Soriculus dexingensis Zhang, Liu & Chen, 2025

Soriculus dexingensis Zhang, Liu & Chen sp. nov.

Holotype.

SAF 11216 , adult male, collected on 29 October 2011 by Rui Liao. The specimen was deposited at the Sichuan Academy of Forestry ( SAF). GoogleMaps

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, M 2 M 2 = 6.11, BB = 11.23, BH = 6.75, ML = 14.96, LTR = 9.39.

Type locality.

Dexing Town   GoogleMaps , Medog County, Tibet, China ( 29.41778°N, 95.05969°E, 2100 m a. s. l.).

Paratypes.

Seven specimens SAF 11200 ( male), SAF 11215 ( male), SAF 11237 ( female), SAF 11238 ( male), SAF 11243 ( male), SAF 11245 ( male), SAF 11246 ( 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 GoogleMaps .

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 (M 2 M 2) 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 View Figure 4 ). The tail is bicolored: dorsal part dark brown; ventral part slightly lighter (Fig. 4 View Figure 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, fused with the basisphenoid in the central region. The coronoid process of the mandible is robust and long, with a spatulate tip that rises straight upward. The condyloid process forms an angle of roughly 45 ° with the coronoid process. The angular process is long and thin, slightly bent, with an expanded, upwardly bent tip.

The dental formula of S. dexingensis sp. nov. is: I 3 / 2, C 1 / 0, P 2 / 1, M 3 / 3 (× 2) = 30, which is consistent with that of the genus Soriculus . The teeth are robust. The apex of the first upper incisor points straight downward, with a broad posterior cusp. Four upper unicuspids (U 1 – U 4) are present: U 2 is the largest in size, U 1 is slightly smaller and similar to U 3, and U 4 is minute. M 1 and M 2 are similar in size, whereas M 3 is significantly reduced. The lower incisor (I 1) is straight and long, with a low cusp. Half of the lower unicuspid (U 1) is in contact with I 1. M 1 is larger than M 2, and M 3 is the smallest. The tips of all teeth are pigmented red-orange.

Suggested common name.

Dexing Large-clawed Shrew (English), 德兴大爪鼩鼱 (Chinese).

Etymology.

The specific Latin name dexingensis is named for Dexing, the type locality, with the Latin adjectival suffix – ensis meaning “ belonging to ”.

Comparison.

Morphologically, Soriculus dexingensis sp. nov. is similar to S. nivatus , but can be distinguished from the latter by many characters. The tail of S. dexingensis sp. nov. is relatively longer ( TL = 57.45 ± 3.31 mm) than that of S. nivatus ( TL = 49.38 ± 5.05 mm); nine of eleven S. dexingensis sp. nov. individuals have a tail length greater than 56 mm, whereas most individuals of S. nivatus (18 of 20) have a tail length less than 56 mm. The TL / HB ratio of S. dexingensis sp. nov. (74 %) is much larger than that of S. nivatus (64 %). In the skull, S. dexingensis sp. nov. is similar to S. nivatus and cannot be distinguished from it by skull measurements. However, the teeth of S. nivatus are much more slender and delicate than those of S. dexingensis sp. nov. The posterior of the skull of S. dexingensis sp. nov. is flattened, whereas that of S. nivatus is rounded. In addition, S. dexingensis sp. nov. has more lightly pigmented teeth than those of S. nivatus .

Soriculus dexingensis sp. nov. can be easily distinguished from S. minor and S. beibengensis by its larger size, and all measurements of S. dexingensis sp. nov. show nearly no overlap with measurements of S. minor and S. beibengensis (Table 1 View Table 1 ). Furthermore, it can be distinguished by its longer tail ( TL / HB ratio: 56 % in S. minor and 56 % in S. beibengensis ) and by its distinctly more heavily pigmented teeth compared to these two species.

Soriculus dexingensis sp. nov. can also be distinguished from S. nigrescens by its longer tail ( TL = 57 ± 3 mm, range 50–62 mm vs. TL = 42 ± 2 mm, range 38–46 mm in S. nigrescens ). Besides, the rostrum of S. dexingensis sp. nov. is relatively narrower than that of S. nigrescens , and the range of M 2 M 2 ( 5.90–6.12 mm in S. dexingensis sp. nov. vs. 6.19–6.82 mm in S. nigrescens ) does not overlap between the two species.

Compared to its sister species S. medogensis , S. dexingensis sp. nov. can be distinguished by its smaller skull and more heavily pigmented teeth. Except for two skull measurements ( PPL, PIL), all other measurements of S. dexingensis sp. nov. are smaller than those of S. medogensis with no overlap. Additionally, the fourth upper unicuspid (U 4) of S. dexingensis sp. nov. is smaller than that in S. medogensis .

Comments.

Specimens ( CSD 536 – CSD 546) previously assigned to Soriculus medogensis by Chen et al. (2024) were re-examined using an integrative approach combining morphological and molecular data. Our analyses reveal that these individuals exhibit substantial genetic divergence and significant morphological differences from all known Soriculus species. Consequently, we describe them herein as a new species.

Distribution.

Soriculus dexingensis sp. nov. is currently only known from elevations of 2100–2830 m in the eastern Himalayas, specifically in Medog County, Tibet, China. The specimens were all captured from broadleaf forests.