[Herpetology • 2026] Dibamus irregularis • A New Species of Blind Skink (Squamata: Dibamidae: Dibamus) from Chu Yang Sin National Park, southern Vietnam, with the first description of a Dibamus clutch

 

Dibamus irregularis Kliukin, Poyarkov, Bragin, Krone & Nguyen, 

in Kliukin, Bragin, Nguyen, Vu, Le, Gorin, Krone & Poyarkov, 2026

Chu Yang Sin Blind Skink  |  DOI: doi.org/10.11646/zootaxa.5760.5.1  

Thằn lằn giun Chư Yang Sin  ||  Researchgate.net/publication/401227726  

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Abstract

A new species of dibamid lizard, Dibamus irregularis sp. nov. is described based on molecular (three mitochondrial genes) and morphological (external and skeletal) characters of twelve specimens collected from the Chu Yang Sin National Park, Dak Lak Province, southern Vietnam. The new species can be distinguished from other congeners by the following combination of characters: medial rostral suture absent or incomplete, nasal sutures incomplete, labial sutures complete or incomplete; two to three postoculars; three to four scales on the posterior edge of infralabial; 22–24 midbody scale rows; 180–211 ventral scales; 39–46 subcaudal scales; and maximum snout-vent length 147 mm. Moreover, two eggs of a new species were collected in the same locality. The only known clutch of Dibamus was described more than 120 years ago based on a single egg of D. alfredi collected from Bukit Besar, Thailand. Herein, we provide the first description of a complete clutch of the genus Dibamus based on two eggs of Dibamus irregularis sp. nov. Our study brings the total number of species in the genus Dibamus to 30; Dibamus irregularis sp. nov. is the 10th species of Dibamus recorded from Vietnam, highlighting the importance of the country as a hot spot of reptilian diversity in Southeast Asia.

Reptilia, Dibamus irregularis sp. nov., Dak Lak Province, conservation, Southeast Asia, systematics, morphology, reproduction

 Dibamus irregularis sp. nov. in life.
(A) holotype ZMMu re-18313, male; (B) Paratype ZMMu re-18315, female.

Photographs by Andrey M. Bragin

Dibamus irregularis sp. nov.

Kliukin, Poyarkov, Bragin, Krone & Nguyen

Etymology. the new species epithet is a latin adjective in nominative singular, meaning “irregular,” andis given in reference to the high intraspecific variability of external morphological features in the new species,especially to the irregularity and asymmetry of the number of postocular scales (Fig. 6). Since Allen greer’s revision(greer 1985) and in all subsequent papers describing new species of Dibamus, the number of postocular scales wasconsidered as a relatively stable diagnostic character underlying diagnoses for new species of dibamids, which in partcould be explained by generally small sample sizes of Dibamus spp. available for examination. however, Dibamus irregularis sp. nov. demonstrates an unexpectedly irregular and asymmetrical number of postocular scales: fivespecimens have two postoculars, four specimens have three postoculars, and three specimens have two postocularson the left side and three on the right side of the head.

Suggested common names: Chu Yang Sin Blind Skink (English); Thằn lằn giun Chư Yang Sin (Vietnamese),Chuyangsinskaya cherveobraznaya yascheritsa (Чуянгсинская червеобразная ящерица, Russian).  

Nikita S. KLIUKIN, Andrey M. BRAGIN, Tan Van NGUYEN, Duy Dinh VU, Son Xuan LE, Vladislav A. GORIN, Isaac W. KRONE, Nikolay A. POYARKOV. 2026. A New Species of Blind Skink (Squamata: Dibamidae: Dibamus) from Chu Yang Sin National Park, southern Vietnam, with the first description of a Dibamus clutch.  Zootaxa. 5760(5); 501-528. DOI: doi.org/10.11646/zootaxa.5760.5.1 [2026-02-26] 

 Researchgate.net/publication/401227726_A_new_species_of_Dibamus_from_ChuYangSin_NP_southern_Vietnam 

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[Herpetology • 2025] Dibamus annae • A New Species of Dibamus from the Central Highlands of Vietnam with Redescription of Dibamus montanus Smith, 1921 (Squamata: Dibamidae)

 

