Eothenomys luojishanensis, 2019

EOTHENOMYS LUOJISHANENSIS SHAOYING , SP. NOV.

LUOJISHAN CHINESE VOLE

Holotype: Adult female, field number LJS010 (museum number: SAF081183), collected in Sichuan by Yang Liu on 6 August 2008. The specimen was deposited at Sichuan Academy of Forestry as a skin with cleaned skull and tissue. The external and cranial measurements (in millimetres) are as follows (abbreviations in Material and Methods): HBL 108 mm; TL 55.0 mm; HFL 18.0 mm; EL 13.0 mm; SGL 25.07 mm; SBL 23.70 mm; CBL 25.03 mm; ZB 13.36 mm; IOW 4.16 mm; MB 11.26 mm; SH 9.07 mm; ABL 6.5 mm; LMxT 5.20 mm; LMbT 5.50 mm; LM 17.91 mm; M-M 5.00 mm; and OLLI 7.50 mm. Body mass 30 g. The skull, dentition and mandible shown in Fig. 6C 1–C 6, C 8, and pictures of the holotype are provided in Supporting Information ( Fig. 4C).

Type locality: Luojishan Nature Reserve, Puge County, Liangshan Canton, southwestern Sichuan, 27.578903°N, 102.374423°E; elevation 3680 m. This specimen was trapped with large steel trap (made by JMDF) in original fir forest .

Paratypes: Thirteen specimens (eight males and five females). Nine intact adults (five males and four females): five specimens (LJS011 ♀, LJS013 ♂, LJS015 ♂, LJS025 ♀ and LJS026 ♂) paratopotypes . Four specimens (LJS16001 ♂, LJS16014 ♀, LJS16015 ♀ and LJS16017 ♀) from 30 km south of the type locality (27.33176 – 27.33856 °N, 102.46640– 102.47954E, elevation 3113–3300 m). Four adults with skulls broken, of which two are topotypes (LJS012 ♂ and LJS014 ♀) and two are from 30 km south of the type locality (LJS16012 ♂ and LJS16013 ♂), Luojishan Nature Reserve , Puge County, Sichuan .

Distribution: Known only from the high-elevation region of the Luoji Mountains (Luojishan;> 3000 m), at the borders of Dechang, Puge, Ningnan and Miyi counties. Luojishan Nature Reserve occurs in the Luoji Mountains, Puge County, Sichuan.

Etymology: The new species is named for the type locality, Luojishan Nature Reserve, on the mountain ridge between Puge and Dechang counties. This reserve has a high biodiversity that is facing severe threats from tourism. This new species is endemic to this reserve.

Diagnosis: Relatively large body and head, usually> 95 mm in length (average 103 mm); TL is slightly larger than HBL on average; hindfeet 17–18 mm. Compared with other species of subgenus Ermites, HBL larger than that of E. jinyangensis and E. meiguensis on average; and TL / HBL smaller than those of E. tarquinius and E. hintoni , but longer than those of E. jinyangensis and E. meiguensis . ( Fig. 7C). Third upper molar relatively stable; ~80% of specimens with five inner and four outer angles, and 20% of specimens with five inner and five outer angles ( Fig. 7C). Glans penis with two two outer crater papillae on each side, and dorsal papilla with a single tip ( Fig. 8C).

Description: Pelage (summer) from neck to hip uniform brown-black. Top of head and area surrounding eyes back. Entire back covered with fine, velvet hair ~ 10 mm in length. Ventral hairs with grey-black base and a yellow-brown tip, but some specimens with yellow-white tips. Transition between darker dorsal and lighter ventral pelage relatively abrupt. Margin of lip grey. Approximately 20 mystacial vibrissae on both sides; half of the hairs white, and the other half black-grey. Shortest vibrissa ~ 4 mm and longest 25 mm.

Ears project obviously above pelage; 2.5 mm margin of front part of ears covered with dense grey-black hairs. Lower part and area surrounding of auditory meatus with very few hairs; 2 mm margin of back of ears with dense, shorter black hairs. Remaining back of ear covered with long, villous grey-white furs. Back and ventral area of tail almost uniform grey-black; ventral part slightly thinner, with no hair bundle at the top of the tail. Base of hair on dorsal surface of forefoot grey-black; tip yellow-white and glossy. Hairs on venter of forefeet yellow-white, glossy. Claws yellow-white. Six palmar and six plantar pads. Females with one pair of inguinal and one pair of pectoral mammae.

Skull slender, in dorsal profile straight, and brain case flattened ( Fig. 7C); mid-parietal bone highest point of skull. Nasal broad anteriorly narrowing posteriorly. Posterior margin of nasals rounded, protruding in front of the maxilla ( Fig. 7C). Posterior and anterior of frontal broad, middle a little narrower. Interparietal broad, anterior part triangle shaped and posterior margin arc shaped ( Fig. 7C). Interorbital and temporal ridges absent. Zygomatic arches slender and middle part slightly broader. Auditory bullae moderately sized. Incisory foramen 1.5 mm wide and 4.5 mm long. Posterior palate typical of Eothenomys , ending as a thin transverse shelf without a median bony bridge ( Fig. 7C). Mandibles medium sized ( Fig. 7C).

Upper incisors medium and orange. Molars rootless. The first upper molar with four triangles after the anterior transverse space, two inner and two outer triangles open and confluent, and three outer and three inner angles. The second upper molar with three closed triangles after the anterior transverse space, one inner and two outer closed triangles, thus forming two inner and three outer angles. The third upper molar of the holotype with five inner and four outer angles; and the third upper molar of the type series specimens have two patterns: ~80% of specimens as in the holotype, with five inner and four outer angles; remaining 20% with five inner and five outer angles ( Fig. 7C 6, C 7).

The OLLI is 6.93 (6.49–7.50) mm. Lower incisors relatively short, only slightly exceeding the concavity of the mandibular condyle and coronoid process. The first lower molar ( Fig. 7) has six inner and four outer angles. The second lower molar has a transverse posterior space, with two opposing pairs of triangles widely open and confluent at their bases, three outer and three inner angles. The third lower molar has three transverse superimposed spaces and three inner and three outer angles ( Fig. 7C 8).

Glans penis ( Fig. 8C) pole-like and slender, with a ventral groove ( Table 6). The LG averages 3.67 mm and DG averages 1.77 mm ( Table 6). Outer crater with two obvious papillae on all sides ( Fig. 8C). Urethral lappet with three forks, the middle being very short ( Fig. 8C 2). Dorsal papilla large, with only one tip, and slightly short of dorsal outer crater ( Fig. 8C 3). Proximal baculum bony and rhombus shaped and slightly concave at base. Total length of baculum averages 3.57 mm; PBL averages 2.20 mm ( Table 6). Distal baculum also bony and stick shaped, with proximal part bulgy. Lateral bacular processes also stick shaped. The DBL averages 1.32 mm and LBL averages 0.93 mm ( Table 6).

Reproduction: Begins to reproduce in late May. Approximately 50% of adult males show orchidoptosis. Pregnancy ratio of adult females was very low in late May.

Habitat: This species inhabits azalea shrubs with sparse fir at elevations> 3000 m. Azalea shrub height 2–3 m, 50% coverage; sparse fir height approximately 6–7 m, 20% coverage. Understorey, humus 10 cm thick. Moss very abundant, 80% coverage.