šM“®ŠwŽ•(J. Mamm. Soc. Japan) 10 (2): 69-80 (1984) A Review of the Shrew-moles (Genus Uropsilus) of China and Burma Robert S. HOFFMANN The University of Kansas, Museum of Natural History and Department of Systematics and Ecology, Lawrence, Kansas 66045, U.S.A. The genus Uropsilus was first described by MILNE-EDWARDS (1871) from material sent back from Muping (Moupin, now Baoxing), Sichuan, by Pere Armand DAVID; the type species is U. soricipes. These small insectivores are shrew-like in external appearance, but exhibit a mole-like skull and dentition. The tail is long and forefeet are not enlarged, while the zygomatic arch is complete, and the tympanic bones form an auditory bulla (Fig. 1). Thus, this•gshrew-mole•hlacks skeletal specializations for digging found in more derived moles, and the derived characters of skull and dentition found in shrews. However, Uropsilus soricipes exhibits a derived dental formula compared to the primitive eutherian condition seen in some genera of moles (Ta/pa, Parascalops, Scapanus, Condylura; i 3/3, c 1/1, p 4/4, m 3/3=44), possessing, i 2/1, c 1/1, p 3/3, m 3/3=34 according to Mime-Edwards (Fig. 1a). Subsequent to the initial record, other specimens from Yunnan (POUSARGUES, 1896) and southern Sichuan (THOMAS, 1911) came to light in which the dental formula differed from that of the specimen described by Mime-Edwards; additional upper and lower incisors seemed to be present (i 3/2, c 1/1, p 3/3, m 3/3=38). This was in- terpreted as individual variation (Fig. 1b). Soon, however, THOMAS (1912) changed his mind. Receipt of new specimens from western and southeastern Sichuan revealed still a third dental formula, and prompted THOMAS to erect two new monotypic genera to encompass the variation. These were: Rhynchonax andersoni THOMAS, 1911, type locality Omi-san (Emei Shan), Sichuan; dental formula i 2/2, c 1/1, p 4/3, m 3/3=38 (corrected from THOMAS, 1911, see above); and Nasillus gracilis Thomas, 1911, type locality Mt. Chin-fu-san (Jingfu Shan) near Nan-chwan (Nanchuan), Sichuan (Fig. 2); dental formula i 2/1, c 1/1, p 4/4, m3/3=38 (Fig. 1c). This arrangement was not greeted with universal acceptance. ALLEN (1912a) continued to regard the several dental formulae as individual variation within a single species, U. soricipes, as did HOWELL (1929) and OsGooD (1937). Later, however, ALLEN (1938) changed his views somewhat, stating:•gThe fact that... these three groups [genera] seem to have fairly distinct areas of geographic distribution, may be interpreted as favoring their distinctness.•h That Allen may have begun to change his mind earlier is evidenced by his having described two new subspecies, Rhynchonax andersoni atronates from the Salween drainage in southwestern Yunnan, and R. a. nivatus from the Likiang (Lichiang) Range, western Yunnan (Fig. 2) (ALLEN, 1923). These new subspecies were described 70 哺 乳 動 物 学 雑 誌 Vol. 10, No. 2 1984”N8ŒŽ Shrew-moles of China and Burma 71 Fig. 2. Localities of occurrence of the genus Uropsilus. Open circles, U. gracilis; squares, U. andersoni; solid circles, U. soricipes. as smaller than typical R. andersoni, and having different tooth proportions. The reason for these differences became apparent when OSGOOD (1937) pointed out that the topotypical series of these two taxa, including both holotypes, possessed the dentitions described by THOMAS (1912) for Nasillus rather than Rhynchonax. I have subsequently examined these specimens and confirm OsGooD's conclusion. Meanwhile, THOMAS (1922) had described a new species, Nasillus investigator, from the Kiu-kiang•\Salween divide, Yunnan. This type locality is north, up the Salween River from the type locality of•gR. a.•hatronates, and not far west of the type locality of•gR. a.•hnivatus (Fig. 2). THOMAS (op. cit.) described N. investigator as larger than N. gracilis, but ALLEN (1938) observed that •gundoubtedly it will eventual- ly prove to be at most a slightly larger subspecies of N. gracilis ...•h 72 哺乳動 物 学雑誌 Vol. 10, No. 2 It is curious that even though ALLEN (op. cit.) listed OscooD's 1937 paper (wherein atronates and nivatus were said to have Nasillus dentition) in his bibliography, he did not cite the paper in the pertinent text passages. He instead retained these taxa as subspecies of Rhynchonax andersoni, even though recognizing the occurrence of Nasillus in that part of Yunnan. Subsequently ANTHONY (1941) compounded this confusion by referring a series of Burmese shrew-moles with Nasillus dentition to Rhynchonax a. andersoni, after comparing them to•g... a series of over eighty a. andersoni, collected in western Szechwan by the Sage West China Expedition and nine a. atronates Allen, including the type ...