Idiiatullina et al.
(2023); Idiiatullina
et al. (2024b)
40 ZMMU Re-
17664
OR470567 OR470535 OR471627 Trimeresurus
(Trimeresurus)
kraensis
Thailand Chumphon,
Wat Tham
Sanook
temple
Idiiatullina et al.
(2023); Idiiatullina
et al. (2024b)
41 ZMMU Re-
17212
OR470570 OR470547 OR471632 Trimeresurus
(Trimeresurus)
venustus
Thailand Krabi,
Mueang
Krabi,
Tiger Cave
viewpoint
Idiiatullina et al.
(2023)
......continued on the next page
IDIIATULLINA ET AL.
392 · Zootaxa 5474 (4) © 2024 Magnolia Press
TABLE 2. (continued)
No. Sample ID Genbank accession number Species Country Locality References
cytb ND4 16S
42 ZMMU Re-
17667
OR470579 OR470553 PP032810 Trimeresurus
(Trimeresurus)
kanburiensis
Thailand Kanchanaburi,
Sai Yok, Khao
Yai N P.
Idiiatullina et al.
(2023); Idiiatullina et
al. (2024b)
43 B522 — AY289231 AY352737 Trimeresurus
(Trimeresurus)
kanburiensis
Thailand Kanchanaburi Malhotra & Thorpe
(2003)
44 ZMMU Re-
17661
OR470557 OR470538 OR471621 Trimeresurus
(Trimeresurus)
ciliaris
Thailand Trang, Palian,
Thum Khao
Ting
Idiiatullina et al.
(2023)
45 QSMI Tpur74 /
CAS 212246
OR470556 AY352772 OR471642 Trimeresurus
(Trimeresurus)
ayeyarwadyensis
Myanmar Ayeyarwade,
Mwe Hauk
Malhotra & Thorpe
2004a; Idiiatullina et
al. (2023)
46 AM A85 AF171899 U41891 AY352741 Trimeresurus
(Trimeresurus)
cantori
India Nicobar Malhotra & Thorpe
(2004a); Kraus et al.
1996
47 CAS243566AM
A20
ON804490 ON804505 —Trimeresurus
(Trimeresurus)
erythrurus
Myanmar Rangoon Malhotra & Thorpe
(2004a); Chan et al.
(2022)
48 AM B487 AY352755 AY352818 AY352724 Trimeresurus
(Trimeresurus)
septentrionalis
Nepal Kathmandu Malhotra & Thorpe
(2004a)
49 QSMI
TA091164
OR470562 OR470536 OR471641 Trimeresurus
(Trimeresurus)
albolabris
Thailand Bangkok Idiiatullina et al.
(2023)
50 ZMMU NAP-
11772
OR470580 OR470554 OR471643 Trimeresurus
(Trimeresurus)
guoi
Thailand Nan, Doi Phu
Kha Mt.
Idiiatullina et al.
(2023)
Outgroups
51 AUP-01988 OR470561 OR470555 AF517181 Trimeresurus
(Viridovipera)
gumprechti
Thailand Loei Idiiatullina et al.
(2023); Creer et al.
(2003)
52 B416 / CHS824 AY352765 AY352831 MK194252 Trimeresurus
(Viridovipera)
medoensis
China Tibet, Motuo Malhotra & Thorpe
(2004); Li et al.
(2020)
53 CHS 677 MK201269 — MK194143 Trimeresurus
(Viridovipera)
stejnegeri
China Fujian, China Li et al. (2020)
54 AM B97 AY059574 AF517225 AF517183 Trimeresurus
(Viridovipera)
vogeli
Laos Champasak,
Pakxong
Creer et al. (2003)
55 SCUM 035045
/ CHS 644
(=SYS r001235)
EF597522 EF597528 MK194535 Trimeresurus
(Viridovipera)
yunnanensis
China Yunnan,
Ailaoshan
Dawson et al (2008);
Li et al. (2020)
56 AM B4 / CHS
895
AY352764 AY352830 MK194293 Trimeresurus
(Parias)
flavomaculatus
Philippines — Malhotra & Thorpe
(2004);
Li et al. (2020)
......continued on the next page
TRIMERESURUS CYANOLABRIS S P. NOV. Zootaxa 5474 (4) © 2024 Magnolia Press · 393
TABLE 2. (continued)
No. Sample ID Genbank accession number Species Country Locality References
cytb ND4 16S
57 AM B33 /
16hageNS
AY059567 AY059585 MG561492 Trimeresurus
(Parias) hageni
Indonesia — Malhotra & Thorpe
(2004);
Priambodo et al.
(unpublished data)
58 B349 AY371832 AY371861 AY371786 Trimeresurus
(Parias)
malcolmi
Malaysia Sabah Sanders et al.
(2004)
59 B210 AY352756 AY352819 AY352725 Trimeresurus
(Parias)
schultzei
Philippines — Malhotra & Thorpe
(2004)
60 B368 AY371824 AY371865 AY371792 Trimeresurus
(Parias)
sumatranus
Indonesia Sumatra Sanders et al.
(2004)
61 ZMMU Re-
16158
OR470572 OR470544 PP032797 Trimeresurus
(Popeia) sabahi
fucatus
Malaysia Pahang,
Fraser’s Hill
Idiiatullina et al.
(2023); Idiiatullina
et al. (2024b)
62 ZMMU Re-
16761
OR470573 OR470546 PP032799 Trimeresurus
(Popeia)
popeiorum
Myanmar Kachin,
Indawgyi NR
Idiiatullina et al.
(2023); Idiiatullina
et al. (2024b)
63 AUP-00061 OR470571 OR470534 PP032791 Trimeresurus
(Popeia) lanna
Thailand Chiang Mai,
Doi Inthanon
NP
Idiiatullina et al.
(2023); Idiiatullina
et al. (2024b)
64 B467 AY371807 AY371851 AY371781 Trimeresurus
(Popeia)
phuketensis
Thailand Phang Nga Sanders et al.
(2006)
65 ZMMU Re-
17668
OR470574 OR470550 PP032801 Trimeresurus
(Popeia)
tenasserimensis
Thailand Ratchaburi,
Suan Phueng
Idiiatullina et al.
(2023); Idiiatullina
et al. (2024b)
66 B345 AY371811 AY371849 AY371775 Trimeresurus
(Popeia)
nebularis
Malaysia Pahang,
Cameron
Highlands
Malhotra & Thorpe
(2004)
67 APF/SFRI-
1871
MK720609 — MK722155 Trimeresurus
(Himalayophis)
arunachalensis
India — Captain et al.
(2019 )
68 B258 AY352749 AY352810 AY352715 Trimeresurus
(Himalayophis)
tibetanus
Nepal — Malhotra & Thorpe
(2004a)
69 B301 AY352754 AY352817 AY352722 Craspedocephalus
borneensis
Malaysia Sabah Malhotra & Thorpe
(2004)
70 B213 AY352757 AY352820 AF517177 Craspedocephalus
puniceus
Indonesia — Creer et al. (2003)
71 B261 AY352762 AY352828 AY352732 Peltopelor
gramineus
India — Malhotra & Thorpe
(2004)
72 A218 AY059569 AY352829 AY059564 Peltopelor
malabaricus
India — Malhotra & Thorpe
(2004)
......continued on the next page
IDIIATULLINA ET AL.
394 · Zootaxa 5474 (4) © 2024 Magnolia Press
TABLE 2. (continued)
No. Sample ID Genbank accession number Species Country Locality References
cytb ND4 16S
73 A58 / RAP
0453
KC347479 AY059597 AY059565 Peltopelor
trigonocephalus
Sri Lanka — Malhotra & Thorpe
(2004); Pyron et al.
(2013)
74 B499 AY352747 AY352808 KJ872487 Azemiops feae China — Malhotra & Thorpe
(2004);
Geng & Yan
(unpublished data)
TABLE 3. List of morphological variables recorded from specimens examined.
