Remarkable new species of epedanid from Vietnam (Arachnida: Opiliones Laniatores: Epedanidae) Author Tchemeris, Aleksey N. text Zootaxa 2020 2020-10-01 4858 3 427 437 journal article 9100 10.11646/zootaxa.4858.3.8 129edbf2-2a5a-4c7f-84eb-13334fca6c19 1175-5326 4412537 B48283E5-D2D7-4134-B7C5-0FF74C736BFA Euepedanus vietnamicus sp. nov. Figs. 1–18 , 28 Types. Holotype male ( MMUE , G7641.1 ) from Vietnam , Dong Noi Province , Cat Tien National-Park , October– December 2011 , A.A. Goncharov . Paratypes : 1 male (damaged), 3 females and 3 females (damaged) ( MMUE , G7641.2 ) , 1 male , 1 female ( ISEA 001.8549 ) — idem . Comparative material. Euepedanus trispinosus Roewer, 1915 : Holotype ♂ ( SMF9901124 ) from Singapore , Malakka ; see Roewer (1915: 63, fig. 31 a–b), for its general appearance see Figs. 19–27 . Etymology . The species epithet originates from Vietnam , the country from where the type series was collected. Diagnosis. By the structure of body and appendages, this species is closest to Euepedanus flavimaculatus Zhu & Lian, 2006 and E. dividuus Suzuki, 1969 . The main diagnostic characters are as follows: 1) penis apex truncate, not trapeziform ( Figs. 11–18 ); 2) cheliceral basal segment relatively long, somewhat curved and armed with numerous large and robust setae-tipped tubercles (but not strongly drawn), except for ectal and ventral surfaces ( Figs. 1, 3–5 ); 3) distal cheliceral segment markedly swollen, with an apophysis-like structure near chelae formed by several long spines, protruding forward beyond the segment limit ( Figs. 2–4 , 9–10 ); 4) fingers of chelae widened and long ( Figs. 2–5 , 9–10 ); 5) palpal armament ( Table 1 ; Figs. 6–8, 10 ). Morphological differences between the new species and three other Euepedanus species, including E. trispinosus ( Figs. 19–27 ), are shown in Table 1 . Description. MALE. Measurements . Body: length 5.92; maximal width 4.03. Scutum length: 4.90; width in the middle 3.58. ‘Clypeus’ length: 0.68. Eye tubercle width: 1.58; height (from the base of eye tubercle to top) 2.0. Chelicera: basal segment 2.57 long; distal segment 2.81 long; chela 2.35 long. Length of palp segments: 1.08 + 3.53 + 1.62 + 2.05 + 1.80 + claw 1.93 = 12.01. Length of leg segments: I: 4.92 + 1.13 + 3.40 + 6.02 + 1.32 = 16.79; II: 8.82 + 1.63 + 7.58 + 11.12 + 5.09 = 34.24; III: 6.76 + 1.53 + 3.63 + 8.16 + 3.28 = 23.36. IV: 9.28 + 1.78 + 4.65 + 10.95 + 4.12 = 30.78. Penis 2.58 long. Body. Almost rectangular, slightly trapezoid-like as shown in Fig. 1 . Scutum with a wide portion consisting of four sclerites, of which the most narrow one is situated near the rear end. Abdomen widely rounded behind. Anterior carapace margin with 6–8 granules. Eye tubercle separated from the anterior carapace margin and armed with a long median spine on its top. Carapace region with small dome-shaped hump situated around odoriferous glands and a big dome-shaped hump on both sides beloweye tubercle. Opisthosomal region of scutum with four scuta; scutal area II with a pair of median sharp relatively long spines, others areas smooth; fourth area in corners with short spine; each lateral margin of the scutum with a longitudinal row of conical and distinctly transparent tiny tubercles. Each of the free tergites with a row of granules spread out across its entire width. Last granule from a longitudinal row modified to short spine. Venter. Palpal coxae distally armed with 2–3 blunt tubercles. Leg coxae I–II considerably narrower than the others. I—armed with a row of irregular blunt tubercles, IIwith a row of setae-tipped granules and 2–3 distal blunt tubercles, III—on its sides with a row of pointed tubercles, IV—with 1–2 distal blunt tubercles situated at its corners. Tracheal stigma clearly visible; it is equal to about half length of coxa IV. Each of the free sternites