Type species: Idiops compactus Gerstaecker, 1873, described from the female holotype from “Dafeta” (today called “Taveta”), a town in Kenya, at the border with Tanzania, not from the Zanzibar Archipelago as could be misunderstood from the original publication. Gerstaecker (1873: V-VI, 485) placed the type locality in the “Sansibar-Gebiet (= Zanzibar Region)”, a name then applied to an area that includes the Zanzibar islands and parts of mainland eastern Africa.

Species included: In addition to the nine species currently listed under Titanidiops (see World Spider Catalog, 2024) we here transfer the following ten species from Idiops (see also Discussion): Titanidiops bombayensis (Siliwal, Molur & Biswas, 2005) comb. nov.; T. bonny (Siliwal, Hippargi, Yadav & Kumar, 2020) comb. nov.; T. crassus (Simon, 1884) comb. nov.; T. joida (Gupta, Das & Siliwal in Gupta et al., 2013) comb. nov.; T. medini (Pratihar & Das in Pratihar et al., 2020) comb. nov.; T. nilagiri (Das & Diksha in Das et al., 2019) comb. nov.; T. oriya (Siliwal in Gupta et al., 2013) comb. nov.; T. pylorus (Schwendinger, 1991) comb. nov.; T. robustus (Pocock, 1898) comb. nov.; T. vankhede (Siliwal, Hippargi, Yadav & Kumar, 2020) comb. nov.

Distribution: Africa (including the Canary Islands), Near East, India, Myanmar, Thailand, Indonesia (newly reported here).

Diagnosis: Titanidiops is distinguished from the other idiopine genera by possessing a normally developed, membranous opisthosoma (carrying a strongly sclerotized posterior plate in Galeosoma Purcell, 1903), a cylindrical tibia III (saddle-shaped, i.e. dorsally concave, in Heligmomerus), only two pairs of sternal sigilla (three pairs in Segregara Tucker, 1917 and Gorgyrella Purcell, 1902), two well developed rows of strong teeth on margins of cheliceral groove [according to Raven (1985: 138) only one row (i.e. the promarginal one) present in Ctenolophus Purcell, 1904 (known from South Africa); according to Dippenaar-Schoeman et al. (2021: 5, fig. F) no teeth or only a few small proximal denticles on retromargin in Ctenolophus], retromargin of cheliceral groove with a long row of large teeth (see, e.g., Fig. 7C; one or several small denticles, arranged in a row or randomly, confined to the proximal third of the retromargin in Idiops, see Fig. 2A, Fonseca-Ferreira et al., 2021: 7, fig. 5, there “prolateral” inadvertently given for “retrolateral” and vice versa).

Idiops crassus Simon, 1884: 357-358 (original description of female in Latin).

Acanthodon crassus (Simon, 1884): Thorell, 1895: 1-2 (transfer; Latin description of female). – Pocock, 1900: 161-162, fig. 54 (English description and illustration of female).

Pachyidiops crassus (Simon, 1884): Simon, 1903: 890 (transfer and listing in French).

Titanidiops crassus (Simon, 1884): Yamamoto, 2013: 177-179, fig. 64A-B (informal transfer in unpublished thesis; Portuguese re-description of female holotype and illustration of its vulva).

Idiops colletti Pickard-Cambridge, 1889: 37-41, pl. 2, fig. 2a-g (English description and illustration of female).

Holotype: MNHN 4189; female (not examined); Myanmar, Magway (= Magwe) Region, Thayet District, Minhla (= Min Hla), 19°58'N, 95°02'E, 50 m; leg. J.B. Comotto.

Remark: According to the unpublished Ph. D. thesis of Yamamoto (2013: 177) the type specimen is deposited in the MNHN and not in the Museo Civico di Storia Naturale, Genova (Italy) as the title of the original publication (Simon, 1884) indicates.