Dibamus montanus Smith, 1921

 Dibamus annae

Kliukin, Nguyen, Pawangkhanant,  Pham, Le, Gorin, Bos, Krone & Poyarkov, 2025

Anna’s Blind Skink | Thằn lằn giun An-na  || 

DOI: doi.org/10.11646/zootaxa.5693.1.1  

Researchgate.net/publication/395525435 

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Abstract

The Langbian Blind Skink, Dibamus montanus Smith, 1921, was described more than 100 years ago based on two specimens from Langbian Plateau, southern Vietnam. Herein, we provide a revised diagnosis of D. montanus based on re-examination of the type series and two additional specimens collected during our recent field survey in Lam Dong Province, southern Vietnam. Furthermore, we describe a new species of dibamid lizard based on a single specimen collected from Kon Ka Kinh National Park, Gia Lai Province, central Vietnam, which was previously confused with D. montanus. We present an updated genealogy for the family Dibamidae based on three mitochondrial genes (16S rRNA, ND2, and COI) and demonstrate that D. montanus and the Gia Lai specimen form two deeply divergent matrilines with sequence divergence p = 18.6% in the ND2 gene and p = 6.4% in the 16S rRNA gene. The new species Dibamus annae sp. nov. can be readily distinguished from D. montanus and other congeners by the following combination of morphological characters: labial and nasal sutures present and complete; rostral suture present and incomplete; three scales posterior to interparietal; maximum SVL of 92.7 mm; tail comparatively long, TL comprising 18.9% of SVL in a single male; two scales bordering the posteromedial edge of the first infralabial; the medial sublabial scale not enlarged; 19 midbody scale rows; 21 transverse scale rows just posterior to head; 18 transverse scale rows just anterior to vent; 180 ventral scales; 45 subcaudal scales; relative size of frontal to frontonasal 136.3%; relative size of interparietal to nuchal scale 133.9%. Our study brings the total number of species in the genus Dibamus to 28; Dibamus annae sp. nov. is the ninth species of Dibamus recorded from Vietnam, which further highlights the importance of this country as a center of reptilian diversity in Southeast Asia. We also provide an identification key for the species of Dibamus that occur in Indochina.

Reptilia, Dibamus annae sp. nov., Kon Ka Kinh National Park, Langbian Plateau, Blind Skinks, conservation, Southeast Asia, systematics, morphology

Dibamus montanus Smith, 1921 in life.
(a) Male specimen ZMMu re-18136 from Di linh town, Di linh, lam Dong Province; (B) Male specimen (not collected) from Suoi lanh, gung re, ca. 12 km southwards from Di linh, lam Dong Province.

Photographs by Parinya Pawangkhanant (a) and Hieu Minh Pham (B).

Photographs of head scalation of the holotype of Dibamus annae sp. nov. ZMMU Re-15720 (A–C); and male specimen of D. montanus ZMMU Re-18136 (D–F).
Head is shown in lateral (A, D, G), dorsal (B, E, H), and ventral (C, F, I) aspects.

Scale bar equals 1 mm. Photographs by Nikita S. Kliukin.

Dibamus annae sp. nov.

Etymology. The new species epithet honors Dr. Anna B. Vassilieva, a Russian herpetologist currently working at the A.N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences. Dr. Vassilieva collected the holotype of the new species; furthermore, she has also spent over 10 years researching the herpetofauna of Vietnam. 

Nikita S. KLIUKIN, Tan Van NGUYEN, Parinya PAWANGKHANANT, Hieu Minh PHAM, Son Xuan LE, Vladislav A. GORIN, Collin BOS, Isaac W. KRONE and Nikolay A. POYARKOV. 2025. A New Species of Dibamus from the Central Highlands of Vietnam with Redescription of Dibamus montanus Smith, 1921 (Squamata: Dibamidae).  Zootaxa. 5693(1); 1-31. DOI: doi.org/10.11646/zootaxa.5693.1.1 [2025-09-16]

 Researchgate.net/publication/395525435_A_new_species_of_Dibamus_from_the_Central_Highlands_of_Vietnam

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[Herpetology • 2024] Dibamus elephantinus • A New Species of Blind Skink of the Genus Dibamus Duméril et Bibron, 1839 (Squamata: Dibamidae) from Cambodia

Dibamus elephantinus

 Kliukin, Bragin, Thy, Gorin ... et Poyarkov, 2024 

 