with a row of tiny translucentsetae. Chelicerae ( Figs. 1–5 , 9–10 ) strong and robust. Basal segment relatively long, not swollen, somewhat curved and armed with numerous large and robust setae-tipped tubercles, except for ectal and ventral surfaces. Distal segment large and swollen, frontally armed with two irregular rows of setae-tipped tubercles, the three lowermost long setae-tipped tubercles at the base of chelae are fused, forming a prominent apophysis resembling a crown. Chela fingers relatively long, widened and strong, movable finger curved with strong and robust cutting teeth, their cutting edges toothed as in Figs. 2–5 , 9–10 . Palps ( Figs. 1–2 , 6–8, 10 ) relatively long, slightly swollen, armed with strong spines. Coxa DE—with strong crescent -shaped tubercle, D and M with rare LCT. Palpal spinulation formula: Tr: D—2 LCT, V—1 SLT; Fm: D—7–8 LCT, V—5 SLT + 2 SMT, E—2 distal SLT, DE and VE—5–6 TCT; Pt: VE—2 SLT, VM—1 SLT; Tb: VE—3 SLT, VM—4 SLT; Tr: VE and VM—3 SLT. Tarsal claw almost equal to tarsus long, slightly curved. Legs ( Figs. 1–2 , 10 ) slender and relatively long, III–IV thicker than others. Femora I slightly curved, II–IV straight, femoral bases of all legs with 1–2 pseudosegments. All metatarsi with numerous pseudosegments. Tarsi III–IV with a pair of claws, no scopulae. Distitarsus I leg with two tarsomeres. Tarsal articulations: I: 9, II: 25–28, III: 8, IV: 9. Penis ( Figs. 11–18 ) long and slender, its truncus is gradually widened distad. Distal area with broad deepening along the middle line and rows of spicules, glans (capsules externa and interna) are located inside the depression. Apex of the ventral plate emarginate in the middle. Base very narrow. FIGURES 6–10. Euepedanus vietnamicus sp. nov. , male holotype: 6—palp mesal view, 7—palp dorsal view, 8—palp ectal view, 9—distal segments of chelicerae dorsofrontal view, 10—habitus left side lateral view. Scale bar 1.0 mm. FIGURES 11–18. Euepedanus vietnamicus sp. nov. , 11–14 penis of male holotype: 11—distal area dorsal view, 12—distal area lateral view, 13—distal area ventral view. Scale bar 0.125 mm, 14—corpus dorsally. Scale bar 0.5 mm. 15–18 penis of male paratype: 15—distal area dorsal view, 16—distal area dorsolateral view, 17—distal area ventral view. Scale bar 0.125 mm, 18—corpus dorsally. Scale bar 0.5 mm. FIGURES 19–21. Habitus of the male holotype Euepedanus trispinosus : 19—lateral view, 20–21 dorsal view. Scale bar 1.0 mm. FIGURES 22–27. Male holotype of Euepedanus trispinosus Roewer, 1915: 22–23 —lateral view of anterior part of male (22— focused of chelicerae, 23—focused of palp), 24–25—habitusdorsolateral view, 26—habitus frontal view (focused of chelicerae). Scale bar 1.0 mm, 27—the original label. FIGURE 28 . The type and paratype locality of Euepedanus vietnamicus sp. nov. in Vietnam. Scale bar 200 km. TABLE 1. Main diagnostic characters of four Euepedanus species

Characters	E. vietnamicus sp.nov.	E. flavimaculatus Zhu et Lian, 2006	E. dividuus Suzuki, 1969	E. trispinosus Roewer, 1915
Median spine of eye tubercle	Long (Figs. 2, 10)	Long ( Zhu & Lian 2006 : fig. 1)	Long ( Suzuki 1969 : fig. 6)	Short (Figs. 19–25) Remark: Roewer 1915, fig. 31a is inaccurate)
Pair of spines on scutal area II	Long (Figs. 1–2, 10)	Long ( Zhu & Lian 2006 : fig. 1)	Short ( Suzuki 1969 : fig. 6)	Short (Figs. 19–21) Remark: Roewer 1915, fig. 31a is inaccurate)
Basal segment of chelicera	Relatively long somewhat curved and armed with numerous large and robust setae- tipped tubercles (but not strongly drawn), except for ectal and ventral surface (Figs. 1, 3–5)	Relatively long and curved, swollen distal- dorsally. Dorsally and mesally almost not armed, with sparse tiny setae-tipped tubercles ( Zhu & Lian 2006 : figs. 1–3)	Considerably elongated and swollen distal- dorsally. Dorsally with strong prominent setae-tipped tubercles of different forms. One long and conical others short and robust ( Suzuki 1969 : figs. 6, 7 B–D)	Some elongated and swollen distal-dorsally. Dorsally with small prominent setae-tipped tubercles (Figs. 20–21, 23–25 and Roewer 1915: fig. 31a)
