Zoosyst. Evol. 100 (2) 2024, 705-720 | DOI 10.3897/zse.100.124160 > PENSUFT. Gee BERLIN Five new species of the spider genus Bifurcia Saaristo, Tu & Li, 2006 (Araneae, Linyphiidae) from Sichuan, China Lan Yang', Shugiang Li*, Zhiyuan Yao! 1 College of Life Science, Shenyang Normal University, Shenyang 110034, Liaoning, China 2 Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China https://zoobank. org/0E 190BDE-BF4D-4F7E-A8C0-9A B5383D&BC8 Corresponding authors: Zhiyuan Yao (yaozy@synu.edu.cn); Shuqiang Li (lisq@ioz.ac.cn) Academic editor: Danilo Harms # Received | April 2024 Accepted 11 May 2024 Published 4 June 2024 Abstract Five new species of the genus Bifurcia are described: B. kangding sp. nov. (¢°), B. labahe sp. nov. (3), B. luding sp. nov. (4°), B. shuanggiao sp. nov. (4Q), and B. xiaojin sp. nov. (3'2) from western Sichuan, China. A distribution map of the species and illustrations of genital characters are provided in this paper. Key Words Biodiversity, micronetine, morphology, sheet-web spiders, taxonomy Introduction The spider family Linyphiidae Blackwall, 1859, is the sec- ond-largest family in the world, consisting of 4,847 species in 634 genera (WSC 2024). It has a worldwide distribution, but members of the family are found mostly in temperate re- gions and mountainous regions in the tropics (Murphy and Murphy 2000; Irfan et al. 2022a). Their habitats can range from foliage in the forest canopy to vegetation at eye level, among leaf litter, and under rocks at ground level (Murphy and Murphy 2000; Platnick 2020). Linyphiidae is composed of seven subfamilies: Dubiaraneinae Millidge, 1993; Erigo- ninae Emerton, 1882; Ipainae Saaristo, 2007; Linyphiinae Blackwall, 1859; Micronetinae Hull, 1920; Mynogleninae Lehtinen, 1967; and Stemonyphantinae Wunderlich, 1986 (Saaristo 2007; Tanasevitch 2024), but such a classifica- tion has not been supported by any phylogenetic analyses and seems to be controversial. In Arnedo et al. (2009), the phylogenetic analyses agreed on the monophyly of ‘linyph- ioids’, Pimoidae Wunderlich, 1986, Linyphiidae, Erigo- ninae, Mynogleninae, as well as Stemonyphantes Menge, 1866, as a basal lineage within Linyphiidae. Wang et al.’s (2015) analyses resulted in seven robustly supported clades within Linyphiidae, but the placements of four deep and long branches are sensitive to variations in both outgroup and ingroup sampling. Hormiga et al. (2021) confirmed that Weintrauboa Hormiga, 2003; Putaoa Hormiga & Tu, 2008; Pecado Hormiga & Scharff, 2005; and Stemonyphantes form a clade (Stemonyphantinae) sister to all remaining linyphiids, and they re-circumscribed Stemonyphantinae. Bifurcia Saaristo, Tu & Li, 2006 is classified as Micronet- inae (Tanasevitch 2024), but no phylogenetic analysis has ever found Micronetinae to be a monophyletic group. Bi- furcia comprised ten known species, including four from Russia (south of the Far East) and six from China, stretch- ing from Hebei Province to Sichuan Province (Saaristo et al. 2006; Irfan et al. 2022b; WSC 2024). Sichuan Province, in the southwest of China, is a biodi- versity hotspot with 22 genera and 46 species of linyphiids recorded so far (Tanasevitch 2006; Tu and Li 2006; Song and Li 2010; WSC 2024). Nevertheless, only one species of Bifurcia, namely B. curvata (Sha & Zhu, 1987), has been recorded from Sichuan Province (Li et al. 1987). In the pres- ent study, we describe five new species belonging to Bifur- cia from western Sichuan (Fig. 1). This region of Sichuan may be characterized as a highland (2,000 to 7,500 meters above sea level), although one of the type localities (Tian- quan County) has an elevation of only 600 to 800 meters. Copyright Yang, L. et al. