A new species of the genus Soriculus (Soricidae, Eulipotyphla, Mammalia) from Medog, Tibet, China, based on morphological and molecular data

175 A new species of the genus Soriculus (Soricidae, Eulipotyphla, Mammalia) from Medog, Tibet, China, based on morphological and molecular data Tao Zhang1, Siyu Yang1, Haijun Jiang2,3, lin Gu1, Qingfang Zou1, Changkun Fu1,4, Keji Guo5, Tong Zhang5, Shaoying Liu6, Shunde Chen1 1 College of Life Sciences, Sichuan Normal University, Chengdu 610066, China 2 School of Life Sciences, Zhengzhou University, Zhengzhou, China 3 Institute of Biodiversity and Ecology, Zhengzhou University, Zhengzhou, China 4 Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650201, China 5 Central South Inventory and Planning Institute of National Forestry and Grassland Administration, Changsha, Hunan 410014, China 6 Sichuan Academy of Forestry, Chengdu 610081, China Corresponding authors: Shunde Chen ([email protected]); Shaoying Liu (Shao[email protected]) Copyright: © Tao Zhang et al. This is an open access article distributed under terms of the Creative Commons Attribution License (Attribution 4.0 International – CC BY 4.0). Research Article Abstract The genus Soriculus (Soricidae, Eulipotyphla) currently comprises five recognized species, predominantly distributed in the Himalayas and the Gaoligong Mountains. During our survey of small mammals in Medog County, Tibet, China, 11 Soriculus specimens were collected. In this study, we conducted phylogenetic analyses of the genus using one mitochondrial gene (Cytb) and three nuclear genes (BRCA1, APOB, and RAG2) to assess the phylogenetic relationships of these specimens. The morphology of the 11 specimens was compared with other species within the genus. Our results demonstrate that these specimens represent a new species, Soriculus dexingensis sp. nov. Phylogenetic analyses revealed that S. dexingensis sp. nov. forms a distinct sister clade to S. medogensis, and the Kimura 2-Parameter (K2P) distances between all known species of Soriculus ranged from 0.111 to 0.187, indicating interspecific divergence. Morphologically, the new species is distinguished by a relatively longer tail and a significantly higher TL/HB ratio. The discovery of S. dexingensis sp. nov. in Medog County suggests that the diversity of Soriculus species remains underestimated. Further biodiversity surveys of small mammals across the Himalayan region are warranted. Key words: Morphology, new species, phylogeny, shrew, small mammals, Soriculus, taxonomy Introduction The genus Soriculus Blyth, 1854 comprises shrews primarily distributed at moderate to high elevations in the Himalayan region (Hutterer 2005; Motokawa et al. 2008). Members of the genus possess enlarged foreclaws, likely adapted for digging and fossorial habits (Hoffman 1986). Initially, the genus Soriculus was considered to include two subgenera: Episoriculus and Chodsigoa (Ellerman and Morrison-Scott 1951; Hoffman 1986; Motokawa 2003). However, Academic editor: Nedko Nedyalkov Received: 8 July 2025 Accepted: 4 November 2025 Published: 4 December 2025 ZooBank: https://zoobank.org/ FBA69C83-1F2B-41FC-BDF24CCA64BA1067 Citation: Zhang T, Yang S, Jiang H, Gu L, Zou Q, Fu C, Guo K, Zhang T, Liu S, Chen S (2025) A new species of the genus Soriculus (Soricidae, Eulipotyphla, Mammalia) from Medog, Tibet, China, based on morphological and molecular data. ZooKeys 1262: 175–189. https://doi.org/10.3897/ zookeys.1262.164459 ZooKeys 1262: 175–189 (2025) DOI: 10.3897/zookeys.1262.164459 176 ZooKeys 1262: 175–189 (2025), DOI: 10.3897/zookeys.1262.164459 Tao Zhang et al.: A new species of the genus Soriculus from Medog, Tibet, China these three taxa were