 https://istina.msu.ru/publications/article/723221169  

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Abstract

We describe a new species of blind skink of the genus Dibamus Duméril et Bibron, 1839 based on five specimens collected from Bokor National Park, Kampot Province, southern Cambodia. Dibamus elephantinus sp. n. can be distinguished from its congeners by the following combination of morphological characters: snout-vent length (SVL) up to 129.3 mm; tail length comprises 17–22% of SVL; rostral suture incomplete; nasal and labial sutures complete; single postocular; three scales at the posteromedial edge of first infralabial; two scales at the posterior edge of second infralabial; the medial sublabial scale enlarged; 19 midbody scale rows; 22 transverse scale rows just posterior to head; 17–19 transverse scale rows just anterior to vent; 178–202 ventral scales; 46–52 subcaudal scales; relative size of frontal to frontonasal (FSW/FNSW) 127–136%; relative size of interparietal to surrounding scales (IPW/NSW) 111–140%; in males hindlimbs longer than head length (HLL/HL 74–78%); the light colored band on the body may be present or absent. We provide an osteological description of the new species based on micro-CT data. Genetically and morphologically Dibamus elephantinus sp. n. is most closely related to D. dalaiensis inhabiting the western part of the Cardamom Mountains in Cambodia. The new species inhabits montane evergreen forests of Damrei Range (also known as Elephant Mountains) at elevations of ca. 1000 m a. s. l. Our study brings the number of species in the genus Dibamus to 27; Dibamus elephantinus sp. n. is the second species of Dibamus to be recorded from Cambodia.

Dibamus elephantinus sp. n.

 

Nikita S Kliukin, Andrey Bragin, Neang Thy, Vladislav Gorin ... and Nikolay A. Poyarkov. 2024. A New Species of Blind Skink of the Genus Dibamus Duméril et Bibron, 1839 (Squamata, Dibamidae) from Cambodia [Новый вид червеобразных ящериц рода Dibamus Duméril et Bibron, 1839 (Squamata, Dibamidae) из Камбоджи].  Зоологический журнал. 103(11): 97–120. DOI: 10.31857/S0044513424110077 https://istina.msu.ru/publications/article/723221169 

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  Researchgate.net/publication/387377678_A_new_species_of_Dibamus_from_Cambodia

[Herpetology • 2024] Dibamus deimontis • Another New Species of Dibamus Duméril & Bibron, 1839 (Squamata: Dibamidae) from Nui Chua National Park, Ninh Thuan Province, Vietnam

 

 Dibamus deimontis  Kliukin, Bragin, Nguyen & Poyarkov, 

in Kliukin, Bragin, Nguyen, Le, Tran, Gorin & Poyarkov, 2024. 

DOI: 10.11646/zootaxa.5406.1.4

 facebook.com: Nguyen Van Tan

Researchgate.net/publication/377895743

Abstract

A new species of dibamid lizard, Dibamus deimontis sp. nov., is described based on eight specimens collected from the highlands of Nui Chua Mountain within Nui Chua National Park, Ninh Thuan Province, southern Vietnam. Dibamus deimontis sp. nov. co-occurs with the recently described Dibamus tropcentr, but is recorded at higher elevations (670–700 m a.s.l. vs. 200–280 m a.s.l.), and in a different habitat and microhabitats than the previous species. Our study represents the first report on the near sympatric occurrence of two Dibamus species. The new species can be distinguished from other congeners by the following combination of characters: rostral, labial and nasal sutures incomplete; two to three postoculars; three to five scales on the posterior edge of infralabial; 22–25 midbody scale rows; 193–225 ventral scales; 47–55 subcaudal scales; 115 presacral and 27 tail vertebrae (in a single male specimen examined); and maximum snout-vent length 136.2 mm. We suggest this species should be considered as Vulnerable (VU) following the IUCN’s Red List categories. Our study brings the number of species in the genus Dibamus to 26; Dibamus deimontis sp. nov. is the eighth species of Dibamus recorded in Vietnam, and underlines the importance of the country as a local center of reptilian diversity in Southeast Asia.

 

 Reptilia, Dibamus deimontis sp. nov., Nui Chua Mountain, Blind Skinks, conservation, Southeast Asia. systematics. morphology. sympatric distribution, endemism

 Morphology of Dibamus deimontis sp. nov. in life.
A, B—holotype of Dibamus deimontis sp. nov. (ZMMu re- 17821, male) in life in situ; C—cloacal region of female paratype ZMMu re-17823; D—cloacal region of holotype (ZMMu re-17821, male); E—cloacal region of male paratype (VrtC NAP-13708) showing partially everted hemipenes.

Photographs by Andrey M. Bragin and Nikolay A. Poyarkov.

