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Research Article
Fourteen new species of the spider genus Thaiderces from Southeast Asia (Araneae, Psilodercidae)
expand article infoWan-Jin Chang, Shuqiang Li
‡ Institute of Zoology, Chinese Academy of Sciences, Beijing, China
Open Access

Abstract

Fourteen new species of the genus Thaiderces F.Y. Li & S.Q. Li, 2017 from Indonesia, Myanmar, and Thailand are described: T. shuzi Li & Chang, sp. nov. (♂♀), T. peterjaegeri Li & Chang, sp. nov. (♂), T. ganlan Li & Chang, sp. nov. (♂♀), T. ngalauindahensis Li & Chang, sp. nov. (♂), T. yangcong Li & Chang, sp. nov. (♂♀), T. zuichun Li & Chang, sp. nov. (♀), T. miantiao Li & Chang, sp. nov. (♀), T. jiazi Li & Chang, sp. nov. (♀), T. tuoyuan Li & Chang, sp. nov. (♂♀), T. fengniao Li & Chang, sp. nov. (♂♀), T. haima Li & Chang, sp. nov. (♂♀), T. chujiao Li & Chang, sp. nov. (♀), T. thamphadaengensis Li & Chang, sp. nov. (♂♀), and T. thamprikensis Li & Chang, sp. nov. (♂♀). In addition, two species of Psiloderces Simon, 1892 are transferred to Thaiderces: Thaiderces rimbu (Deeleman-Reinhold, 1995) comb. nov. (♂♀) and Thaiderces djojosudharmoi (Deeleman-Reinhold, 1995) comb. nov. (♂♀).

Keywords

endemic, Indonesia, Myanmar, new combination, Ochyroceratidae, Sumatra, Thailand, tropical

Introduction

The spider family Psilodercidae Machado, 1951 was recently elevated from a subfamily of Ochyroceratidae Fage, 1912 to family rank (Wunderlich 2004, 2008). Psilodercidae currently includes 127 species belonging to eleven genera (Li and Quan 2017; WSC 2019). All species are restricted to tropical Asia. More than half the genera were described only recently: Flexicrurum Y.F. Tong & S.Q. Li, 2007, Luzonacera F.Y. Li & S.Q. Li, 2017, Priscaleclercera Wunderlich, 2017, Qiongocera F.Y. Li & S.Q. Li, 2017, Relictocera F.Y. Li & S.Q. Li, 2017, Sinoderces F.Y. Li & S.Q. Li, 2017, and Thaiderces F.Y. Li & S.Q. Li, 2017 (Liu et al. 2017).

Prior to this study, only two species of Thaiderces were known: T. jian Li & Li, 2017 and T. vulgaris (Deeleman-Reinhold, 1995) (WSC 2019). Both species are endemic to Thailand. While studying new material collected in Southeast Asia, we found fourteen new species of Thaiderces from Myanmar, Thailand, and Sumatra Island of Indonesia. The goal of this paper is to provide detailed descriptions of these new species.

Materials and methods

Types are deposited in the Institute of Zoology, Chinese Academy of Sciences (IZCAS) in Beijing, except Thaiderces peterjaegeri sp. nov. which is lodged in the Senckenberg Research Institute in Frankfurt, Germany (SMF). All specimens collected were preserved and observed in a 95% ethanol solution. The specimens were measured and examined under a Leica M205 C stereomicroscope, and further morphological details were observed using an Olympus BX41 compound microscope. The left male palp was dissected for further examination. The carapace measurements exclude the clypeus. The endogyne and the male palp were dissected and immersed in lactic acid for digestion. An Olympus C7070 wide zoom digital camera (7.1 megapixels) mounted on an Olympus SZX12 stereomicroscope was used to take photos at different focal planes. The photos were assembled with the image stacking software Helicon Focus 6.7.1. to generate high quality photos before further revision with Adobe Photoshop CC 2014. Leg measurements are given as total length (femur, patella, tibia, metatarsus, and tarsus). Leg segments were measured from their retrolateral side. All measurements are given in millimetres (mm). All terminology follows Li et al. (2014).

Taxonomy

Family Psilodercidae Machado, 1951

Thaiderces F.Y. Li & S.Q. Li, 2017

Type species

Thaiderces jian from Thailand, details and figures of the type species as in figs 1A, 2A, and Liu et al. (2017: figs 11–12).

Emended diagnosis

Thaiderces resembles Sinoderces by the absence of an apical protrusion on the cymbium, cheliceral lamina with 3 triangular extensions, shallow fovea, and clypeus and labium slanting, but it can be differentiated by the following combination of characters: 1) presence of embolic stalk or embolic ‘stubble’ (vs. absence of embolic stalk or ‘stubble’); 2) absence of setae on ocular region (vs. presence of numerous setae); 3) embolus shorter than bulb (vs. embolus longer than bulb); 4) absence of conductor (vs. presence); and 5) 3 retromarginal cheliceral teeth (vs. one retromarginal tooth).

Composition

Thaiderces jian (♂♀) (the type species), T. vulgaris (Deeleman-Reinhold, 1995) (♂♀), T. shuzi sp. nov. (♂♀), T. peterjaegeri sp. nov. (♂), T. ganlan sp. nov. (♂♀), T. ngalauindahensis sp. nov. (♂), T. yangcong sp. nov. (♂♀), T. tuoyuan sp. nov. (♂♀), T. fengniao sp. nov. (♂♀), T. haima sp. nov. (♂♀), T. thamphadaengensis sp. nov. (♂♀), T. thamphrikensis sp. nov. (♂♀), T. jiazi sp. nov. (♀), T. zuichun sp. nov. (♀), T. chujiao sp. nov. (♀), and T. miantiao sp. nov. (♀).

Distribution

Thailand, Myanmar, and Sumatra Island of Indonesia.

Key to species of Thaiderces, males only

1 Embolic stubble absent 2
Embolic stubble present 7
2 Embolus is shorter than bulb 3
Embolus and bulb almost equal in length (Fig. 1H) T. ganlan sp. nov.
3 Embolus with long stalk 4
Embolus without stalk 5
4 Bulb with lamina, embolic stalk with distinct inclination of 30° (Fig. 1B) T. ngalauindahensis sp. nov.
Bulb without lamina, embolic stalk flat and tapering (Fig. 1I) T. thamphadaengensis sp. nov.
5 Embolus thin, straight and elongated, perpendicular to the axis of the bulb (Fig. 1C) T. peterjaegeri sp. nov.
Embolus thick, curved and short, directed upward 6
6 Bulb obovate; embolus originating prolaterally (Fig. 1D) T. tuoyuan sp. nov.
Bulb oblong; embolus originating retrolaterally (Fig. 1A) T. jian
7 Embolic stalk long 8
Embolic stalk absent (Fig. 1E) T. yangcong sp. nov.
8 Embolic stubble divided into 2 rows 9
Embolic stubble not divided 10
9 Bulb with lamina (Fig. 1F) T. fengniao sp. nov.
Bulb without lamina (Fig. 1G) T. vulgaris
10 Embolic stubble serrated, covers the entire embolic stalk (Fig. 1J) T. shuzi sp. nov.
Embolic stubble not serrated, covers only distal end of embolic stalk 11
11 Embolic stubble aligned, almost as wide as bulb (Fig. 1K) T. thamphrikensis sp. nov.
Embolic stubble not aligned, 3 times thinner than bulb (Fig. 1L) T. haima sp. nov.
Figure 1. 

