A new species of the genus Soriculus (Soricidae, Eulipotyphla, Mammalia) from Medog in the eastern Himalaya Author Pei, Xiaoxin https://orcid.org/0000-0001-7137-2600 State Key Laboratory of Genetic Resources and Evolution & Yunnan Key Laboratory of Biodiversity and Ecological Security of Gaoligong Mountain, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China & Kunming College of Life Sciences, University of Chinese Academy of Sciences, Kunming, China Author Chen, Zhongzheng https://orcid.org/0000-0003-3821-0145 State Key Laboratory of Genetic Resources and Evolution & Yunnan Key Laboratory of Biodiversity and Ecological Security of Gaoligong Mountain, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China & Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, Anhui Normal University, Wuhu, China zhongzheng112@126.com Author Li, Quan https://orcid.org/0000-0001-7536-5475 State Key Laboratory of Genetic Resources and Evolution & Yunnan Key Laboratory of Biodiversity and Ecological Security of Gaoligong Mountain, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China Author Li, Xueyou State Key Laboratory of Genetic Resources and Evolution & Yunnan Key Laboratory of Biodiversity and Ecological Security of Gaoligong Mountain, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China Author Pu, Changzhe State Key Laboratory of Genetic Resources and Evolution & Yunnan Key Laboratory of Biodiversity and Ecological Security of Gaoligong Mountain, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China Author Luo, Kang State Key Laboratory of Genetic Resources and Evolution & Yunnan Key Laboratory of Biodiversity and Ecological Security of Gaoligong Mountain, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China Author Luo, Jing State Key Laboratory of Genetic Resources and Evolution & Yunnan Key Laboratory of Biodiversity and Ecological Security of Gaoligong Mountain, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China Author Pu, Mingjin State Key Laboratory of Genetic Resources and Evolution & Yunnan Key Laboratory of Biodiversity and Ecological Security of Gaoligong Mountain, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China Author Wang, Hongjiao State Key Laboratory of Genetic Resources and Evolution & Yunnan Key Laboratory of Biodiversity and Ecological Security of Gaoligong Mountain, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China Author Khanal, Laxman https://orcid.org/0000-0003-2411-3627 Central Department of Zoology, Institute of Science and Technology, Tribhuvan University, Kathmandu, Nepal Author Jiang, Xuelong https://orcid.org/0000-0003-2052-2490 State Key Laboratory of Genetic Resources and Evolution & Yunnan Key Laboratory of Biodiversity and Ecological Security of Gaoligong Mountain, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China jiangxl@mail.kiz.ac.cn text ZooKeys 2024 2024-03-14 1195 139 155 http://dx.doi.org/10.3897/zookeys.1195.115699 journal article http://dx.doi.org/10.3897/zookeys.1195.115699 1313-2970-1195-139 385083C2BB0D460A867033D69D2FA586 3C65EDBE875E515A822311EFF85AB46A Soriculus beibengensis sp. nov. Suggested common name. Beibeng large-clawed shrew, 背崩大爪鼩鼱 . Type material. Holotype . KIZ042755, adult female, collected on 08 April 2023 by Mingjin Pu, at Beibeng Town, Medog County, southeast Tibet, China ( 29.219°N , 95.189°E , 1610 m a.s.l.). Dried skin, cleaned skull and muscle tissue are deposited in KIZ. Paratypes . Five specimens KIZ042756 (adult female), KIZ042757 (adult female), KIZ042758 (adult female), KIZ042759 (adult female), KIZ042760 (adult female). Collected from the type locality at Medog in April 2023 at elevations from 1500 m to 2125 m. All specimens are deposited in KIZ. Specimens examination. Four specimens KIZ042761 (adult female), KIZ042762 (adult male), KIZ042763 (adult female), KIZ042764 (adult female). Etymology. The specific Latin name Soriculus beibengensis named for Beibeng, the type locality, with the Latin adjectival suffix - ensis means "belonging to". Diagnosis. The new species is assigned to the genus Soriculus , based on the typically enlarged forefeet and claws (Fig. 5 ). Dark grey to black pelage; nearly similar ventral and dorsal pelage colour, similar to S. minor (Fig. 5 ); size (CIL: 20.8 +/- 0.3 mm, 20.4-21.3 mm vs. 19.6 +/- 0.4 mm, 19.2-20.2 mm; ML: 11.6 +/- 0.2 mm, 11.3-11.9 mm vs. 10.8 +/- 0.2 mm, 10.5-11.0 mm) larger than S. minor , but much smaller than S. nivatus , S. nigrescens and S. medogensis . The tail (40.6 +/- 1.8 mm) is longer than S. minor (36.7 +/- 4.1 mm), but shorter than S. nivatus (51.6 +/- 2.7 mm), S. nigrescens (45.8 +/- 3.2 mm) and S. medogensis (50.7 +/- 3.6 mm). The TL/HBL (53%) is close to that of S. minor (52%) and S. nigrescens (52%), but smaller than S. nivatus (63%) and S. medogensis (60%). The nasal and rostrum are not clearly transitioned and seem to be stubby. The posterior process of the incisors widens, forming a narrow funnel-shaped channel between the processes. The basioccipital and basisphenoid are fused and narrowed, like a spade (Fig. 6 ). Figure 5. Dorsal and ventral view of the skin of A S. beibengensis sp. nov. (KIZ042755) B S. minor (KIZ020545). Figure 6. Dorsal, ventral and lateral views of the skull and mandibles of A S. beibengensis sp. nov. (KIZ042755) B S. minor (KIZ020545). Description. Amongst five species of the genus Soriculus , S. beibengensis sp. nov. is the second smallest species. Its size is larger than S. minor , but smaller than S. nivatus , S. nigrescens and S. medogensis (Table 1 ). External morphology is similar to S. minor , with the dorsal pelage being dark grey to black and ventral pelage slightly paler. Tail is ambiguously bicoloured, dark above and pale below (Fig. 5 ). The tail is short (TL = 40.6 +/- 1.8 mm, 38-44 mm), averages 53% of the head and body length and 8 of 10 specimens examined have a tail length more than 40 mm. The foreclaws are enlarged, similar to other Soriculus species. The back of hands and feet are covered by light brown to black hairs. The skull is distinctly smaller than S. nivatus , S. nigrescens and S. medogensis , but larger than S. minor . Braincase is low and relatively flattened and the posterior of the skull is rounded. The sagittal and lambdoidal crest are well-developed and clear, the latter is especially prominent. The nasal and rostrum are not clearly transitioned and are stubby. The posterior process of incisor is widened, forming a narrowed funnel-shaped channel between the processes of adjacent teeth. The basioccipital and basisphenoid are fused and narrowed markedly in the middle region, forming a spade-like structure (Fig. 6 ). The coronoid process is high and straight, with a concave anterior surface and a spatulate tip. The condyloid process has a single slender point and is angled upward at roughly 45 degrees, with the tip sitting below the coronoid process (Fig. 6 ). The angular process is long, straight and very thin, the tip slightly expands and bends upwards. The condyloid process is double-faceted, having two projections. The dental formula of the S. beibengensis sp. nov.is the same as the genus is: I 3/2, C 1/0, P 2/1, M 3/3 ( x 2) = 30. The apex of the first upper incisor is straight downwards, the tip of the first upper incisor is slightly pigmented with orange. There are four upper unicuspids (U1-U4); U1 is the highest, followed by U2, U3 and U4 is the smallest. M1 and M2 are similar in size, while M3 is reduced. The lower incisor (I1) is long, with only a low cusp and the tips are pigmented with orange. The lower unicuspid (U1) and P4 are crowded. M1 is larger than M2; M3 is the smallest. Comparison. Amongst species of the genus Soriculus , S. beibengensis sp. nov. is morphologically similar to its sister species, the S. minor . Both of them have a darker pelage and smaller size than other species. However, the new species can be distinguished from S. minor by multiple features. S. beibengensis sp. nov. is larger than S. minor for most of the external and craniomandibular measurements (Table 1 ). Especially, the skull of S. beibengensis sp. nov. is significantly longer than that of the S. minor , the measurements of CIL (20.4-21.3 mm vs. 19.2-20.2 mm) and ML (11.3-11.9 mm vs. 10.5-11.0 mm) between the two species do not overlap. The nasal and rostrum of S. beibengensis sp. nov. are not clearly transitioned and seem to be stubby, while S. minor , as well as the other species, has a clear transition of the nasal and rostrum (Fig. 6 ). The posterior process of incisors in S. beibengensis sp. nov. are widened, forming a narrowed funnel-shaped channel between the processes, whereas they are not widened in S. minor (Fig. 6 ). Soriculus beibengensis sp. nov. can be easily distinguished from S. nigrescens , S. nivatus and S. medogensis by its smaller size, the darker pelage colour and almost no pigmentation of the teeth (Fig. 5 ). Compared to S. nivatus , the measurements of CIL, PIL, BL, UTL, P4M3, IOB, CB, CH, PPD, ML and LTR of S. beibengensis sp. nov. are smaller, with no overlap and the teeth of S. nivatus are slender, appear to be the most delicate in the genus. Amongst S. beibengensis sp. nov., S. nigrescens and S. medogensis , the ranges of most of their external and craniodental measurements do not overlap (Table 1 ). The teeth of S. beibengensis sp. nov. are significantly smaller, but the teeth of S. medogensis are robust, with the broadest ramus region and the highest coronoid process in the genus. Compared to S. nivatus (TL/HBL = 63%) and S. medogensis (TL/HBL = 60%), the tail of S. beibengensis sp. nov. (TL/HBL = 53%) is shorter and the tail length of S. nivatus more than 46 mm, the tail length of S. medogensis usually more than 50 mm (6 of 7 (species measurements?)), while S. beibengensis sp. nov. less than 44 mm. The size arrangement of the unicuspids of S. beibengensis sp. nov. is similar to S. minor , U1 is the highest, followed by U2, U3 and U4 is the smallest, while other species usually have the largest U2, followed by U1, U3 and U4. Distribution and habits. Soriculus beibengensis sp. nov. is known only from the type locality in Beibeng and Damu Town, Medog, Tibet, China at elevations from 1501 to 2123 m a.s.l. They were mainly distributed in mixed forest dominated by oak and a few individuals were distributed in conifer-broadleaf mixed forest.