subsequently recognized as distinct genera based on morphological and molecular evidence (Repenning 1967; Hutterer 2005; He et al. 2010). Despite these revisions, the diversity of Soriculus has long been underestimated. For decades, Soriculus was regarded as monotypic, containing only one species (Soriculus nigrescens Gray, 1840) and two subspecies (S. n. nigrescens and S. n. minor Dobson, 1890). This classification was widely accepted by scholars (Smith and Xie 2009; Burgin and He 2018). The divergence of Soriculus was first revealed by Jiang et al. (2023). Their study supported the classification of the genus Soriculus into three evolutionary clades, but morphological evidence was not incorporated to further clarify the phylogenetic relationships within the genus. Subsequently, Chen et al. (2024) conducted a comprehensive integrated analysis of the genus, elevating S. n. minor to species status. Furthermore, they described two new species: Soriculus nivatus (Chen & Jiang, 2024) and Soriculus medogensis (Chen & Jiang, 2024). They also identified a new species (known from a single specimen), which was later described as Soriculus beibengensis (Pei et al. 2024) based on nine additional specimens from Medog, following molecular and morphological analyses (Pei et al. 2024). During fieldwork in 2011, we collected 11 Soriculus specimens from Medog, Tibet, China. These specimens were previously assigned to S. medogensis (Chen et al. 2024; Pei et al. 2024). However, recent integrated molecular and morphological analyses have revealed substantial genetic divergence from known congeners. They are therefore recognized as a putative new species (referred to as Soriculus sp. in the Material and methods and Results sections). Material and methods Ethics statement All specimens were obtained in accordance with the guidelines of the American Society of Mammalogists and the laws and regulations of China concerning the protection of wild terrestrial animals (State Council Decree 1992; Sikes and Animal 2016), and the Guidelines for Care and Use of Laboratory Animals at the Ethics Committee at Sichuan Normal University (Chengdu, China). Samples and sequencing In October 2011, a total of eleven individuals (Soriculus sp.) were collected using snap traps from Medog, Tibet, China (Suppl. material 1: table S1). Fresh muscle and liver tissues were taken from each individual, immediately preserved in 95% ethanol, and stored at -80 °C for molecular analyses. Tissue samples and all specimens used in this study are deposited in Sichuan Normal University (SCNU) and the Sichuan Academy of Forestry (SAF). Total DNA was extracted from muscle or liver tissues using an animal tissue DNA extraction kit (Chengdu Fuji Biotechnology Co., Ltd, Sichuan, China). One mitochondrial gene (Cytb, 1140 bp) and three nuclear genes [apolipoprotein B (APOB), breast cancer 1 (BRCA1), and recombination activating protein 2 (RAG2)] were amplified. The primers used and the PCR program conditions were the same as those described in Jiang et al. (2023). All DNA sequences 177 ZooKeys 1262: 175–189 (2025), DOI: 10.3897/zookeys.1262.164459 Tao Zhang et al.: A new species of the genus Soriculus from Medog, Tibet, China were edited with EditSeq (DNASTAR, Lasergene v. 7.1) and further aligned in MEGA 11 (Tamura et al. 2021). Corresponding sequences of published Soriculus individuals and sequences of other soricid genera were obtained from GenBank (Suppl. material 1: table S2). Phylogenetic analysis Two datasets were constructed for phylogenetic analysis: (1) a dataset of the mitochondrial gene (mtDNA); (2) a dataset of concatenated nuclear genes (nDNA). MrBayes v. 3.2.7 (Ronquist et al. 2012) was used