Ryojius furcatus, Irfan & Zhang & Peng, 2022

Irfan, Muhammad, Zhang, Zhi-Sheng & Peng, Xian-Jin, 2022, Survey of Linyphiidae (Arachnida: Araneae) spiders from Yunnan, China, Megataxa 8 (1), pp. 1-292 : 254-256

Ryojius furcatus sp. nov. (ĀḦƥŜƦ)

Figures 287–290

Types. Holotype ♂, CHINA, Yunnan, Fugong County, Lumadeng Township , Shibali forest station trap area, 27.16636°N, 98.77667°E, alt. 2563m, 4 May 2004, Charles Griswold and D. H. Kavanaugh leg. ( CGY28 ) . Paratypes: 1♂ 10♀, same data as holotype male ( CGY28 ) ; 1♀, Forest along shelf above Yamu river, 0.4 km SE Shibali, 27.16337°N, 98.78208°E, alt. 2475m, 8 May 2004, Charles Griswold and D. H. Kavanaugh and Heng-mei Yan leg. ( CGY37 ) .

Etymology. This epithet derives from the Latin adjective “ furcatus ”, meaning “forked”, referring to the forked tip of the terminal apophysis in ventral view in the male palp.

Diagnosis. The new species resembles Ryojius nanyuensis ( Chen & Yin, 2000) in having a similar paracymbium and scape of epigyne ( Figs 287A–D , 288A–D ; Tu, Saaristo & Li, 2006 figs 15–23), but can be distinguished by the distal tip of lamella characteristca webbed feet-shaped in R. furcatus sp. nov. ( Fig. 287A, D ), whereas flower-shaped in R. nanyuensis ( Tu, Saaristo & Li, 2006 figs 15, 16). Terminal apophysis tip forked in R. furcatus sp. nov. ( Fig.287D ), whereas relatively broad with round end in R. nanyuensis ( Tu, Saaristo & Li, 2006 fig. 18). Apex of embolus finger-shaped in R. furcatus sp. nov. ( Fig. 287A, D ), whereas tongue-shaped in R. nanyuensis ( Tu, Saaristo & Li, 2006 fig. 18). Posterior median plate of epigyne posteriorly with two tooth-shaped apophyses in R. furcatus sp. nov. ( Fig. 288D ), whereas without apophysis in R. nanyuensis ( Tu, Saaristo & Li, 2006 figs 20–22). Dorsal part of scape as wide as long in R. furcatus sp. nov. ( Fig. 288A, C ), whereas longer than wide in R. nanyuensis ( Tu, Saaristo & Li, 2006 figs 20–22)

Description. Male (holotype, Fig. 289A, B ): Total length: 1.87. Carapace 0.99 long, 0.77 wide, brown; fovea, cervical and radial grooves distinct. Clypeus 0.22 high. Sternum longer than wide, dark yellow,, sparsely covered with microsetae. Labium wider than long. Maxillae long, distal end broad with scopulae. Chelicerae with four promarginal and five retromarginal teeth. AER recurved, PER straight, slightly wider. Eye sizes and interdistances: AME 0.04, ALE 0.06, PME 0.05, PLE 0.06, AME–AME 0.02, PME–PME 0.05, AME–ALE, 0.03, PME–PLE 0.07, AME–PME 0.04, ALE–ALE 0.28, PLE–PLE 0.33, ALE–PLE 0.01. Length of legs: I 2.47 (0.71, 0.85, 0.52, 0.39), II 2.14 (0.66, 0.75, 0.47, 0.36), III 1.70 (0.53, 0.56, 0.32, 0.29), IV 2.22 (0.70, 0.79, 0.39, 0.34). Leg formula I-IV-II-III. Tm I 0.28 and Tm IV 0.17. Tibial spine formula: 2-2-1-1. Abdomen 1.03 long, 0.69 wide, oval, greenish-grey, dorsally with two pairs of sigillae; ventral side greenish-grey.

Palp ( Fig. 287A–D ): Patella as long as tibia with a long dorsal spine; tibia with strongly sclerotized dorsal apophysis pointing laterally in dorsal view; with one retrolateral and one dorsal trichobothria. Cymbium with shallow depression at base. Paracymbium strongly scleortized, distal arm with V-shaped apex. The distal suprategular apophysis small, covered by the tegulum with narrow hook-shaped dorsal tip. Radix C-shaped. Lamella characteristca with two branches; posterior one hornshaped, anterior one long, extending forward, tip webbed feet-shaped. Terminal apophysis longer than wide, tip forked. Embolus conspicuously large, posteriorly curved about half circle, apex strongly sclerotized, finger-shaped with blunt end; thumb short, covered by the lamella characteristca; embolus proper with pointed end.

Female (one of the paratypes, Fig. 289C, D ): Total length: 2.15. Carapace 0.88 long, 0.67 wide, brown; fovea, cervical and radial grooves distinct. Clypeus 0.22 high. Sternum longer than wide, yellow,, sparsely covered with microsetae. Labium wider than long. Maxillae long, distal end broad with scopulae. Chelicerae with four promarginal and five retromarginal teeth. AER recurved, PER straight, slightly wider. Eye sizes and interdistances: AME 0.04, ALE 0.07, PME 0.05, PLE 0.07, AME–AME 0.02, PME–PME 0.06, AME–ALE, 0.03, PME–PLE 0.05, AME–PME 0.05, ALE–ALE 0.28, PLE–PLE 0.31, ALE–PLE 0.01. Length of legs: I 2.27 (0.68, 0.78, 0.44, 0.37), II 1.98 (0.59, 0.66, 0.39, 0.34), III 1.68 (0.51, 0.53, 0.35, 0.29), IV 2.19 (0.68, 0.76, 0.41, 0.34). Leg formula I-IV-II-III. Tm I 0.23 and Tm IV 0.13. Tibial spine formula: 2-2-1-1. Abdomen 1.39 long, 1.03 wide, oval, pale, posteriorly with two greenish-grey chevrons; ventral side pale greenish-grey.

Epigyne ( Fig. 288A–D ) protruding; basal part of scape wide, posteriorly projecting, dorsally with a narrow tongue-shaped stretcher. Distal part of scape longer than wide with small lateral pockets. Posterior median plate posteriorly with two tooth-shaped apophyses. Spermathecae globular, situated at the anterior lateral sides of dorsal plate apices.

Distribution. Known only from the type locality ( Fig. 290 ).

Figures

FIGURE 287. Ryojius furcatus sp. nov., male palp of holotype. A prolateral view B retrolateral view C dorsal view D ventral view.

FIGURE 288. Ryojius furcatus sp. nov., female (one of paratypes). A, C Epigyne, ventral view B Epigyne, lateral view D Vulva, dorsal view.

FIGURE 289. Ryojius furcatus sp. nov., male holotype (A, B) and female (one of paratypes, C, D). A, C Habitus, dorsal view B, D Habitus, ventral view.

FIGURE 290. Distribution of Ryojius furcatus sp. nov..