Sunday, December 3, 2023

[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  ||
Ninthuanskayacherveobraznaya yascheritsa ||
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