Diagnosis: In the original publication the female holotype is described as a large specimen with 11.5 mm cephalothorax (= carapace) length and 9.6 mm width. The thesis of Yamamoto (2013: 177-179, fig. 64A-B) gives an updated diagnosis and a comprehensive re-description of the holotype (its measurements – carapace length 10.38, width 9.13 – are slightly lower than those given by Simon, 1884), plus illustrations of its vulva in ventral and “frontal” (i.e. anterior) view. The T. crassus comb. nov. holotype is roughly of the same size as females of T. birmanicus sp. nov. It differs from females of congeneric species examined here by having receptacular heads that are much wider than the corresponding receptacular stalks (Fig. 3H; Yamamoto, 2013: fig. 64A-B).

Remark: The fact that the receptacular heads of the holotype are flattened in anterior view is probably an artefact (see, e.g., Fig. 9D-E cf. Fig. 9F-H for T. tenuis sp. nov. females) and not a diagnostic character. Receptacular heads often collapse in exuviae, in partly decomposed specimens, or when the vulva is exposed to chemicals for too long [specimens examined by us were cleared by carefully using cold KOH for not longer than one minute, specimens examined by Yamamoto presumably by using Ultrazyme® (Fonseca-Ferreira et al., 2021: 6)].

Description: The most recent re-description of the holotype (in Portuguese language) and the first ever illustration of its vulva was given by Yamamoto (2013: 177-179, fig. 64A-B).

Distribution: This species is only known from its type locality, south of the town of Magway, west of the Ayeyarwady (= Irrawaddy) River, in the northern part of central Myanmar (Fig. 1A).

Idiops pylorus Schwendinger, 1991: 235-239, figs 13, 15, 17-18, 20 (description of males and females in English). – Schwendinger, 1996: 578 (listing). – World Spider Catalog, 2024 (listing).

Holotype: MHNG-ARTO-24380; male; Thailand, Chiang Mai Prov., Doi Saket Distr., near Ban Pong Kum, 18°55'N, 99°14'E, 450 m; 9.III.1987; leg. P.J. Schwendinger.

Paratypes: MHNG-ARTO-24379, MHNG-ARTO-24378; 1 male, 1 female; same locality as for holotype; 9.III.1987, 17.V.1987. – NHML; 1 female; Thailand, Chiang Mai Prov. & Distr., Mae Hia Nai, 18°46'N, 98°55'E, 380 m; 7.III.1986. – MHNG-ARTO-24376, MHNG-ARTO-24377; 2 females; Thailand, Chiang Mai Prov., Mae Taeng Distr., north of Mae Taeng, 19°09'N, 98°57'E, 450 m; 21.I.1987. – NHML; 1 male; Thailand, Tak Prov., Lan Sang, 16°47'N, 99°01'E, 180 m; 25.VII.1987. All leg. P.J. Schwendinger.