Markedly swollen, with an apophysis-like
Distal segment of chelicera	structure near chelae, which is formed by several long spines, protruding forward beyond the segment limit (Figs. 2–4, 9–10)	Slightly swollen, near chelae with a structure made of low setae, e.g., tipped tubercles, slightly protruding forward. ( Zhu & Lian 2006 : figs. 2, 4)	Markedly swollen. No complicated structure near chelae ( Suzuki 1969 : figs. 6, 7 C and E)	Slightly swollen. No complicated structure near chelae (Figs. 19, 21–26) Remark: Roewer 1915: fig. 31b is innacurate)
Fingers of chelae	Widened and long. Movable finger curved with strong and robust cutting teeth (Figs. 2–5, 9–10)	Usual for the epedanids ( Zhu & Lian 2006 : figs. 2, 4)	Usual for the epedanids ( Suzuki 1969 : figs. 6–7 B–C, E)	Thin and long. Movable finger markedly curved, with strong and cutting teeth (Figs. 19, 22, 26 and Roewer 1915: fig. 31b)
Armament of palp femur	Fm: V—5 SLT + 2 SMT (Figs. 1, 6–7, 10)	Fm: V—6 SLT + 1 SMT ( Zhu & Lian 2006 : figs. 1, 5–6)	Fm: V—6 SLT ( Suzuki 1969 : figs. 6, 7 F)	Fm: V—5 SLT (Figs. 19–25 and Roewer 1915: fig. 31a)
Armament of palp patella	Pt: VE—2 SLT, VM—1 SLT (Fig. 7)	Pt: VE—2 SLT, VM—2 SLT ( Zhu & Lian, 2006 : figs. 1, 5–6)	Pt: VE—2 SLT, VM—1 SLT ( Suzuki 1969 : figs. 6, 7 F)	Pt: VE—2 SLT, VM—1 SLT (Figs. 20–24 and Roewer 1915: fig. 31a)
Armament of palp tibia	Tb: VE—3 SLT, VM—4 SLT (Fig. 7)	Tb: VE—3 SLT, VM—4 SLT + 1 SMT ( Zhu & Lian 2006 : figs. 1, 5–6)	Tb: VE—3 SLT, VM—4 SLT ( Suzuki 1969 : figs. 6, 7 F)	Tb: VE—3 SLT, VM—3 SLT (Figs. 22–25 and Roewer 1915: fig. 31a)
Corpus of penis	Gradually expanded from its base to apex (Figs. 14, 18)	Gradually expanded from its base to apex ( Zhu & Lian 2006 : figs. 10)	Sharply expanded in its distal portion ( Suzuki 1969 : figs. 8 A–B)	–
Distal part of penis	Not trapeziform, with truncate apex (Figs. 11, 15, 13, 17)	Clearly trapeziform, with tapering prominent apex ( Zhu & Lian 2006 : figs. 7–10)	Clearly trapeziform, with truncate apex ( Suzuki 1969 : figs. 8 A–C)	–
Distribution	Vietnam	China: Hainan Island	Thailand	Singapore and Malaysia

FEMALE. Measurements . Body: length 5.50; maximal width 4.11. Scutum length 4.42; width in middle 4.12. ‘Clypeus’ length: 0.60. Eye tubercle width 0.97, height (from the base of eye tubercle to its top) 1.47. Chelicera: basal segment 1.42 long; distal segment 1.48 long; chela 1.22 long. Length of palp segments: 0.60 + 2.91 + 1.48 + 1.70 + 1.58 + claw 1.68 = 9.95. Length of leg segments: I: 4.36 + 0.91 + 2.98 + 5.47 + 1.98 = 15.70; II: 7.44 + 1.12 + 6.35 + 9.82 + 3.85 = 28.58; III: 5.68 + 1.28 + 3.10 + 6.82 + 2.73 = 19.61; IV: 7.95 + 1.27 + 4.07 + 9.36 + 3.43 = 26.08. Female general appearance as in the male, but body trapezoid and smaller. Chelicerae smaller, not swollen, basal segment without any apophysis-like structure as in the male. Females darker than the males, their prevailing colour—dirty yellowish, on the dorsal surface with a pattern resembling the Latin letter X. Carapace region, in front and eye tubercle, with a dark brown reticulation. Opistosomal region and each lateral margin of the scutum with the similar reticulation and dark brown spots and patches. Dome-shaped humps yellowish, situated on both sides below eye tubercle. Chelicerae and palps yellowish, with the same reticulation. Distal cheliceral segment with a zebra-pattern. Legs yellowish, with an ochre-brown reticulation, distal segments lighter, grey-milky. Venter yellowish, darkest at its distal end. Distribution . Vietnam : the type locality only ( Fig. 28 ).