# Taxonomic revision of the Long-tailed Mole (Talpidae: Scaptonyx) with description of a new species from the Gaoligong Mountains

## TL;DR

Scientists revise the taxonomy of the Long-tailed Mole, identifying a new species from the Gaoligong Mountains and clarifying the status of related species.

## Contribution

A new species of Long-tailed Mole is described, and the taxonomic status of S. fusicauda and S. f. affinis is clarified using morphological and genetic data.

## Key findings

- Scaptonyx fusicauda, S. f. affinis, and a new species (S. wangi) are distinct species supported by morphological and genetic differences.
- Phylogenetic analysis shows S. wangi split from the S. fusicauda lineage around 19.79 million years ago.
- The type locality of S. fusicauda is confirmed to be in the Minshan Mountain region of Sichuan, China.

## Abstract

Scaptonyx fusicauda Milne-Edwards, 1872, is a mole species and a burrowing animal occurring from central China to northeastern Myanmar and northern Vietnam. This is the only extant species currently known in the genus Scaptonyx (Talpidae), but recent studies have revealed highly diverse lineages within this taxon. However, the broken type specimen and unspecified type locality of this species have hindered comparison between specimens towards a taxonomic evaluation. We reviewed the literature documenting the expeditions of the collector Armand David and narrowed down the type locality of this species to Minshan Mountain, western Sichuan, China. We compared S. fusicauda topotypes with specimens from 2 separated mountain ranges in western Yunnan, China—S. f. affinis Thomas, 1912 from the Baima Mountain and an undescribed species (S. sp. 1) from the Gaoligong Mountains. Specimens from the 3 localities can be distinguished by multiple external, craniomandibular, and dental characteristics. Phylogenies based on mitochondrial and nuclear genes also provided consistent topologies supporting S. fusicauda, S. f. affinis, and S. sp. 1 as distinct monophyletic species. Scaptonyx sp. 1 split from the sister clade (S. fusicauda + S. f. affinis) ca. 19.79 Ma, while S. f. affinis split from S. fusicauda ca. 9.56 Ma. Following these findings, we recognize S. f. affinis as a distinct species, S. affinis, and describe S. sp. 1 as a new species. Scaptonyx fusicauda occurs in the Sichuan Basin to the west, S. affinis from the mountains in the east of the Salween River to central China and northern Vietnam, and S. sp. 1 in the Gaoligong Mountains on the watersheds of the Irrawaddy and Salween rivers—encompassing western Yunnan, China, and northeastern Myanmar.

We reviewed the journey of Armand David from 1868 to 1869. On these grounds, we clarify the type locality of Scaptonyx fusicauda Milne-Edwards, 1872 within the vicinity of the Minjiang River source, Minshan Mountain, Sichuan, China. Based on our study of newly collected topotype specimens of S. fusicauda, we recognize S. affinis Thomas, 1912, previously treated as a subspecies of S. fusicauda, as a distinct species. We also describe a new species from the Gaoligong Mountains, S. wangi, based on morphological examinations and phylogenetic analyses. We provide an updated taxonomy of the genus Scaptonyx, along with ecological and distribution information for the 3 extant species.