New material: MHNG-ARTO-29051, sample TA-13/10; 1 female; Thailand, Chiang Mai Prov. & Distr., near Ban Pong, 18°45'N, 98°53'E, 300 m; 18.XII.2013. – MHNG-ARTO-29052, sample TH-06/21; 1 female; Thailand, Chiang Mai Prov., Doi Saket Distr., near Ban Pong Kum, 18°55'N, 99°14'E, 460 m (the type locality); 29.XII.2006. – MHNG-ARTO-29053-29054, THNHM; 2 males (both hatched VII.1988, one matured 25.V.1992, the other 25.VI.1992), 1 female; Thailand, Chiang Mai Prov., Mae Taeng Distr., north of Mae Taeng, 19°09'N, 98°57'E, 450 m; 21.I.1987. – MHNGARTO-29055; 1 female; Thailand, Lamphun Prov., Mae Tha Distr., Doi Kunthan, 18°30'N, 99°17'E, 950 m; 9.X.1992. – THNHM; 1 male (collected mature); Thailand, Lampang Prov., Ngao Distr., Tham Pa Tai, 18°36'N, 99°53'E, 360 m; 24.VI.2001; leg. S. Sonthichai. – MHNG-ARTO-29056-29057; 2 males (one collected mature, the other matured 8.V.1996); Thailand, Sakon Nakhon Prov., Kutbak Distr., Phu Phan, 17°03'N, 103°58'E and 16°49'N, 103°53'E, 280 m and 500 m; 24.XI.1992, 8.XII.1995. – MHNGARTO-29058-29059; 1 male (matured 14.VII.1995), 1 female; Thailand, Mukdahan Prov. & Distr., Phu Pha Thoeb, 16°26'N, 104°46'E, 350 m; 7.XII.1994. – MHNG-ARTO-29060-29061, sample TA-13/08; 1 male (matured 26.VIII.2014), 1 female; Thailand, Surin Prov. & Distr., near Ramkhamhaeng University Campus, 14°55'N, 103°28'E, 150 m; 12.XII.2013. – MHNGARTO-29062, sample TH-11/19; 1 female; Thailand, Saraburi Prov., Kaeng Khoi Distr., near Jedkhod Nuea W.F., 14°29'N, 101°10'E, 280 m; 21.XII.2011. – MHNG-ARTO-29063, sample TH-11/20; 1 female; Thailand, Saraburi Prov., Kaeng Khoi Distr., near Sabpawan Reservoir, 14°29'N, 101°09'E, 310 m; 21.XII.2011. All specimens leg. P.J. Schwendinger unless otherwise stated.

Extended diagnosis: This is a relatively small species. Its males are distinguished from those of known congeneric species in South-east Asia (the male of T. crassus comb. nov. is unknown), except for T. inermis sp. nov. which uniquely lacks a mating clasper, by having an essentially smooth carapace with only few indistinct wart-like hair bases in its anterior part (Fig. 4A-B), by having a row of dorsal spines on leg femora (these less pronounced than in males of T. inermis sp. nov. which also have such spines on the palpal femur) and by possessing a row of 4-6 denticles on the paired tarsal claws. Males also lack a wart-like tubercle (see Discussion) in the mating clasper complex (Fig. 3B). Tibia I of males is not incrassate (it is as wide as patella I); the palpal tibia is more strongly incrassate, especially in the median zone (Fig. 4D-E), than in other species treated here (see, e.g., Fig. 6F-G). The embolus apex is spatulate (Fig. 4F), without a notch or tooth. The pseudoscopula (composed of distally bent scopulate hairs with a terminal pore which presumably allows perception of female pheromones; see Foelix et al., 2010: 602, figs 11-13) is very weak in the distal half of leg I, denser in the distal four-fifths of tarsus II and on the entire ventral surface of tarsi III-IV. Females are most similar to those of T. inermis sp. nov. by having vulvae with widely separated receptacles (Fig. 5E-O; see also Fig. 13F-P for T. inermis sp. nov.), but they differ by the absence of spinules on the ventral side of leg coxae I-II and by the absence of an enlarged retrolateral-distal heel on coxa IV. Macro-spigots are usually (see Variation) present on the PMS and on the proximal article of the PLS of both sexes (Fig. 5C-D) whereas in other species treated here (Figs 7E, 11D-E), except for T. inermis sp. nov., macro-spigots are usually absent from these parts.