No. Abbreviation Meaning Code
1 Sex Sex 1: male; 2: female; 3: unsexed
2 SVL Snout-vent length Value
3 TaL Tail length Value
4 TL Total length Value
5 TaL/TL Ratio tail length / TL Value
7 VEn Number of ventrals Value (counted after Dowling (1958))
9 SC Number of subcaudals Value (excluding scale of the tip)
11 ASR Number of scale rows on neck
Value (counted at one head-length behind the angle of
the jaws)
12 MSR Number of scale rows at midbody Value (counted at SVL/2)
13 DSR Number of scale rows before vent Value (counted at one head-length before the cloaca)
14 KSR Keeling of dorsal scales at midbody in males 0: smooth; 1: weakly keeled; 2 distinctly keeled
16 SL-l Number of supralabials at left Value
17 SL-r Number of supralabials at right Value
18 Σ SL Total number of supralabials Value
19 C3SL/SubOc-l
Number of scales between 3rd SL and
subocular (left) Value
20 C3SL/SubOc-r
Number of scales between 3rd SL and
subocular (right) Value
19 C4SL/SubOc-l
Number of scales between 4th SL and
subocular (left) Value
20 C4SL/SubOc-r
Number of scales between 4th SL and
subocular (right) Value
27 C45SL/SubOc-l
Number of scales between 4th and 5th SL and
subocular (left) Value
28 C45SL/SubOc-r
Number of scales between 4th and 5th SL and
subocular (right) Value
31 CEP
Number of cephalic scales between the
supraoculars Value (counted between the middle of supraoculars)
32 SC/SpOc-l
Number of scales surrounding the supraocular
at left Value
33 SC/SpOc-r
Number of scales surrounding the supraocular
at right Value
......continued on the next page
TRIMERESURUS CYANOLABRIS S P. NOV. Zootaxa 5474 (4) © 2024 Magnolia Press · 395
TABLE 3. (continued)
No. Abbreviation Meaning Code
34 Σ SC/SpOc
Total number of scales surrounding both
supraoculars Value
35 K-Occ Keeling of occipital scales in males 0: smooth; 1: weakly keeled; 2: distinctly keeled
37 K-Tem Keeling of temporal scales in males 0: smooth; 1: weakly keeled; 2: distinctly keeled
39 IN-sep Number of scales between the internasals Value
40 Sn-SC Number of scales on the snout
Value (counted between the limit of internasals or the
scale separating the internasals and a line connecting
the anterior margins of supraoculars)
41 He-SC Number of scales on upper head
Value (counted between the limit of internasals or the
scale separating the internasals and a line connecting
the angle of the jaws)
42 IL-l Number of infralabials at left Value
43 IL-r Number of infralabials at right Value
44 Σ IL Total number of infralabials Value
45 HL Head length Value (from tip of snout to the angle of the jaws)
46 HL/SVL Ratio head length / snout-vent length in males Value
47 HW Head width
Value (measured at the widest part of the head on
posterior side)
48 SnL Snout length
Value (measured between the tip of the snout and the
anterior margin of the eye)
49 SnL/HL Ratio snout length / head length in males Value
51 ED Eye diameter (vertical) Value
52 DEL Distance eye-lip
Value (measured between the lower margin of the eye
and the edge of the upper lip)
53 SnL/ED Ratio snout length / eye diameter in males Value
55 ED/DEL Ratio eye diameter / distance eye-lip in males Value
57 D E-nostril Distance eye-nostril
Value (measured between the posterior edge of the
nostril and the anterior edge of the eye)
58 D E-pit Distance eye-pit
Value (measured between the posterior edge of the
loreal pit and the anterior edge of the eye)
59 D E-nostril/HL
Ratio distance eye-nostril / head length in
males Value
61 D E-pit/HL Ratio distance eye-pit / head length in males Value
63
D E-pit/D E-
nostril
Ratio distance eye-pit / distance eye-nostril
in males Value
65 W-In Width of internasal Value (usually measured on right internasal)
66 L-SpOc Length of supraocular(s) Value
67 W-SpOc Width of supraocular(s) Value
68 L-SpOc/W-SpOc Ratio length of SupOc / Width of SupOc Value
69 W-In/W-SpOc Ratio width of internasals / Width of SupOc Value
70 W-SpOc/W-In Ratio width of SupOc / Width of internasals Value
71 L-3SL Length of 3rd supralabial Value
72 H-3SL Heigth of 3rd supralabial Value (measured along the edge of the upper lip)
73 L-3SL/H-3SL
Ratio length of 3rd supralabial / height of 3rd
supralabial Value
74 L-3SL/HL Ratio length of 3rd SL / head length in males Value
......continued on the next page
IDIIATULLINA ET AL.
396 · Zootaxa 5474 (4) © 2024 Magnolia Press
TABLE 3. (continued)
No. Abbreviation Meaning Code
76 H-4SL Height of 4th supralabial Value
77 H-4SL/H-3SL
Ratio height of 4th supralabial / heigth of 3rd
supralabial Value
78 BoCol Body color (in life) 1: green (various shades)
79 DorBan Presence of dark dorsal bands 0: absent; 1: present
80 DorDots Presence of white vertebral dots 0: absent; 1: present
81 EyeCol Eye color (in life)
1: red; 2: yellow, gold or greenish yellow; 3: green; 4:
orange
82 POcStr Postocular streak 0: absent; 1: present
83 COLPOcStr Postocular streak 0: absent; 1: white; 2: red above, white below
84 VLSTRIPE Ventrolateral stripe 0: absent; 1: present
85 COLVLSTRIPE Ventrolateral stripe
0: absent; 1: cream or bluish-white; 2: white above,
red below
86 TAILPAT Tail pattern (dorsal surface)
1: blotched, no sharp limit with green; 2: uniform,
sharp limit with green
TABLE 4. Uncorrected p–distances (percentage) between the sequences of cyt b mtDNA gene of species of the subgenus
Trimeresurus included in the phylogenetic analyses.
No. Species 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
1
Trimeresurus
cyanolabris sp. nov.
2T. macrops 8.5
3T. cardamomensis 8.0 5.3
4T. rubeus 6.0 7.2 6.5
5T. honsonensis 10.7 6.1 7.5 9.4
6T. ciliaris 8.3 8.2 8.1 8.2 10.3
7T. kuiburi 9.3 5.5 6.0 7.9 7.6 9.3
8T. venustus 8.6 5.3 3.8 7.2 7.6 8.7 5.9
9T. kanburiensis 7.6 6.1 5.1 7.7 6.8 8.8 7.2 6.9
10 T. kraensis 9.1 6.0 5.9 8.0 6.9 9.3 6.6 5.9 7.2
11 T. guoi 13.8 11.2 12.2 12.5 14.2 13.0 13.3 12.9 13.4 12.3
12 T. albolabris 16.0 13.6 14.6 14.1 14.7 14.6 14.9 14.0 14.9 13.8 3.9
13 T. cantori 13.2 12.0 12.6 12.6 12.6 13.4 13.4 12.9 13.2 13.0 4.2 7.0
14 T. erythrurus 15.2 13.4 14.8 13.7 15.5 14.3 15.0 15.0 15.1 14.0 5.0 6.4 5.2
15 T. ayeyarwadyensis 14.2 13.3 13.8 12.5 14.9 14.5 14.4 14.9 15.0 13.9 4.9 7.7 5.0 2.0
16 T. septentrionalis 14.1 12.9 13.6 14.4 15.5 14.1 14.9 14.3 15.4 13.3 7.0 8.0 7.6 8.1 8.7
TRIMERESURUS CYANOLABRIS S P. NOV. Zootaxa 5474 (4) © 2024 Magnolia Press · 397
TABLE 5. Morphological data on the type series of Trimeresurus cyanolabris sp. nov. Notes: for abbreviations see
Materials and methods section; N/a: Data not available.
No. Collection
number
Type
status
Locality Sex SVL
(mm)
TaL
(mm)
TL
(mm)
HW
(mm)
HL
(mm)
ED
(mm)
EN
(mm)
1 ZMMU Re-
17678
Paratype Nui Chua NP, Ninh Thuan,
Vietnam
M 475 105 580 13.5 20.0 3.7 4.8
2 ZMMU Re-
17679
Holotype Nui Chua NP, Ninh Thuan,
Vietnam
M 464 106 570 13.0 21.2 3.5 5.2
3 ZFMK
94670
Ba To, Quang Ngai,
Vietnam
M 478 129 607 14.1 25.8 3.4 4.4
4 DTU 605 Paratype Hon Ba NR, Cam Lam,
Khanh Hoa, Vietnam
F 437 65 502 14.1 21.3 3.9 5.2
5 DTU 606 Paratype Am Chua, Diem Khanh,
Khanh Hoa, Vietnam
F 435 70 505 13.9 20.2 3.4 5.3
6 DTU 635 Quy Nhon, Binh Dinh,
Vietnam
F 638 105 743 15.1 23.3 3.9 n/a
7 DTU 636 Van Canh, Binh Dinh,
Vietnam
F 578 91 669 14.5 22.4 3.6 n/a
8 ZMMU Re-
17680
Paratype Nui Chua NP, Ninh Thuan,
Vietnam
F 544 86 630 17.3 24.8 4.0 6.0
9 ZMMU Re-
17681
Paratype Nui Chua NP, Ninh Thuan,
Vietnam
F 532 89 621 16.0 24.1 4.0 5.3
10 ZMMU Re-
17682
Paratype Nui Chua NP, Ninh Thuan,
Vietnam
F 511 93 604 16.2 23.8 4.0 6.0
11 ZMMU Re-
17684
Paratype Phuoc Binh NP, Ninh
Thuan, Vietnam
F 522 84 606 15.9 24.0 3.8 6.1
12 DTU 650 Paratype Hon Heo Isl., Ninh Hoa,
Khanh Hoa, Vietnam
F 435 75 510 13.0 20.1 3.3 5.1
13 ZMMU Re-
17683
Paratype Phuoc Binh NP, Ninh
Thuan, Vietnam
SF 393 61 453 12.8 19.8 3.6 4.1
......continued on the next page
IDIIATULLINA ET AL.