for the Bayesian inference analysis. Each run was performed using four Markov chain Monte Carlo (MCMC) algorithms, with 10,000,000 generations for both the single-gene dataset and the concatenated gene datasets. IQ-TREE v. 3.0.1 (Nguyen et al. 2015) was used for maximum likelihood (ML) analyses, with 10,000 ultrafast bootstraps to estimate branch support. ModelFinder (in IQ-TREE) was used to determine the optimal model for each gene, and the fitness of the model was estimated by the Akaike Information Criterion (AIC) (Luo et al. 2010). All the above analyses were conducted in PhyloSuite v. 1.2.3 (Zhang et al. 2020). Posterior probabilities (PP) > 95% and ultrafast bootstrap values (UFBoot) ≥ 95 were considered strongly supported (Huelsenbeck and Rannala 2004; Minh et al. 2018). Genetic distances and species delimitation The Kimura-2-parameter (K2P) distances for species/putative species based on the Cytb gene were calculated in MEGA 11 (Kimura 1980; Tamura et al. 2021). Bayesian Phylogenetics and Phylogeography (BPP) analyses were performed using the nDNA dataset and the combined mtDNA+nDNA dataset in BPP v. 3.1 (Yang and Rannala 2010). Following Chen et al. (2022), we used two alternative rjMCMC algorithms (algorithms 0 and 1). The ancestral population size and root age were represented by θ and τ, respectively. The three combination priors on θ and τ were adopted: (1) G (1, 10) for θ and G (1, 10) for τ; (2) G (1, 10) for θ and G (2, 2000) for τ; and (3) G (2, 2000) for θ and G (2, 2000) for τ. Each rjMCMC was run for 100,000 generations, with samples collected every 100 generations after discarding 10,000 generations as pre-burn-in. Each clade was supported as an independent species if the posterior probability was greater than 0.95. Divergence time We used the nDNA dataset to estimate the divergence times in BEAST v. 2.6 (Bouckaert R et al. 2014). Two fossil calibration points were used following Chen et al. (2024): (1) The split between Crocidurinae and Soricinae was approximately 36 Ma (Springer et al. 2018). The offset was set to 0 and the mean to 36, with a standard deviation of 0.135; and (2) The first fossil record of Blarinellini was from the Early Middle Miocene (Harris 1998; Rzebik-Kowalska 1998), and the oldest divergence of Blarinini occurred in the Barstovian (13.6–16.3 Ma) (Repenning 1967). We set the offset to 15, the mean to 0, and the standard deviation to 0.98. The BEAST analysis used a Birth-Death tree prior and a relaxed lognormal clock model. Each analysis ran for 100 million generations and was sampled every 5000 generations. The posterior distributions 178 ZooKeys 1262: 175–189 (2025), DOI: 10.3897/zookeys.1262.164459 Tao Zhang et al.: A new species of the genus Soriculus from Medog, Tibet, China and ESSs of each parameter greater than 200 was calculated in Tracer v. 1.7 (Rambaut et al. 2018). TreeAnnotator v. 1.6.1 was used to determine the burnin fraction, set to the first 25% of the generations. Morphological analysis A total of 62 preserved specimens of Soriculus, including S. beibengensis (N = 8), S. nigrescens (N = 14), S. medogensis (N = 4), S. nivatus (N = 20), S. minor (N = 5), and 11 specimens of Soriculus sp. were used for morphological analysis. The external measurements of these specimens were taken in the field, including weight (W), head-body length (HBL), tail length (TL), hind foot length (HL), and ear length (EL). Eleven craniodental metrics were measured by a digital caliper graduated to 0.01 mm following Pan et al. (2007) and Yang et al. (2007). The morphological characters of the skull and their abbreviations are: condyle-incisive length (CIL), braincase height (BH), interorbital breadth (IOB), rostral breadth (RB), braincase breadth (BB), upper toothrow length (UTR), palatoincisive length (PIL), postpalatal length (PPL), maximum width across the upper second molars (M2–M2), mandibular length (ML), lower toothrow length (LTR). All craniodental measurements were taken by Siyu Yang, except for measurements of five S. minor specimens provided by the Kunming Institute of Zoology (KIZ). Measured specimens were listed in the Suppl. material 1: table S3. The measurements of the skull were analyzed using SPSS v. 26.0 (SPSS, Chicago, IL, USA) for principal component analysis (PCA) and canonical discriminant function analysis (DFA). The terminologies for morphological descriptions followed Motokawa and Lin (2005) and Chen et al. (2024). Results Morphological analysis The external (N = 62) and craniodental (N = 58) measurements of Soriculus are given in Table 1. Results of the Kaiser–Meyer–Olkin measure of sampling adequacy indicated that the data were suitable for PCA (KMO = 0.904, Bartlett’s test < 0.001). In the PCA analysis, two principal components were extracted, which explained 87.41% of the total variance (Table 2). The eigenvalues of two PCs exceeded 1.0. PC1 explained 75.27% of the variation, and all factor loadings were positive. The factor loadings of CIL, PIL, UTR and LTR were greater than 0.9, and the factor loadings of PPL, IOB, BB, BH and ML were greater than 0.8. PC2 explained 12.14% of the variance and was negatively correlated with most variables except IOB, RB, M2M2, BB and BH. PCA scatterplots (Fig. 1A) showed that different species in Soriculus exhibited a clear separation trend. However, S. nivatus and Soriculus sp. overlapped to a high degree. Soriculus sp. specimens occupied the positive region of PC1 and the negative region of PC2, indicating that this new species had a larger and narrower skull than other recognized species, but smaller than S. medogensis. The results of the DFA correctly classified 89.8% of the specimens. One individual of Soriculus sp. was assigned to S. nivatus. Four S. nivatus individuals were assigned to Soriculus sp., and one S. nivatus individual was assigned to S. medogensis. Plots of CAN1 and CAN2 (Fig. 1B) showed that most species separated well, but S. nivatus and Soriculus sp. still could not be separated from each other. 179 ZooKeys 1262: 175–189 (2025), DOI: 10.3897/zookeys.1262.164459 Tao Zhang et al.: A new species of the genus Soriculus from Medog, Tibet, China Table 1. Means (mm), standard deviation and ranges of the measurement data of the skull and external morphology for different species of Soriculus used in this study. Variable S. nigrescens S. nivatus S. medogensis S. beibengensis S. minor Soriculus sp. N = 14 N = 20 N = 4 N = 8 N = 5 N = 11 W 16.7 ± 1.7 13.1 ± 2.8 15.8 ± 1.4 10.0 ± 2.0 9.3 ± 1.0 12.7 ± 1.2 13.0–19.0; 14 7.0–19.0; 20 14.5–18.0; 4 7.0–12.3; 8 8.2–10.7; 5 11.7–15.3; 11 HBL 87 ± 3 80 ± 5 82 ± 3 71 ± 6 68 ± 4 78 ± 4 82–92; 14 73–89; 19 77–84; 4 59–77; 8 62–71; 5 71–84; 11 TL 42 ± 2 49 ± 5 54 ± 2 40 ± 3 38 ± 4 57 ± 3 38–46; 14 40–57; 20 52–56; 4 34–43; 6 32–43; 4 50–62; 11 HL 15 ± 0 15 ± 1 16 ± 1 13 ± 1 12.4 ± 1 15 ± 0 14–16; 14 13–15.5; 20 15–16; 4 12–15; 8 12–14; 5 15; 11 EL 5 ± 0 7 ± 1 7 ± 2 4 ± 1 8 ± 1 7 ± 0 5; 7 5–10; 12 4–8; 4 3–6; 8 7–10; 5 7; 11 CIL 22.07 ± 0.39 22.69 ± 0.49 23.79 ± 0.24 20.27 ± 0.18 19.63 ± 0.39 22.87 ± 0.38 21.43–22.68; 14 21.71–23.92; 20 23.62–24.01; 4 20.03–20.68; 8 19.18–20.22; 5 22.20–23.54; 6 PIL 10.11 ± 0.19 10.24 ± 0.34 11.19 ± 0.26 9.09 ± 0.14 8.86 ± 0.27 10.52 ± 0.32 9.82–10.50; 14 9.53–10.82; 20 10.82–11.38; 4 8.87–9.26; 8 8.6–9.28; 5 9.94–11.01; 8 PPL 9.62 ± 0.20 9.7 ± 0.3 10.14 ± 0.26 9.01 ± 0.12 8.76 ± 0.13 9.69 ± 0.19 9.29–9.99; 14 9.04–10.24; 20 9.8–10.42; 4 8.86–9.25; 7 8.58–8.94; 5 9.37–10.06; 7 UTR 9.95 ± 0.17 10.03 ± 0.31 10.92 ± 0.17 8.91 ± 0.13 8.51 ± 0.23 10.20 ± 0.16 9.57–10.17; 14 9.36–10.51; 20 10.78–11.11; 4 8.78–9.17; 8 8.29–8.89; 5 9.89–10.38; 8 IOB 5.24 ± 0.17 4.96 ± 0.17 5.3 ± 0.08 4.55 ± 0.16 4.78 ± 0.12 5.00 ± 0.12 4.87–5.48; 14 4.75–5.46; 20 5.21–5.41; 4 4.35–4.87; 8 4.67–4.96; 5 4.78–5.13; 8 RB 6.35 ± 0.17 6.03 ± 0.25 6.65 ± 0.25 5.82 ± 0.27 6 ± 0.13 6.10 ± 0.18 6.13–6.72; 14 5.64–6.48; 20 6.38–6.55; 4 5.44–6.25; 8 5.79–6.12; 5 5.82–6.32; 8 M2M26.46 ± 0.16 6 ± 0.3 6.66 ± 0.19 5.65 ± 0.25 5.67 ± 0.07 6.01 ± 0.09 6.19–6.82; 14 5.36–6.37; 20 6.41–6.83; 4 5.30–6.04; 8 5.57–5.75; 5 5.90–6.12; 8 BB 11.16 ± 0.31 11.05 ± 0.39 11.93 ± 0.12 10.43 ± 0.28 10.56 ± 0.16 11.37 ± 0.17 10.52–11.72; 14 9.99–11.79; 19 11.78–12.06; 4 9.99–10.75; 8 10.38–10.71; 5 11.16–11.68; 8 BH 6.65 ± 0.13 6.55 ± 0.19 6.91 ± 0.36 6.04 ± 0.25 6.20 ± 0.24 6.56 ± 0.13 6.35–6.82; 14 6.08–6.9; 20 6.39–7.2; 4 5.69–6.54; 8 5.94–6.57; 5 6.38–6.75; 7 ML 13.90 ± 0.29 14.29 ± 0.37 15.42 ± 0.22 12.73 ± 0.15 10.85 ± 0.11 14.51 ± 0.28 13.14–14.25; 14 13.28–15.01; 20 15.21–15.62; 4 12.43–12.93; 8 10.68–10.99; 5 14.20–14.96; 8 LTR 8.89 ± 0.26 9.18 ± 0.35 9.99 ± 0.08 8.12 ± 0.13 7.78 ± 0.20 9.23 ± 0.16 8.42–9.35; 14 7.99–9.7; 20 9.89–10.09; 4 7.92–8.27; 8 7.65–8.11; 5 8.91–9.39; 8 Phylogenetic analyses Cytb and nuclear genes from all 11 specimens of the new species were obtained: 1140 bp for the mitochondrial gene and 1894 bp for the nuclear genes (APOB, BRCA1, and RAG2). Sequences generated for the new species were deposited in GenBank (Suppl. material 1: table S1). Phylogenetic trees reconstructed using Bayesian inference and maximum likelihood analyses based on two datasets (mtDNA and nuDNA) exhibited similar topological structures (only the BI tree is shown in Fig. 2). The phylogenetic trees 180 ZooKeys 1262: 175–189 (2025), DOI: 10.3897/zookeys.1262.164459 Tao Zhang et al.: A new species of the genus Soriculus from Medog, Tibet, China Table 2. Factor loadings, eigenvalues, and total variance explained by the two principal components of the PCA of 11 craniodental measurements of 58 specimens of Soriculus. Variables Component 1 2 CIL 0.938 -0.298 PIL 0.960 -0.185 PPL 0.882 -0.210 UTR 0.953 -0.217 IOB 0.806 0.446 RB 0.706 0.619 M2–M2 0.772 0.551 BB 0.858 0.101 BH 0.822 0.139 ML 0.895 -0.363 LTR 0.913 -0.273 Eigenvalue 8.280 1.335 Total variance explained (%) 75.273 12.142 Figure 1. Results of principal component analysis (A) and discriminant function analysis (B) based on the skull measurements of the genus Soriculus. (A) (B) Soriculus sp. Soriculus sp. generated from two datasets both supported the classification of these 11 specimens into a new species. Furthermore, the phylogenetic trees based on nDNA strongly supported the monophyly of Soriculus, which was divided into two primary clades: Clade I comprised S. minor and S. beibengensis; Clade II consisted of S. nigrescens, Soriculus sp., S. medogensis, and S. nivatus. Within Clade II, Soriculus sp. first formed a distinct branch, which then grouped as a sister clade to S. medogensis with high statistical support (PP = 1.00, UFBoot = 97). The mtDNA tree also showed a sister relationship between Soriculus sp. and S. medogensis (PP = 0.90, UFBoot = 83). However, the support for this relationship between S. nivatus and (Soriculus sp. + S. medogensis) was low (PP = 0.50, UFBoot = 61). 181 ZooKeys 1262: 175–189 (2025), DOI: 10.3897/zookeys.1262.164459 Tao Zhang et al.: A new species of the genus Soriculus from Medog, Tibet, China Figure 2. Phylogenetic trees of the genus Soriculus based on the mtDNA dataset and the concatenated nDNA dataset. Node numbers indicate ultrafast bootstrap values (left) and Bayesian posterior probabilities (right). 