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. 706 Yang, L. et al.: New species of Bifurcia from China Sichuan 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. shuanggiao sp. nov.; 5. B. xiaojin sp. nov. Materials and methods Specimens were examined and measured with a Leica M205 C stereomicroscope. Left palps were photographed. Epigynes in ventral view were photographed before dis- section. Epigynes in dorsal view were photographed after being treated with lactic acid to dissolve soft tissues. Im- ages were captured with an Olympus C7070 wide-zoom digital camera (7.1 megapixels) mounted on the stereomi- croscope mentioned above and assembled using Helicon Focus v. 6.7.1 image stacking software (Khmelik et al. 2005). All measurements are given in millimeters (mm). Leg measurements are shown as total length (femur, pa- tella, tibia, metatarsus, and tarsus). Leg segments were measured on their dorsal side. The distribution map was generated with ArcGIS v. 10.8 (ESRI Inc.). The speci- mens studied were preserved in 75% ethanol and depos- ited in the Institute of Zoology, Chinese Academy of Sci- ences in Beijing (IZCAS). Terminology and taxonomic descriptions follow Saaris- to et al. (2006). Metatarsal trichobothrium (Tm) is given as the ratio of the distance between the proximal margin of the metatarsus and the root of the trichobothrium divided by the total length of the metatarsus (Denis 1949; Locket and Millidge 1953). The following abbreviations are used: Somatic morphology: ALE = anterior lateral eye; AME = anterior median eye; AME-AME = distance be- tween AMEs; AME-ALE = distance between AME and ALE; PLE = posterior lateral eye; PME = posterior me- dian eye; PME-PME = distance between PME; PME- PLE = distance between PME and PLE. Male palp: APR = anterior part of radix; ATA = an- terior terminal apophysis; AX = apex of embolus; CPM = chitinized part of median membrane; E = em- bolus; EP = embolus proper; FG = Fickert’s gland; LE = lamellar extension of pseudolamella, MM = median membrane; MTA = median terminal apophysis; P = para- zse.pensoft.net cymbium; PCA = proximal cymbial apophysis; PH = pit hook on suprategulum; PL = pseudolamella; PTA = pos- terior terminal apophysis; R = radix; SPT = suprategulum; ST = subtegulum; T = tegulum; TH = thumb of embolus. Epigyne: BS = basal part of scape; DPS = distal part of scape; LL = lateral lobe; PMP = posterior median plate; S = spermatheca. Taxonomy Family Linyphiidae Blackwall, 1859 Genus Bifurcia Saaristo, Tu & Li, 2006 Type species. Arcuphantes ramosus Li & Zhu, 1987. The five new species described below are assigned to the genus Bifurcia by the following characters: prox- imal cymbial apophysis (PCA) pointing retrolaterally; bifurcated paracymbium (P); distal part of suprategulum (SPT) large, blunt, and strongly sclerotized in retrolat- eral view; suprategular pit hook (PH) reduced to small; median membrane (MM) with chitinized basal part (CPM); relatively thick and stout tipped pseudolamella (PL); basal part of scape (BS) nearly T-shaped (Saaristo et al. 2006). Bifurcia kangding sp. nov. https://zoobank.org/BFCA 8CFF-92DE-4C0F-97B3-5A27552EA929 Figs 2-4, 16A, D Type material. Holotype ¢ (IZCAS-Ar44925) and para- types 1429 (IZCAS-Ar44926-28), Mugecuo Scenic Area (30°11.72'N, 101°54.43'E, 3760 m elev.), Wangmu Vil- lage, Yala Town, Kangding, Garze Tibetan Autonomous Prefecture, Sichuan, China, 14/07/2004, Lihong Tu leg. Zoosyst. Evol. 