 Nui Chua Blind Skink 

Dibamus deimontis 

Kliukin, Bragin, Nguyen & Poyarkov, 2024

Nikita S. Kliukin, Andrey M. Bragin, Tan Van Nguyen, Son Xuan Le, Tin Trong Vo Tran, Vladislav A. Gorin, Nikolay A. Poyarkov. 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. DOI: 10.11646/zootaxa.5406.1.4

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Researchgate.net/publication/377895743_new_species_of_Dibamus_from_NuiChua_NP_NinhThuan__Vietnam

[Herpetology • 2023] Dibamus tropcentr • A New Species of the Genus Dibamus Duméril & Bibron, 1839 (Squamata: Dibamidae) from the Driest and Hottest Place of Vietnam

Dibamus tropcentr Kliukin, Nguyen, Bragin & Poyarkov, 

in Kliukin, Nguyen, Le, Bragin, Tran, Gorin et Poyarkov, 2023.

Ninh Thuan Blind Skink || DOI: 10.11646/zootaxa.5380.4.1 

Thằn lằn giun Ninh Thuận  ||  facebook.com/TanNguyen91VN

Ninthuanskayacherveobraznaya yascheritsa ||  Researchgate.net/publication/376110506

 

Abstract

A new species of the genus Dibamus Duméril & Bibron, 1839 is described based on seven specimens collected from Nui Chua National Park, Ninh Thuan Province, southern Vietnam, the hottest and driest place of the country. Dibamus tropcentr sp. nov. is superficially similar to Dibamus smithi Greer, 1985, but can be distinguished from the latter by: the presence of a rudimentary labial suture; by larger number of subcaudal scales; by comparatively longer tail; by generally larger number of midbody scale rows; by having the interparietal scale not enlarged, subequal to the nuchal scale; by having frontal and frontonasal scales subequal in size as compared to almost twice larger frontal scale in D. smithi; by having three scales posterior to interparietal; by having the medial scale posterior to mental not enlarged; by having three to four scales on the posteromedial edge of infralabials; and by having supralabial scale larger than ocular scale. We suggest the new species should be considered as Vulnerable (VU) following the IUCN’s Red List categories. The new species occurs in dry maritime mixed low evergreen forests at elevations of 200–280 m a.s.l. and was recorded in association with termite species Globitermes sulphureus (Haviland). Our study brings the total number of species of the genus Dibamus to 25; this is the seventh species of the genus recorded from Vietnam.

Keywords: Reptilia, Dibamus tropcentr sp. nov., Nui Chua National Park, Ninh Thuan Province, Blind Skinks, conservation, Southeast Asia, morphology, systematics,

Distribution of the genus Dibamus in southern Indochina.

Holotype of Dibamus tropcentr sp. nov. (ZMMU Re-17443, female) in life in situ (A) and prior to preservation (B).

Photographs by Nikolay A. Poyarkov. Scale bar equals 5 mm.

Skeletal morphology of the male paratype of Dibamus tropcentr sp. nov. (ZMMU Re-17444).

Photographs (A–C) and line drawings (D–F) of head scalation of the holotype of Dibamus tropcentr sp. nov. (ZMMU Re-17443, female), and line drawings (G–I) of the paratype of Dibamus smithi (NHMUK 1946.8.21.24, female).
Head is shown in lateral (A, D, G), ventral (B, E, H), and dorsal (C, F, I) aspects.

Scale bar equals 1 mm. Small dots on the rostral and labial area indicate sensory papillas. Photographs A–C and line drawings D–F by Nikolay A. Poyarkov; line drawings G–I modified from Greer (1985).

 

Dibamus tropcentr sp. nov.

 Kliukin, Nguyen, Bragin & Poyarkov

Etymology. The name of the new species is a noun in apposition and is therefore invariable; the species name is given in reference to the Joint Vietnam - Russia Tropical Science and Technology Research Centre (VRTC).This international organization has been conducting research on ecology and biodiversity of Vietnam for over 35years (1989–2023). Herpetological studies by VRTC staff have resulted in the description of over 60 new taxa of amphibians and reptiles from Vietnam. We recommend the names “Ninh Thuan Blind Skink” “Ninthuanskayacherveobraznaya yascheritsa” and “Thằn lằn giun Ninh Thuận” as common names of the new species in English, Russian, and Vietnamese, respectively. 

Natural macrohabitat (A) and microhabitat (B) of Dibamus tropcentr sp. nov. at the type locality in Da Vach Mountain, Nui Chua National Park, Ninh Thuan Province, Vietnam. The rotten log shown in (B) was the habitat where the holotype of the new species was found together with Globitermes sulphureus (Haviland) colony.

Photographs by Nikolay A. Poyarkov.

