Bifurcia xiaojin, Yang & Li & Yao, 2024

Yang, Lan, Li, Shuqiang & Yao, Zhiyuan, 2024, Five new species of the spider genus Bifurcia Saaristo, Tu & Li, 2006 (Araneae, Linyphiidae) from Sichuan, China, Zoosystematics and Evolution 100 (2), pp. 705-720 : 705-720

Bifurcia xiaojin sp. nov.

Figs 13 , 14 , 15 , 16 H, J

Type material.

Holotype ♂ ( IZCAS - Ar 44934 ) and paratypes 2 ♂ 3 ♀ ( IZCAS - Ar 44935 –39), Changpinggou (31 ° 0.29 ' N, 102 ° 51.16 ' E), Siguniangshan National Scenic Area , Siguniangshan Town, Xiaojin County, Aba Tibetan and Qiang Autonomous Prefecture, Sichuan, China, 01 / 08 / 2004, Lihong Tu leg.

Etymology.

The specific name refers to the type locality; noun in apposition.

Diagnosis.

The new species resembles B. kangding sp. nov. with similar paracymbium (P) and epigyne (Figs 13 B , 14 A ), but can be distinguished by embolus thumb (TH) with spinous end (Figs 13 C , 16 H vs. dentate, Figs 2 C , 16 A ), by chitinized basal part of median membrane ( CPM) finger-shaped (Fig. 16 H vs. pointed, Fig. 16 A ), and by spermathecae (S) close to each other (Fig. 14 C vs. widely separated, Fig. 3 C ).

Description.

Male (holotype). Total length: 2.12, carapace 1.01 long, 0.99 wide, abdomen 1.11 long, 0.81 wide. Eye inter-distances and diameters: AME 0.05, AME-AME 0.02, ALE 0.06, AME-ALE 0.08, PME 0.06, PME-PME 0.06, PLE 0.07, and PME-PLE 0.08. Sternum 0.55 long, 0.53 wide. Clypeus 0.15 high. Chelicerae promargin with 2 teeth, retromargin with 1 tooth. Length of legs: I 5.49 (1.45, 0.31, 1.46, 1.38, 0.89), II 4.51 (1.22, 0.28, 1.17, 1.10, 0.74), III 3.29 (0.94, 0.25, 0.75, 0.77, 0.58), IV 4.34 (1.27, 0.27, 1.06, 1.02, 0.72). Leg formula: I-II-IV-III. TmI 0.17, TmIV absent. Tibial spine formula: 2-2 - 2 - 2. Carapace brown. Sternum dark brown. Abdomen with greenish gray dorsal spots (Fig. 15 A, B ).

Palp (Fig. 13 ). Patella with long dorsal bristle. Tibia unmodified. Cymbium with hook-shaped proximal apophysis ( PCA) pointing retrolaterally. Paracymbium (P) bifurcate with three curved branches. Pit hook ( PH) on stout distal part of suprategulum ( SPT) extremely reduced to small outgrowth. Embolic division (Fig. 16 H, J ): anterior part of radix ( APR) hook-shaped; sperm duct inside the radix ( R) inconspicuous with Fickert’s gland ( FG); pseudolamella ( PL) strongly sclerotized, with distally angular end and lamellar extension ( LE) absent. Anterior terminal apophysis ( ATA) pointing anterodorsally; median terminal apophysis ( MTA) membranous with four branches; posterior terminal apophysis ( PTA) serrated. Embolus (E) with conical embolus proper ( EP), short apex ( AX), and thumb (TH) with a long thorn. Median membrane ( MM) leaf-shaped with finger-shaped chitinized basal part ( CPM).

Female (paratype). Total length: 2.22, carapace 1.04 long, 0.86 wide, abdomen 1.20 long, 0.92 wide. Eye inter-distances and diameters: AME 0.06, AME-AME 0.03, ALE 0.09, AME-ALE 0.06, PME 0.07, PME-PME 0.07, PLE 0.09, and PME-PLE 0.06. Sternum 0.58 long, 0.55 wide. Clypeus 0.15 high. Chelicerae promargin with 3 teeth, retromargin with 5 teeth. Length of legs: I 5.95 (1.60, 0.39, 1.58, 1.42, 0.96), II 4.93 (1.36, 0.33, 1.29, 1.17, 0.78), III 3.67 (1.09, 0.28, 0.84, 0.87, 0.59), IV 4.68 (1.45, 0.28, 1.11, 1.14, 0.70). Leg formula: I-II-IV-III. TmI 0.21, TmIV absent. Tibial spine formula: 2-2 - 2 - 2. Carapace yellowish-brown. Coloration generally as in male (Fig. 15 C, D ).

Epigyne (Fig. 14 ). Basal part of scape ( BS) long and sparsely clothed with long, curved hairs. Posterior part of posterior median plate ( PMP) M-shaped. Distal part of scape ( DPS) forming a circle with basal part of scape together. Spermathecae (S) round.

Distribution.

China (Sichuan, type locality; Fig. 1 ).

Figures

Figure 1. Distribution of the new Bifurcia species from Sichuan, China: 1. B. kangding sp. nov.; 2. B. labahe sp. nov.; 3. B. luding sp. nov.; 4. B. shuangqiao sp. nov.; 5. B. xiaojin sp. nov.

Figure 2. Bifurcia kangding sp. nov., holotype male palp: A. Prolateral view; B. Retrolateral view; C. Ventral view; D. Dorsal view. Scale bars: 0.10 mm (A – D).

Figure 3. Bifurcia kangding sp. nov., paratype female epigyne: A. Ventral view; B. Lateral view; C. Dorsal view. Scale bar: 0.10 mm (A – C).

Figure 13. Bifurcia xiaojin sp. nov., holotype male palp: A. Prolateral view; B. Retrolateral view; C. Ventral view; D. Dorsal view. Scale bars: 0.10 mm (A – D).

Figure 14. Bifurcia xiaojin sp. nov., paratype female epigyne: A. Ventral view; B. Lateral view; C. Dorsal view. Scale bar: 0.10 mm (A – C).

Figure 15. Bifurcia xiaojin sp. nov., holotype male (A, B) and paratype female (C, D) habitus: A, C. Dorsal view; B, D. Ventral view. Scale bars: 0.50 mm (A – D).

Figure 16. Bifurcia spp., embolic division: A, D. B. kangding sp. nov.; B, E. B. labahe sp. nov.; C, F. B. luding sp. nov.; G, I. B. shuangqiao sp. nov.; H, J. B. xiaojin sp. nov.; A – C, G, H. Prolateral view; D – F, I, J. Retrolateral view. Scale bars: 0.10 mm (A – J).