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| Tylototriton vietnamirabilis Ong, T. Q. Phan, Hoang, M. H. T. Nguyen, T. T. Nguyen, Ziegler, T. Q. Nguyen and C. T. Pham, 2026 |
Abstract
A new species of crocodile newt, Tylototriton vietnamirabilis sp. nov., is described from Phu Xai Lai Leng Mountain, Nghe An Province, in the border area between Vietnam and Laos, based on molecular divergence and morphological differences. Tylototriton vietnamirabilis sp. nov. differs from other species in the subgenus Tylototriton by its body size, tail length, glandular ridge on the midline of crown of head, parotoid shape, appearance of vertebral ridge, number of dorsolateral glandular warts, the presence of a gular fold, coloration of head and body, and the presence of lateral grooves on tail. In terms of genetic distance, the new species differs from other congeners for which comparable sequences are available by at least 5.33–5.35% (T. panwaensis) and 5.35–5.37% (T. anguliceps), based on the mitochondrial NADH dehydrogenase subunit 2 (ND2) gene. Our new finding brings the total number of known species in the genus Tylototriton from Vietnam to 10. Because the new species is currently known to be restricted to evergreen montane forests on Phu Xai Lai Leng Mountain, we recommend to be classified as Endangered (EN) on the IUCN Red List.
Key words: Crocodile newts, morphology, ND2 gene, phylogenetic relationships, taxonomy, Tylototriton vietnamirabilis sp. nov.
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| Paratypes of Tylototriton vietnamirabilis sp. nov. in life. A. Dorsolateral view (IB A.6427, male); B. Dorsolateral view (IB A.6429, female). Photos: Cuong The Pham. |
Tylototriton vietnamirabilis sp. nov.
Diagnosis. The new species is assigned to the subgenus Tylototriton based on the results of the molecular phylogenetic analyses and the following morphological attributes: back with dorsal granules, head with dorsolateral bony ridges, knob-like warts or rib nodules present on dorsolateral body, and the absence of quadrate spine (Le et al. 2015; Fei and Ye 2016; Pomchote et al. 2021, 2024). The new species is diagnosed from its congeners by a combination of the following morphological characteristics: (1) size medium (SVL 61.2–67.9 mm, TL 64.3–75.2 mm in males, and SVL 71.6 mm, TL 78.3 mm in a single female); (2) tail longer than the snout-vent length; (3) head longer than wide; (4) glandular ridge on midline of crown distinct; (5) parotoids prominent and enlarged, projecting backwards; (6) vertebral ridge large, raised, and glandular in appearance; (7) 15 or 16 distinct dorsolateral glandular warts; (8) gular fold present; (9) dorsolateral bony ridges, parotoids, rib nodules, and vertebral ridge dull orange; and (10) tail with distinct lateral grooves.
Etymology. The name “vietnamirabilis” is a Latinized form of the modern word creation Vietnamazing. The new species is named to highlight the Vietnamazing conservation campaign 2024–2025 of the European Association of Zoos and Aquariums (EAZA). The Vietnamazing campaign aimed to raise public awareness of Vietnam’s unique biodiversity and its conservation, establish conservation projects with crocodile newts being one of the flagship groups of the campaign and raise funds for species conservation, following and higlighting IUCN's "One Plan Approach to Conservation". From 2026 onwards, after the completion of the EAZA campaign, Vietnamazing will continue as the Vietnamazing conservation network, a program under ZGAP (Zoological Society for the Conservation of Species and Populations). As common names, we suggest Vietnamazing Crocodile Newt (English), Cá cóc việt nam kỳ thú (Vietnamese).
An Vinh Ong, Tien Quang Phan, Chung Van Hoang, Mai Hong Thi Nguyen, Tao Thien Nguyen, Thomas Ziegler, Truong Quang Nguyen and Cuong The Pham. 2026. A New Species of Tylototriton (Amphibia, Salamandridae) from Phu Xai Lai Leng Mountain, Nghe An Province, Vietnam. ZooKeys. 1276: 285-305. DOI: doi.org/10.3897/zookeys.1276.173848 [08 Apr 2026]