Prolateral view of left bulb in Thaiderces species A T. jian B T. ngalauindahensis sp. nov. C T. peterjaegeri sp. nov. D T. tuoyuan sp. nov. E T. yangcong sp. nov. F T. fengniao sp. nov. Ventral view of the bulb in Thaiderces species G T. vulgaris H T. ganlan sp. nov. I T. thamphadaengensis sp. nov. J T. shuzi sp. nov. K T. thamphrikensis sp. nov. L T. haima sp. nov. Abbreviations: LA, laminal apophysis, ST, stubble. A, G Modified from Liu et al. (2017).

Key to species of Thaiderces, females only

1 One pair of spermathecae 2
Two pairs of spermathecae 7
2 Spermathecae tubular, without stalks 3
Spermathecae with stalks 4
3 Wavy ducts present medially, connected with tubular spermathecae laterally (Fig. 2C) T. thamprikensis sp. nov.
Wavy ducts lacking, tubular spermathecae bend towards each other (Fig. 2D) T. fengniao sp. nov.
4 Spermathecae with twisted stalks 5
Stalk of spermatheca not twisted or simply bent at a right angle 6
5 Spermathecae with globular heads 2 times wider than stalk (Fig. 2E) T. ganlan sp. nov.
Spermathecae with globular heads 3 times wider than stalk (Fig. 2F) T. tuoyuan sp. nov.
6 Spermathecae connected by a funnel-like base (Fig. 2G) T. jiazi sp. nov.
Spermathecae connected by a wavy horizontal duct (Fig. 2H) T. zuichun sp. nov.
7 Spermathecae without stalks, tubular 8
Spermathecae with stalks, twisted 11
8 Paired spermathecae touching 9
Paired spermathecae separated .10
9 Lateral spermathecae similar to median spermathecae but embedded with ovoid duct structure (Fig. 2I) T. haima sp. nov.
Lateral spermathecae distinctly shorter and wider than median spermathecae (Fig. 2J) T. chujiao sp. nov.
10 Lateral spermathecae with stalks (Fig. 2K) T. thamphadaengensis sp. nov.
Lateral spermathecae 2 times longer than median pair and directed horizontally (Fig. 2B) T. vulgaris
11 Lateral and median spermathecae of similar shape 12
Lateral spermathecae short and tubular, median spermathecae long and twisted (Fig. 2A) T. jian
12 Spermathecae with globose heads 13
Spermathecae without globose heads (Fig. 2L) T. yangcong sp. nov.
13 Heads of spermathecae 3 times wider than stalk (Fig. 2M) T. shuzi sp. nov.
Heads of spermathecae almost equally as wide as stalk (Fig. 2N) T. miantiao sp. nov.
Figure 2. 

Endogyne of Thaiderces species A T. jian B T. vulgaris C T. thamprikensis sp. nov. D T. fengniao sp. nov. E T. ganlan sp. nov. F T. tuoyuan sp. nov. G T. jiazi sp. nov. H T. zuichun sp. nov. I T. haima sp.nov. J T. chujiao sp. nov. K T. thamphadaengensis sp. nov. L T. yangcong sp. nov. M T. shuzi sp. nov. N T. miantiao sp. nov. Abbreviation: SP, spermathecae. A, B Modified from Liu et al. (2017).

Thaiderces shuzi Li & Chang, sp. nov.

Figs 1J, 2M, 3, 4, 27C, 29

Types

Holotype: ♂ (IZCAS), Thailand, Prachuap Kiri Khan Province, Hua Hin District, Nong Phiap Subdistrict, Dao Cave, 12°35.449'N, 99°43.692'E, 123 m, 30.X.2014, Zhao H., Li Y., and Chen Z. Paratype: 1♀ (IZCAS), same data as holotype.

Etymology

The species name is a noun in apposition derived from the Chinese pinyin shūzǐ (comb) and refers to the serrated stubble on the embolic stalk that resembles a comb.

Diagnosis

Males of T. shuzi sp. nov. can be distinguished from all other species of the genus by the unique structure of the male bulb with a long embolic stalk bearing serrated embolic stubble (Fig. 4A) that resembles a comb (vs. absence of serrated embolic stubble in congeners); females can be differentiated from congeners by two pairs of stalked spermathecae with globose distal parts (Fig. 3A) (vs. one pair of spermathecae or spermathecae without stalk in congeners).

Figure 3. 

Thaiderces shuzi sp. nov., male holotype and female paratype A endogyne, dorsal view B female epigastric area, ventral view C male habitus, dorsal view D female habitus, dorsal view E female habitus, ventral view. Abbreviation: SP, spermatheca.

Description

Male (holotype). Total length 1.78; carapace 0.78 long, 0.70 wide; abdomen 1.00 long, 0.70 wide. Carapace round and pale yellow (Fig. 3C). Chelicerae brown (Fig. 27C). Clypeus pale yellow. Endites pale yellow. Labium light brown. Sternum with purplish pattern. Abdomen elongated, dorsum with 3 distinct brown spots medially (Fig. 3C), anteroventrally with a pair of circular purplish patches, posterior part with a pattern ranging from light purple to dark purple. Legs uniformly brown; measurements: I 5.29 (1.40, 0.20, 1.56, 1.25, 0.88), II 7.36 (2.00, 0.20, 2.19, 1.88, 1.09), III 5.27 (1.56, 0.31, 1.40, 1.30, 0.70), IV 7.25 (2.00, 0.25, 2.20, 1.80, 1.00). Palp (Fig. 4A–D): femur slender, 5 times longer than patella; patella not swollen, tibia almost equal in length to femur, basally swollen (length/width = 2.30); cymbium pale, three times shorter than femur; bulb light yellow, spatulate, with a long embolic stalk bearing serrated stubble, embolic stalk almost equal in length to the bulb, 2/3 the width of the bulb; embolus straight and short apically (Fig. 4B).

Figure 4. 

Thaiderces shuzi sp. nov., male holotype A palp, ventral view B palpal bulb, ventral view C palp, prolateral view D palp, retrolateral view. Abbreviations: EM, embolus, ST, stubble.

