Abstract: Crocidura is the most speciose mammalian genus. The taxonomy of Chinese taxa remains controversial and unexplored. In this study, a total of 189 specimens of eight large-sized white-toothed shrews (mean condyloincisor length > 19.5 cm) were collected in China, including C. attenuata, C. tanakae, C. anhuiensis, C. dracula, C. lasiura, C. pullata and two undescribed species (Crocidura sp. 1 and Crocidura sp. 3) from Xizang, China. Their fur, skull and tooth morphology were compared with each other. A principal component analysis (PCA) was conducted to assess morphological variation, including cranial characters, on 14 measurements among six Crocidura species and the two undescribed species. A canonical discriminant analysis was also computed for these specimens. For further comparison, we retrieved Cyt b sequences from GenBank, which included 86 Crocidura species from China and adjacent areas. BEAST was used for Byesian Inference (BI) analyses for these Crocidura species and a general mixed Yule-coalescent model (GMYC) was used to delineate species boundaries. Two undescribed species (Crocidura sp. 1 and Crocidura sp. 3) are recognized based on morphological and molecular evidence from Zhada County of Xizang (Western China) and Motuo County of Xizang, respectively. The two new Crocidura species are described as Crocidura zhadaensis Chen, Wu et Liu, sp. nov. and Crocidura medogensis Chen, Wu et Liu, sp. nov. The diagnostic characteristics of Crocidura zhadaensis are headbody length 69 ? 77 mm, tail length 49 ? 56 mm, and condyloincisive length 20.04 ? 20.74 mm. The hair is light in color, and the whole color is brown. Three quarters of the tail is covered with sparse white long hairs, and the tail ends form short hair bundles. Cranium is flattened. There are a pair of large oval foramen on the medial side of the inferior articular surface. Maxillary U³ was significantly greater than U² in size. There is a small depression near the protocone of P⁴. The diagnostic characteristics of Crocidura medoensis are head-body length 67- 76 mm, tail length, 62-65 mm, condyloincisive length 20.33-22.21 mm. The body color is dark, the back hair is dark brown, and the belly hair is dark gray. The tail is long, often more than 85% of the head length. The cranium is full and the parietal bone is protuberant. The U¹ is the largest, two times the height of U² and U³. The lingual surface of hypocone of the M¹ is extended, and appear a half-moon shape. The mastoid process is prominent. This article includes a taxonomic key to these species, which provides basic data for further clarifying the classification and species diversity of the genus Crocidura in China.

Key words: Xizang, Crocidura, Taxonomy, Morphology, Small mammals

摘要： 麝鼩属(Crocidura)是哺乳动物中物种数量最多的属。中国麝鼩属的分类存在诸多争议，需要进一步开展基础研究。本文整理了灰麝鼩(C. attenuata)、台湾灰麝鼩(C. tanakae)、安徽麝鼩(C. anhuiensis)、白尾梢大麝鼩(C. dracula)、大麝鼩(C. lasiura)、黑袍麝鼩(C. pullata)和2个疑似新种共8种大型麝鼩189号标本，比较了假剥制标本、头骨和牙齿形态，对测量数据进行了主成分分析(PCA)和判别分析(DA)。结合中国及邻近地区麝鼩属物种Cyt b基因的分子系统学和分子物种界定结果，我们描记了两个从中国西藏发现的麝鼩新种，即札达麝鼩Crocidura zhadaensis Chen, Wu et Liu, sp.nov.和墨脱麝鼩Crocidura medogensis Chen, Wu et Liu, sp.nov.。札达麝鼩的鉴定特征：头体长69~77 mm，尾长49~56 mm，颅全长20.04~20.74 mm。体色较浅，整体呈褐色。尾距尾基3/4长有稀疏的白色长针毛，尾末端形成短毛束。脑颅扁平，下关节面内侧卵圆孔大，第三上单尖齿(U³)明显大于第二上单尖齿(U²)，第一上前臼齿(P⁴)原尖附近有一小凹陷。墨脱麝鼩的鉴定特征：头体长67~76 mm，尾长62~65 mm，颅全长20.33~22.21 mm。体色深，背毛深黑褐色，腹毛黑灰色；尾长，常超过头体长的85%；脑颅饱满，顶骨较隆起；第一上单尖齿(U¹)最大，高度约是第二上单尖齿(U²)和第三上单尖齿(U³)的两倍；第一上臼齿(M¹)的次尖舌面侧缘延展呈半月形；乳突明显。为进一步厘清中国麝鼩物种的分类和物种多样性，本文编制了它们的物种检索表。

关键词: 西藏, 麝鼩, 分类, 形态学, 小型兽类