398 · Zootaxa 5474 (4) © 2024 Magnolia Press
TABLE 5. (continued)
No. Collection
number
Type
status
Locality Sex ASR MSR PSR VEN SC SL IL
1 ZMMU Re-
17678
Paratype Nui Chua NP, Ninh Thuan,
Vietnam
M 21 21 15 172 71 10/10 12/12
2 ZMMU Re-
17679
Holotype Nui Chua NP, Ninh Thuan,
Vietnam
M 21 21 15 175 72 10/10 12/12
3 ZFMK
94670
Ba To, Quang Ngai, Vietnam M 21 21 15 166 75 10/9 12/13
4 DTU 605 Paratype Hon Ba NR, Cam Lam, Khanh
Hoa, Vietnam
F 21 21 15 172 52 10/10 13/13
5 DTU 606 Paratype Am Chua, Diem Khanh, Khanh
Hoa, Vietnam
F 21 21 15 178 58 11/11 13/13
6 DTU 635 Quy Nhon, Binh Dinh, Vietnam F 21 21 15 175 62 9/10 10/10
7 DTU 636 Van Canh, Binh Dinh, Vietnam F 23 21 15 173 62 10/10 11/11
8 ZMMU Re-
17680
Paratype Nui Chua NP, Ninh Thuan,
Vietnam
F 21 21 15 178 57 11/11 13/13
9 ZMMU Re-
17681
Paratype Nui Chua NP, Ninh Thuan,
Vietnam
F 21 21 15 177 59 10/11 13/13
10 ZMMU Re-
17682
Paratype Nui Chua NP, Ninh Thuan,
Vietnam
F 21 21 15 176 60 10/10 12/12
11 ZMMU Re-
17684
Paratype Phuoc Binh NP, Ninh Thuan,
Vietnam
F 23 21 15 170 53 10/10 12/12
12 DTU 650 Paratype Hon Heo Isl., Ninh Hoa, Khanh
Hoa, Vietnam
F 21 21 15 173 59 10/10 12/12
13 ZMMU Re-
17683
Paratype Phuoc Binh NP, Ninh Thuan,
Vietnam
SF 21 21 15 169 55 10/10 12/12
TABLE 6. Comparison of morphological characters of Trimeresurus cyanolabris sp. nov. with T. cardamomensis,
T. macrops, and T. rubeus. Remarks: Diagnostic differences from the new species are marked in bold. (?): requires
verification.
Species T. cyanolabris sp.
nov.
T. cardamomensis T. macrops T. rubeus
max SVL (mm,
males)
478 (n=3) 535 (n=5) 557 (n=42) 586 (n=2)
max SVL (mm,
females)
638 (n=10) 536 (n=5) 570 (n=23) 503 (n=5)
TaL/TL (males) 0.18–0.21
(X=0.19, n=3)
0.17–0.20
(X=0.19, n=5)
0.17–0.22
(X=0.19, n=32)
0.21–0.22
(X=0.22, n=2)
TaL/TL (females) 0.13–0.15
(X=0.14, n=10)
0.14–0.17
(X=0.15, n=4)
0.13–0.17
(X=0.15, n=22)
0.15–0.19
(X=0.17, n=5)
HW/HL (males) 0.55–0.68
(X=0.61, n=3)
0.58–0.72
(X=0.65, n=4)
0.56–0.82
(X=0.68, n=45)
0.53–0.60
(X=0.56 , n=2)
HW/HL (females) 0.65–0.70
(X=0.66, n=10)
0.44–0.76
(X=0.64, n=4)
0.60–0.77
(X=0.68, n=21)
0.46–0.72
(X=0.61, n=3)
ED/EN (males) 0.67–0.78
(X=0.74, n=3)
0.66–0.91
(X=0.78, n=4)
0.62–1.12
(X=0.89, n=42)
0.66–0.74
(X=0.70, n=2)
ED/EN (females) 0.62–0.88
(X=0.71, n=8)
0.51–0.97
(X=0.74, n=2)
0.64–0.97
(X=0.83, n=23)
0.79–0.95
(X=0.85, n=3)
......continued on the next page
TRIMERESURUS CYANOLABRIS S P. NOV. Zootaxa 5474 (4) © 2024 Magnolia Press · 399
TABLE 6. (continued)
Species T. cyanolabris sp.
nov.
T. cardamomensis T. macrops T. rubeus
VEN (males) 166–175
(X=171.0, n=3)
165–170
(X=167.0, n=5)
158–173
(X=165.2, n=42)
164–171
(X=167.5, n=2)
VEN (females) 169–178
(X=174.1, n=10)
168–175
(X=171.8, n=5)
159–173
(X=166.4, n=23)
158–163
(X=159.8, n=5)
SC (males) 71–75
(X=72.7, n=3)
60–75
(X=67.0, n=5)
63–74
(X=68.1, n=33)
78–80
(X=79.0, n=2)
SC (females) 52–62
(X=57.7, n=10)
58–63
(X=59.8, n=4)
50–62
(X=55.6, n=22)
54–69
(X=61.6, n=5)
VEN+SC (males) 241–247
(X=243.7, n=3)
226–243
(X=234.0, n=5)
225–240
(X=233.0, n=33)
244–249
(X=246.5, n=2)
VEN+SC (females) 223–237
(X=231.8, n=10)
228–234
(X=231.8, n=4)
214–235
(X=222.1, n=22)
214–228
(X=221.4, n=5)
Postocular stripe
in males
Absent present present present
Ventrolateral
body stripes
indistinct, white present, white or red and
white
present, white or red and
white
present, white or red
and white
Size scales on head
behind internasal
scales
Small large small small
Head shape more elongate-oval more triangular more elongate-oval more elongate-oval
Ventral of body green blue green yellow green yellow green yellow
Iris color golden yellow golden yellow golden yellow bright or deep reddish-
orange
Distributions Vietnam (South
Central Coast )
Cambodia (southwestern),
Thailand (southeastern),
Vietnam (Phu Quoc Isl.)
Thailand (northern?,
central, southern), Laos?
(central, southern),
Cambodia?
Vietnam (southern of
Langbiang plateau);
Cambodia (eastern)
Sources our data Malhotra et al. (2011);
Ziegler et al. (2018); our
data
Malhotra et al. (2011); our
data
Malhotra et al. (2011);
our data
ACKNOWLEDGMENTS
The fieldwork was completed within the frameworks and with partial financial support from the research project E-
1.2 of the Joint Vietnam-Russia Tropical Science and Technology Research Centre for 2023. Permission to conduct
fieldwork in Ninh Thuan Province, including Phuoc Binh National Park and Nui Chua National Park, was granted
by the Bureau of Forestry, Ministry of Agriculture and Rural Development of Vietnam and local administration
(Peoples’ Committee of Ninh Thuan Province: #317/UBNDVXNV of 03.02.2023). We thank Silke Schweiger,
Georg Gassner (NHMW), Dennis Rödder, Wolfgang Böhme (ZFMK), Valentina F. Orlova, Roman A. Nazarov
(ZMMU) for the opportunity to examine specimens deposited in the collections of their respective institutions.
NAP and AMB are grateful to Andrei N. Kuznetsov, Svetlana P. Kuznetsova, Hoi Dang Nguyen, and Leonid P.
Korzoun for their support and organization of fieldwork. We thank Andrei N. Kuznetsov and Svetlana P. Kuznetsova
for plant identification, as well as Evgeniy S. Popov (BIN RAS) for field support and assistance. We are deeply
grateful to Thuc Van Phan, and Tu Duc Nguyen (SIFASV, Vietnam) for their help during the field surveys. We
thank Andaman Kaosung (Thailand), Anita Malhotra (United Kingdom), Andrew Pierce (Thailand), and Huy Xuan
Ngoc Nguyen (Vietnam) for sharing information and providing us photographs of Trimeresurus spp. NAP thanks
the members of MSU HerpLab, including Vladislav A. Gorin, Evgeniya N. Solovyeva, Alexey V. Trofimets, Nikita
S. Klyukin, and Dmitriy V. Akhipov for their support and assistance. We also warmly thank Ngoc Quynh Nguyen
(SIFASV, Vietnam) for the great help in the preparation of the figures. We thank L.L. Grismer (USA), V. Deepak
IDIIATULLINA ET AL.
400 · Zootaxa 5474 (4) © 2024 Magnolia Press
(UK/Germany), and an anonymous reviewer for helpful comments that allowed us to improve the previous version
of the manuscript. This work was supported by the Russian Science Foundation to N.A. Poyarkov (Grant No. 22-
14-00037, specimen collection and preservation, molecular and morphological analyses, data analyses), and in part
by the Rufford Foundation to T.V. Nguyen (Grant No. 39897-1, data analysis).
References
Castoe, T.A. & Parkinson, C.L. (2006) Bayesian mixed models and the phylogeny of pitvipers (Viperidae: Serpentes). Molecular
Phylogenetics and Evolution, 39, 91–110.
https://doi.org/10.1016/j.ympev.2005.12.014
Chan-ard, T., Nabhitabhata, J. & Parr, J.W. (2015) A field guide to the reptiles of Thailand. Oxford University Press, New York,
New Yor,, 352 pp.