Female (Paratype). General features and coloration similar to that of male (Fig. 3D–E). Measurements: total length 2.00; carapace 0.70 long, 0.70 wide; abdomen 1.30 long, 1.00 wide. Leg measurements: I‒II missing, III 4.54 (1.28, 0.25, 1.25, 1.13, 0.63), IV 4.51 (1.25, 0.25, 1.25, 1.13, 0.63). Endogyne: two pairs of stalked spermathecae bearing globose distal parts, lateral spermathecae directed horizontally, medial spermathecae pointed vertically, width of globose part ca. 3 times wider than stalk. (Fig. 3A).

Distribution

Known only from the type locality (Fig. 29).

Thaiderces peterjaegeri Li & Chang, sp. nov.

Figs 1C, 5, 6, 27E, 29

Types

Holotype: ♂ (SMF), Myanmar, Chin State, Nat Ma Taung National Park, Road S of Nat Ma Taung Summit, Pristine Primary Forest, 21°10.125'N, 93°54.892'E, 2543 m, 16.V.2014, P. Jäger leg.

Etymology

The species is named in honor of Peter Jäger (Frankfurt am Main, Germany), a prolific spider taxonomist.

Diagnosis

Males of T. peterjaegeri sp. nov. resemble those of T. ganlan sp. nov. but can be distinguished by the narrow oblong shape of the bulb (Fig. 6C) (vs. elliptical in T. ganlan sp. nov. (Fig. 8C)), the embolus is half the length of the entire bulb (Fig. 6C) (vs. embolus almost equal in length to the entire bulb in T. ganlan sp. nov. (Fig. 8C)), and the embolus is thin and straight (Fig. 6C) (vs. embolus is thicker and curved in T. ganlan sp. nov. (Fig. 8B)).

Figure 5. 

Thaiderces peterjaegeri sp. nov., male holotype A habitus, dorsal view B habitus, ventral view.

Description

Male (holotype). Total length 1.87; carapace 0.78 long, 0.75 wide; abdomen 1.09 long, 0.75 wide. Carapace round and brown, with 3 longitudinal brown bands, lateral bands 5 times wider than the middle band (Fig. 5A). Chelicerae brown (Fig. 27E). Clypeus light brown. Endites light brown. Labium dark brown. Sternum with dark brown pattern. Abdomen elongated, dorsum with gradual light to dark brown pattern extending from anterior to posterior (Fig. 5A), ventrum with gradual brown to dark brown pattern extending from anterior to posterior, anterior with elliptical dark brown patch medially, and a pair of lateral pale yellow patches, posterior part delimited with a pair of pale yellow straight lines (Fig. 5B). Legs uniformly brown. Measurements: I‒III missing, IV 3.80 (1.00, 0.20, 1.00, 1.00, 0.60). Palp with scattered purplish spots (Fig. 6C–D): femur four times longer than patella; patella not swollen, tibia 2/3 the length of femur; cymbium dark with concentrated purplish spots, half the length of femur; bulb light yellow, narrow, and oblong, length/width ratio = 1.90; embolus thin and straight, arises distally, half the length of the entire bulb (Fig. 6).

Female. Unknown.

Distribution

Known only from the type locality (Fig. 29).

Figure 6. 

Thaiderces peterjaegeri sp. nov., male holotype A palp, ventral view B palpal bulb, ventral view C palp, prolateral view D palp, retrolateral view. Abbreviation: EM, embolus.

Thaiderces ganlan Li & Chang, sp. nov.

Figs 1H, 2E, 7, 8, 28E, 29

Types

Holotype: ♂ (IZCAS), Myanmar, Chin State, roadside between Kampellet to Nat Ma Taung National Park, 21°13.436'N, 93°58.819'E, 2402 m, 1.V.2017, Wu J. and Chen Z. Paratype: 1♀ (IZCAS), same data as holotype.

Etymology

The species name is a noun in apposition derived from the Chinese pinyin gănlăn (olive) and refers to the structure of the bulb that resembles an olive or a rugby ball (Fig. 8A).

Diagnosis

Diagnostic features of males are discussed under T. peterjaegeri sp. nov. Females of T. ganlan sp. nov. can be distinguished by a pair of twisted ribbon-liked spermathecae, with globular distal ends two times wider than stalk (vs. spermathecae with globular heads three times wider than stalk in T. tuoyuan sp. nov., Fig. 6A).

Description

Male (holotype). Total length 1.63; carapace 0.63 long, 0.63 wide; abdomen 1.00 long, 0.75 wide. Carapace round and brown with 3 longitudinal brown bands, lateral bands three times wider than the median band (Fig. 7C). Chelicerae brown (Fig. 28E). Clypeus dark brown medially and light brown laterally. Endites light brown. Labium dark brown. Sternum with dark brown pattern. Abdomen brown and elongated, dorsum with complex yellow dotted patterns, anteroventrally brown with pair of dark brown circular patches followed by a light brown elliptical patch, posterior part with a pair of yellow dotted lines laterally and a V-shaped mark medially. Legs uniformly brown; measurements: I 5.23 (1.40, 0.20, 1.60, 1.25, 0.78), II 4.99 (1.09, 0.15, 1.41, 1.25, 1.09), III 3.54 (0.94, 0.25, 0.90, 0.90, 0.55), IV 4.80 (1.20, 0.20. 1.40, 1.25, 0.75). Palp with scattered purplish spots (Fig. 8C, D): femur three times longer than patella; patella not swollen, tibia 2/3 the length of femur; cymbium dark with concentrated purplish spots, half the length of femur; bulb light yellow and elliptical, with a distinct protrusion arising distally, adjacent to embolus; embolus thick and branched, arising distally, almost equal in length to the entire bulb (Fig. 8A).

Figure 7. 

Thaiderces ganlan sp. nov., male holotype and female paratype A endogyne, dorsal view B female epigastric area, ventral view C male habitus, dorsal view D female habitus, dorsal view E female habitus, ventral view. Abbreviation: SP, spermatheca.

Female (Paratype). General features and coloration similar to that of male (Fig. 7D, E). Measurements: total length 2.03; carapace 0.78 long, 0.75 wide; abdomen 1.25 long, 0.94 wide. Leg measurements: I 5.23 (1.28, 0.32, 1.60, 1.25, 0.78), II 4.84 (1.28, 0.32, 1.40, 1.09, 0.75), III missing, IV 5.61 (1.44, 0.32, 1.60, 1.50, 0.75). Endogyne with a pair of twisted ribbon-liked spermathecae with long stalks and globular heads, heads 2 times wider than stalks, stalks almost equal to the interdistance of stalk bases (Fig. 7A).

Distribution

Known only from the type locality (Fig. 29).

Figure 8. 

Thaiderces ganlan sp. nov., male holotype A palp, ventral view B palpal bulb, ventral view C palp, prolateral view D palp, retrolateral view. Abbreviation: EM, embolus.

Thaiderces ngalauindahensis Li & Chang, sp. nov.