0.02 MT201904489 Blarina brevicauda KIZ042756 MT201811221 MT201811260 Chodsigoa hypsibia CY20206940 KIZ2387 MT201811285 Episoriculus caudatus Crocidura fuliginosa CY20206914 ML20205380 Chimarrogale himalayica Nectogale elegans ML20205278 KIZ2330 KIZ2345 GLGS6028 KIZ042760 Sorex bedfordiae KIZ042759 C SD545 KIZ042755 CS D538 MT201904573 GLGS6117 KIZ2316 ML20205214 CS D546 ML20205300 MT201904261 Chodsigoa parca CS D544 MT201904169 Blarinella griselda C SD540 MT201811181 ML20205195 KIZ042758 MT201904246 CS D541 CS D542 Neomys fodiens ML20205378 CS D543 MT201904951 CS D537 CS D536 // S. minor S. beibengensis S. nigrescens S. nivatus S. medogensis Soriculus sp. S. minor S. beibengensis S. nigrescens S. nivatus S. medogensis Soriculus sp. (A) mtDNA (B) nDNA 98/1.00 98/1.00 87/0.81 88/0.99 99/1.00 97/1.00 61/0.50 83/0.90 86/1.00 40/0.49 65/0.93 53/0.53 100/1.00 79/0.74 79/0.74 100/1.00 96/1.00 85/0.94 93/1.00 100/1.00 96/1.00 97/1.00 100/1.00 0.05 CSD544 Sorex bedfordiae Chodsigoa parca MT201811276 KIZ020548 MT201904246 CSD6910 CY20206914 MT201904573 KIZ020550 CSD540 GLGS6028 KIZ042760 Blarinella griselda MT201811260 CSD7627 CSD546 MT201904489 ML20205380 CSD536 MT201904951 CSD539 CSD6913 MT201811221 KIZ042756 ML20205278 MT201811285 CSD7289 CSD538 CY20206904 KIZ042755 Crocidura fuliginosa CSD6919 CSD7209 CSD541 Episoriculus caudatus MT201904169 ML20205195 Cryptotis magna Blarina brevicauda Nectogale elegans Neomys fodiens ML20205215 CY20206940 CSD543 Notiosorex crawfordi KIZ042758 CSD7545 Chodsigoa hypsibia CSD537 CSD7216 ML20205300 GLGS6117 KIZ042759 CSD542 MT201811181 KIZ020545 ML20205378 CSD545 MT201904261 CSD7198 MT201811230 CSD6904 KIZ020551 Chimarrogale himalayica100/1.00 Genetic distances and species delimitation The Kimura-2-parameter (K2P) genetic distances of the Cytb gene among species in the genus Soriculus ranged from 0.111 to 0.187. The genetic distances between Soriculus sp. and other species ranged from 0.111 (with S. nivatus and S. medogensis) to 0.181 (with S. beibengensis). Genetic distances among species were consistent with species-level divergence (Table 3). The BPP results based on the mtDNA + nuDNA and nuDNA datasets produced 36 outcomes, all of which strongly supported six species (PP > 0.99; Suppl. material 1: table S4). Table 3. Kimura two-parameters genetic distances of Soriculus based on the Cytb gene. S. minor S. beibengensis S. nigrescens S. nivatus S. medogensis S. beibengensis 0.100 S. nigrescens 0.187 0.175 S. nivatus 0.170 0.169 0.131 S. medogensis 0.184 0.189 0.145 0.122 Soriculus sp. 0.177 0.181 0.118 0.111 0.111 182 ZooKeys 1262: 175–189 (2025), DOI: 10.3897/zookeys.1262.164459 Tao Zhang et al.: A new species of the genus Soriculus from Medog, Tibet, China Molecular divergence estimation The topological structure of the divergence time tree based on nDNA was the same as that of the nDNA tree (Fig. 3). The results showed that the latest common ancestor of Soriculus can be traced back to the Late Miocene (7.86 Ma, 95% CI = 3.72–15.03). Both the divergence time of S. nivatus and (S. medogensis + Soriculus sp.) (2.96 Ma, 95% CI = 1.37–5.21) and the divergence time of Soriculus sp. and S. medogensis (2.3 Ma, 95% CI =1–4.08) occurred in the Early Pleistocene. Taxonomy Order Eulipotyphla Waddell et al., 1999 Family Soricidae G. Fischer, 1814 Subfamily Soricinae G. Fischer, 1814 Tribe Nectogalini Anderson, 1879 Genus Soriculus Blyth, 1854 Soriculus dexingensis Zhang, Liu & Chen, sp. nov. https://zoobank.org/EA040A43-90E1-4132-937B-F754909E6E32 Holotype. SAF11216, adult male, collected on 29 October 