Variation: Carapace lengths of males (n = 9) range 4.00-5.13, carapace widths 3.41-4.45; the largest female (from Phu Pha Thoeb) has a 5.78 long and 4.81 wide carapace. One of two males from Phu Phan has a straight metatarsus on its right leg I and an abnormally bent metatarsus on its left leg I (Fig. 4I) whereas in the second male from the same locality both metatarsi I display a distinct prolateral knee (Fig. 4H) similar to the metatarsal knees in the holotype (Fig. 4G) and other conspecific males. In the male from Phu Pha Thoeb both metatarsi I have a less pronounced knee than the holotype. All males examined have a row of dorsal spines on all leg femora (these are less conspicuous than in males of T. inermis sp. nov.) whereas on the palpal femur they have a dorsal row of long, strong bristles instead. The thin pseudoscopula on tarsus I of males extends over the distal third to distal half of the article; no relevant variation was found in the expanse of the pseudoscopula of other leg tarsi. Females possess 1-4 strong labial spinules, some of them additionally 1-2 smaller ones; all males lack labial spinules. In most males the AME are slightly or distinctly larger than the PLE (the largest of the remaining eyes; Fig. 4A-B); only in one of two males from Phu Phan (the aberrant one with straight and abnormally bent metatarsi I) AME and PLE are of the same size. In all females examined the AME are slightly smaller than the PLE (Fig. 5A). See also Discussion. Females (males between parentheses) have 1-4 (0-2) macro-spigots on the proximal article of their PLS, 6-11 (2-9) on the median article, 1-2 (0-2) on the distal article; the PMS carry 0-3 (0-2) macro-spigots. Variation in vulva morphology is shown in Fig. 5G-O.

Distribution: This species is widely distributed in northern, north-eastern and central Thailand (Fig. 1A).

Biology: Burrow structure: The remarkable defence mechanism of this species, which employs a soil pellet (Fig. 2B-C) to plug its burrow, was described and illustrated by Schwendinger (1988: 233-234, fig. 1; 1991: 238, figs 21-23). It was then unique among Southeast Asian mygalomorphs, but subsequently very similar burrow plugging devices have been found in Thailand, not only in a congeneric species (in T. inermis sp. nov.; Fig. 2D-G), but also in a species belonging to the distantly related family Bemmeridae (i.e. Damarchus pylorus Schwendinger & Hongpadharakiree, 2023; see Schwendinger & Hongpadharakiree, 2023: 488-489, figs 5A-B, 6). All burrows of T. pylorus comb. nov. were equipped with a soil pellet that has a smooth frontal surface (Fig. 2B-C) whereas soil pellets of T. inermis sp. nov. have a pronounced circular depression in the frontal surface (Fig. 2D-G). In most soil pellets of T. pylorus comb. nov. the dorsal surface (apex) is slightly invaginated (see Schwendinger, 1991: fig. 23) whereas in soil pellets of male MHNG-ARTO-29056 from Phu Phan and in female MHNG-ARTO-29061 from Surin there is no recognizable invagination (Fig. 2C).

Phenology: Males (n = 9) matured in captivity between May and November (most of them in June). The late November date is a unique outlier. In captivity it took males almost four years from hatching to maturity. For further information see Schwendinger (1991: 238-239).

Holotype: MHNG-ARTO-28936, sample MT-14/10; male (matured 17.I.2017); Myanmar, Bago Region, Thandaung Lay (= Pathi Village), 19°01'N, 96°35'E, 140 m; 16.VII.2014; leg. P.J. Schwendinger & S. Huber.

Paratypes: MHNG-ARTO-28937-28943; 7 females (including allotype MHNG-ARTO-28937); collected together with the holotype. – MHNGARTO-28944-28946, sample MT-14/09; 3 females; Myanmar, Kayin State, along road from Thandaung Lay to Thandaung Gyi, 19°01'N, 96°38'E, 760 m; 16.VII.2014; leg. P.J. Schwendinger & S. Huber. – MHNG-ARTO-28947, sample MT-14/09; 1 female; same locality, 650 m; 16.VII.2014; leg. P.J. Schwendinger & S. Huber.