Figs 1B, 9, 10, 27F, 29

Types

Holotype: ♂ (IZCAS), Indonesia, Sumatra, West Sumatra Province, Pavakumbuh, Ngalau Indah Cave, 00°15.296'S, 100°36.256'E, 626 m, 14.V.2014, Yao Z.

Etymology

The species name is an adjective referring to the type locality.

Diagnosis

Thaiderces ngalauindahensis sp. nov. is similar to T. rimbu, but males can be distinguished by lamina connected to the embolus (Fig. 10D) (vs. the absence of lamina connected to the embolus in T. rimbu) and the embolic stalk is slanted at a 30° incline (Fig. 10D) (vs. embolic stalk rather round and curved in T. rimbu).

Description

Male (holotype). Total length 1.16; carapace 0.54 long, 0.55 wide; abdomen 0.62 long, 0.31 wide. Carapace round and brown, with three longitudinal dark brown bands, median band with distinct patch centrally, lateral bands four times wider than the middle band (Fig. 9A). Chelicerae brown (Fig. 27F). Clypeus dark brown medially and light brown laterally. Endites light brown. Labium dark brown. Sternum with dark brown pattern. Abdomen elongated, dorsum with dark brown complicated veined pattern (Fig. 9A), ventrum dark brown with indistinct pattern (Fig. 9B). Legs uniformly brown; measurements: I missing, II 3.35 (0.90, 0.20, 0.93, 0.78, 0.54), III missing, IV missing. Palp (Fig. 10C–D): femur four times longer than patella; patella not swollen, tibia almost equal in length to femur; cymbium with concentrated purplish spots, 1/2 the length of femur; bulb light brown, with 30° inclined embolic stalk, embolic stalk half the width of the bulb, lamina attached to embolus; embolus short and dark, arising distally (Fig. 10).

Figure 9. 

Thaiderces ngalauindahensis sp. nov., male holotype A habitus, dorsal view B habitus, ventral view.

Female. Unknown.

Distribution

Known only from the type locality (Fig. 29).

Figure 10. 

Thaiderces ngalauindahensis sp. nov., male holotype A palp, ventral view B palpal bulb, ventral view C palp, prolateral view D palp, retrolateral view. Abbreviations: EM, embolus, LA, lamina apophysis.

Thaiderces yangcong Li & Chang, sp. nov.

Figs 1E, 2L, 11, 12, 27B, 29

Types

Holotype: ♂ (IZCAS), Indonesia, Sumatra, Jambi Province, Kerinci, Talang Cindang, near river, 02°04.834'S, 101°22.448'E, 1054 m, 23.V.2014, Yao Z. Paratype: 1♀ (IZCAS), same data as holotype.

Etymology

The species name is a noun in apposition derived from the Chinese pinyin yángcōng (onion) and refers to the entire structure of the bulb which resembles an onion bulb.

Diagnosis

Thaiderces yangcong sp. nov. is similar to T. djojosudharmoi, but males can be distinguished by the thin and long embolus (vs. a thick and short embolus in T. djojosudharmoi), a rather plump and rounded bulb (vs. a rather ovate bulb), and the presence of embolic stubble (vs. absence of embolic stubble); females can be distinguished by a pair of short, twisted, and rather distant wavy spermathecae (vs. two pairs of short petal-like spermathecae that are close together in T. djojosudharmoi).

Description

Male (holotype). Total length 1.95; carapace 0.70 long, 0.75 wide; abdomen 1.25 long, 0.90 wide. Carapace round and pale brown, with three longitudinal dark brown bands, median band only half the length of carapace, lateral bands three times wider than the middle band (Fig. 11C). Chelicerae brown (Fig. 27B). Clypeus dark brown medially and light brown laterally. Endites pale yellow. Labium light brown. Sternum with dark brown pattern. Abdomen elongated, dorsum with brown stripes medially (Fig. 11C), anteroventrally brown with pair of dark brown circular patches followed by a light brown elliptical patch, posterior part with a pair of yellow dotted lines laterally and a V-shaped mark medially. Legs uniformly brown; measurements: I missing, II 5.15 (1.25, 0.16, 1.56, 1.40, 0.78), III 4.68 (1.25, 0.31, 1.25, 1.25, 0.62), IV 6.32 (1.56, 0.25, 1.87, 1.71, 0.93). Palp (Fig. 12A–D): femur four times longer than patella; patella not swollen, tibia 2/3 the length of femur; cymbium darker anteriorly, half the length of femur; bulb light yellow, round with sparse embolic stubble; embolus thin and dark, arising distally, almost the same length as bulb (Fig. 12A).

Figure 11. 

Thaiderces yangcong sp. nov., male holotype and female paratype A endogyne, dorsal view B female epigastric area, ventral view C male habitus, dorsal view D female habitus, dorsal view E female habitus, ventral view. Abbreviation: SP, spermatheca.

Female (paratype). General features and coloration similar to that of male (Fig. 11D–E). Measurements: total length 1.62; carapace 0.62 long, 0.70 wide; abdomen 1.00 long, 0.70 wide. Leg measurements: I 5.39 (1.40, 0.25, 1.56, 1.40, 0.78), II 5.50 (1.00, 0.25, 1.25, 1.13, 1.12, 0.75), III 3.72 (0.87, 0.25, 1.00, 1.00, 0.60), IV 5.42 (1.37, 0.25, 1.60, 1.40, 0.80). Endogyne: a pair of short, twisted, and paired coiled spermathecae, ratio of spermathecae interdistance and spermatheca width 1 : 5 (Fig. 11A).

Distribution

Known only from the type locality (Fig. 29).

Figure 12. 

Thaiderces yangcong sp. nov., male holotype A palp, ventral view B palpal bulb, ventral view C palp, prolateral view D palp, retrolateral view. Abbreviations: EM, embolus, ST, stubble.

Thaiderces zuichun Li & Chang, sp. nov.

Figs 2H, 13, 27G, 29

Types

Holotype: ♀ (IZCAS), Thailand, Satun Province, Thung Wa District, Cave without name, 07°3.04278'N, 99°48.03915'E, 28 m, 01.XII.2013, F. Ballarin.

Etymology

The species name is a noun in apposition derived from the Chinese pinyin zuǐchún (lip) and refers to the overall structure of the spermathecae which is similar to a human lip.

Diagnosis

Thaiderces zuichun sp. nov. is similar to T. miantiao sp. nov. but can be easily distinguished by a pair of stalked spermathecae with an oblong distal part connected to a wavy horizontal duct (vs. two pairs of strongly twisted spermathecae in T. miantiao sp. nov.).