2011 by Rui Liao. The specimen was deposited at the Sichuan Academy of Forestry (SAF). Measurements of holotype (mm). W = 12.1 g, HB = 80, TL = 59, HL = 15, EL = 7, CIL = 23.54, PIL = 11.01, PPL = 10.06, UTR = 10.38, IOB = 5.13, RB = 6.32, M2M2 = 6.11, BB = 11.23, BH = 6.75, ML = 14.96, LTR = 9.39. Type locality. Dexing Town, Medog County, Tibet, China (29.41778°N, 95.05969°E, 2100 m a.s.l.). Paratypes. Seven specimens SAF11200 (male), SAF11215 (male), SAF11237 (female), SAF11238 (male), SAF11243 (male), SAF11245 (male), SAF11246 (male). Collected from the type locality in Medog in October 2011 at elevations from 2100 m to 2832 m. All specimens are deposited in SAF. Diagnosis. Size similar to S. nivatus, much larger than S. minor and S. beibengensis, but smaller than S. nigrescens and S. medogensis. The tail averages 74% of the head and body length, the longest within Soriculus. The teeth are more robust than those in S. nivatus. The maximum width across the upper second molars (M2M2) is less than that of S. medogensis and S. nigrescens. The pigmentation of the teeth is much heavier than that in S. minor and S. beibengensis. Description. Soriculus dexingensis sp. nov. is a medium-sized shrew in the genus Soriculus (W=12.74 ± 1.20 g, BH=77.81 ± 4.28 mm). The dorsal hair is brownish with a blackish-gray base and dark brown tip. The ventral hair is dark gray, not distinctly different from the dorsal hair (Fig. 4). The tail is bicolored: dorsal part dark brown; ventral part slightly lighter (Fig. 4). The tail is relatively long (nine of eleven specimens with TL ≥ 56 mm, 57.45 ± 3.47 mm), averaging 74% of the head and body length (HB). The foreclaws are enlarged. The dorsal surfaces of the hands and feet are covered with short, dark brown hairs. The skull is relatively large within the genus Soriculus, but smaller than that of S. medogensis. Braincase is domed but low, and the posterior of the skull is flattened. The sagittal and lambdoidal crests are moderately developed. The rostrum is relatively low, and the maxillary region is narrow. The basioccipital is slender, 183 ZooKeys 1262: 175–189 (2025), DOI: 10.3897/zookeys.1262.164459 Tao Zhang et al.: A new species of the genus Soriculus from Medog, Tibet, China 4.0 35 30 25 20 15 10 5 0 CSD545 ML20205195 MT201904489 CSD542 ML20205278 Blarinella griselda Chodsigoa parca MT201904169 Blarina brevicauda CSD541 KIZ2387 MT201904246 KIZ042755 CSD546 MT201811221 GLGS6117 ML20205380 CSD538 KIZ042758 Crocidura fuliginosa KIZ042756 CSD540 ML20205378 CSD536 KIZ2345 CSD544 Sorex bedfordiae MT201811285 KIZ2330 Neomys fodiens MT201811260 KIZ2316 CSD543 GLGS6028 KIZ042760 Nectogale elegans MT201904951 ML20205214 KIZ042759 CSD537 MT201811181 Chodsigoa hypsibia CY20206914 CY20206940 MT201904261 ML20205300 Episoriculus caudatus MT201904573 Chimarrogale himalayica 1/2.30 1/2.96 1/3.80 0.99/7.86 0.91/9.04 1/9.99 1/2.66 1/12.48 1/34.91 (26.74,44.07) 1/15.84 (15.06,18.41) (6.14,21.18) (4.98,16.37) (4.49,15.03) (1.07,5.34) (3.72,13.05) (1.75,6.78) (1.37,5.21) (1,4.08) S. beibengensis S. nigrescens S. nivatus S. medogensis Soriculus sp. S. minor Ma Figure 3. Divergence times estimated using BEAST based on the nDNA dataset. Branch lengths represent time (Ma). The two red asterisks indicate fossil-calibrated nodes. Numbers left of the slash represent the posterior probabilities (PP) of each node, numbers right of the slash represent the median divergence time, and numbers within parentheses indicate the confidence interval. Figure 4. Left: Dorsal, ventral and lateral views of the skull and mandibles of S. dexingensis sp. nov. (SAF11216). Right: dorsal, ventral, and lateral views of S. dexingensis sp. nov. (SAF11216).