Diagnosis: Similar to T. crassus comb. nov., distinguished by much smaller receptacular heads in females (Fig. 7F-P cf. Fig. 3H and Yamamoto, 2013: fig. 64A-B). Different from other species in South-east Asia by the following combination of characters: Large body size. Males with a distinct but not very dense cover of wart-like hair bases on carapace (Fig. 6A; absent in T. pylorus comb. nov., Fig. 4A-B, and in T. inermis sp. nov., Fig. 12A-B, very dense in T. tenuis sp. nov., Fig. 8A); apex of embolus with a pronounced notch and a laterad- to distad-directed tooth (Fig. 6D-E; no embolic tooth or notch in T. pylorus comb. nov., Fig. 4F, no notch and less pronounced proximaddirected tooth in T. inermis sp. nov., Fig. 12H-M); tibia I of males incrassate (not incrassate in T. pylorus comb. nov. and T. inermis sp. nov.); a wart-like tubercle present in mating clasper complex (Fig. 3G; absent in T. pylorus comb. nov. and T. inermis sp. nov., Fig. 3B and Fig. 3A, respectively) and a relatively large conical process dorso-distally to it [Fig. 3G; equally large in the male syntype of T. constructor (Pocock, 1900) from India (see Schwendinger, 1991: fig. 16); distinctly smaller in T. insularis sp. nov., Fig. 3E-F; absent in T. inermis sp. nov., T. pylorus comb. nov., T. tenuis sp. nov. and T. sayamensis sp. nov., Fig. 3A, 3B, 3C and 3D, respectively]; distal spur of mating clasper stout (much weaker in T. sayamensis sp. nov.), its megaspine relatively narrow (wider in all other species) and directed distad (Figs 3G, 6H-J; directed dorsad in T. sayamensis sp. nov., Figs 3D, 10I-O); metatarsus I of males with a low, very wide prolateral knee (Fig. 6I-J; with a more prominent knee in T. sayamensis sp. nov., Fig. 10I-J, no knee in T. inermis sp. nov., Fig. 12N). Females with sperm receptacles close to each other, each with a rather narrow entrance from the genital atrium (Fig. 7F-P; more widely spaced and with wider entrances in T. pylorus comb. nov., Fig. 5G-O, and in T. inermis sp. nov., Fig. 13F-P).

Description: MALE (holotype). Colour in alcohol (for living spider see Fig. 2H): Carapace reddish brown; area between eyes almost black (Fig. 6A, C). Chelicerae, palps and legs greyish brown; palpal tibia and leg tibia II dorsally slightly lighter than other articles, metatarsus I and distal part of tibia I slightly darker than other articles. Ventral side of prosoma (including limbs) generally lighter than dorsal side. Leg coxae, labium and sternum light brown; palpal coxae dark orange-coloured in prolateral half, lighter in retrolateral half. Opisthosoma dorsally dark greyish brown, with small light speckles mostly in anterior part, ventrally light greyish brown; genital area, booklung covers and spinnerets light orange-coloured.

Morphology and measurements: Body 16.40 long. Carapace 6.28 long, 5.99 wide, covered with relatively small and quite widely spaced wart-like hair bases (Fig. 6A, C). Eight eyes on bipartite mound, with a saddle between ALE and main eye group (AME + PME + PLE); entire eye group 1.11 long, 1.32 wide; ALE and AME separated by 0.33. MOQ 0.60 long, 0.79 wide. Eye diameters: AME 0.39, ALE 0.31, PME 0.16, PLE 0.35. Several transversal wrinkles to left and right of anterior half of eye mound. Posterior zone of pars cephalica with a pronounced boss, slightly lower than eye mound in lateral view. Fovea slightly procurved, 1.16 wide, occupying 20% of carapace width at that point. Proximal article of chelicera 2.11 long, fairly strong; ventral groove with six strong teeth on promargin and 6/7 strong teeth (plus a small denticle on one side) on retromargin; fang claw with sharp, straight proventral keel and with serrate retroventral keel; rastellum on long and narrow process, composed of 10-15 short, thick spines and several weaker and more pointed spines. Palpal coxa 2.40 long, 1.40 wide; with about 10 weak spinules (much shorter but not thicker than nearby bristles) in prolateral half. Labium 0.91 long, 0.74 wide, without spinules. Sternum 3.35 long, 3.10 wide; labio-sternal suture distinct but shallow; two pairs of free sigilla distinct, submarginal (Fig. 6B). Palp 10.95 long (3.97 + 2.11 + 3.88 + 0.99). Tibia moderately incrassate, 1.74 wide, retrolaterally with a curved band of 33/35 spines of various lengths in distal half (Fig. 6G). Tarsus short, distally with two short lobes and 1/2 dorso-distal spines. Palpal organ typical for the genus (Fig. 6F-G); apex of embolus with a distinct, laterad- or distad-directed tooth situated proximal to a distinct notch (Fig. 6D-E).