Creer, S., Malhotra, A. & Thorpe, R.S. (2003) Assessing the phylogenetic utility of four mitochondrial genes and a nuclear intron
in the Asian pit viper genus, Trimeresurus: separate, simultaneous, and conditional data combination analyses. Molecular
Biology and Evolution, 20, 1240–1251.
https://doi.org/10.1093/molbev/msg136
Dahn, H.A., Strickland, J.L., Osorio, A., Colston, T.J. & Parkinson, C.L. (2018) Hidden diversity within the depauperate genera
of the snake tribe Lampropeltini (Serpentes, Colubridae). Molecular Phylogenetics and Evolution, 129, 214–225.
https://doi.org/10.1016/j.ympev.2018.08.018
David, P., Vogel, G. & Dubois, A. (2011) On the need to follow rigorously the rules of the code for the subsequent designation
of a nucleospecies (type species) for a nominal genus which lacked one: the case of the nominal genus Trimeresurus
Lacépède, 1804 (Reptilia: Squamata: Viperidae). Zootaxa, 2992 (1), 1–51.
https://doi.org/10.11646/zootaxa.2992.1.1
Dawson, K., Malhotra, A., Thorpe, R.S., Guo, P., Mrinalini & Ziegler, T. (2008) Mitochondrial DNA analysis reveals a new
member of the Asian pitviper genus Viridovipera (Serpentes: Viperidae: Crotalinae). Molecular Phylogenetics and
Evolution, 49, 356–361.
https://doi.org/10.1016/j.ympev.2008.05.044
De Koninck, R. (1999) Deforestation in Viet Nam. International Research Centre, Ottawa, Ontario, 100 pp.
Dowling, H. (1951) A proposed standard system of counting ventrals in snakes. British Journal of Herpetology, 11, 97–99.
Duong, T.V., Do, D.T., Ngo, C.D., Nguyen, T.Q. & Poyarkov, N.A. (2018) A new species of the genus Leptolalax (Anura:
Megophryidae) from southern Vietnam. Zoological Research, 39 (3), 185–201.
https://doi.org/10.24272/j.issn.2095-8137.2018.009
Figueroa, A., McKelvy, A.D., Grismer, L.L., Bell, C.D. & Lailvaux, S.P. (2016) A species-level phylogeny of extant snakes with
description of a new Colubrid subfamily and genus. Plos One, 11, e0161070.
https://doi.org/10.1371/journal.pone.0161070
Golay, P., Smith, H.M., Broadley, D.G., Dixon, J.R., McCarthy, C., Rage, J.-C., Schätti, B., & Toriba, M. (1993) Endoglyphs and
other major venomous snakes of the world. A checklist. Azemiops Herpetological Data Center, Aïre, xv + 478 pp.
Gorin, V.A., Trofimets, A.V., Gogoleva, S.S., Le, D.X. & Poyarkov, N.A. (2023) A new species of Nanohyla (Anura: Microhylidae)
from the lowland forests of southern Vietnam. Zoological Research, 44, 732–736.
https://doi.org/10.24272/j.issn.2095-8137.2023.029
Green, M.D., Orlov, N.L. & Murphy, R.W. (2010) Toward a phylogeny of the Kukri snakes, genus Oligodon. Asian Herpetological
Research, 1, 1–21.
https://doi.org/10.3724/SP.J.1245.2010.00001
Gumprecht, A., Tillack, F., Orlov, N.L., Captain, A. & Raybov, S. (2004) Asian Pitvipers. GeitjeBooks, Berlin, 368 pp.
Hall, T.A. (1999) BioEdit: a user-friendly biological sequence alignment editor and analysis program for Windows 95/98/NT.
Nucleic acids symposium series, 41, 95–98.
Hoang, M.D., Luu, H.T., Tran, B.V., Le, D., To, V.Q., Dang, V.D. & Nguyen, H.N. (2019) Forest biodiversity in Khanh Hoa
province—Part 2 Animals. Publishing House for Science and Technology, 215 pp. [in Vietnamese]
Huelsenbeck JP, Hillis DM (1993) Success of phylogenetic methods in the four-taxon case. Systematic Biology 42: 247–264.
https://doi.org/10.1093/sysbio/42.3.247
Huelsenbeck, J.P. & Ronquist, F. (2001) MRBAYES: Bayesian inference of phylogenetic trees. Bioinformatics, 17, 754–755.
https://doi.org/10.1093/bioinformatics/17.8.754
Idiiatullina, S.S., Pawangkhanant, P., Tawan, T., Worranuch, T., Dechochai, B., Suwannapoom, C., Nguyen, T.V.,
Chanhome, L. & Poyarkov, N.A. (2023) Limestone jewel: A new colourful karst-dwelling pitviper (Serpentes:
Viperidae: Trimeresurus) from the poorly explored borderlands of southern peninsular Thailand. Vertebrate Zoology,
73, 697–716.
https://doi.org/10.3897/vz.73.e109854
Idiiatullina, S.S., Pawangkhanant, P., Suwannapoom, C., Tawan, T., Chanhome, L., Nguyen, T.V., David, P., Vogel, G. &
Poyarkov, N.A. (2024a) Another new species of karst-associated pitviper (Serpentes, Viperidae: Trimeresurus) from the
TRIMERESURUS CYANOLABRIS S P. NOV. Zootaxa 5474 (4) © 2024 Magnolia Press · 401
Isthmus of Kra, Peninsular Thailand. European Journal of Taxonomy, 930, 20–52.
https://doi.org/10.5852/ejt.2024.930.2489
Idiiatullina, S.S., Nguyen, T.V., Pawangkhanant, P., Suwannapoom, C., Chanhome, L., Mirza, Z.A., David, P., Vogel, G. &
Poyarkov, N.A. (2024b) An integrative taxonomic revision of the Trimeresurus popeiorum species complex (Reptilia:
Serpentes: Viperidae), with descriptions of two new species from the Indo-Burma biodiversity hotspot. Vertebrate Zoology,
74, 303–342.
https://doi.org/10.3897/vz.74.e113347
IUCN Standards and Petitions Subcommittee (2019) Guidelines for Using the IUCN Red List Categories and Criteria. Version
14. Prepared by the Standards and Petitions Subcommittee, IUCN, Cambridge and Gland 113pp.
Katoh, K., Rozewicki, J. & Yamada, K.D. (2019) MAFFT online service: multiple sequence alignment, interactive sequence
choice and visualization. Briefings in Bioinformatics, 20, 1160–1166.
https://doi.org/10.1093/bib/bbx108
Klemmer, K. (1963) Liste der rezenten Giftschlangen: Elapidae, Hydropheidae, Viperidae und Crotalidae. In: Die Giftschlangen
der Erde: Wirkungen und Antigenität der Gifte Therapie von Giftschlangenbissen. N.G. Elwert Universitäts- und
VerlagsBuchhandlung, Marburg, pp. 255–464, 37 col. pls. [in German]
Kliukin, N.S., Nguyen, T.V., Le, S.X., Bragin, A.M., Tran, T.T.V., Gorin, V.A. & Poyarkov, N.A. (2023) A new species of the
genus Dibamus Duméril & Bibron, 1839 (Squamata: Dibamidae) from the driest and hottest place of Vietnam. Zootaxa,
5380 (4), 301–320.
https://doi.org/10.11646/zootaxa.5380.4.1
Kliukin, N.S., Bragin, A.M., Nguyen, T.V., Le, S.X., Tran, T.T.V., Gorin, V.A. & Poyarkov, N.A. (2024) Another new species of
Dibamus Duméril & Bibron, 1839 (Squamata: Dibamidae) from Nui Chua National Park, Ninh Thuan Province, Vietnam.
Zootaxa, 5406 (1), 87–104.
https://doi.org/10.11646/zootaxa.5406.1.4
Kramer, E. (1977) Zur Schlangenfauna Nepals. Revue Suisse de Zoologie, 84 (3), 721–761, 5 figs. [in German]
https://doi.org/10.5962/bhl.part.91420
Kraus, F., Mink, D.G. & Brown, W.M. (1996) Crotaline Intergeneric Relationships Based on Mitochondrial DNA Sequence.
Copeia, 1996, 763–773.
https://doi.org/10.2307/1447637
Kuznetsov, A. & Kuznetsova, S. (2011) Botany of Bidoup-Nui Ba National Park. In: Nguyen, D.H. & Kuznetsov, A. (Eds.),
Biodiversity and ecological characteristics of Bidoup-Nui Ba National Park. Vietnam Academy of Science and Technology
Publishing House for Science and Technology, Hanoi, pp. 37–105. [in Vietnamese]
Lanfear, R., Calcott, B., Ho, S.Y.W. & Guindon, S. (2012) PartitionFinder: Combined selection of partitioning schemes and
substitution models for phylogenetic analyses. Molecular Biology and Evolution, 29, 1695–1701.
https://doi.org/10.1093/molbev/mss020
Laopichienpong, N., Muangmai, N., Supikamolseni, A., Twilprawat, P., Chanhome, L., Suntrarachun, S., Peyachoknagul, S. &
Srikulnath, K. (2016) Assessment of snake DNA barcodes based on mitochondrial COI and Cytb genes revealed multiple
putative cryptic species in Thailand. Gene, 594, 238–247.
https://doi.org/10.1016/j.gene.2016.09.017
Laurance, W.F. (2007) Forest destruction in tropical Asia. Current Science, 93 (11), 1544–1550.
