Uropsilus fansipanensis Bui & Okabe & Le & Nguyen & Motokawa 2023, sp. nov.
Creators: name: Bui, Hai Tuan
name: Okabe, Shinya
name: Le, Linh Tu Hoang
name: Nguyen, Ngan Thi
name: Motokawa, Masaharu
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Mammalia
Soricomorpha
Talpidae
Uropsilus
Uropsilus fansipanensis

description: Uropsilus fansipanensis sp. nov.
urn:lsid:zoobank.org:act: 6C15FBA6-D73B-44A0-A72F-0C326F92EB51
Holotype. IEBR-M-8101 (field number Motokawa 837), an adult male, from Mount Fansipan, Hoang Lien National Park, close to the 2900-m camping station (22°18.804 N and 103°45.92 E), Lao Cai Province, Vietnam collected by Masaharu Motokawa on May 1, 2022, deposited in the Department of Vertebrate Zoology, Institute of Ecology and Biological Resources (IEBR), Vietnam Academy of Science and Technology, Hanoi. Skull was extracted. The body was preserved in 70% ethanol as a wet specimen.
Paratype. IEBR-M-8102 (field number Motokawa 914), an adult male, from Mt. Fansipan, Hoang Lien National Park, along the Tram Ton–Fansipan peak trail (22°18.783 N and 103°45.92 E), Lao Cai Province, Vietnam, collected by Shinya Okabe on May 5, 2022, deposited in the IEBR. Skull was extracted. The body was preserved in 70% ethanol as a wet specimen.
Diagnosis. Medium-sized shrew mole. Body bicolor, dorsum lightly reddish-brown and venter dark gray, but the separation between the dorsum and venter is not obvious. The tip of the fur on the back reddish-brown, and the rest is gray. The tail uniformly dark gray, long, slender, and covered with small scales arranged in rings; gradually darken from base to tip. Short bristle hairs sparsely covering the tail from the base to the tip, and longer at the tip of the tail. The mastoid process developed sideways and pointed out. The interorbital region broad and parallel. The zygomatic arch stouter. The foramen magnum very large. The lacrimal foramen well developed and much larger than the infraorbital foramen. The orbital process oriented upwards anteroposteriorly. Dental formula I 2/1, C 1/1, P 4/4, M 3/3 = 38 including teeth of I1, I2, C1, P1, P2, P3, P4, M1, M2, M3 / i2, c1, p1, p2, p3, p4, m1, m2, m 3 in the dentition. The buccal view of the upper fourth premolar (P4) triangular shape. The lower third premolar (p3) large in size. The lower first and third premolars (p1 and p3, respectively) approximately the same size. The lower canine (c1) larger than p1.
Description of holotype. Adult male, medium-sized shrew mole with a total length of 140.0 mm and a body mass of 8.0 g (Fig. 2). The reddish-brown dorsal pelage distinct from the dark gray ventral pelage. The tail dark gray, its length (62.5 mm) slightly more than 80% of the head-body length (77.5 mm). Nose elongated with nostrils facing outwards; snout bicolored, upper part dark gray and lower part yellowish. The pinna protrudes (E 8.51 mm) covered by sparse gray hair. Limbs covered with scales down to the toes with long, sharp, and opaque claws; forefoot short but fat (FF1 = 8.66 mm, FF2 = 9.66 mm); hindfoot long and slender (HF1 = 13.41 mm, HF2 = 15.16 mm), and the four limbs have the same color as the tail, with small black speckled scales. The small eyes, barely noticeable under the fur.