•hANTHONY (op. cit.) concluded that atronates was a synonym of andersoni•g... not only on the basis of the characters shown but on geographical grounds, since the range of atronates appears to be midway of the range of andersoni (as I am now extending it) [i.e., from western Sichuan to northern Burma] and not isolated from it by virtue of special conditions such as altitude.•h There the matter rested, until ELLERMAN and MoRRISON-ScoTT (1951) suggested that there was insufficient evidence to retain the taxa as distinct, monotypic genera. They recognized one species, Uropsilus soricipes, with five subspecies : U. s, soricipes; U. s. gracilis; U. s. andersoni (incl. atronates); U. s. investigator and U. s. nivatus. Since then this arrangement has been adopted by other workers (CRANBROOK 1960- 61; CORSET and HILL, 1980; HONACKI et al., 1982), although GUREEV (1979) con- tinued to recognize three genera and four species. I have examined all but one of the holotypes, as well as the majority of extant specimens in North America and Europe, and have concluded that the present taxonomic arrangement is incorrect. For reasons detailed below, I recognize three species in a single genus, Uropsilus. Materials and Methods A total of 522 specimens was examined. Many of these had broken skulls and the number of intact skulls studied was much lower (see Specimens Examined; Tables). Three external measurements were taken, where available, from collector's original labels. Seven cranial measurements were made to the nearest 0.05 mm with dial calipers. These included: 1) condyloincisor length (CIL); occipital condyles to anterior tips of first incisors; 2) cranial breadth (CB), greatest breadth of braincase, approximately across the mastoids; 3) maxillary breadth (MB), greatest distance between tips of maxillary processes; 4) M2 to M2 breadth (M2-M2), greatest distance between anterior labial margins of second upper molars ; 5) interorbital breadth (IOB), least lateral diameter of skull at anterior end of orbits, just posterior to maxil- lary processes; 6) palatoincisor length (PIL), posterior margin of palate in midline to anterior tips of first incisors; 7) upper tooth row length (UTRL), greatest length of tooth row from posterior margin of alveolus of M3 to anterior tip of I1. These meas- urements were selected for the speed and accuracy with which they could be made, and in some cases differ from those of earlier investigators. For example, condy- lobasal length is a traditional measure of skull length, but it is usually difficult and time-consuming to measure the anterior margin of the premaxillary bone. Employ- ing the anterior tips of the first incisors for the anterior terminator results in a more accurate and repeatable measurement. 1984年8月 Shrew-moles of China and Burma 73 Results The basis for placing all Chinese shrew-moles in a single species, Uropsilus soricipes, is the view that the different dental patterns, formerly the basis for recogniz- ing other genera and species, are in fact attributable to individual variation. There- fore, particular attention was paid to the occurrence of dental anomalies. The largest series of specimens were those from the Chen Lliang Shan (Qionlai Shan), western Sichuan, collected by the Sage Expedition (see SHELDON,1975; LAWRENCE,1982); from northern Burma by the Vernay-Cutting Expedition (see ANTHONY,1941); and from several adjacent localities in west-central Sichuan by F. T. SMITHfor the Field Table 1. Individual variability in dentition among Uropsilus pop- ulations. Table 2. Altitudinal distribution of Uropsilus soricipes and U. gracilis in the Qionlai Shan, Sichuan, China. 74 哺 乳 動 物 学 雑 誌 Vol. 10, No. 2 1984年8月 Shrew-moles of China and Burma 75 76 哺 乳 動 物 学 雑 誌 Vol. 10, No. 2 Museum (see OsGooD, 1937). In these series, a few dental anomalies were found, but overall, dentition was not highly variable (Table 1). Note that the three basic dental patterns formed the basis for identification of three taxa. If all specimens from Sichuan in Table 1 were to be regarded as belonging to a single species, then out of 386 individuals, 99 (25.6 %) would possess dental anomalies, and individual variation might indeed be considered frequent in U. soricipes. Several considerations militate against this view. First, of the 99•ganomalies•h, all but five are bilateral in occurrence. This preponderance of bilateral consistency in presence or absence of teeth is not what would be expected if individual variation were the cause of the anomalies. Second, in the Quonlai Shan, 25-30 mi W of Wenchuan, Sichuan, both U. soricipes and U. gracilis dental patterns are represented by large samples (Table 1). If only a single species with a high frequency of individual tooth variation was present here, one would expect that dental anomalies might be randomly distributed through the local populations of the Qionlai Shan. This is not the case; the U. gracilis pattern is more frequent at higher elevations, while the U. soricipes pattern is more frequent lower down (Table 2).