Sicista concolor ( Büchner, 1892 )

Deng, Yu, Liu, Qing, Wang, Xuming, Li, Binbin V., Wang, Jing, Liu, Shuang, Liao, Rui, Liu, Shaoying & Chen, Shunde, 2025, Molecular phylogeny and taxonomy of the Sicista concolor group (Mammalia, Rodentia, Sicistidae) with the description of a new species, Zoosystematics and Evolution 101 (3), pp. 1197-1211 : 1197-1211

Sicista concolor ( Büchner, 1892)

Type locality.

Xining City, Qinghai Province, China.

Diagnosis.

The brown tail is unicolored and measures approximately 150–170 % of the head-body length. The back of the body is brown, lacking black stripes along the spine, and the abdomen is light brown in color (Fig. 7 a 1 – a 3 ). The Palatine Foramina are located along the line connecting the metacone and the hypocone of the second upper molar (Fig. 6 a 5 ).

Remarks.

A small jerboa, with a body length ranging from 65 to 73 mm, tail length from 103 to 122 mm, hind foot length from 18 to 20 mm, ear length from 12 to 16 mm, and body weight between 10 and 13 g (Table 2 ). The dorsal fur is brown, interspersed with black hairs, and lacks distinct vertical black stripes along the spine (Fig. 7 a 1 – a 3 ). The glans penis is relatively short and thick, with a surface densely covered in evenly distributed keratinized spines. The urethral opening is elongated and Y-shaped, while the external tissue surrounding the urethral opening forms a U-shape. The outer annular layer lacks papillae, and no urethral valves, dorsal projections, or lateral branches are observed. The baculum exhibits an ossified, rod-like structure with two lateral wings at the tip. The base is slightly concave, without differentiation into distal and proximal ends. It has a tendency to curve ventrally. The ventral tip is Y-shaped, with a central longitudinal groove, and an additional groove is present on the dorsal side (Fig. 5 a 1 – a 4 ).

This species is extremely rare in the wild. Specimens are only available from Qinghai Province, and there is limited knowledge regarding populations in Gansu and Shaanxi Provinces. The geographical isolation caused by numerous mountain ranges and rivers may have led to the formation of distinct species. Further sampling is necessary to verify this hypothesis.

Distribution.

This species is distributed along the northeastern edge of the Tibetan Plateau, primarily in the provinces of Gansu, Qinghai, and Shaanxi, China. It is commonly found in temperate forest edges, shrublands, and grassland shrub communities. The species constructs nearly spherical nests made of grass, typically placed in the gaps between shrubs.

Figures

Figure 5. Comparison of the glans penis of three species within the S. concolor group. a. Sicista concolor; b. Sicista sp 2; c. Sicista weigoldi. 1. Penis; 2. Midventral cut view of glans; 3. Lateral view of baculum; 4. Dorsal view of baculum. (1) Urethral opening; (2) Outer crater; (3) Glans; (4) Prepuce; (5) Body of penis; (6) Baculum.

Figure 6. Skulls and tooth comparison among species of the S. concolor group. a. Sicista concolor (a 1 – a 6) (museum number: SAF 13331); b. Sicista meiguites sp. nov. (b 1 – b 6) (museum number: SAF 191012); c. Sicista weigoldi (c 1 – c 6) (museum number: SAF 240595).

Figure 7. Pelage and tail comparisons among species of the S. concolor group. a. Sicista concolor (a 1 – a 3) (museum number: SAF 13331); b. Sicista meiguites sp. nov. (b 1 – b 3) (museum number: SAF 191014); c. Sicista weigoldi (c 1 – c 3) (museum number: SAF 240595).