Malhotra, A. & Thorpe, R.S. (2000) A phylogeny of the Trimeresurus group of pitvipers: new evidence from a mitochondrial
gene tree. Molecular Phylogenetics and Evolution, 16, 199–211.
https://doi.org/10.1006/mpev.2000.0779
Malhotra, A. & Thorpe, R.S. (2004) A phylogeny of four mitochondrial gene regions suggests a revised taxonomy for Asian
pitvipers (Trimeresurus and Ovophis). Molecular Phylogenetics and Evolution, 32, 83–100.
https://doi.org/10.1016/j.ympev.2004.02.008
Malhotra, A., Thorpe, R.S., Mrinalini & Stuart, B.L. (2011) Two new species of pitviper of the genus Cryptelytrops Cope 1860
(Squamata: Viperidae: Crotalinae) from Southeast Asia. Zootaxa, 2757 (1), 1–23.
https://doi.org/10.11646/zootaxa.2757.1.1
Mallik, A.K., Srikanthan, A.N., Ganesh, S.R., Vijayakumar, S.P., Campbell, P.D., Malhotra, A. & Shanker, K. (2021) Resolving
pitfalls in pit viper systematics–A multi-criteria approach to species delimitation in pit vipers (Reptilia, Viperidae,
Craspedocephalus) of Peninsular India reveals cryptic diversity. Vertebrate Zoology, 71, 577–619.
https://doi.org 10.3897/vz.71.e66239
Meijer, W. (1973) Devastation and regeneration of lowland dipterocarp forests in Southeast Asia. BioScience, 23 (9), 528–533.
https://doi.org/10.2307/1296481
Meyfroidt, P. & Lambin, E.F. (2008) Forest transition in Vietnam and its environmental impacts. Global Change Biology, 14(6),
1319–1336.
https://doi.org/10.1111/j.1365-2486.2008.01575.x
Minh, Q., Nguyen, M.A.T. & von Haeseler, A. (2013) Ultrafast approximation for phylogenetic bootstrap. Molecular Biology
and Evolution, 30, 1188–1195.
https://doi.org/10.1093/molbev/mst024
Mrinalini, Thorpe, R.S., Creer, S., Lallias, D., Dawnay, L., Stuart, B.L. & Malhotra, A. (2015) Convergence of multiple markers and
IDIIATULLINA ET AL.
402 · Zootaxa 5474 (4) © 2024 Magnolia Press
analysis methods defines the genetic distinctiveness of cryptic pitvipers. Molecular Phylogenetics and Evolution, 92, 266–279.
https://doi.org/10.1016/j.ympev.2015.06.001
Nemes, L., Babb, R., Devender, W.V., Nguyen, K.V., Le, Q.K., Vu, T.N., Rauhaus, A., Nguyen, T.Q. & Ziegler, T. (2013) First
contribution to the reptile fauna of Quang Ngai province, central Vietnam. Biodiversity Journal, 4 (2), 301–326.
Ngo, H.T., Nguyen, T.Q., Nguyen, H.V.M., Luu, V.Q., Phimphasone, V., Ha, N.V., Ziegler, T. & Le, M.D. (2022) Molecular
assessement of Pitviper populations (genus Trimeresurus) in Laos and Vietnam reveals new country record and overlooked
diversity. Vietnam Journal of Biotechnology, 20 (4), 589–598.
https://doi.org/10.15625/1811-4989/16863
Nguyen, L.T., Schmidt, H.A., Von Haeseler, A. & Minh, B.Q. (2015) IQ-TREE: A fast and effective stochastic algorithm for
estimating maximum-likelihood phylogenies. Molecular Biology and Evolution, 32, 268–274.
https://doi.org/10.1093/molbev/msu300
Nguyen, S.V., Ho, C.T. & Nguyen, T.Q. (2009) Herpetofauna of Vietnam. Chimaira, Frankfurt, 768 pp.
Nguyen, T.V., Duong, L.D. & Duong, T.T.A. (2019) New records and an updated list of snakes (Squamata: Serpentes) from Binh
Dinh Province, Central-Southern Vietnam. Hue University Journal of Science: Natural Science, 128 (1B), 35–41.
https://doi.org/10.26459/hueuni-jns.v128i1B.5203
Orlov, N.L., Ryabov, S.A., Nguyen, S.V. & Nguyen, T.Q. (2003) New records and data on the poorly known snakes of Vietnam.
Russian Journal of Herpetology, 10 (3), 217–240.
https://doi.org/10.30906/1026-2296-2003-10-3-217-240
Pauwels, O.S.G., Nazarov, R.A., Bobrov, V.V. & Poyarkov, N.A. (2018) Taxonomic status of two populations of Bent-toed
Geckos of the Cyrtodactylus irregularis complex (Squamata, Gekkonidae) with description of a new species from Nui
Chua National Park, southern Vietnam. Zootaxa, 4403 (2), 307–335.
https://doi.org/10.11646/zootaxa.4403.2.5
Poyarkov, N.A., Nguyen, T.V., Popov, E.S., Geissler, P., Pawangkhanant, P., Neang, T., Suwannapoom, C., Ananjeva, N.B. &
Orlov, N.L. (2023) Recent progress in taxonomic studies, biogeographic analysis and revised checklist of Reptilians in
Indochina. Russian Journal of Herpetology, 30 (5), 255–476.
https://doi.org/10.30906/1026-2296-2023-30-5-255-476
Poyarkov, N.A., Nguyen, T.V., Popov, E.S., Geissler, P., Pawangkhanant, P., Neang, T., Suwannapoom, C. & Orlov, N.L. (2021)
Recent progress in taxonomic studies, biogeographic analysis and revised checklist of Amphibians in Indochina. Russian
Journal of Herpetology, 28 (3A), 1–110.
https://doi.org/10.30906/1026-2296-2021-28-3A-1-110
Pyron, R.A., Kandambi, H.K.D., Hendry, C.R., Pushpamal, V., Burbrink, F.T. & Somaweera, R. (2013) Genus-level phylogeny
of snakes reveals the origins of species richness in Sri Lanka. Molecular Phylogenetics and Evolution, 66, 969–978.
https://doi.org/10.1016/j.ympev.2012.12.004
Rambaut, A., Drummond, A.J., Xie, D., Baele, G. & Suchard, M.A. (2018) Posterior summarization in bayesian phylogenetics
using tracer 1.7. Susko E (Ed.). Systematic Biology, 67, 901–904.
https://doi.org/10.1093/sysbio/syy032
Rathee, Y.S., Purkayastha, J., Lalremsanga, H.T., Dalal, S., Biakzuala, L., Muansanga, L. & Mirza, Z.A. (2022) A new cryptic
species of green pit viper of the genus Trimeresurus Lacépède, 1804 (Serpentes, Viperidae) from northeast India. Plos One,
17, 1–17.
https://doi.org/10.1371/journal.pone.0268402
Regenass, U. & Kramer, E. (1981) Zur Systematik der grünen Grubenottern der Gattung Trimeresurus (Serpentes, Crotalidae).
Revue suisse de Zoologie, 88 (1), 163–205. [in German]
https://doi.org/10.5962/bhl.part.82363
Salvi, D., Harris, D.J., Kaliontzopoulou, A., Carretero, M.A. & Pinho, C. (2013) Persistence across Pleistocene ice ages in
Mediterranean and extra-Mediterranean refugia: phylogeographic insights from the common wall lizard. BMC Evolutionary
Biology, 13, 1–18.
https://doi.org/10.1186/1471-2148-13-147
Sambrook, J., Fritsch, E.F. & Maniatis, T. (1989) Molecular cloning: a laboratory manual. Cold Spring Harbor Laboratory
Press, Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, 473 pp.
Tamura, K., Stecher, G., Peterson, D., Filipski, A. & Kumar, S. (2013) MEGA6: Molecular Evolutionary Genetics Analysis
Version 6.0. Molecular Biology and Evolution, 30, 2725–2729.
https://doi.org/10.1093/molbev/mst197
Uetz, P., Freed, P. & Hošek, J. (2024) The Reptile Database. Available at http://www.reptile-database.org/ (accessed 1 March 2024)
Vassilieva, A.B., Galoyan, E.A., Poyarkov, N.A. & Geissler, P. (2016) A Photographic Field Guide to the Amphibians and
Reptiles of the Lowland Monsoon Forests of Southern Vietnam. Edition Chimaira, Frankfurt am Main, 324 pp.
