Platybunoides songi, Zhang, Chao & Zhang, Feng, 2012

Zhang, Chao & Zhang, Feng, 2012, On the subfamilial assignment of Platybunoides (Opiliones: Eupnoi: Phalangiidae), with the description of a new species from China, Zootaxa 3190, pp. 47-55 : 48-53

Platybunoides songi sp. nov.

( Figs 1–29 )

Type material. Holotype 3, CHINA: Ningxia Hui Autonomous Region, Jingyuan County, Liupanshan Natural Reserve, Hongxia Forest Farm, about 2082 m asl., 35°27´N, 106°18.´E, 25 June 2008, C. Zhang leg. (MHBU-Opi- NX1025). Paratypes, 23, 1Ƥ, same data as holotype (MHBU-Opi-NX 1026–1028); 13, 1Ƥ, Liupanshan Natural Reserve, Erlonghe Forest Farm, about 2200 m asl., 35°22.953´N, 106°16.527´E, 23 June 2008, C. Zhang leg. (MHBU-Opi-NX 1029–1030).

Diagnosis. The new species is similar to P. argaea ( Šilhavý 1955: 36–37, pl. III, figs 1–6), the only other know species of the genus, but can be easily distinguished by the following characters: (1) chelicera with only hairs, rather than denticles; (2) male pedipalpal femur with only two conspicuous denticles retrolaterlly, rather than setiferous tubercles dorsally; (3) glans posteriorly with a medial protrusion in profile.

Etymology. The specific name is a patronym in honor of the late Prof. Daxiang Song (1935–2008), a well known arachnologist in China.

Description. Male (holotype) habitus as in Figs 1–2 . Coloration: dorsum with brown background. Central area of propeltidium with two brown parallel stripes on the preocular region. Propeltidium divided by a ledge, parallel to lateral borders, in a central area and two lateral ones: lateral areas with a marginal white background and discontinuous brown stripes, central area with a few dark brown patches or stripes around the ocularium. Ocularium brown, with blackish eye rings, also with somewhat pale yellow patches laterally and darker median band dorsally. Meso- and metapeltidium with imperfect transverse rows of light spots medially and darker patches laterally. Opisthosomal scutum with obscure light brown saddle, darker anteriorly and lighter posteriorly. Many light yellow spots on the saddle surface. Lateral saddle with pairs of pale yellow stripes. Remainder of abdominal surface with brown and light brown spots and patches. Free tergites yellow brown.

Venter. Distal part of coxae brown, remainder of coxae pale yellow, scattered with brown spots. Genital operculum and postgenital sternites white, with light brown patches laterally. Proximal segment of chelicerae yellow, reddish brown dorsoventrally; second segment reddish brown prolaterally and retrolaterally, remainder brown. Pedipaplus pale yellow but femur medially, patella and tibia dorsally and ventrally somewhat brown. Legs brown, but with somewhat yellowish annulations on each segment, apical femur, patella and tibia yellowish white.

Dorsum ( Fig. 1 ). Entire body soft and leathery. Propeltidium with a few denticles, without trident. Each side of ocularium with six denticles. Supracheliceral laminae with one denticle on each lamina. Ozopores visible from above and with one anterior and two posterior small denticles. Ocularium prominent (about 1/3 of width and 2/3 of length of carapace) with a medial groove and rows of nine to ten acute tubercles (ten on the right, nine on the left). Mesopeltidium with a few micro-denticles. Metapeltidium and abdominal scutum smooth.

Venter. Surface of all coxae only with hair. Genital operculum ( Fig. 3 ) almost trapezioid, surface with irregularly arranged setae. Anterior margin convex. Lateral margin somewhat concave, almost twice as long as posterior margin. Opisthosomal sternites smooth, with sparse setae.

Chelicera ( Figs 4–6 ). Proximal segment short, without a ventral spur, only with a few dorsal setae. Second segment with setae on the frontal surface, and a cluster of short setae at base of fixed finger. Fingers short, inner edges toothed as illustrated ( Fig. 6 ): teeth on the fingers serrated, altered by a few larger and further smaller ones.

Pedipalpus ( Figs 7–10 ). Coxa retrolaterally with one apophysis which composed of five setiferous tubercles. Femur retrolaterally with two conspicuous distomesal denticles, on the prolateral distal side having an bump with a cluster of setae. Patella and tibia prolaterally with large bump covered the same setae as that of femur, respectively. Tarsus prolaterally with a longitudinal row of micro-denticles. Remainder of each pedipalpal segment only with hair. Claw without teeth.

Legs. All trochanters prolaterally and trochanter I–III retrolaterally with a few denticles. Femur with rows of teeth, the rest of each segment only with rows of setae.