100 (2) 2024, 705-720 707 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). zse.pensoft.net 708 Yang, L. et al.: New species of Bifurcia from China 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). ‘es ¥ Figure 4. Bifurcia kangding 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). zse.pensoft.net Zoosyst. Evol. 100 (2) 2024, 705-720 Etymology. The specific name refers to the type local- ity; noun in apposition. Diagnosis. The new species resembles B. xiaojin sp. nov. with similar paracymbium (P) and epigyne (Figs 2B, 3A), but can be easily distinguished by embolus thumb (TH) with dentate end (Figs 2B, 16D vs. spinous, Figs 13B, 16J), by chitinized basal part of median membrane (CPM) small with tip end (Fig. 16A vs. finger-shaped, Fig. 16H), and by spermathecae (S) separated by diame- ter less than their inter-distance (Fig. 3C vs. inter-distance less than their diameter, Fig. 14C). Description. Male (holotype). Total length: 2.12, carapace 0.92 long, 0.74 wide, abdomen 1.30 long, 0.80 wide. Eye inter-distances and diameters: AME 0.06, AME-AME 0.03, ALE 0.08, AME-ALE 0.06, PME 0.08, PME-PME 0.05, PLE 0.07, and PME-PLE 0.06. Sternum 0.54 long, 0.52 wide. Clypeus 0.12 high. Chelicerae pro- margin with 3 teeth, retromargin with 4 teeth. Length of legs: I 5.50 (1.54, 0.28, 1.44, 1.34, 0.90), II 4.90 (1.26, 0.26, 1.44, 1.14, 0.80), III 3.10 (0.78, 0.22, 0.76, 0.76, 0.58), IV 4.44 (1.24, 0.24, 1.12, 1.10, 0.74). Leg formula: I-H-IV-III. TmI 0.16, TmIV absent. Tibial spine formula: 2-2-2-2. Carapace brown. Sternum dark brown. Abdo- men with greenish gray dorsal spots (Fig. 4A, B). Palp (Fig. 2). Patella with long dorsal bristle. Tibia un- modified. Cymbium with hook-shaped proximal apoph- ysis (PCA) pointing retrolaterally. Paracymbium (P) bi- furcate with three branches: distally triangular branch, sharp-pointed branch and lower sclerotized branch. Pit hook (PH) on stout distal part of suprategulum (SPT) extremely reduced to small outgrowth. Embolic division (Fig. 16A, D): anterior part of radix (APR) hook-shaped; sperm duct inside the radix (R) inconspicuous with Fick- ert’s gland (FG); pseudolamella (PL) strongly sclerotized and lamellar extension (LE) absent. Anterior terminal apophysis (ATA) short-pointing anterodorsally; median terminal apophysis (MTA) membranous with many slen- der branches; posterior terminal apophysis (PTA) with serrated margin. Embolus (E) with short basal part, apical part with conical embolus proper (EP), L-shaped thumb (TH), and sharp apex (AX). Median membrane (MM) leaf-shaped with numerous papillae, and basal part of median membrane chitinized (CPM). Female (paratype). Total length: 2.42, carapace 0.94 long, 0.72 wide, abdomen 1.48 long, 1.10 wide. Eye in- ter-distances and diameters: AME 0.05, AME-AME 0.02, ALE 0.07, AME-ALE 0.05, PME 0.07, PME-PME 0.05, PLE 0.08, and PME-PLE 0.04. Sternum 0.56 long, 0.52 wide. Clypeus 0.12 high. Chelicerae promargin with 3 teeth, retromargin with 5 teeth. Length of legs: I 5.28 (1.44, 0.32, 1.34, 1.30, 0.88), II 4.74 (1.32, 0.30, 1.18, 1.14, 0.80), III 3.38 (1.02, 0.30, 0.80, 0.72, 0.54), IV 4.36 (1.26, 0.30, 1.06, 1.06, 0.68). Leg formula: I-II-I'V-HI. TmlI 0.15, TmIV absent. Tibial spine formula: 2-2-2-2. Coloration generally as in male (Fig. 4C, D). Epigyne (Fig. 3). Basal part of scape (BS) nearly T-shaped. Posterior part of posterior median plate (PMP) 709 M-shaped. Distal part of scape (DPS) forming a circle with basal part of scape. Spermathecae (S) round. Distribution. China (Sichuan, type locality; Fig. 1). Bifurcia labahe