Vogel, G., Nguyen, T.V. & David, P. (2023) A new green pitviper of the complex of Trimeresurus albolabris complex (Reptilia,
Serpentes, Viperidae) from central and southern Myanmar. Zootaxa, 5357 (4), 515–554.
https://doi.org/10.11646/zootaxa.5357.4.3
Zhu, F., Liu, Q., Che, J., Zhang, L., Chen, X., Yan, F., Murphy, R., Guo, C. & Guo, P. (2016) Molecular phylogeography of
white-lipped tree viper (Trimeresurus; Viperidae). Zoologica Scripta, 45 (3), 252–262.
https://doi.org/10.1111/zsc.12156
TRIMERESURUS CYANOLABRIS S P. NOV. Zootaxa 5474 (4) © 2024 Magnolia Press · 403
Ziegler, T., Pham, C.T., Nguyen, T.Q., Berger, M., Ngo, H.T. & Le, M.D. (2018) First record of the White-lipped Pitviper
(Trimeresurus albolabris) from Hai Phong City, report of an unusual colour morph from Bach Long Vy Island in the Gulf
of Tonkin, northern Vietnam and identification of previously erroneously determined T. rubeus. Sauria, 40 (2), 1–24.
Appendix I. Characteristics of analyzed DNA sequences and the proposed optimal evolutionary models for gene and
codon partitions as estimated in PartitionFinder v1.0.1. Total length (in b.p.), number of conservative (Cons.), variable
(Var.) and parsimony informative (Pars.-Inf.) sites, estimated Transition/ Transversion bias (R), and nucleotide frequencies
(in %) are given. The optimal partitioning scheme and model fit was estimated as suggested by the Akaike information
criterion (AIC).
No. Gene Total
length Cons. Var. Pars.-
Inf. R A T C G Codon
partition Model
1
16S
rRNA 515 bp 383 bp 131 bp 75 bp 2.66 35.94% 24.69% 21.44% 17.93% — GTR+I+G
2 cyt b
1091
bp 588 bp 503 bp 380 bp 5.79 30.24% 29.14% 30.20% 10.42% cyt b - 1 GTR+I+G
cyt b - 2 GTR+I
cyt b - 3 GTR+G
3 ND4 800 bp 454 bp 341 bp 254 bp 7.28 33.01% 26.25% 29.17% 11.54% ND4 - 1 GTR+I+G
ND4 - 2 GTR
ND4 -3 GTR+I+G
Appendix II. Comparative materials of the Trimeresurus macrops species complex examined in this study
No. Species Collection number Status Locality Sex SVL
(mm)
TaL
(mm)
1T. cyanolabris sp. nov. ZMMU Re-17678 Paratype Nui Chua NP, Ninh Thuan,
Vietnam M 475 105
2T. cyanolabris sp. nov. ZMMU Re-17679 Holotype Nui Chua NP, Ninh Thuan,
Vietnam M 464 106
3T. cyanolabris sp. nov. ZFMK 94670 Ba To, Quang Ngai, Vietnam M 478 129
4T. cyanolabris sp. nov. DTU 605 Paratype Hon Ba NR, Cam Lam, Khanh
Hoa, Vietnam F 437 65
5T. cyanolabris sp. nov. DTU 606 Paratype Am Chua, Diem Khanh, Khanh
Hoa, Vietnam F 435 70
6T. cyanolabris sp. nov. DTU 635 Quy Nhon, Binh Dinh, Vietnam F 638 105
7T. cyanolabris sp. nov. DTU 636 Van Canh, Binh Dinh, Vietnam F 578 91
8T. cyanolabris sp. nov. ZMMU Re-17680 Paratype Nui Chua NP, Ninh Thuan,
Vietnam F 544 86
9T. cyanolabris sp. nov. ZMMU Re-17681 Paratype Nui Chua NP, Ninh Thuan,
Vietnam F 532 89
10 T. cyanolabris sp. nov. ZMMU Re-17682 Paratype Nui Chua NP, Ninh Thuan,
Vietnam F 511 93
11 T. cyanolabris sp. nov. ZMMU Re-17684 Paratype Phuoc Binh NP, Ninh Thuan,
Vietnam F 522 84
12 T. cyanolabris sp. nov. DTU 650 Paratype Hon Heo Isl., Ninh Hoa, Khanh
Hoa, Vietnam F 435 75
13 T. cyanolabris sp. nov. ZMMU Re-17683 Paratype Phuoc Binh NP, Ninh Thuan,
Vietnam SF 393 61
......continued on the next page
IDIIATULLINA ET AL.
404 · Zootaxa 5474 (4) © 2024 Magnolia Press
Appendix II. (Continued)
No. Species Collection number Status Locality Sex SVL
(mm)
TaL
(mm)
14 T. rubeus DTU 609 Gung Re, Di Linh, Lam Dong,
Vietnam M 405 112
15 T. rubeus ZFMK 91897 Cat Tien NP, Dong Nai,
Vietnam M 586 159
16 T. rubeus DTU 637 Gung Re, Di Linh, Lam Dong,
Vietnam F 457 98
17 T. rubeus DTU 638 Gung Re, Di Linh, Lam Dong,
Vietnam F 450 83
18 T. rubeus DTU 607 Gung Re, Di Linh, Lam Dong,
Vietnam F 440 93
19 T. rubeus DTU 608 Gung Re, Di Linh, Lam Dong,
Vietnam F 440 100
20 T. cardamomensis MNHN 1970.0584 Kirirom NP, Kampong Speu,
Cambodia SM 326 72
21 T. cardamomensis MNHN 1985.0074 Kirirom NP, Kampong Speu,
Cambodia M 535 134
22 T. cardamomensis DTU 592 Phu Quoc, Kien Giang,
Vietnam M 425 85
23 T. cardamomensis DTU 593 Phu Quoc, Kien Giang,
Vietnam M 430 110
24 T. cardamomensis DTU 594 Phu Quoc, Kien Giang,
Vietnam F 458 N/a
25 T. cardamomensis MNHN 1970.0585 Kirirom NP, Kampong Speu,
Cambodia F 420 72
26 T. cardamomensis RIM 00052 Ko Chang, Trat, Thailand F 450 74
27 T. macrops MHNG 1400.085 Holotype Bangkok, Thailand M 478 130
28 T. macrops NHMW 23922.5 Dong Phayayen-Khao Yai FC,
Nakhon Ratchasima, Thailand M 461 121
29 T. macrops NHMW 23922.11 Dong Phayayen-Khao Yai FC,
Nakhon Ratchasima, Thailand M 438 N/a
30 T. macrops NHMW 39591.1 Khao Yai NP, Nakhon
Ratchasima, Thailand M 557 N/a
31 T. macrops NHMW 40595.6 Khao Yai NP, Nakhon
Ratchasima, Thailand M 503 N/a
32 T. macrops NHMW 23911.8 Muak Lek, Saraburi, Thailand M 434 107
33 T. macrops NHMW 23897.2 Dong Phaya Yen Mt., Thailand M 422 110
34 T. macrops NHMW 23897.3 Dong Phaya Yen Mt., Thailand M 432 115
35 T. macrops NHMW 23897.6 Dong Phaya Yen Mt., Thailand M 442 N/a
36 T. macrops NHMW 23897.7 Dong Phaya Yen Mt., Thailand M 441 115
37 T. macrops NHMW 23897.15 Dong Phaya Yen Mt., Thailand M 473 127
38 T. macrops NHMW 23897.17 Dong Phaya Yen Mt., Thailand M 413 117
39 T. macrops NHMW 23899.12 Dangrek Mt., Thailand M 495 N/a
40 T. macrops NHMW 23900.5 Prachinburi, Thailand M 442 N/a
41 T. macrops NHMW 23900.13 Prachinburi, Thailand M 444 108
42 T. macrops NHMW 23900.15 Prachinburi, Thailand M 470 N/a
......continued on the next page
TRIMERESURUS CYANOLABRIS S P. NOV. Zootaxa 5474 (4) © 2024 Magnolia Press · 405
Appendix II. (Continued)
No. Species Collection number Status Locality Sex SVL
(mm)
TaL
(mm)
43 T. macrops MNHN 1885.0389 Between Prachinburi and
Bangkok M 410 109
44 T. macrops NHMW 23897.5 Dong Phaya Yen Mt., Thailand M 432 N/a
45 T. macrops NHMW 23922.10 Dong Phayayen-Khao Yai FC,
Nakhon Ratchasima, Thailand SM 319 74
46 T. macrops NHMW 23911.6 Bangkok, Thailand SM 368 94
47 T. macrops NHMW 23897.11 Dong Phaya Yen Mt., Thailand SM 305 69
48 T. macrops NHMW 23897.12 Dong Phaya Yen Mt., Thailand SM 355 82
49 T. macrops NHMW 23897.16 Dong Phaya Yen Mt., Thailand SM 365 95
50 T. macrops NHMW 23922.8 Dong Phaya Yen Mt., Thailand SM 265 N/a
51 T. macrops NHMW 23899.3 Dangrek Mt., Thailand SM 370 92
52 T. macrops NHMW 23899.6 Dangrek Mt., Thailand SM 310 66
53 T. macrops NHMW 23899.11 Dangrek Mt., Thailand SM 349 82
54 T. macrops NHMW 23900.1 Prachinburi, Thailand SM 257 56