Penis ( Figs 11–16 ). Shaft widened basally, tapering until half of its length, then somewhat widened at distal end. Distal 3/5 of shaft flattened ventrally and arched dorsally; the other two fifths of shaft oval, and its ventral surface medially concave to form a shallow ditch, gradually extending to 1/3 base of shaft. Base without bifurcation. Shaft stright from lateral view, base broad, gradually tapering until half of the shaft. Musculature limited to proximal 2/5. Glans slightly widened distally to form a ‘bullet’ end from dorsal view, but of somewhat triangle from lateral view, dorsal surface almost straight. Glans expanded dorsally and ventrally, especially close to the stylus, forming a sink mark in the centre of glans from lateral view. Two pairs of short setae close to the distal glans. Stylus long, acicular.

Female ( Figs 22–29 ). Similar to male but much large, and abdomen wide. Ocularium ( Fig. 23 ) almost ovalrectangular, acute tubercles only lying on the surface (nine on the right, ten on the left). Cheliceral fingers short, inner edges toothed as illustrated ( Fig. 24 ). Pedipalpal coxa retrolaterally with one apophysis, femur and tarsus without any denticles and micro-denticles ( Figs 25–28 ).

Ovipositor ( Fig. 29 ) with three forceps and 21 normal segments, each segment strongly stained with a coil of brown. Seminal receptacles between segments three and six, rather elongated, monovesicular.

Measurements. Male holotype (female paratype): body 1.83 (3.52) long, 1.35 (1.58) wide, BLI 1.81 (1.09). Eye tubercle 0.48 (0.55) long, 0.55 (0.60) wide, 0.43 (0.48) high. Penis shaft 1.03 long, 0.20 wide at base, glans 0.30 long, stylus 0.15 long. Measurements of left pedipalpus and right legs as in Table 1.

Trochanter Femur Patella Tibia Metatarsus Tarsus Total

Pedipalpus 0.25(0.25) 0.70(0.83) 0.43(0.55) 0.38(0.40) 0.78(0.90) 2.54(2.93) Leg I 0.25(0.28) 2.45(1.73) 0.51(0.51) 1.63(1.38) 2.30(1.79) 3.83(2.60) 10.97(8.29) Leg II 0.27(0.33) 4.49(4.13) 0.77(0.77) 3.93(3.47) 4.18(3.47) 6.53(5.61) 20.17(17.78) Leg III 0.25(0.33) 2.45(2.45) 0.51(0.51) 1.63(1.73) 2.75(2.70) 4.08(3.98) 11.67(11.70) Leg IV 0.27(0.33) 4.08(3.47) 0.61(0.66) 2.55(2.24) 4.39(3.83) 5.65(4.49) 17.55(15.02) Habitat. The specimens were collected by pit fall trap placed near rivulet, the habitat was somewhat wet and dark because of a dense of broad-leaved cloudforest.

Distribution. China: Ningxia, Jingyuan County, so far known only form the Liupanshan Natural Reserve. Variation. Size range of male (female). Body length 1.85–1.94 (3.10–3.20); width 1.35–1.45(1.88–2.15). “In Phalangiidae the glans at rest is usually held at an angle with the corpus. It is articulated, at the jointed zone, by a long tendon operated from the muscle” ( Hillyard & Sankey 1989). The glans can be bent at any angle from 0° to about 160° to the plane of the truncus ( Cokendolpher 1985). The angle between glans and truncus within same species may show variations in different individuals, e.g., the glans is at about 80° to the truncus in holotype, however, another male (MHBU-Opi-NX1029) is at more angle to the truncus, nearly 100°; the stylus orientation, like that of the glans, is not rigidly fixed ( Figs 17–21 ).

Figures

FIGURES 1 – 10. Platybunoides songi sp. nov., male holotype. 1. Body, dorsal view. 2. Same, lateral view. 3. Genital operculum, ventral view. 4. Left chelicera, prolateral view. 5. Same, retrolateral view. 6. Distal segment of left chelicera, frontal view. 7. Left pedipalpus, prolateral view. 8. Same, retrolateral view. 9. Femur of left pedipalpus, dorsal view. 10. Patella and tibia of left pedipalpus, dorsal view. Scale lines: 1 mm (1 – 2); 0.5 mm (3 – 10).

FIGURES 11 – 21. Platybunoides songi sp. nov., male holotype (11 – 16); male paratype (17 – 21). 11. Penis, dorsal view. 12. Same, lateral view. 13. Glans, dorsal surface. 14. Same, ventral surface. 15. Same, lateral view. 16. Stylus, lateral view. 17. Penis, dorsal view. 18. Same, lateral view. 19. Glans, dorsal surface. 20. Same, ventral surface. 21. Same, lateral view. Scale lines: 0.4 mm (11 – 12, 17 – 18); 0.125 mm (13 – 15, 19 – 21); 0.05 mm (16).

FIGURES 22 – 29. Platybunoides songi sp. nov., female paratype. 22. Body, dorsal view. 23. Eye tubercle, lateral view. 24. Distal segment of left chelicera, frontal view. 25. Left pedipalpus, retrolateral view. 26. Same, prolateral view. 27. Femur of left pedipalpus, dorsal view. 28. Patella and tibia of left pedipalpus, dorsal view. 29. Seminal receptacle in ovipositor. Scale lines: 1 mm (22); 0.5 mm (23 – 29).