Legs 3214. Leg I 20.83 long (6.45 + 3.39 + 4.38 + 4.79 + 1.82); leg II 17.32 long (5.41 + 2.73 + 3.64 + 3.97 + 1.57); leg III 14.87 long (4.21 + 2.60 + 2.40 + 3.88 + 1.78); leg IV 21.44 long (6.07 + 3.06 + 4.83 + 5.29 + 2.19). Leg tarsi with a light ventral pseudoscopula: in distal half of tarsus I, in distal three-fifth of tarsus II, in distal two-third of tarsus III, developed as a narrow median band in distal three-fourth of tarsus IV. Leg I: metatarsus slightly curved outward, its prolateral side with a low, very wide knee (Fig. 6I-J); tibia distinctly incrassate (2.02 wide; tibia II in comparison only 1.12 wide), carrying a prolateral-distal mating clasper complex composed of: 1) a stout distal spur carrying a relatively narrow, distad-directed megaspine; 2) a smaller subdistal spur carrying a short, wide, pointed megaspine; 3) a wart-like tubercle (without smooth, shiny surface) between both spurs; 4) a relatively large prodorsal-distal process (Figs 3G, 6H; see also Discussion).

Spines: Palp: femur p2 (one long and one short spine distally); patella, 0; tibia r33/35; tarsus d1/2. Leg I: patella, 0; tibia p2 (megaspines), v7/8; metatarsus p4, r8; tarsus p4, r4/7. Leg II: patella, 0; tibia p0/1, v8/11; metatarsus p7/9, v10/12; tarsus p3/4, r6/7. Leg III: patella d2, p7/8; tibia p7/8, r3, v7/9; metatarsus d10/11, v13/14; tarsus p5, r7/8. Leg IV: patella p12/13; tibia v12 (all weak); metatarsus v12 (all weak); tarsus p12/13, r5, v3. Trichobothria in two curved, distally convergent rows in proximal fourth of tibiae; in a broad band in distal half of metatarsi; in a broad band on entire dorsal side of tarsi. Paired leg claws with one large and usually one (rarely two) small proximal denticle; unpaired leg claws bare.

Opisthosoma oval, 7.77 long, 5.87 wide, densely covered with short dark hairs and with few longer interspersed hairs in posterior zone. PMS 0.50 long, without macro-spigots; PLS 1.33 long: proximal article 0.75, without macro-spigots; median article 0.27, carrying 5/6 macro-spigots; distal article 0.31, with one macro-spigot. FEMALE (allotype). Colour in alcohol (darker in living spider): Dorsal side of prosoma uniformly dark brown, ventral side slightly lighter. Leg coxae, labium and sternum mostly reddish brown, except for darker labio-sternal suture and sternal sigilla. Opisthosoma dorsally dark greyish brown, with numerous light speckles, ventrally mostly cream-coloured, except for brown genital area and light brown spinnerets.

