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| Euroscaptor darwini Nguyen, Bui, Dau, Le & Vu, 2025 |
Abstract
A new species of fossorial mole (Eulipotyphla, Talpidae, Euroscaptor) is described from Pu Luong Nature Reserve, north-central Vietnam, based on distinct genetic and morphological characteristics. The species inhabits a geographically small and isolated upland patch (900–1100 m a.s.l.), sharply bounded by a nearly vertical escarpment. The new taxon is diagnosed by an extremely reduced tail both externally and osteologically, comprising only six or seven caudal vertebrae, the lowest number documented in the genus to date. The species differs further from known congeners in Southeast Asia by its slender cranium, narrow rostrum, elongated inner zygomatic arches, and significantly smaller anterior dentition. Phylogenetic analyses of the mitochondrial Cyt b gene indicate genetic distances of 5.41–6.35% from its closest relative, E. subanura, and clarify the evolutionary placement of the species within the genus. Multivariate analyses of 36 craniodental measurements identified key variables contributing to interspecific differentiation among Vietnamese moles, including breadth between infraorbital foramina, length of zygomatic arch, upper incisor–canine length, premolars length, and lower incisor–canine length. Specimens from the type locality show that females are larger than males. The discovery of this new Euroscaptor species currently raises the total number of recognized species in the genus to eleven worldwide and brings the number of fossorial mole species recorded in Vietnam to six. It highlights both the underestimated mammalian diversity of Vietnam and the importance of continued integrative surveys in montane landscapes, where micro-endemic and evolutionarily distinct taxa remain insufficiently documented and vulnerable to environmental change.
Key words: Annamite Range, Darwin, mitochondrial gene, PCA, small mammal, taxonomy
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| Cranium, mandible, and pelvic bone of Euroscaptor darwini sp. nov.: (I) ♂ holotype, NTS.2024.PL.01, and (II) ♀ paratype, NTS.2025.PL.02. From top to bottom: a. Dorsal; b. Ventral; c, d. Lateral views of cranium and mandible, respectively; e, f. Lingual view (right side) of upper toothrow and lower toothrow, respectively; g. Four aspects of pelvis bone and caudal vertebrae. |
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| External morphology of Euroscaptor darwini sp. nov. a. Lateral–ventral view of partial body in laboratory; b. Dorsal view; c. Ventral view; d. Lateral view; e. Truncated–tailed of paratype specimen (NTS.2025.PL.02, ♀). |
Mammalia Linnaeus, 1758
Eulipotyphla Waddell et al., 1999
Talpidae G. Fischer, 1814
Euroscaptor Miller, 1940
Euroscaptor darwini sp. nov.
Diagnosis. Euroscaptor darwini sp. nov. is clearly distinguished from congeners by its extremely short, vestigial tail, which protrudes slightly less than 2 mm beyond the skin surface. It is entirely covered by short, sparse bristle hairs that progressively lengthen toward the distal end, reaching approximately twice the length of the underlying tail. The tail is composed of only six or seven caudal vertebrae, significantly fewer than in other Euroscaptor species. The interorbital region is moderately narrow, with the inter-foraminal distance between the infraorbital foramina being conspicuously constricted. The zygomatic arches are weakly developed but exhibit an atypically elongated form. The osseous junction between the infraorbital foramina and the palate is slender and lacks lateral expansion. In lingual view of mandible, the fourth lower premolar and all three lower molars have crowns that are broader than height, with overall small tooth dimensions. The mandible is delicate, characterized by a narrow ascending ramus and fragile angular process. The pelvic girdle is delicate, markedly reduced in both size and structural robustness.
Etymology. The specific epithet darwini honors the eminent naturalist Charles Darwin, whose foundational contributions to evolutionary biology have profoundly influenced modern systematics and the understanding of speciation. Darwin’s insights have had a particularly strong impact on the authors of this study. We propose “Darwin’s mole” as the English common name, and “Chuột chũi Darwin” as the Vietnamese common name, reflecting the most prominent morphological trait and honoring the individual commemorated.
Distribution. Euroscaptor darwini sp. nov. is currently known only from its type locality within Pu Luong NR, Thanh Hoa Province, north-central Vietnam. All known specimens were collected along a forested elevational transect on the southwestern ridge of Pu Luong Mountain, at altitudes ranging from 900 to 1100 meters a.s.l.
Son Truong Nguyen, Hai Tuan Bui, Vinh Quang Dau, Phuong Dinh Le and Yen Huong Vu. 2025. Euroscaptor darwini sp. nov., A New Species of mole (Mammalia, Eulipotyphla, Talpidae) from the north-central mountains in Vietnam. ZooKeys. 1255: 239-274. DOI: doi.org/10.3897/zookeys.1255.161942
