Chodsigoa hoffmanni, Chen & He & Huang & Wan & Lin & Liu & Jiang, 2017

CHODSIGOA HOFFMANNI SP. NOV.

( FIGS 6, S 1)

Common name : Hoffmann’s Long-tailed Shrew; 霍氏缺 齿鼩 (= Huoshi Quechiqu).

Holotype: KIZ 032249 View Materials (field number: AL 1305335). An adult female collected by ZZC on 21 April 2013. Dried skin, cleaned skull and alcohol-preserved carcass.

Type locality: The eastern slope of the Ailao Mountain (24.590 N, 101.508 E, 2600 m a.s.l.), Shuangbai, Chuxiong, Yunnan, China GoogleMaps .

Paratypes: KIZ 019442 View Materials , 019443 View Materials , 019448 View Materials , 019458 View Materials , 019459 View Materials , collected from Wuliang Mountain in January 1998 ; KIZ 032025 View Materials , 032249 View Materials , 032254 View Materials , 032777 View Materials , 032778 View Materials , collected on the western slope of Ailao Mountain , Zhenyuan (24.279 N, 101.263 E) and GoogleMaps KIZ 032248 View Materials , 032776 View Materials was collected on the eastern slope of Ailao Mountain , Shuangbai (24.590 N, 101.508 E) from March 2013 GoogleMaps to January 2014. All specimens are prepared as dried skins with cleaned skulls; skull of KIZ 032254 View Materials is missing .

Diagnosis: Body size larger than C. parva , C. sodalis and C. caovansunga , but smaller than all the other known species of Chodsigoa ( Table S1). Tail longer than the HB, so relatively longer than those of C. hypsibia (TL ≤ HB), C. parva (TL ≤ HB) and C. sodalis (TL = HB). Tail bicoloured with a tuft of longer hair on the tip, similar to C. parca and C. sodalis (tail not bicoloured in C. parva ; the tip of tail naked in C. caovansunga , C. furva and C. smithii ). Braincase higher than C. caovansunga , C. hypsibia , C. parva and C. sodalis . Skull similar to C. parca in shape, with overall smaller craniomandibular measurements. Upper incisors shorter than C. parca ; upper unicuspids overlap slightly, but are less crowded than in C. parca . Coronoid process of mandible shorter than C. parca .

Description: A medium-sized (HB = 67 mm) Chodsigoa with a long tail (TL = 82 mm; TL/HB = 120%). Dorsal pelage slate grey; ventral pelage slate grey and paler than the dorsum. Dorsal surface of tail pigmented brown, ventral surface paler. Tip of tail white (c. 5 mm) in most specimens with a tuft of slightly longer hair. The skin of the hands and hind feet is creamy white. Braincase is domed. The rostrum is short and gradually tapering in the premaxillary region. First upper incisor falciform; anterior cusp short, hook-like. Three upper unicuspids quite similar in size, are slightly overlapping, and in lateral aspect appear to gradually decrease in size from U 1 to U 3. Upper M 3 reduced, with a very narrow talon. Pigmentation only present on tips of upper and lower incisors and first unicuspids. Horizontal ramus short but stout. Ascending ramus noticeably broader at the level of the upper sigmoid notch. Coronoid spicule clear and very low, clearly ventral to the level of upper sigmoid notch.

Comparisons: Among the species of Chodsigoa , C. hoffmanni is most similar to its sister species C. parca , but it is clearly smaller in most measurements of its skull. Chodsigoa hoffmanni also has smaller upper incisors, with a shorter and more hook-shaped anterior cusp. The upper unicuspids of C. hoffmanni overlap only slightly, while in C. parca , the unicuspids extend anteriorly overlapping to a greater degree, and appeared crowded. The mandible of C. hoffmanni is shorter than that of C. parca . Coronoid spicule of C. hoffmanni is clearly ventral to the level of upper sigmoid notch, more ventrally positioned than that of C. parca , which is entirely at the level of the upper sigmoid notch ( Fig. 7). When compared with the other species, C. hoffmanni differs from C. hypsibia , C. parva and C. sodalis by its relatively longer tail (TL/ HB = 120%). Chodsigoa hoffmanni has a tuft of longer hair on the tip of the tail, making it different from C. caovansunga , C. furva and C. smithii . External morphology is similar to C. caovansunga . The braincase of C. hoffmanni is more domed-shaped and higher than that of C. caovansunga . Chodsigoa hoffmanni also differs from C. furva and C. smithii by its shorter hind feet.