Nikita S. Kliukin, Tan Van Nguyen, Son Xuan Le, Andrey M. Bragin, Tin Trong Vo Tran, Vladislav A. Gorin and Nikolay A. Poyarkov. 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. DOI: 10.11646/zootaxa.5380.4.1 

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  Researchgate.net/publication/376110506_A_new_species_of_Dibamus_from_the_driest_and_hottest_place_of_Vietnam

[Herpetology • 2017] Dibamus floweri • A New Species of Dibamus Duméril & Bibron 1839 (Squamata: Dibamidae) from A Hill Station in Peninsular Malaysia

 Dibamus floweri 

 Quah, Anuar, Grismer & Grassby-Lewis, 2017

 RAFFLES BULLETIN OF ZOOLOGY. 65.

Abstract 

A new species of worm-like lizard, Dibamus floweri, is described from Fraser’s Hill, Pahang, in the central highlands of Peninsular Malaysia based on the following unique combination of characters: maximum SVL of 112 mm; tail length 11.4–15.2% of SVL; labial and nasal sutures absent; rostral suture present but incomplete; a single postocular; four scales bordering the posterior edge of first infralabial; no enlarged, medial, sublabial scale; 21 scale rows around midbody; 23 scale rows around the body immediately posterior to head; 21 scale rows around the body immediately anterior to vent; 175–194 ventral scales; 23–46 subcaudal scales and light coloured bands on body. Dibamus floweri, new species, is the third species of dibamid discovered in Peninsular Malaysia and is the first montane species. Its discovery underscores the importance of uplands regions as important habitats for herpetological diversity and their understudied nature. 

Key words: herpetofauna, montane, new species, taxonomy, conservation, systematics

SYSTEMATICS

Dibamidae Boulenger, 1884

Dibamus Duméril & Bibron, 1839

Dibamus floweri, new species

Flower’s blind lizard

Diagnosis. Dibamus floweri, new species, differentiated from all other congeners by this combination of characters: maximum SVL of 112 mm; tail length 11.4–15.2% of SVL; labial, nasal sutures absent; rostral suture present but incomplete; single postocular; four scales bordering posterior edge of first infralabial; no enlarged, medial, sublabial scale; 21 midbody scale rows; 23 transverse scale rows just posterior to head; 21 transverse scale rows just anterior to vent; 175–194 ventral scales; 23–46 subcaudal scales; relative size of frontal to frontanasal 1.1–1.5; relative size of interparietal to surrounding scales 1.3–1.8; and light coloured bands on the body. These characters are scored across all nominal species of Dibamus in Table 2.

Etymology: The specific epithet, floweri, is in honour of Major Stanley Smyth Flower, who was one of the pioneers for herpetological discoveries in the Malay Peninsula. He made many notable discoveries over the course of his explorations in the region and his natural history observations well over a century ago were very detailed and contributed tremendously to improving our understanding of the ecology and behaviour of many species to this day.

 Distribution: Dibamus floweri, new species, is presently known only from Fraser’s Hill, Pahang, Peninsular Malaysia at elevations between 1,207 and 1,500 m (Fig. 3). 

  (A) Holotype of Dibamus floweri, new species (LSUHC 12481) from Fraser’s Hill, Pahang (Photograph by Rupert Grassby-Lewis).
(B) Paratype of Dibamus floweri, new species (ZRC 2.7240) from Fraser’s Hill, Pahang at ease. Photographs by Evan Quah.
(F) Leaf litter microhabitat at Fraser’s Hill, Pahang where the paratype of Dibamus floweri, new species, was found.

Natural history: Both specimens were found while digging through leaf litter that had accumulated along the banks of roads. The holotype was discovered at night in a drainage ditch along Jalan Girdle in a damp and shaded area. The paratype was uncovered during the day underneath approximately 3 cm beneath the soil (Fig. 2F), and in the same pile of leaf-litter, the skink, Larutia miodactyla (Boulenger, 1903) was also found. When handled, both specimens flared up their body scales, giving them a wrinkled appearance (Fig. 1C). This behaviour is interpreted as a defensive, anti-predator mechanism employed by Dibamus to mimic a possible non-palatable species of worm (Darevsky, 1992). The other two Peninsular Malaysian species, D. booliati and D. tiomanensis display the same behaviour when agitated (Das & Yaakob, 2003; Diaz et al., 2004; Grismer, 2011).

Evan S. H. Quah, Shahrul Anuar M. S., L. Lee Grismer and Rupert Grassby-Lewis. 2017. 

A New Species of Dibamus Duméril & Bibron 1839 (Squamata: Dibamidae) from A Hill Station in Peninsular Malaysia. RAFFLES BULLETIN OF ZOOLOGY. 65; 681–690. 

https://lkcnhm.nus.edu.sg/app/uploads/2017/04/65rbz681-690.pdf

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