sp. nov. https://zoobank.org/0C7C6235-50F6-4DAE-B2AB-C1B996ACE792 Figs 5, 6, 16B, E Type material. Holotype 3 (IZCAS-Ar44929), Laba- he Nature Reserve (30°9.89'N, 102°27.24'E), Tianquan County, Ya’an, Sichuan, China, 10/07/2004, Lihong Tu leg. Etymology. The specific name refers to the type local- ity; noun in apposition. Diagnosis. The species resembles B. kangding sp. nov. with similar pseudolamella (PL) and median membrane (MM) (Fig. 16B, E), but can be easily distinguished by thumb of embolus (TH) 0.6 times radix (R) length (Figs 5A, 16B vs. 0.3, Figs 2A, 16A), by anterior part of radix (APR) round (Fig. 16E vs. hooked, Fig. 16D), by median terminal apophysis (MTA) with jagged edge (Fig. 16B vs. branched, Fig. 16A), and by posterior terminal apoph- ysis (PTA) thick and 0.7 times pseudolamella (PL) length (Fig. 16B vs. thin and 0.2, Fig. 16A). Description. Male (holotype). Total length: 2.24, carapace 1.06 long, 0.96 wide, abdomen 1.18 long, 0.78 wide. Eye inter-distances and diameters: AME 0.05, AME-AME 0.02, ALE 0.09, AME-ALE 0.06, PME 0.06, PME-PME 0.07, PLE 0.09, and PME-PLE 0.05. Sternum 0.61 long, 0.45 wide. Clypeus 0.08 high. Chelicerae pro- margin with 2 teeth, retromargin with | tooth. Length of legs: I 7.00 (1.84, 0.34, 1.92, 1.80, 1.10), II 5.80 (1.64, 0.28, 1.62, 1.44, 0.82), II 4.34 (1.27, 0.27, 1.08, 1.09, 0.63), IV 5.70 (1.68, 0.28, 1.54, 1.48, 0.72). Leg formula: I--IV-II. TmI 0.17, TmIV absent. Tibial spine formula: 2-2-2-2. Carapace brown. Sternum dark brown. Abdo- men with greenish gray dorsal spots (Fig. 6). Palp (Fig. 5). Patella with long dorsal bristle. Tibia un- modified. Cymbium with hook-shaped proximal apophy- sis (PCA) pointing retrolaterally. Paracymbium (P) bifur- cate with three branches: mushroom-shaped branch and two short branches proximally. Pit hook (PH) on stout distal part of suprategulum (SPT) extremely reduced to small outgrowth. Embolic division (Fig. 16B, E): anterior part of radix (APR) round; sperm duct inside the radix (R) inconspicuous with Fickert’s gland (FG); pseudola- mella (PL) smooth and pointed; lamellar extension (LE) absent. Anterior terminal apophysis (ATA) short; medi- an terminal apophysis (MTA) board; posterior terminal apophysis (PTA) thick with dentate anterior margin. Em- bolus (E) with conical embolus proper (EP), large thumb (TH), and apex (AX). Median membrane (MM) round with numerous papillae, and basal part of median mem- brane chitinized (CPM). Female. Unknown. Distribution. China (Sichuan, type locality; Fig. 1). zse.pensoft.net 710 Yang, L. et al.: New species of Bifurcia from China Figure 5. Bifurcia labahe sp. nov., holotype male palp: A. Prolateral view; B. Retrolateral view; C. Ventral view; D. Dorsal view. Scale bars: 0.10 mm (A-D). zse.pensoft.net Zoosyst. Evol. 100 (2) 2024, 705-720 Jalal Figure 6. Bifurcia labahe sp. nov., holotype male habitus: A. Dorsal view; B. Ventral view. Scale bar: 0.50 mm (A, B). Bifurcia luding sp. nov. https://zoobank. org/3031952B-E440-40FB-8DB8-A 68AC1D35336 Figs 7-9, 16C, F Type material. Holotype ¢ (IZCAS-Ar44930) and para- type 12 (IZCAS-Ar44931), Luding County (29°51.60'N, 102°2.83'E, 2936 m elev.), Garze Tibetan Autonomous Prefecture, Sichuan, China, 20/07/2004, Lihong Tu leg. Etymology. The specific name refers to the type local- ity; noun in apposition. Diagnosis. The new species can be easily distin- guished from other congeners by having embolus apex (AX) that is curved and distally pointed (Fig. 16C vs. an- gular, column-shaped, distally blunt, Fig. 16A, B, G, H, Saaristo et al. 2006: figs 4, 12), by embolus thumb (TH) membranous (Figs 7C, 16C vs. sclerotized, Figs 2C, 5C, 13C, 16A, B, G, H), by lamellar extension of pseudol- amella (LE) with flower-shaped distal end (Figs 7C, 16C vs. lacking LE or LE ribbon-shaped, Figs 2C, 5C, 10C, 13C, 16A, B, G, H, Saaristo et al. 2006: figs 4, 12), and by basal part of scape (BS) shield-shaped (Fig. 8A vs. T-shaped, Figs 3A, 11A, 14A, Saaristo et al. 2006: figs 6, 14). Description. Male (holotype). Total length: 2.23, carapace 1.10 long, 0.90 wide, abdomen 1.12 long, 0.74 wide. Eye inter-distances and diameters: AME 0.06, AME-AME 0.02, ALE 0.07, AME-ALE 0.06, PME 0.08, PME-PME 0.05, PLE 0.07, and PME-PLE 0.06. Sternum 0.50 long, 0.48 wide. Clypeus 0.11 high. Chelicerae pro- margin with 4 teeth, retromargin with 4 teeth. Length of less sal 7-57 (GP 98.033. de 960200" 130). CU G78 G90: 0.32, 1.70, 1.74, 1.12), I 4.78 (1.38, 0.30, 1.10, 1.24, 0.76), IV 6.28 (1.84, 0.32, 1.58, 1.62, 0.92). Leg formula: I--IV-II. TmI 0.16, TmIV absent. Tibial spine formula: 2-2-2-2. Carapace yellowish. Sternum dark brown. Abdo- men with greenish gray dorsal spots (Fig. 9A, B). Palp (Fig. 7). Patella with long dorsal bristle. Tibia un- modified. Cymbium with hook-shaped proximal apophy- sis (PCA) pointing retrolaterally. Paracymbium (P) bifur- cate with three branches: S-shaped branch, finger-shaped branch and lower branch. Pit hook (PH) on stout distal part of suprategulum (SPT) extremely reduced to small outgrowth. Embolic division (Fig. 16C, F): anterior part of radix (APR) hook-shaped; sperm duct inside the radix (R) inconspicuous with Fickert’s gland (FG); pseudola- mella (PL) strongly sclerotized; and lamellar extension (LE) slightly sclerotized with flower-shaped distal end. Anterior terminal apophysis (ATA) longer than wide; median terminal apophysis (MTA) membranous with ser- rated margin; posterior terminal apophysis (PTA) small and semicircle. Embolus (E) with conical embolus proper (EP), indistinct thumb (TH), and hooked apex (AX). Me- dian membrane (MM) fan-shaped and small chitinized basal part of median membrane (CPM). Female (paratype). Total length: 2.53, carapace 0.96 long, 0.84 wide, abdomen 1.66 long, 1.16 wide. zse.pensoft.net 712 Yang, L. et al.: New species of Bifurcia from China Figure 7. Bifurcia luding sp. nov., holotype male palp: A. Prolateral view; B. Retrolateral view; C. Ventral view; D. Dorsal view. Scale bars: 0.10 mm (A-D). zse.pensoft.net Zoosyst. Evol. 100 (2) 2024, 705-720 Tats) pant ft its, Figure 8. Bifurcia luding sp. nov., paratype female epigyne: A. Ventral view; B. Lateral view; C. Dorsal view. Scale bar: 0.10 mm (A—C). Figure 9. Bifurcia luding 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). Eye inter-distances and diameters: AME 0.06, AME- 17.01 (1.82, 0.36, 1.92, 1.80, 1.11), Il 6.27 (1.74, 0.32, AME 0.02, ALE 0.09, AME-ALE 0.06, PME 0.09, PME- 1.63, 1.56, 1.02), III 4.62 (1.42, 0.28, 1.14, 1.10, 0.68), IV PME 0.06, PLE 0.07, and PME-PLE 0.06. Sternum 0.66 5.90 (1.78, 0.30, 1.50, 1.46, 0.86). Leg formula: I-II-IV- long, 0.56 wide. Clypeus 0.09 high. Chelicerae promar- III. TmI 0.16, TmIV absent. Tibial spine formula: 2-2-2- gin with 3 teeth, retromargin with 5 teeth. Length of legs: 2. Coloration generally as in male (Fig. 9C, D). zse.pensoft.net 714 Epigyne (Fig. 8). Basal part of scape (BS) shield-shaped. Both sides of posterior median plate (PMP) developed well. Distal part of scape (DPS) forming an incomplete circle with basal part of scape. Spermathecae (S) nearly elliptic. Distribution. China (Sichuan, type locality; Fig. 1). Bifurcia shuanggiao