Baiyuerius Zhao, B. Li & S. Li, 2023

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 : 403

Genus Baiyuerius Zhao, B. Li & S. Li, 2023

Type species. Baiyuerius zuojiang Zhao, B. Li & S. Li, 2023

Diagnosis. Baiyuerius resembles Yunguirius B. Li, Zhao & S. Q. Li, 2023 in 1) carapace with high and broad cephalic region, and legs usually red or orange ( Figs 6A, B , 10A, B , 24A, B ; fig. 4A, B in Liu et al. 2020; fig. 4A, B in Luo et al. 2023; fig. 7A, B in Wei et al. 2024); 2) conductor large and crescent, with modified dorsal margin, median apophysis human-ear-shaped ( Fig. 1A–E ; fig. 317 in Wang et al. 2012); 3) epigyne with large atrium, and copulatory ducts with distinct blind sac ( Fig. 2A–D ; figs 2A, B, 8A, B in Wei et al. 2024). But males of Baiyuerius are diagnosed by the process on the dorsal margin of the conductor strongly sclerotized, except of the digitus- group species, which without the process ( Fig. 1A–E ) [vs. weakly sclerotized in the Yunguirius (fig. 317 in Wang et al. 2012)]; 2) embolic base enlarged ( Fig. 1A–E ) [vs. not so large in Yunguirius (fig. 317 in Wang et al. 2012)]. Females are distinguished from those of Yunguirius by 1) atrium without anterior margin, and the epigynal plate without sclerotized structure above atrium ( Fig. 2A, C ) [vs. atrium with or without anterior margin, but the epigynal plate with sclerotized part above atrium (fig. 3A in Zhao et al. 2023; figs 2A, 8A in Wei et al. 2024)]; 2) spermathecae nearly spherical, sometimes with tubercles ( Fig. 2B, D ) [vs. long and divided into two parts (fig. 2B in Zhao et al. 2023; fig. 2B in Wei et al. 2024)].

Figures

FIGURE 1. Male palps of Baiyuerius spp. from different species groups, in ventral view A Baiyuerius arcticus sp. nov. from chongzu-group, (a) cymbial furrow of B. arcticus sp. nov., retrolateral view, and the white arrows point out the extended dorsal margin of the the cymbial furrow B Baiyuerius loong sp. nov. from chongzu-group C Baiyuerius jiquanyui sp. nov. from cuii- group D Baiyuerius digitus sp. nov. from digitus-group E Baiyuerius carcharus sp. nov. from zuojiang-group. The colored areas indicate the different parts of conductors: blue areas indicate the ventral margins, yellow areas indicate the dorsal margins (excluding the modified processes of dorsal margin), green areas indicate the modified processes of dorsal margin, red areas indicate the dorsal apophyses of conductor. The white dashed outlines show the tegular concave. Scale bars: 0.50 mm.

FIGURE 2. Epigynes and internal genitals of Baiyuerius spp. from two species groups. A, B Baiyuerius shaanxiensis sp. nov. from chongzu-group C, D Baiyuerius shenyunxiaoi sp. nov. from rutolus-group A, C epigynes, ventral view B, D internal genitals, dorsal view.Abbreviations:A = atrium; BS = blind sac; CD = copulatory duct; CO = copulatory opening; ET = epigynal teeth; FD = fertilization duct; H = hood; PES = posterior epigynal sclerite; S = spermatheca; SE = swollen epigyne. The colored areas indicate the different part of epigynes: blue areas indicated the epigynal pockets, the yellow areas indicate the atriums. The black dash lines divide the posterior epigynal sclerite and the swollen epigyne. Scale bars: 0.50 mm.

FIGURE 6. Characters of the male of Baiyuerius chongzu sp. nov. A habitus, dorsal view B habitus, prolateral view C eye area, frontal view D eye area, dorsal view E cephalic rigion, lateral view. Scale bars: A, B 2.00 mm, C, D 0.50 mm, E 0.25 mm.

FIGURE 10. Characters of the female of Baiyuerius imitatus sp. nov. A habitus, dorsal view B habitus, prolateral view C eye area, frontal view D eye area, dorsal view E cephalic rigion, lateral view. Scale bars: A, B 2.00 mm, C, D 0.50 mm, E 0.25 mm.

FIGURE 24. Characters of the female of Baiyuerius shenyunxiaoi sp. nov. A habitus, dorsal view B habitus, prolateral view C eye area, frontal view D eye area, dorsal view E cephalic rigion, lateral view. Scale bars: A, B 3.00 mm, C, D 0.50 mm, E 0.25 mm.