Description

Female. Total length 1.58; carapace 0.50 long, 0.63 wide; abdomen 1.08 long, 0.78 wide. Carapace round and brown, with three longitudinal purplish bands, median band rather pale and only half the length of the carapace, lateral bands three times wider than the median band (Fig. 13C). Chelicerae brown (Fig. 27G). Clypeus purple. Endites purple. Labium brown. Sternum with purplish pattern. Abdomen elongated, posterior with indistinct dark brown pattern (Fig. 13C), ventrum with indistinct brown pattern, anterior epigastric area forming a semi-circle (Fig. 13D). Legs uniformly brown; measurements: I missing, II 4.13 (1.09, 0.15, 1.25, 1.09, 0.55), III 3.45 (0.94, 0.16, 0.94, 0.94, 0.47), IV 4.70 (1.20, 0.20, 1.40, 1.30, 0.60). Endogyne: a pair of stalked spermathecae, with oblong distal parts, stalk almost equal in length to and half the width of the oblong distal part, connected by a wavy horizontal duct (Fig. 13A)

Figure 13. 

Thaiderces zuichun sp. nov., female paratype A endogyne, dorsal view B epigastric area, ventral view C habitus, dorsal view D habitus, ventral view. Abbreviation: SP, spermatheca.

Male. Unknown.

Distribution

Known only from the type locality (Fig. 29).

Thaiderces miantiao Li & Chang, sp. nov.

Figs 2N, 14, 27H, 29

Types

Holotype: ♀ (IZCAS), Thailand, Nakhon Srithammarat Province, Thung Song District, outside of Ta Lod Cave, 08°2.3667'N, 99°44.8333'E, 120 m, 14.X.2015, Zhao Q., Zhou G., Chen Z.

Etymology

The species name is a noun in apposition derived from the Chinese pinyin miàntiáo (noodle) and refers to the spermathecae structure which resembles curly noodles (twisted structure).

Diagnosis

See diagnosis for T. zuichun sp. nov.

Description

Female. Total length 1.56; carapace 0.54 long, 0.60 wide; abdomen 1.02 long, 0.86 wide. Carapace round and brown, with two longitudinal dark brown bands laterally, and a central dark brown patch (Fig. 14C). Chelicerae brown (Fig. 27H). Clypeus brown. Endites brown. Labium dark brown. Sternum with dark brown pattern. Abdomen elongated, with indistinct brown pattern (Fig. 14C), ventrum with two circular patches followed by an ovate epigastric area anteriorly, posterior with yellow dotted lines laterally and indistinct brown pattern (Fig. 14D). Legs uniformly brown; measurements: I 5.05 (1.20, 0.15, 1.50, 1.50, 0.70), II‒IV missing. Endogyne: two pairs of strongly twisted helical spermathecae, with globose distal part nearly the same width as the stalk, stalk en times longer than the globose head, ratio of lateral pairs of spermathecae interdistance to median pair interdistance 1 : 3.5 (Fig. 14A).

Figure 14. 

Thaiderces miantiao sp. nov., female paratype A endogyne, dorsal view B epigastric area, ventral view C habitus, dorsal view D habitus, ventral view. Abbreviation: SP, spermatheca.

Male. Unknown.

Distribution

Known only from the type locality (Fig. 29).

Thaiderces jiazi Li & Chang, sp. nov.

Figs 2G, 15, 27I, 29

Types

Holotype: ♀ (IZCAS), Thailand, Satun Province, Khuang Kalong District, Khao Wang Cave, 06°56.3167'N, 100°1.3083'E, 127 m, 17.X.2015, Zhao Q., Zhou G., Chen Z.

Etymology

The species name is a noun in apposition derived from the Chinese pinyin jiázǐ (clamp) and refers to the spermathecae structure which resembles a face clamp (Fig. 15A).

Diagnosis

Thaiderces jiazi sp. nov. can be distinguished from other species by the unique pattern on the carapace, with trident purplish stripes medially and purplish stripes laterally (Fig. 15C), a pair of spermathecae that resemble a face clamp (curved perpendicularly and oppositely directed), attached to a funnel-shaped structure posteriorly (Fig. 15A) (vs. stalked spermathecae with oblong heads connected by a horizontal arched duct in T. zuichun sp. nov.).

Description

Female. Total length 1.47; carapace 0.54 long, 0.62 wide; abdomen 0.93 long, 0.65 wide. Carapace round and pale yellow, with trident purplish stripes medially and purplish stripes laterally. Chelicerae brown (Fig. 27I). Clypeus brown medially. Endites purple. Labium yellow. Sternum with purplish pattern. Abdomen elongated, pale yellow, almost plain without distinct pattern (Fig. 15C), ventrum with purplish and yellowish indistinct pattern, with medial epigastric area semi-circular (Fig. 15D). Legs uniformly brown; measurements: I missing, II 5.27 (1.40, 0.25, 1.50, 1.37, 0.75), III 4.23 (1.12, 0.20, 1.20, 1.09, 0.62), IV 4.12 (1.09, 0.20, 1.20, 1.09, 0.54). Endogyne: a pair of stalked spermathecae curved perpendicularly and oppositely directed, stalk length is eight times the width of the spermathecae, spermathecae connected by stalks to funnel-shaped base, ratio of the width of funnel to the width of a stalked spermatheca 1 : 10 (Fig. 15A).

Figure 15. 

Thaiderces jiazi sp. nov., female paratype A endogyne, dorsal view B epigastric area, ventral view C habitus, dorsal view D habitus, ventral view. Abbreviation: SP, spermatheca.

Male. Unknown.

Distribution

Known only from the type locality (Fig. 29).

Thaiderces tuoyuan Li & Chang, sp. nov.

Figs 1D, 2F, 16, 17, 28B, 29

Types

Holotype: ♂ (IZCAS), Thailand, Yala Province, Than To District, outside Krasaeng Cave, 02°11.9998'N, 101°11.5512'E, 86 m, 25.X.2015, Yao Z. Paratype: 1♀ (IZCAS), same data as holotype.

Etymology

The species name is a noun in apposition derived from the Chinese pinyin tuŏyuán (oval) and refers to the ovoid shape of the bulb.

Diagnosis

Thaiderces tuoyuan sp. nov. is similar to T. jian, but males can be distinguished by the obovate bulb (vs. oblong bulb in T. jian), the position of the entire bulb is a mirror image of that of T. jian but theembolus arises from the opposite position in the two species; females can be distinguished by having one pair of spermathecae (vs. two pairs in T. jian).

Description

Male (holotype). Total length 1.40; carapace 0.54 long, 0.55 wide; abdomen 0.86 long, 0.54 wide. Carapace round and brown, with three longitudinal dark brown bands of nearly equal width (Fig. 16C). Chelicerae brown (Fig. 28B). Clypeus dark brown medially and light brown laterally. Endites pale yellow. Labium dark brown. Sternum dark brown, with median pale yellow band delimitating the two halves of the sternum. Abdomen elongated, dorsum with light brown stripes posteriorly (Fig. 16C), anteroventrally with a brown semi-circle, posterior part with pair of pale yellow vertical dotted lines laterally and a V-shaped mark medially. Legs uniformly brown; measurements: I‒III missing, IV 5.38 (1.38, 0.20, 1.60, 1.40, 0.80). Palp (Fig. 17A–D): femur four times longer than patella; patella not swollen, tibia 2/3 the length of femur; cymbium scattered with concentrated purplish spots, half the length of femur; bulb light yellow, obovate with embolus arising distally; embolus short and curved, 1/3 the length of the bulb (Fig. 17C, D).

