Baiyuerius chongzu 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 : 406-412

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.15561589
persistent identifier	https://treatment.plazi.org/id/24487D50-B405-FFC7-9B91-F9DCFD68FE12
treatment provided by	Plazi
scientific name	Baiyuerius chongzu Wei & J. Liu
status	sp. nov.

Treatment

Baiyuerius chongzu Wei & J. Liu sp. nov.

Figs 5–8 View FIGURE 5 View FIGURE 6 View FIGURE 7 View FIGURE 8 , 35 View FIGURE 35

Type material. Holotype ♂ ( CBEE), CHINA: Hunan Province: Fenghuang City, Liaojiaqiao Town , 27.9271°N, 109.5212°E, elevation: 468 m, 15.Ⅴ ⅠⅠⅠ.2019, local collector leg GoogleMaps .; Paratypes: 2♀♀ ( CBEE), same data as holotype, 2.Ⅴ ⅠⅠ.2024, local collector leg GoogleMaps .

Etymology. The specific name is the screen name of Mr. Xihao Wang who provided all the type specimens of this new species, noun (name) in genitive case.

Diagnosis. Males of Baiyuerius chongzu sp. nov. resemble those of B. arcticus sp. nov. and B. subyanlingensis comb. nov., see in diagnosis of B. arcticus sp. nov. for detailed statement. And the new species can be distinguished from the latter by 1) prolateral tibial apophysis present ( Fig. 5F View FIGURE 5 ) [vs. absent in the latter ( Fig. 3B View FIGURE 3 ; figs 7A in Liu et al. 2020)]; 2) process of dorsal margin of conductor cattle-tongue-shaped ( Fig. 5B View FIGURE 5 ) [vs. leaf-shaped in the latter ( Fig. 3B View FIGURE 3 ; figs 5D, 7B in Liu et al. 2020)]. Females of B. chongzu sp. nov. resemble those of B. loong sp. nov. and B. rugosus by 1) epigyne and posterior epigynal pocket extremely large, pocket occupying more than 3/4 of the epigynal plate ( Figs 7A View FIGURE 7 , 13A View FIGURE 13 ; fig. 3A in Luo et al. 2023); 2) copulatory ducts twice longer than spermathecae ( Figs 7B View FIGURE 7 , 13B View FIGURE 13 ; fig. 3B in Luo et al. 2023). But the new species can be distinguished from the latter by 1) atrium bowl-shaped, and the anterior margin of the posterior epigynal pocket arc-shaped ( Fig. 7A View FIGURE 7 ) [vs. atrium triangular, and the anterior margin of posterior epigynal pocket V-shaped in the latter ( Fig. 13A View FIGURE 13 ; fig. 3A in Luo et al. 2023)]; 2) posterior epigynal sclerite timeglass-shaped, swollen epigyne membranous ( Fig. 7A View FIGURE 7 ) [vs. posterior epigynal sclerite subpentagonal and with sclerotized swollen epigyne in B. loong sp. nov. ( Fig. 13A View FIGURE 13 ), or with axe-shaped posterior epigynal sclerite in B. rugosus (fig. 3A in Luo et al. 2023); 3) copulatory ducts narrowing, blind sacs with membranous connection with epigyne, and the spermathecal head membranous ( Fig. 7B View FIGURE 7 ) [vs. with sclerotized spermathecal head in B. loong sp. nov. ( Fig. 13B View FIGURE 13 ), or with copulatory ducts not narrowing, blind sacs without connections in B. rugosus (fig. 3B in Luo et al. 2023); 4) spermathecae oval, extended downward, with a hole on each side ( Fig. 7B View FIGURE 7 ) [vs. spherical in B. loong sp. nov. ( Fig. 13B View FIGURE 13 ), or oval but extended upward, and without holes in B. rugosus (fig. 3B in Luo et al. 2023).

Description. Male holotype ( Fig. 6 View FIGURE 6 ). Carapace brown, cervical and radial groove distinct. Cephalic region dark and moderately raised, lateral margin with distinct wide grooves. 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 dark red, metatarsi and tarsi of the first and second legs with long and dense hairs. Total length 11.30. Carapace 6.79 long, 4.80 wide, cephalic region 3.68 wide. Abdomen 5.64 long, 3.95 wide. Eye size and interdistance: AME 0.24, ALE 0.34, PME 0.30, PLE 0.37; AME–AME 0.11, AME–ALE 0.20, AME–PME 0.18, ALE–PLE 0.07, PME–PME 0.09, PME–PLE 0.41. Leg measurements: I 17.90 (4.87, 2.19, 4.36, 4.41, 2.62), II 16.09 (4.42, 1.81, 3.84, 3.93, 2.37), III 13.09 (3.76, 1.67, 2.71, 3.43, 1.70), IV 17.88 (5.08, 2.02, 4.01, 4.85, 2.02).

Male palp ( Fig. 5 View FIGURE 5 ). Patellar apophysis digitate, pointed dorsally. Retrolateral tibial apophysis longer than tibia, with distal tip extended extremely beyond tibia. Lateral tibial apophysis spine-shaped, subequal to the length of tibia. Prolateral tibial apophysis present. Cymbial furrow subequal to 1/2 the length of cymbium, with distinct dorsal margin extending anteriorly. Conductor long, bent downward, distal tip shoe-shaped, process of dorsal margin of conductor long and tongue-shaped, dorsal apophysis of conductor short, basal lamellar small. Embolus long. Median apophysis human-ear-shaped, with a sclerotized basal process.

Female paratype ( Fig. 8 View FIGURE 8 ). Same in colour and abdominal patterns as male. Cephalic region strongly raised, lateral margin with distinct grooves. Chelicerae with three promarginal teeth and two retromarginal teeth, condyle red. Sternum longer than wide. Total length 11.38. Carapace 6.41 long, 4.89 wide, cephalic region 4.00 wide. Abdomen 5.44 long, 4.02 wide. Eye size and interdistance:AME 0.21, ALE 0.32, PME 0.26, PLE 0.28; AME–AME 0.18, AME–ALE 0.25, AME–PME 0.17, ALE–PLE 0.09, PME–PME 0.12, PME–PLE 0.35. Leg measurements: I 15.54 (4.63, 1.98, 3.76, 3.37, 2.08), II 13.96 (4.07, 1.93, 3.29, 3.07, 1.96), III 11.32 (3.43, 1.71, 2.29, 2.74, 1.53), IV 16.02 (4.54, 2.00, 3.35, 3.96, 2.41).

Epigyne ( Fig. 7A View FIGURE 7 ). Epigynal teeth long. Atrium bowl-shaped. Epigynal pocket large and sclerotized, occupying more than 4/5 of epigyne, anterior margin arc-shaped. Posterior epigynal sclerite sclerotized and large, hourglassshaped. Hoods situated laterally of atrium. Copulatory opening situated centrally.

Internal genitalia ( Fig. 7B View FIGURE 7 ). Copulatory ducts long, broad at beginning and thin at the end; blind sacs elongate and curved, with membranous connections to epigyne. Spermathecae large, connected with copulatory ducts on the top, and with a hole on each side; spermathecal heads membranous and reduced. Fertilization ducts short, situated posteriorly.

Distribution. China (Hunan Province).