Morphology and measurements: Body 25.45 long. Carapace 8.39 long, 7.36 wide, smooth, with relatively long black hairs and bristles in front of eye mound and postero-medially on it, along lateral carapace margins and between eye mound and fovea; elsewhere hairs very small and scattered, most distinct in posterior zone of pars thoracica. Entire eye group 1.53 long, 1.74 wide; ALE and AME separated by 0.53. MOQ 0.74 long, 0.90 wide. Eye diameters: AME 0.35, ALE 0.39, PME 0.27, PLE 0.43. No wrinkles lateral to eye mound. Posterior zone of pars cephalica with a very prominent boss, clearly higher than eye mound in lateral view. Fovea strongly procurved, with angles between posterior and lateral parts (making it look like a hexagon cut in half; Fig. 7A), 1.44 wide, occupying 21% of carapace width at that point. Proximal article of chelicera 3.31 long, stronger than in male; ventral groove with 6/7 strong teeth on promargin and six strong teeth (plus a small denticle on one side) on retromargin; rastellum on long and narrow process, composed of more than 30 short, thick spines (stronger than in male) and several weaker and more pointed spines. Palpal coxa 3.55 long, 2.36 wide, with about 100 spinules of various sizes (most of them much thicker than nearby bristles) spread over almost entire ventral surface. Labium 1.45 long, 1.65 wide, with six spinules (one of them as thin as nearby setae; Fig. 7C). Sternum 4.88 long, 4.55 wide; labio-sternal suture deeper and sigilla darker than in male (Fig. 7B).

Palp 14.05 long (4.55 + 3.06 + 3.22 + 3.22); tarsus distinctlyspindle-shaped;tibiadorsallywithapronounced subdistal pseudosegmentation (see Schwendinger & Hongpadharakiree, 2023: fig. 3J for pseudosegmentation in Damarchus).

Legs 2314. Leg I 15.98 long (5.12 + 3.51 + 3.47 + 2.64 + 1.24); leg II 14.54 long (4.63 + 3.14 + 2.81 + 2.56 + 1.40); leg III 14.88 long (4.13 + 3.39 + 2.40 + 3.06 + 1.90); leg IV 20.38 long (5.79 + 4.01 + 4.21 + 4.30 + 2.07). Leg tarsi without pseudoscopula; metatarsus I distinctly, metatarsus II indistinctly spindle-shaped.

Spines: Palp: femur p2 (one long and one short spine distally); patella p1; tibia p26/29, r27/30; tarsus p26/27, r28/29, v3/4. Leg I: patella, 0; tibia p25/31, r35/37; metatarsus p23, r27; tarsus p8/9, r10, v3/4. Leg II: patella, 0; tibia p17/19, r10/15; metatarsus p20/21, r15/17; tarsus p8/10, r5/7, v2/3. Leg III: patella d4, p22/23; tibia p13/14, r12/13, v3/4; metatarsus d26/28, v13/14; tarsus p2, v8/9. Leg IV: patella p37/39; tibia, 0; metatarsus v14; tarsus p4/5, v21/25. A cluster of about 20 spinules dorso-distally on leg tibiae I-II; a cluster of 7/8 spinules at same place on palpal tibia.

Trichobothria mostly as in male; on palpal tarsus arranged as a dorsal band in distal half, but not reaching tip. Paired leg claws with one large and usually one small proximal denticle; unpaired leg claws bare. Palpal claw with one large and 0/1 small denticles.

Opisthosoma oval, 12.81 long, 8.68 wide, long interspersed hairs on dorsal side more numerous than in male. PMS 0.80 long, without macro-spigots; PLS 2.51 long: proximal article 1.24, with 0/1 macro-spigot; median article 0.61, with 11/12 macro-spigots; distal article 0.66, with one macro-spigot.

Vulva (of paratypes; Fig. 7F-P): Receptacles relatively long and relatively close to each other; receptacular heads only moderately wider than receptacular stalks.