The skull (Fig. 3) long, and pyriform shaped with a short rostrum and a rounded braincase; palate relatively broad and possessing a sudden edge at the posterior end; pterygoid region deeply set; temporal ridges recognizable and converge in an X-shape; squamosal arm of the zygomatic arch sturdy; orbit locating at the midpoint of the skull; squamous processes sharp; bullae incomplete; pterygoid processes pointed saw-shaped; lacrimal foramen well developed and much larger than the infraorbital foramen; orbital process oriented upwards anteroposteriorly (Fig. 4). The mandible long and slender; coronoid process sharp and rear-facing crest; masseteric fossa arachnoid. Dental formula I 2/1, C 1/1, P 4/4, M 3/3 = 38 including teeth of I1, I2, C1, P1, P2, P3, P4, M1, M2, M3 / i2, c1, p1, p2, p3, p4, m1, m2, m 3 in the dentition (Fig. 3). The upper first incisor (I1) taller than the second incisor (I2); both I1 and I2 lingually concave; the upper canine (C1) slightly larger than the upper first premolar (P1); the upper third premolar (P3) small and the smallest tooth in the upper tooth row. The remaining upper premolars are shown from larger size to smaller size in the following order: upper fourth premolar (P4), upper second premolar (P2), and P1. The upper first molar (M1) larger than the upper second molar (M2); length and width of M1 are almost equal, and the same was observed in M2. The lower first incisor absent; the lower first and third premolars (p1 and p3, respectively) approximately the same size; the lower canine (c1) larger than p1; the lower second molar (m2) possesses a large concavity on its lingual side and protoconids from m2 is the highest cusp in the lower toothrow.
Variation. The discoloration of the scales at the base of the tail showed substantial variation between the holotype and the paratype; the latter is strongly discolored. This is probably because the paratype is older than the holotype.
Etymology. The specific epithet “ fansipanensis ” refers to the type locality of the new species, Mt. Fansipan. We suggest “Fansipan shrew mole” and “Chuột chũi vòi phan-xi-pan” for the common names in English and Vietnamese, respectively.
Ecological notes. U. fansipanensis was found in a dwarf mountain forest on Mt. Fansipan, at an elevation of approximately 2800–2900 m. The surrounding habitat was grassy with shrubs on a thick and moist humus layer close to a small bamboo forest and a travel trail. During the field survey in May, which corresponds to the end of spring in northern Vietnam, the daily temperature fluctuates from 1 to 20°C, and sometimes rain occurs (Fig. 5A).
Distribution. U. fansipanensis is presently known only from the type locality in Mt. Fansipan, Hoang Lien National Park, Lao Cai Province, northwestern Vietnam (Figs. 5B, 6).
Comparisons (measurements are in mm). All members of Uropsilus have a primary coloration of brown dorsal and gray ventral fur, while they differ in terms of their tail color. U. fansipanensis, U. soricipes, U. gracilis, U. andersoni, and U. atronates have a uniformly colored tail. On the other hand, U. investigator, U. nivatus, U. aequodonenia, and U. dabieshanensis have a bicolor tail, with the upper part being darker than the underside (Table 2; Liu et al. 2013; Wan 2015; Hu et al. 2021).
U. fansipanensis overlaps basic external morphological measurements with most of the other species of Uropsilus (Table 3). Nevertheless, it has a longer tail (T: 61.0–62.5) and hindfoot (HF: 13.41–13.57) than U. dabieshanensis (T: 52.4–54.1, HF: 12.8–12.9), and a shorter tail than U. aequodonenia (T: 67–73).
U. fansipanensis shows overlap in most cranial measurements (Table 4) with U. soricipes, U. nivatus, and U. atronates, except a slightly larger anterior labial margin of the second upper molars than U. nivatus and U. atronates (M2-M2: 6.36–6.40 vs. 6.15–6.35 vs. 5.95–6.3). Nevertheless, it can be distinguished in several cranial measurements from the other five Uropsilus species as detailed below. U. fansipanensis has smaller upper toothrow length (UTRL: 9.03–9.07 vs. 9.1–10.7), palatal length (MPL: 9.62–9.75 vs. 9.68–11.2), lower toothrow length (MTRL: 8.30–8.31 vs. 8.43–9.09), mandible length (LM: 13.52–13.77 vs. 14.01–15.00), and braincase height (BH: 6.90–6.91 vs. 7.18–7.6) than U. gracilis.