Figure 16. 

Thaiderces tuoyuan sp. nov., male holotype and female paratype A endogyne, dorsal view B female epigastric area, ventral view C male habitus, dorsal view D female habitus, dorsal view E female habitus, ventral view. Abbreviation: SP, spermatheca.

Female (Paratype). General features and coloration similar to that of male (Fig. 16D, E). Measurements: total length 1.62; carapace 0.50 long, 0.62 wide; abdomen 1.12 long, 0.70 wide. Leg measurements: I 4.30 (1.09, 0.20, 1.30, 1.09, 0.62), II missing, III 3.46 (0.80, 0.16, 0.94, 0.93, 0.63), IV 5.47 (1.25, 0.16, 1.56, 1.41, 1.09). Endogyne: a pair of twisted spermathecae, opposing one another, blunt distal parts 3 times wider than the width of stalks, stalk 2 times longer than the head (Fig. 16A).

Distribution

Known only from the type locality (Fig. 29).

Figure 17. 

Thaiderces tuoyuan sp. nov., male holotype A palp, ventral view B palpal bulb, ventral view C palp, prolateral view D palp, retrolateral view. Abbreviation: EM, embolus.

Thaiderces fengniao Li & Chang, sp. nov.

Figs 1F, 2D, 18, 19, 27D, 29

Types

Holotype: ♂ (IZCAS), Thailand, Kanchanaburi Province, Sai Yok District, Wang Krachae Subdistrict, unnamed Cave, 14°12.127'N, 99°01.195'E, 438 m, 1.XI.2014, Zhao H., Li Y., Chen Z. Paratype: 1♀ (IZCAS), same data as holotype.

Etymology

The species name is a noun in apposition derived from the Chinese pinyin fēngniăo (hummingbird) and refers to the entire structure of the bulb, including the embolic stalk and laminar apophysis, resembling the head of a hummingbird.

Diagnosis

Thaiderces fengniao sp. nov. is similar to T. haima sp. nov. but can be distinguished by a lighter color of pale yellow and purplish pattern as a whole (vs. rather darker color of brown pattern as a whole in T. haima sp. nov.), the embolic stubble is divided into two rows (Fig. 19C) (vs. the embolic stubble is undivided in T. haima sp. nov.), presence of laminar apophysis adjacent to embolus (Fig. 19C) (vs. the absence of laminar apophysis in T. haima sp. nov.), and the tibia is 2/3 the length of femur (vs. tibia almost equal to the length of femur in T. haima sp. nov.); females can be distinguished by a pair of short tubular spermathecae (vs. a pair of circular doublet spermathecae in T. haima sp. nov.).

Description

Male (holotype). Total length 1.70; carapace 0.80 long, 0.78 wide; abdomen 0.90 long, 0.50 wide. Carapace round and brown, with 3 longitudinal dark brown bands, lateral bands four times wider than the median band (Fig. 18C). Chelicerae brown (Fig. 27D). Clypeus purplish medially and light brown laterally. Endites pale yellow. Labium brown. Sternum with purplish pattern. Abdomen elongated, dorsum with indistinct purplish pattern, posterior with dark purple stripes, ventrum with indistinct brown pattern. Legs uniformly brown; measurements: I 7.18 (1.87, 0.25, 2.18, 1.88, 1.00), II missing, III 5.72 (1.60, 0.25, 1.62, 1.50, 0.75), IV 9.63 (2.60, 0.31, 2.81, 2.66, 1.25). Palp (Fig. 19A–D): femur four times longer than patella; patella not swollen, tibia 2/3 the length of femur; cymbium lightly scattered with purplish spots, 1/3 the length of the femur; bulb light yellow, lanceolate with bent distal part, presence of two rows of embolic stubble on distal part of embolic stalk, embolic stalk half the width of bulb, embolus short, arising distally, with laminar apophysis adjacent to embolus, greatly resembles the head of hummingbird with the distinct beak (Fig. 19C, D).

Figure 18. 

Thaiderces fengniao sp. nov., male holotype and female paratype A endogyne, dorsal view B female epigastric area, ventral view C male habitus, dorsal view D female habitus, dorsal view E female habitus, ventral view. Abbreviation: SP, spermatheca.

Female (Paratype). General features and coloration similar to that of male (Fig. 18D–E). Measurements: total length 1.85; carapace 0.75 long, 0.60 wide; abdomen 1.10 long, 1.00 wide. Leg measurements: I 6.80 (1.80, 0.25, 2.00, 1.75, 1.00), II 5.26 (1.40, 0.20, 1.56, 1.30, 0.80), III 4.35 (1.28, 0.20, 1.12, 1.13, 0.62), IV 6.18 (1.56, 0.20, 1.80, 1.62, 1.00). Endogyne: a pair of short, tubular spermathecae bent towards each other, with a length 2 times the width, ratio of interdistance between spermatheca and the width of spermatheca 1 : 3.75 (Fig. 18A).

Distribution

Known only from the type locality (Fig. 29).

Figure 19. 

Thaiderces fengniao sp. nov., male holotype A palp, ventral view B palpal bulb, ventral view C palp, prolateral view D palp, retrolateral view. Abbreviations: EM, embolus, LA, laminal apophysis, ST, stubble.

Thaiderces haima Li & Chang, sp. nov.

Figs 1L, 2I, 20, 21, 28C, 29

Types

Holotype: ♂ (IZCAS), Thailand, Tak Province, Uaphang District, Umphang Subdistrict, Huai Lao Poo Cave, 15°57.680'N, 98°52.510'E, 534 m, 16.XI.2016, Zhao H., Li Y., Chen Z. Paratype: 1♀ (IZCAS), same data as holotype.

Etymology

The species name is a noun in apposition derived from the Chinese pinyin hăIimă (seahorse) and refers to the distal bending of bulb that resembles the head of a seahorse.

Diagnosis

See diagnosis of T. fengniao sp. nov.

Description

Male (holotype). Total length 1.80; carapace 0.60 long, 0.70 wide; abdomen 1.20 long, 0.90 wide. Carapace round and brown, with three longitudinal dark brown bands, lateral bands two times wider than the median band (Fig. 20C). Chelicerae brown (Fig. 28C). Clypeus dark brown medially and light brown laterally. Endites light brown. Labium dark brown. Sternum with dark brown pattern. Abdomen elongated, dorsum with indistinct brown pattern, posterior with brown stripes, anteroventrally with dark brown semi-circle, posterior part with pair of pale yellow vertical dotted lines laterally and a funnel-shaped mark medially. Legs uniformly brown; measurements: I missing, II missing, III 4.78 (1.28, 0.25, 1.38, 1.25, 0.62), IV 7.12 (1.75, 0.31, 2.12, 2.00, 0.94). Palp (Fig. 21A–D): femur 3 times longer than patella; patella not swollen, tibia almost equal in length to femur; cymbium scattered with purplish spots anteriorly, 1/4 the length of femur; bulb brown, lanceolate with bent distal part, presence of embolic stubble on embolic stalk, embolic stalk 1/3 the width of the bulb, embolus short, arises distally, resembles the head of a seahorse (Fig. 21A).