sp. nov. https://zoobank.org/8B4565A A-8C81-4F24-B83D-9067D2795EB4 Figs 10-12, 16G, I Type material. Holotype 3 (IZCAS-Ar44932) and para- type 12 (IZCAS-Ar44933), Shuangqiaogou (31°7.34'N, 102°46.71'E), Siguniangshan National Scenic Area, Siguniangshan Town, Xiaojin County, Aba Tibetan and Qiang Autonomous Prefecture, Sichuan, China, 02/08/2004, Lihong Tu leg. Etymology. The specific name refers to the type local- ity; noun in apposition. Diagnosis. The new species resembles B. curvata (Sha & Zhu, 1987) (Saaristo et al. 2006: figs 9-17) with similar large chitinized basal part of median membrane (CPM) and epigyne (Figs 10B, 11A, 16G, I), but can be distinguished by embolus with hooked apex (AX) (Fig. 16G vs. sharp, Saaristo et al. 2006: fig. 12), by anterior terminal apophy- sis (ATA) finger-shaped (Figs 10A, 16G vs. handle-shaped, Saaristo et al. 2006: figs 11, 12), by lamellar extension of pseudolamella (LE) absent (Figs 10C, 16G vs. present and ribbon-shaped, Saaristo et al. 2006: figs 10, 12), and by posterior part of posterior median plate (PMP) straight (Fig. 11C vs. curved, Saaristo et al. 2006: fig. 17). Description. Male (holotype). Total length: 1.78, cara- pace 0.88 long, 0.78 wide, abdomen 0.89 long, 0.62 wide. Eye inter-distances and diameters: AME 0.05, AME-AME 0.02, ALE 0.08, AME-ALE 0.06, PME 0.08, PME-PME 0.04, PLE 0.08, and PME-PLE 0.04. Sternum 0.53 long, 0.51 wide. Clypeus 0.12 high. Chelicerae promargin with 3 teeth, retromargin with 4 teeth. Length of legs: 15.43 (1.41, 0.28, 1.48, 1.34, 0.92), If 4.63 (1.24, 0.26, 1.21, 1.14, 0.78), III 3.42 (0.97, 0.22, 0.80, 0.83, 0.60), IV 4.47 (1.33, 0.25, 1.13, 1.06, 0.70). Leg formula: I--I'V-II. TmI 0.15, TmIV absent. Tibial spine formula: 2-2-2-2. Carapace yellow- ish-brown. Sternum dark brown. Abdomen with greenish gray dorsal spots (Fig. 12A, B). Palp (Fig. 10). Patella with long dorsal bristle. Tibia un- modified. Cymbium with hook-shaped proximal apophysis (PCA) pointing retrolaterally. Paracymbium (P) bifurcate with three branches: proximally short branch, medianly robust branch with round lateral branch and distal branch. Pit hook (PH) on stout distal part of suprategulum (SPT) extremely reduced to small outgrowth. Embolic division (Fig. 16G, I): anterior part of radix (APR) hook-shaped; sperm duct inside the radix (R) inconspicuous with Fick- ert’s gland (FG); pseudolamella (PL) strongly sclerotized and lamellar extension (LE) absent. Anterior terminal apophysis (ATA) extending out handle-shaped tip pointing anterodorsally; median terminal apophysis (MTA) mem- branous with serrated margin; posterior terminal apophy- zse.pensoft.net Yang, L. et al.: New species of Bifurcia from China sis (PTA) rectangular and strongly sclerotized. Embolus (E) with conical embolus proper (EP), sclerotized thumb (TH), and hooked apex (AX). Median membrane (MM) with large chitinized basal part (CPM). Female (paratype). Total length: 1.86, carapace 0.95 long, 0.80 wide, abdomen 0.94 long, 1.33 wide. Eye in- ter-distances and diameters: AME 0.04, AME-AME 0.02, ALE 0.09, AME-ALE 0.05, PME 0.08, PME-PME 0.05, PLE 0.08, and PME-PLE 0.04. Sternum 0.60 long, 0.56 wide. Clypeus 0.10 high. Chelicerae promargin with 3 teeth, retromargin with 5 teeth. Length of legs: I 5.37 (1.48, 0.33, 1.44, 1.28, 0.84), II 4.79 (1.33, 0.31, 1.22, 1.13, 0.80), III 3.70 (1.10, 0.26, 0.88, 0.86, 0.60), ITV 4.69 (1.42, 0.27, 1.19, 1.11, 0.70). Leg formula: I-II-[V-HI. TmlI 0.17, TmIV absent. Tibial spine formula: 2-2-2-2. Coloration generally as in male (Fig. 12C, D). Epigyne (Fig. 11). Basal part of scape (BS) sparsely