U. fansipanensis has a slightly wider snout (GBSn: 7.39–7.62 vs. 7.13–7.35) and longer mandible length (LM: 13.52–13.77 vs. 11.95–13.42) than U. investigator, while it has a shorter upper toothrow length (UTRL: 9.03–9.07 vs. 9.10–9.80).
* The original source did not distinguish between HF1 and HF2.
U. fansipanensis has a shorter profile length (PL: 20.4–20.69 vs. 20.65–22.28), shorter upper (UTRL: 9.03–9.07 vs. 9.25–9.95) and lower (MTRL: 8.30–8.31 vs. 8.49–9.07) toothrow length than U. andersoni.
U. fansipanensis has a shorter profile length (PL: 20.4–20.69 vs. 20.75–22.03), basal length (BL: 16.62–16.98 vs. 16.70–17.86), and palatal length (MPL: 9.62–9.75 vs. 9.80–10.31) than U. aequodonenia.
U. fansipanensis has a shorter profile length (PL: 20.4–20.69 vs. 21.11–21.76), shorter basal length (BL: 16.62– 16.98 vs. 17.59–17.98), shorter palatal length (MPL: 9.62–9.75 vs. 10.08–10.32), shorter mandible length (LM: 13.52–13.77 vs. 14.47–15.09), shorter lower toothrow length (MTRL: 8.30–8.31 vs. 8.40–8.79), a narrower snout (GBSn: 7.39–7.62 vs. 7.94–8.78), narrower greatest width across the upper second molars (M2-M2: 6.36–6.40 vs. 6.85–7.04), and higher braincase height (BH: 6.90–6.91 vs. 6.57–6.84) than U. dabieshanensis.
Moreover, U. fansipanensis is distinguishable from all other Uropsilus species by the orientation of its orbital process (Fig. 4; Table 2). Specifically, the orbital process in U. fansipanensis is oriented upwards posteriorly, whereas in the other eight species, it is oriented downwards (Fig. 4). Lacrimal foramen and infraorbital foramen are separated by the orbital process, and the development of lacrimal foramen is an important morphological character distinguishing the genus Uropsilus from other genera of the family Talpidae (Hutchison 1968; Motokawa 2004). U. fansipanensis has a well-developed lacrimal foramen much larger than the infraorbital foramen, whereas the other eight species have lacrimal foramen smaller or similar in size to the infraorbital foramen (Fig. 4).
U. fansipanensis has 38 teeth in total, similar to U. gracilis, U. investigator, U. nivatus, U. atronates, and U. dabieshanensis in lacking i3, while different from U. soricipes (34 teeth, it lacks P3, i3, and p3), U. aequodonenia (36 teeth, it lacks P3 and p3), and U. andersoni (38 teeth, it lacks p3) (Table 2; see Thomas 1912). U. fansipanensis is characterized by the size of p3, which is well-developed and approximately equal to the lower first premolar (p1). In contrast, p3 is smaller than p 1 in U. gracilis, U. investigator, U. nivatus, U. atronates, and U. dabieshanensis (Table 2). Additionally, U. fansipanensis is distinguished from U. gracilis and U. atronates by having c1 larger than p1, while these characteristics are shared with the remaining six species (Table 2; Allen 1923).
description: Published as part of Bui, Hai Tuan, Okabe, Shinya, Le, Linh Tu Hoang, Nguyen, Ngan Thi & Motokawa, Masaharu, 2023, A new shrew mole species of the genus Uropsilus (Eulipotyphla: Talpidae) from northwestern Vietnam, pp. 59-78 in Zootaxa 5339 (1) on pages 62-70, DOI: 10.11646/zootaxa.5339.1.3, http://zenodo.org/record/8290254