Figure 20. 

Thaiderces haima sp. nov., male holotype and female paratype A endogyne, dorsal view B female epigastric area, ventral view C male habitus, dorsal view D female habitus, dorsal view E female habitus, ventral view. Abbreviation: SP, spermatheca.

Female (paratype). General features and coloration similar to that of the male (Fig. 20D, E). Measurements: total length 1.60; carapace 0.50 long, 0.63 wide; abdomen 1.10 long, 0.70 wide. Leg measurements: I missing, II 4.29 (1.09, 0.16, 1.25, 1.09, 0.70), III 4.92 (1.25, 0.16, 1.41, 1.30, 0.80), IV missing. Endogyne: two pairs of circular spermathecae, lateral spermathecae embedded with ovoid duct (Fig. 20A).

Distribution

Known only from the type locality (Fig. 29).

Figure 21. 

Thaiderces haima sp. nov., male holotype A palp, ventral view B palpal bulb, ventral view C palp, prolateral view D palp, retrolateral view. Abbreviations: EM, embolus, ST, stubble.

Thaiderces chujiao Li & Chang, sp. nov.

Figs 22, 28A, 29

Types

Holotype: ♀ (IZCAS), Thailand, Chiangmai Province, Mae Cham District, Jeep track, 18°31.677'N, 98°29.963'E, 1649 m, 14.X.2014, Zhao H., Li Y., Chen Z.

Etymology

The species name is a noun in apposition derived from the Chinese pinyin chùjiăo (antenna) and refers to the structure of the spermathecae that resembles two pairs of clavate antennae (Fig. 22A).

Diagnosis

Thaiderces chujiao sp. nov. can be distinguished from other species by the two pairs of tubular spermathecae resembling two pairs of clavate antennae, lateral pair half the length of the median pair (Fig. 22A) (vs. circular spermathecae with with ovoid duct in T. haima sp. nov.).

Description

Female (holotype). Total length 1.62; carapace 0.60 long, 0.70 wide; abdomen 1.02 long, 0.60 wide. Carapace round and brown, with three longitudinal dark brown bands, lateral bands three times wider than the median band. Chelicerae brown (Fig. 28A). Clypeus dark brown medially and light brown laterally. Endites brown. Labium dark brown. Sternum with dark brown pattern. Abdomen elongated, with dark brown pattern (Fig. 22C), anteroventrally with semi-circular light brown epigastric area medially, posterior part with pair of light brown vertical dotted lines laterally and a V-shaped mark medially (Fig. 22D). Legs uniformly brown; measurements: I 4.84 (1.25, 0.31, 1.41, 1.09, 0.78), II 3.87 (1.00. 0.20, 1.10. 0.94, 0.63), III 3.31 (0.88, 0.25, 0.88, 0.80, 0.50), IV 4.46 (1.09, 0.25, 1.25, 1.12, 0.75). Endogyne: two pairs of tubular spermathecae, lateral pair half the length of the median pair, median pair curved and opposing one another, half the width of lateral pair (Fig. 22A).

Figure 22. 

Thaiderces chujiao sp. nov., female paratype A endogyne, dorsal view B epigastric area, ventral view C habitus, dorsal view D habitus, ventral view. Abbreviation: SP, spermatheca.

Male. Unknown.

Distribution

Known only from the type locality (Fig. 29).

Thaiderces thamphadaengensis Li & Chang, sp. nov.

Figs 1I, 2K, 23, 24, 28D, 29

Types

Holotype: ♂ (IZCAS), Thailand, Mae Hong Muang Province, Muang District, Mok Jumpae Subdistrict, Tham PhaDaeng Cave, 19°25.395'N, 97°59.057'E, 293 m, 21.XI.2016, Zhao H., Li Y., Chen Z. Paratype: 1♀ (IZCAS), same data as holotype.

Etymology

The species name is an adjective referring to the type locality.

Diagnosis

Thaiderces thamphadaengensis sp. nov. can be distinguished from other species of the genus by the distinct long, flat and tapered embolic stalk (vs. embolic stalk not flat and tapered in other congeners); females can be distinguished by two pairs of spermathecae, lateral pair with short stalks, median pair circular (vs. one pair of similar spermathecae, tubular or twisted spermathecae in other congeners).

Description

Male (holotype). Total length 1.30; carapace 0.60 long, 0.59 wide; abdomen 0.70 long, 0.44 wide. Carapace round and brown, with three longitudinal dark brown bands, lateral bands three times wider than the median band (Fig. 23C). Chelicerae brown (Fig. 28D). Clypeus dark brown medially and light brown laterally. Endites brown. Labium dark brown. Sternum with dark brown pattern, delimiting an inverted triangle medially. Abdomen elongated, dorsum with indistinct brown pattern, posterior with brown stripes, anteroventrally with dark brown semi-circle, posterior with pair of pale yellow vertical dotted lines laterally. Legs uniformly brown; measurements: I missing, II 4.45 (1.25, 0.20, 1.25, 1.00, 0.75), III 3.70 (1.00, 0.20, 1.01, 0.94, 0.55), IV 5.66 (1.40, 0.25, 1.63, 1.50, 0.88). Palp (Fig. 24A–D): femur 5 times longer than patella; patella not swollen, tibia 2/3 the length of femur; cymbium with dark brown spots anteriorly, 1/3 the length of femur; bulb pale yellow, spatulate, with elongated, tapered embolic stalk, embolic stalk half the width of bulb, embolus short, arises distally from bulb (Fig. 24A).

Figure 23. 

Thaiderces thamphadaengensis sp. nov., male holotype and female paratype A endogyne, dorsal view B female epigastric area, ventral view C male habitus, dorsal view D female habitus, dorsal view E female habitus, ventral view. Abbreviation: SP, spermatheca.

Female (paratype). General features and coloration similar to that of male (Fig. 23D, E). Measurements: total length 1.60; carapace 0.50 long, 0.62 wide; abdomen 1.10 long, 0.70 wide. Leg measurements: I missing, II 3.99 (1.09, 0.25, 1.12, 0.90, 0.63), III 3.38 (0.94, 0.20, 0.87, 0.87, 0.50), IV 4.63 (1.09, 0.16, 1.38, 1.25, 0.75). Endogyne: two pairs of spermathecae, lateral pair with short stalks bearing a globose distal part, head two times longer and wider than stalk, median pair circular, ratio of the interdistance of lateral pair to interdistance of median pair 1 : 1.50 (Fig. 23A).