clothed with long curved hairs, turned under basal part forming large circle. Posterior part of posterior median plate (PMP) curved. Distal part of scape (DPS) T-shaped, laterally directed lateral lobes (LL) extending out of ei- ther side in ventral view. Spermathecae (S) S-shaped. Distribution. China (Sichuan, type locality; Fig. 1). Bifurcia xiaojin sp. nov. https://zoobank.org/7136AE47-587C-47F6-995 1-588B3337E324 Figs 13-15, 16H, J Type material. Holotype 3 (IZCAS-Ar44934) and paratypes 2339 (IZCAS-Ar44935-39), Changpinggou (31°0.29'N, 102°51.16'E), Siguniangshan National Sce- nic Area, Siguniangshan Town, Xiaojin County, Aba Ti- betan and Qiang Autonomous Prefecture, Sichuan, Chi- na, 01/08/2004, Lihong Tu leg. Etymology. The specific name refers to the type local- ity; noun in apposition. Diagnosis. The new species resembles B. kangding sp. nov. with similar paracymbium (P) and epigyne (Figs 13B, 14A), but can be distinguished by embolus thumb (TH) with spinous end (Figs 13C, 16H vs. dentate, Figs 2C, 16A), by chitinized basal part of median membrane (CPM) finger-shaped (Fig. 16H vs. pointed, Fig. 16A), and by spermathecae (S) close to each other (Fig. 14C vs. widely separated, Fig. 3C). 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 pro- margin with 2 teeth, retromargin with | 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), II 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-H-IV-III. TmI 0.17, TmIV absent. Tibial spine formula: 2-2-2-2. Carapace brown. Sternum dark brown. Abdo- men with greenish gray dorsal spots (Fig. 15A, B). Zoosyst. Evol. 100 (2) 2024, 705-720 719 rs _ i ise DE Figure 10. Bifurcia shuanggiao sp. nov., holotype male palp: A. Prolateral view; B. Retrolateral view; C. Ventral view; D. Dorsal view. Scale bars: 0.10 mm (A-D). zse.pensoft.net Yang, L. et al.: New species of Bifurcia from China Figure 11. Bifurcia shuangqiao sp. nov., paratype female epigyne: A. Ventral view; B. Lateral view; C. Dorsal view. Scale bar: 0.10 mm (A-C). Figure 12. Bifurcia shuangqiao 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). Palp (Fig. 13). Patella with long dorsal bristle. Tib- ia 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 re- duced to small outgrowth. Embolic division (Fig. 16H, 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 dis- tally angular end and lamellar extension (LE) absent. An- terior terminal apophysis (ATA) pointing anterodorsally; median terminal apophysis (MTA) membranous with four branches; posterior terminal apophysis (PTA) serrat- ed. Embolus (E) with conical embolus proper (EP), short apex (AX), and thumb (TH) with a long thorn. Median zse.pensoft.net membrane (MM) leaf-shaped with finger-shaped chi- tinized basal part (CPM). Female (paratype). Total length: 2.22, carapace 1.04 long, 0.86 wide, abdomen 1.20 long, 0.92 wide. Eye in- ter-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-FV-HI. TmlI 0.21, TmIV absent. Tibial spine formula: 2-2-2-2. Carapace yellowish-brown. Coloration generally as in male (Fig. 15C, D). Zoosyst. Evol. 100 (2) 2024, 705-720 (Aw ~ ae 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). zse.pensoft.net 718 Yang, L. et al.: New species of Bifurcia from China 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). zse.pensoft.net Zoosyst. Evol. 100 (2) 2024, 705-720 Awe) 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. shuanggiao 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). zse.pensoft.net 720 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. 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