Baiyuerius arcticus Wei & J. Liu, 2025

Wei, Mian, Zhu, Yang, Liu, Jie, Zhang, He & Liu, Fengjie, 2025, New species and new combinations of the spider genus Baiyuerius Zhao, B. Li & S. Q. Li, 2023 (Araneae, Agelenidae, Coelotinae), Zootaxa 5636 (3), pp. 401-442 : 406

publication ID	https://doi.org/10.11646/zootaxa.5636.3.1
publication LSID	lsid:zoobank.org:pub:1A564430-7BA5-4159-A595-3BF3DF2F2D7A
DOI	https://doi.org/10.5281/zenodo.15561579
persistent identifier	https://treatment.plazi.org/id/24487D50-B405-FFC9-9B91-FF10FD97F9B6
treatment provided by	Plazi
scientific name	Baiyuerius arcticus Wei & J. Liu
status	sp. nov.

Treatment

Baiyuerius arcticus Wei & J. Liu sp. nov.

Figs 1A View FIGURE 1 , 3 View FIGURE 3 , 4 View FIGURE 4 , 35 View FIGURE 35

Type material. Holotype ♂ ( CBEE), CHINA: Gansu Province: Longnan City, Li County, Duipo Mountain , 34.1503°N, 104.9491°E, elevation: 2045 m, 1.Ⅴ ⅠⅠⅠ.2020, Q.Y. Ji leg. GoogleMaps ; Paratypes: 8 ♂♂ ( CBEE), same data as holotype GoogleMaps .

Etymology. The specific epithet is taken from the Latin adjective “ arcticus ”, referring to the north distribution; adjective.

Diagnosis. Males of Baiyuerius arcticus sp. nov. resemble those of B. chongzu sp. nov. and B. subyanlingensis comb. nov. by 1) conductor groove long, with the distal tip shoe-shaped and blunt, while the base of conductor slim ( Fig. 3B View FIGURE 3 ; fig. 5E in Liu et al. 2020); 2) process of dorsal margin of conductor leaf-shaped or tongue-shaped and long, more than 2/3 the length of conductor ( Fig. 3B View FIGURE 3 ; fig. 5D, E in Liu et al. 2020). The new species can be distinguished from the latter by 1) patellar apophysis digitate and with sharp tip, longer than patella ( Fig. 3C View FIGURE 3 ) [vs. shorter than patella and bent dorsally in B. subyanlingensis comb. nov. (fig. 5E in Liu et al. 2020); 2) lateral tibial apophysis spine-shaped, less than 1/2 the length of retrolateral tibial apophysis ( Fig. 3C View FIGURE 3 ) [vs. spine-shaped or crowbar-shaped, and more than 1/2 the length of retrolateral tibial apophysis in the latter ( Fig. 5C View FIGURE 5 ; fig. 5E in Liu et al. 2020)]; 3) ventral margin of conductor smooth, process of dorsal margin of conductor leaf-shaped with distal tip pointed upward ( Fig. 3B View FIGURE 3 ) [vs. ventral margin smooth, but with process of dorsal margin of conductor long and cattle-tongue-shaped in B. chongzu sp. nov. ( Fig. 5B View FIGURE 5 ), or with serrated ventral margin and leaf-shaped process, but with the distal tip of the process pointed downward in B. subyanlingensis comb. nov. (fig. 5D in Liu et al. 2020)]; 4) embolic base with a digitate apophysis pointed prolaterally ( Fig. 3A, D View FIGURE 3 ) [vs. without apophysis in the latter ( Fig. 5A View FIGURE 5 ; figs 5C, 7A, B in Liu et al. 2020)].

Description. Male holotype ( Fig. 4 View FIGURE 4 ). Carapace dark brown. Cervical and radial groove distinct. Cephalic region dark and moderately raised, lateral margin with distinct furrows. Chelicerae with three promarginal teeth and two retromarginal teeth, condyle red. Sternum longer than wide. Abdomen gray, with 5 chevron–shaped patterns, covered by hairs. Legs orange, metatarsi and tarsi of the first and second legs with long and dense hairs. Total length 11.30. Carapace 6.09 long, 4.26 wide, cephalic region 3.08 wide. Abdomen 5.03 long, 3.46 wide. Eye size and interdistance: AME 0.19, ALE 0.22, PME 0.25, PLE 0.25; AME–AME 0.11, AME–ALE 0.18, AME–PME 0.14, ALE–PLE 0.09, PME–PME 0.09, PME–PLE 0.30. Leg measurements: I 16.38 (4.55, 1.77, 4.01, 4.00, 2.37), II 14.29 (4.01, 1.71, 3.28, 3.51, 2.05), III 11.64 (3.23, 1.34, 2.21, 3.12, 1.71), IV 16.46 (4.70, 1.76, 3.77, 4.46, 2.03).

Male palp ( Fig. 3 View FIGURE 3 ). Patellar apophysis strong, digitate with sharp tip. Retrolateral tibial apophysis nearly equal to the length of tibia, where distal tip beyond tibia. Lateral tibial apophysis spine-shaped, less than 1/2 the length of tibia. Cymbial furrow subequal to 1/2 the length of cymbium, with distinct dorsal margin and extending anteriorly. Conductor groove long, bent downward, tip broad and shoe-shaped, process of dorsal margin of conductor broad and leaf-shaped with distinct basal stalk, the tip of process pointed upward. Dorsal apophysis of conductor fused with the process of dorsal margin of conductor, with a distinct basal lamellar. Embolus long, embolic base with a digitate apophysis pointed prolaterally. Median apophysis human-ear-shaped.

Female. Unknown.

Distribution. China (Gansu Province).