Distribution

Known only from the type locality (Fig. 29).

Figure 24. 

Thaiderces thamphadaengensis sp. nov., male holotype A palp, ventral view B palpal bulb, ventral view C palp, prolateral view D palp, retrolateral view. Abbreviation: EM, embolus.

Thaiderces thamphrikensis Li & Chang, sp. nov.

Figs 1K, 2C, 25, 26, 27A, 29

Types

Holotype: ♂ (IZCAS), Thailand, Phitsanulok Province, Nakhothai District, Ban Tham Phrik Village, Tham Phrik Cave, 16°55.024'N, 100°42.173'E, 610 m, 17.X.2014, Zhao H., Li Y., Chen Z. Paratype: 1♀ (IZCAS), same data as holotype.

Etymology

The species name is an adjective referring to the type locality.

Diagnosis

Thaiderces thamphrikensis sp. nov. is similar to T. vulgaris but can be distinguished by a short embolus (embolus tip does not exceed the perimeter or bulb) (Fig. 26C) (vs. long embolus in T. vulgaris (embolus tip exceeds perimeter of bulb)), aligned arrangement of embolic stubble on embolic stalk (vs. embolic stubble divided into two rows in T. vulgaris), and palpal tibia is longer than the entire bulb (vs. palpal tibia is shorter than the entire bulb); females can be distinguished by a pair of tubular spermathecae laterally, connected with wavy horizontal ducts medially (vs. two pairs of spermathecae with lateral pair shorter than median pair).

Description

Male (holotype). Total length 1.62; carapace 0.62 long, 0.70 wide; abdomen 1.00 long, 0.55 wide. Carapace round and brown, with three longitudinal dark brown bands, lateral bands almost equally wide with the median band (Fig. 25C). Chelicerae brown (Fig. 27A). Clypeus dark brown medially and light brown laterally. Endites brown. Labium dark brown. Sternum with dark brown pattern, delimiting an inverted triangle medially. Abdomen elongated, dorsum with dark brown striped pattern, posterior with brown stripes, anteroventrally dark brown with pair of light brown kidney-shaped marks, followed by a horizontal, linear brown pattern medially, posterior part with pair of light brown vertical dotted lines laterally. Legs uniformly brown; measurements: I‒II missing, III 3.50 (0.25, 0.25, 1.30, 1.10, 0.60), IV missing. Palp (Fig. 26A–D): femur 4 times longer than patella; patella not swollen, tibia almost equal in length to femur, swollen; cymbium scattered with dark brown spots, 1/3 the length of femur; bulb pale yellow, pyriform, with a patch of aligned embolic stubble distally; embolus short and bent, arises distally.

Figure 25. 

Thaiderces thamphrikensis sp. nov., male holotype and female paratype A endogyne, dorsal view B female epigastric area, ventral view C male habitus, dorsal view D female habitus, dorsal view E female habitus, ventral view. Abbreviation: SP, spermatheca.

Female (paratype). General features and coloration similar to that of male (Fig. 25D, E). Measurements: total length 2.60; carapace 1.40 long, 0.62 wide; abdomen 1.20 long, 0.87 wide. Leg measurements: I 5.40 (1.40, 0.20, 1.60, 1.40, 0.80), II 4.11 (1.00, 0.20, 1.20, 1.09, 0.62), III 4.74 (2.40, 0.15, 0.94, 0.78, 0.47), IV 5.13 (1.25, 0.16, 1.56, 1.41, 0.75). Endogyne: a pair of tubular spermathecae and connected with wavy horizontal ducts medially, lateral spermathecae seven times thinner than the width of the horizontal ducts (Fig. 25A).

Distribution

Known only from the type locality (Fig. 29).

Figure 26. 

Thaiderces thamphrikensis sp. nov., male holotype A palp, ventral view B palpal bulb, ventral view C palp, prolateral view D palp, retrolateral view. Abbreviations: EM, embolus, ST, stubble.

Thaiderces rimbu (Deeleman-Reinhold, 1995), comb. nov.

Psiloderces rimbu Deeleman-Reinhold, 1995: 25, figs 54, 55.

Description

Described by Deeleman-Reinhold (1995). Diagnostic features are discussed under T. ngalauindahensis sp. nov.

Distribution

Indonesia.

Remarks

This species is transferred to Thaiderces due to the similarity of somatic morphology and diagnostic features of the type species of the genus.

Thaiderces djojosudharmoi (Deeleman-Reinhold, 1995), comb. nov.

Psiloderces djojosudharmoi Deeleman-Reinhold, 1995: 21, figs 38–42.

Description

Described by Deeleman-Reinhold (1995). Diagnostic features are discussed under T. yangcong sp. nov.

Distribution

Indonesia.

Remarks

The somatic morphology and diagnostic features are similar to the type species of the genus; therefore, we transfer it to Thaiderces.

Figure 27. 

Chelicerale retromargin, posterior view A Thaiderces thamphrikensis sp. nov. B T. yancong sp. nov. C T. shuzi sp. nov. D T. fengniao sp. nov. E T. peterjaegeri sp. nov. F T. ngalauindahensis sp. nov. G T. zuichun sp. nov. H T. miantiao sp. nov. I T. jiazi sp. nov. Abbreviations: CL, cheliceral lamina, RT, retromarginal teeth.

Figure 28. 

Chelicerae, posterior view A Thaiderces chujiao sp. nov. B T. tuoyuan sp. nov. C T. haima sp. nov. D T. thamphadaengensis sp. nov. E T. ganlan sp. nov. Abbreviations: CL, cheliceral laminal, RT, retromargin teeth.

Figure 29. 

Distribution of Thaiderces species in Southeast Asia. 1 T. thamphrikensis sp. nov. 2 T. yangcong sp. nov. 3 T. shuzi sp. nov. 4 T. fengniao sp. nov. 5 T. peterjaegeri sp. nov. 6 T. ngalauindahensis sp. nov. 7 T. zuichun sp. nov. 8 T. jiazi sp. nov. 9 T. chujiao sp. nov. 10 T. tuoyuan sp. nov. 11 T. haima sp. nov. 12 T. thamphadaengensis sp. nov. 13 T. ganlan sp. nov. 14 T. miantiao sp. nov. 15 T. jian 16 T. vulgaris. Two species not included: T. rimbu, T. djojosudharmoi.

Acknowledgements

The manuscript benefited greatly from comments by Yuri M. Marusik (Magadan, Russia), and anonymous reviewers. Sarah Crews (San Francisco, USA) kindly checked the language. Peter Jäger (Frankfurt am Main, Germany) collected Thaiderces peterjaegeri sp. nov. which is named in his honor. This study was supported by the National Natural Science Foundation of China to Shuqiang Li (NSFC-31530067).

References

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