55 T. macrops NHMW 23900.3 Prachinburi, Thailand SM 296 62
56 T. macrops NHMW 23900.6 Prachinburi, Thailand SM 390 98
57 T. macrops NHMW 23900.8 Prachinburi, Thailand SM 255 51
58 T. macrops NHMW 23900.10 Prachinburi, Thailand SM 306 73
59 T. macrops NHMW 23900.14 Prachinburi, Thailand SM 210 46
60 T. macrops NHMW 23900.16 Prachinburi, Thailand SM 266 59
61 T. macrops NHMW 23900.19 Prachinburi, Thailand SM 229 48
62 T. macrops NHMW 23900.20 Prachinburi, Thailand SM 308 72
63 T. macrops NHMW 23897.14 Dong Phaya Yen Mt., Thailand SM 301 N/a
64 T. macrops NHMW 23897.8 Dong Phaya Yen Mt., Thailand SM 246 53
65 T. macrops NHMW 23897.9 Dong Phaya Yen Mt., Thailand SM 223 52
66 T. macrops NHMW 23897.10 Dong Phaya Yen Mt., Thailand SM 197 47
67 T. macrops NHMW 23897.4 Dong Phaya Yen Mt., Thailand SM 363 87
68 T. macrops NHMW 27946.1 Bangkok, Thailand F 446 89
69 T. macrops NHMW 23911.5 Nakon Sawan, Thailand F 570 102
70 T. macrops NHMW 23899.4 Dangrek Mt., Thailand F 479 83
71 T. macrops NHMW 23899.5 Dangrek Mt., Thailand F 415 69
72 T. macrops NHMW 23899.10 Dangrek Mt., Thailand F 502 93
73 T. macrops NHMW 23899.13 Dangrek Mt., Thailand F 531 100
74 T. macrops NHMW 23900.2 Prachinburi, Thailand F 555 N/a
75 T. macrops NHMW 23900.9 Prachinburi, Thailand F 442 76
76 T. macrops NHMW 23911.5 Nakon Sawan, Thailand F 570 102
77 T. macrops NHMW 23922.7 Dong Phaya Yen Mt., Thailand SF 241 35
78 T. macrops NHMW 40595.9 Khao Yai NP, Nakhon
Ratchasima, Thailand SF 223 40
79 T. macrops NHMW 23897.1 Dong Phaya Yen Mt., Thailand SF 326 60
80 T. macrops NHMW 23897.13 Dong Phaya Yen Mt., Thailand SF 298 52
81 T. macrops NHMW 23899.1 Dangrek Mt., Thailand SF 391 67
82 T. macrops NHMW 23899.8 Dangrek Mt., Thailand SF 292 51
83 T. macrops NHMW 23899.9 Dangrek Mt., Thailand SF 373 64
......continued on the next page
IDIIATULLINA ET AL.
406 · Zootaxa 5474 (4) © 2024 Magnolia Press
Appendix II. (Continued)
No. Species Collection number Status Locality Sex SVL
(mm)
TaL
(mm)
84 T. macrops NHMW 23900.4 Prachinburi, Thailand SF 297 53
85 T. macrops NHMW 23900.7 Prachinburi, Thailand SF 318 57
86 T. macrops NHMW 23900.11 Prachinburi, Thailand SF 306 51
87 T. macrops NHMW 23900.12 Prachinburi, Thailand SF 352 66
88 T. macrops NHMW 23900.17 Prachinburi, Thailand SF 233 41
89 T. macrops NHMW 23900.18 Prachinburi, Thailand SF 370 68
90 T. macrops NHMW 23899.2 Dangrek Mt., Thailand SF 339 57
Appendix III. Literature used for the revised distribution of species of the Trimeresurus macrops species complex.
Locality numbers correspond to those shown on the map in Fig. 1.
Number
in map
Species Verified by
morphology
Verified
by
molecular
Location Sources
1T. cyanolabris sp. nov. yes yes Nui Chua NP, Ninh Thuan, Vietnam
(type locality)
our data
2T. cyanolabris sp. nov. yes yes Phuoc Binh NP, Ninh Thuan, Vietnam our data
3T. cyanolabris sp. nov. yes no Hon Ba NR, Khanh Hoa, Vietnam,
Vietnam
Hoang et al. (2019); our
data
4T. cyanolabris sp. nov. yes no Am Chua, Diem Khanh, Khanh Hoa,
Vietnam
our data
5T. cyanolabris sp. nov. yes no Hon Heo Is, Ninh Hoa, Khanh Hoa,
Vietnam
https://www.inaturalist.org/
observations/157077163;
our data
6T. cyanolabris sp. nov. yes no Quy Nhon, Binh Dinh, Vietnam our data
7T. cyanolabris sp. nov. yes no Van Canh, Binh Dinh, Vietnam our data
8T. cyanolabris sp. nov. yes no Ba To, Quang Ngai, Vietnam Nemes et al. (2013); our
data
9T. cardamomensis yes yes Cardamon Mt, Sre Ambel, Koh Kong,
Cambodia (type locality)
Malhotra et al. (2011);
Mrinalini et al. (2015);
10 T. cardamomensis yes yes Thm Bang, Koh Kong, Cambodia Mrinalini et al. (2015);
https://www.inaturalist.
org/observations/22363355
11 T. cardamomensis yes no Peam Krasaop WS, Krong Khemara
Phoumin, Cambodia
Mrinalini et al. (2015);
https://www.inaturalist.
org/observations/35116012
12 T. cardamomensis yes no Trapeang Rung, Koh Kong, Cambodia https://www.inaturalist.
org/observations/38794778
13 T. cardamomensis yes no Botum Sakor NP, Koh Kong,
Cambodia
https://www.inaturalist.
org/observations/42585938
14 T. cardamomensis yes no Thmor Roung National Resort,
Kampong Seila , Sihanoukville,
Cambodia
https://www.inaturalist.
org/observations/35036445
15 T. cardamomensis yes no Prey Nob, Sihanoukville, Cambodia https://www.inaturalist.org/
observations/116506047
......continued on the next page
TRIMERESURUS CYANOLABRIS S P. NOV. Zootaxa 5474 (4) © 2024 Magnolia Press · 407
Appendix III. (Continued)
Number
in map
Species Verified by
morphology
Verified
by
molecular
Location Sources
16 T. cardamomensis yes no Kaeb, Krong Kaeb, Cambodia https://www.inaturalist.org/
observations/133214229
17 T. cardamomensis yes yes Cua Lap, Phu Quoc NP, Kien Giang,
Vietnam
Ziegler et al. (2018);
https://www.inaturalist.org/
observations/82979381;
our data
18 T. cardamomensis yes no Mu Koh Chang NP, Trat, Thailand Chan-ard et al. (2015);
https://www.inaturalist.org/
observations/47244418;
our data
19 T. cardamomensis yes yes Bo Rai, Trat, Thailand Mrinalini et al. (2015);
https://www.inaturalist.org/
observations/72608167;
our data
20 T. cardamomensis yes no Namtok Pilo NP, Chantaburi, Thailand Chan-ard et al. (2015);
https://www.inaturalist.org/
observations/157990042;
our data
21 T. cardamomensis yes no Khao Khitchakut NP, Chanthaburi,
Thailand
Mrinalini et al. (2015);
Chan-ard et al. (2015);
https://www.inaturalist.org/
observations/88358820;
our data
22 T. cardamomensis yes no Khao Soidao WS, Chanthaburi,
Thailand
Chan-ard et al. (2015);
https://www.inaturalist.org/
observations/151217030;
our data
23 T. cardamomensis yes no Khao Chamao-Khao Wong NP,
Rayong, Thailand
Chan-ard et al. (2015);
https://www.inaturalist.org/
observations/96482084;
our data
24 T. cardamomensis yes no Khao Ang Rue Nai WS,
Chachoengsao, Thailand
Chan-ard et al. (2015); our
data
25 T. macrops yes yes Chom Thong, Bangkok, Thailand
(type locality)
Malhotra et al. (2011);
Mrinalini et al. (2015);
https://www.inaturalist.org/
observations/143345309
26 T. macrops yes no Mueang Ratchaburi, Ratchaburi,
Thailand
Malhotra et al. (2011);
Chan-ard et al. (2015)
27 T. macrops yes no Khlng Luang, Pathum Thani, Thailand Malhotra et al. (2011);
https://www.inaturalist.org/
observations/105596459
28 T. macrops yes no Bang Pa-In, Phra Nakhon Si
Ayutthaya, Thailand
https://www.inaturalist.org/
observations/119741194
......continued on the next page
IDIIATULLINA ET AL.