Comments: Chodsigoa hoffmanni was previously included in C. parca ( Lunde et al., 2003; He et al., 2010). Based on molecular and morphological evidence, it should be recognized as a separate species. The Mekong River probably acts as the geographic barrier between the two species. The populations included in the current study from China and Vietnam are geographically isolated by the Red River ( Fig. 3) and are also genetically divergent from each other.

Distribution: Currently known from Ailao Mountain and Wuliang Mountain, Yunnan, China, Mt. Tay Con Linh II, northern Vietnam. The Mekong River is likely the western boundary of its distribution. This species was collected from evergreen broadleaved forests from 1500 to 2600 m.

Etymology: Named in memory of Dr. Robert Shaw Hoffmann (1929–2010), a Curator of Mammals at the National Museum of Natural History, Smithsonian Institution. He worked with Chinese mammalogists and contributed to the science of mammalogy in China ( Wilson & Timm, 2011).

CHODSIGOA HYPSIBIA (DE WINTON AND STYAN, 1899)

Soriculus hypsibia de Winton and Styan, 1899: 574 . Soriculus beresowskii Kastschenko, 1907: 252 . Chodsigoa hypsibia View in CoL – Thomas, 1908: 639.

Chodsigoa lamula Thomas, 1912a: 399 View in CoL .

Chodsigoa hypsibia lamula View in CoL – Allen, 1938: 106.

Common names : De Winton’s shrew; 川西缺齿鼩 (Chuanxi Quechiqu).

Remarks: A medium- to large-sized species ( Tables 3 and S 5): Dorsal pelage is slate grey, ventral brownish grey. Dorsal surfaces of hands and feet appear creamy white, ventral surfaces light brown. Tail shorter than the HB, not sharply bicoloured, dorsal surface dark brown, ventral surface paler. A tuft of slightly longer hair on tip of the tail. Skull, especially the braincase, markedly flattened. Rostrum gradually narrowed in the premaxillary region.

This species has a wide distribution, and there is considerable shape variation among geographical populations ( Jiang & Hoffmann, 2005). It was first described by De Winton & Styan (1899). Chodsigoa beresowskii ( Kastschenko, 1907) was regarded as a synonym of C. hypsibia by Thomas (1912b). Chodsigoa lamula ( Thomas, 1912a) was recognized as a subspecies of C. hypsibia by Allen (1938). Hoffmann (1985) considered it as distinct species and this was followed by Hutterer (2005). However, our molecular results found that it is genetically indistinguishable from C. hypsibia . We, therefore, consider it as a synonym of C. hypsibia . Two subspecies (the nominal subspecies and C. h. larvarum, Allen, 1938 ) are recognized.

CHODSIGOA HYPSIBIA HYPSIBIA (DE WINTON AND STYAN, 1899)

Type locality: Yangliu-pa (= Yangliu ba), Pingwu, Sichuan, China.

Remarks: Our molecular analyses indicate that the population from Ninglang, Yunnan, China, is a cryptic species. It is morphologically indistinguishable from the nominal subspecies so we provisionally retain it as C. hypsibia . It will need to be re-examined once additional specimens from a wider geographic area are available.

Distribution: Known from Qinghai, Sichuan, Shaanxi, Tibet and Yunnan, China. Most populations occupy mid- to high-mountain forests from 1200 to 3500 m.