408 · Zootaxa 5474 (4) © 2024 Magnolia Press
Appendix III. (Continued)
Number
in map
Species Verified by
morphology
Verified
by
molecular
Location Sources
29 T. macrops yes yes Namtok Samlan NP, Saraburi,
Thailand
Malhotra et al. (2011);
Chan-ard et al. (2015);
Mrinalini et al. (2015); our
data
30 T. macrops yes no Muak Lek, Saraburi, Thailand Malhotra et al. (2011);
Chan-ard et al. (2015); our
data
31 T. macrops yes no Mueang Nakhon Nayok, Nakhon
Nayok, Thailand
Malhotra et al. (2011);
Chan-ard et al. (2015)
32 T. macrops yes no Khao Yai NP, Nakhon Ratchasima,
Thailand
Malhotra et al. (2011);
Chan-ard et al. (2015); our
data
33 T. macrops yes no Thap Lan NP, Nakhon Ratchasima,
Thailand
Malhotra et al. (2011);
Chan-ard et al. (2015); our
data
34 T. macrops yes no Pang Sida NP, Sa Kaeo, Thailand Malhotra et al. (2011);
Chan-ard et al. (2015); our
data
35 T. macrops yes no Ta Phraya NP, Sa Kaeo, Thailand Malhotra et al. (2011);
Chan-ard et al. (2015); our
data
36 T. macrops yes yes Dong Phayayen-Khao Yai, Nakhon
Ratchasima, Thailand
Malhotra et al. (2011);
Chan-ard et al. (2015);
Mrinalini et al. (2015); our
data
37 T. macrops yes yes Sakaerat Environmental Research
Station, Nakhon Ratchasima, Thailand
Malhotra et al. (2011);
Chan-ard et al. (2015);
Mrinalini et al. (2015); our
data
38 T. macrops yes no Pak Chong, Nakhon Ratchasima,
Thailand
Malhotra et al. (2011);
Chan-ard et al. (2015); our
data
39 T. macrops yes no Sikhio, Nakhon Ratchasima, Thailand Malhotra et al. (2011);
Chan-ard et al. (2015); our
data
40 T. macrops yes no Dangrek Mt., Si Sa Ket, Thailand Malhotra et al. (2011);
Chan-ard et al. (2015); our
data
41 T. macrops yes no Phu Chong Na Yoi NP, Ubon
Ratchathani, Thailand
Malhotra et al. (2011);
Chan-ard et al. (2015); our
data
42 T. macrops yes no Lan Sak, Uthai Thani, Thailand Malhotra et al. (2011);
https://www.inaturalist.org/
observations/136782889
......continued on the next page
TRIMERESURUS CYANOLABRIS S P. NOV. Zootaxa 5474 (4) © 2024 Magnolia Press · 409
Appendix III. (Continued)
Number
in map
Species Verified by
morphology
Verified
by
molecular
Location Sources
43 T. macrops yes no Huai Kha Khaeng WS, Uthai Thani,
Thailand
Chan-ard et al. (2015);
https://www.inaturalist.org/
observations//66404639
44 T. macrops yes no Nakon Sawan, Thailand Chan-ard et al. (2015); our
data
45 T. macrops yes no Sai Thong NP, Chaiyaphum, Thailand Chan-ard et al. (2015); our
data
46 T. macrops yes no Phu Khiao WS, Chaiyaphum, Thailand Chan-ard et al. (2015); our
data
47 T. macrops yes no Nam Nao NP, Phetchabun, Thailand Chan-ard et al. (2015); our
data
48 T. macrops yes no Thung Salaeng Luang NP, Phetchabun,
Thailand
Chan-ard et al. (2015);
https://www.inaturalist.org/
observations/138478227
49 T. macrops yes no Wat Ban Mung, Noen Maprang,
Phitsanulok, Thailand
Chan-ard et al. (2015); our
data
50 T. macrops yes no Thung Salaeng Luang NP,
Phitsanulok, Thailand
Chan-ard et al. (2015); our
data
51 T. macrops yes no Phu Suan Sai NP, Loei, Thailand Chan-ard et al. (2015);
Sumontha et al. 2021
52 T. macrops yes no Puan Phu, Nong Hin, Loei, Thailand https://www.inaturalist.
org/observations/47503629
53 T. macrops yes no Phu Kradung, Loei, Thailand https://www.inaturalist.org/
observations/140077180
54 T. macrops yes no Phu Pha Man NP, Khon Kaen,
Thailand
https://www.inaturalist.
org/observations/92908423
55 T. macrops yes no Phu Wiang NP, Khon Kaen, Thailand Chan-ard et al. (2015);
https://www.inaturalist.org/
observations/174873263
56 T. macrops yes no Nong Wua So, Udon Thani, Thailand Chan-ard et al. (2015); our
data
57 T. macrops yes no Ramkhamhaeng NP, Sukhothai,
Thailand
Chan-ard et al. (2015);
https://www.inaturalist.
org/observations/67526118
58 T. macrops yes no Si Satchanalai NP, Sukhothai,
Thailand
https://www.inaturalist.org/
observations/154564996
59 T. macrops yes no Doi Khun Tan NP, Lamphun, Thailand Chan-ard et al. (2015); our
data
60 T. macrops yes no Chae Son NP, Lampang, Thailand Chan-ard et al. (2015); our
data
61 T. macrops yes yes Chom Thong, Chiang Mai, Thailand Chan-ard et al. (2015);
Mrinalini et al. (2015); our
data
62 T. macrops yes no Doi Suthep-Pui NP, Chiang Mai,
Thailand
Chan-ard et al. (2015); our
data
......continued on the next page
IDIIATULLINA ET AL.
410 · Zootaxa 5474 (4) © 2024 Magnolia Press
Appendix III. (Continued)
Number
in map
Species Verified by
morphology
Verified
by
molecular
Location Sources
63 T. macrops yes no Mae Taeng, Chiang Mai, Thailand Chan-ard et al. (2015); our
data
64 T. macrops yes no Phu Wua WS, Bueng Kan, Thailand Chan-ard et al. (2015); our
data
65 T. macrops yes no Phu Langka NP, Nakhon Phanom,
Thailand
Chan-ard et al. (2015);
https://www.inaturalist.
org/observations/30853093
66 T. macrops yes no Nam Phauy, Xaignabouli, Laos Maury et al. (2022); our
data
67 T. macrops yes no Hinhurp, Vientian, Laos https://www.inaturalist.
org/observations/97687
68 T. macrops yes no Xaythany, Vientian, Laos https://www.inaturalist.org/
observations/128205503
69 T. macrops yes yes Phou Khao Khouay NBCA,
Bolikhamxai, Laos
Malhotra et al. (2011);
Mrinalini et al. (2015); our
data
70 T. macrops yes no Phou Hin Boun NBCA, Khammouane,
Laos
Tenye & David (2014)
71 T. macrops yes no Hin Nam No NBCA, Khammuane,
Laos
Malhotra et al. (2011)
72 T. macrops yes yes Dong Hua Sao NBCA, Champasak,
Laos
Malhotra et al. (2011);
Mrinalini et al. (2015)
73 T. macrops yes yes Virachey NP, Ratanakiri, Cambodia Mrinalini et al. (2015);
https://www.inaturalist.org/
observations/18750155;
MVZ 258153
74 T. macrops yes no Tbaeng Mean Chey, Krong Preah
Viher, Cambodia
https://www.inaturalist.
org/observations/18876262
75 T. macrops yes no Phnom Kulen NP, Siem Reap,
Cambodia
Geissler et al. (2019);
https://www.inaturalist.org/
observations/167634426
76 T. rubeus yes yes O Kamen, Seima NP, Mondokirin,
Cambodia (type locality)
Malhotra et al. (2011);
Mrinalini et al. (2015)
77 T. rubeus yes yes Bu Gia Map NP, Binh Phuoc, Vietnam our data; FMNH 47807
78 T. rubeus yes yes Cat Tien NP, Dong Nai, Vietnam Malhotra et al. (2011); Ngo
et al. (2022); our data
79 T. rubeus yes no Ma Da NR, Dong Nai, Vietnam our data
80 T. rubeus yes no Phu My, Tan Thanh, Ba Ria-Vung Tau,
Vietnam
our data
81 T. rubeus yes no Ham Thuan Nam, Binh Thuan,
Vietnam
https://www.inaturalist.org/
observations/144211653;
our data
82 T. rubeus yes no Nui Ong NR, Binh Thuan, Vietnam https://www.inaturalist.org/
observations/179527165;
our data
......continued on the next page
TRIMERESURUS CYANOLABRIS S P. NOV. Zootaxa 5474 (4) © 2024 Magnolia Press · 411
Appendix III. (Continued)
Number
in map
Species Verified by
morphology
Verified
by
molecular
Location Sources
83 T. rubeus yes no Di Linh, Lam Dong, Vietnam our data
84 T. rubeus yes yes Bao Loc, Lam Dong, Vietnam our data
85 T. rubeus yes no Dai Ninh, Duc Trong, Lam Dong,
Vietnam
https://www.inaturalist.org/
observations/181509437;
our data