Variation: The short transversal suture anterior to the fovea of the male holotype (Fig. 6A, C) is an individual deformity, not a species-specific character. Such sutures were also found in several males of other congeners (e.g., in T. inermis sp. nov., Fig. 12A versus Fig. 12B). The largest of eleven females examined has an 11.65 mm long and 10.34 wide carapace. This specimen also differs from all other conspecific females by possessing 1/2 macro-spigots on the basal article of the PLS. Two females (including the allotype) have 0/1 macro-spigots there; all other conspecific females lack macro-spigots on the proximal article of the PLS. All specimens have only a single macro-spigot on the distal article of the PLS and lack them on the PMS; on the medium article of the PLS the number of macro-spigots ranges 6-21. The number of spinules on the labium ranges 3-8. In all females, but not in the male holotype, the AME are slightly smaller than the PLE. Leg II is shorter than leg III in all females. Variation in vulva morphology is shown in Fig. 7F-P.

Distribution: This species is only known from the type locality and nearby localities east of Toungoo, in central Myanmar (Fig. 1A).

Biology: Habitat: All spiders were collected from road side banks at the outskirts of a village and from road side banks in an evergreen hill forest.

Burrow structure: Burrows were straight and unbranched, without a soil pellet. The male matured (in captivity) in a 3.3 cm long borrow closed by a relatively thick, 1.05 cm long and 1.4 cm wide door. The largest female was extracted from a 10 cm long burrow with a 2.35 cm long and 2.6 cm wide door. All burrows were lined with a dense layer of silk.

Phenology: The male holotype matured in captivity in mid-January, about 2.5 years after being captured (thus under unnatural conditions in Europe). When collected in mid-July, four females had egg cases at the bottom of their burrows.

Egg cases: These were 2.0-3.15 cm long, 1.4-2.1 cm wide and 1.1-1.3 cm high. Each egg case was shaped like an elongate bowl with its lateral rims slightly turned upward. The lower surface of the egg cases was brownish and plastered with a quite thick layer of soil, its upper surface composed of a tough and relatively thick, white layer of silk devoid of any soil particles (or only with traces of them) (Fig. 2K-L). The egg cases were not suspended at the bottom of the burrow [as are the egg sacs of T. pylorus comb. nov. (see Schwendinger, 1991: 238, fig. 24) and many other mygalomorph spiders] and not burrowed under its floor (as in mesothelid spiders), but they were lying on the burrow floor, tightly fitting into the lower half of the cross section of the tube, leaving enough space in the upper half so that the spider can sit on top of the egg case. The four egg cases contained 396, 656, 681 and 795 still pale, bristle- and spineless (second instar) spiderlings.

Holotype: MHNG-ARTO-28948, sample MT-18/06; male (matured 1.V.2013); Myanmar, Mon State, Mottama (= Martaban), near Kyaikkalunbon Pagoda, 16°32'N, 97°36'E, 45-90 m; 18.VI.2012; leg. P.J. Schwendinger.

Paratypes: MHNG-ARTO-28949-28954, sample MT-18/06; 6 males (matured 6.V.2013; 7.III.2014; 13.III.2014; 14.III.2014; 16.III.2014; 22.III.2014); collected together with the holotype. – MHNGARTO-28955-28964; 10 females (including allotype MHNG-ARTO-28955); collected together with the holotype.

Etymology: The Latin adjective “tenuis” means “weak, delicate”, referring to the relatively small body size of spiders of this species.

Diagnosis: Both sexes are distinguished from those of T. birmanicus sp. nov. by their much smaller body size. Males of T. tenuis sp. nov. have relatively larger wart-like hair bases on the carapace and on the coxae to the tibiae of legs and palps (Fig. 8A, H-J cf. Fig. 6A, C, H); tibia I is less strongly incrassate; megaspine on distal spur of mating clasper is relatively wider (Figs 3C, 8H cf. Figs 3G, 6H); prolateral knee on metatarsus I is more pronounced (Fig. 8G cf. Fig. 6I-J); no pseudoscopula on tarsus IV. Females of T. tenuis sp. nov. are distinguished from those of T. pylorus comb. nov. and T. inermis sp. nov. by more closely spaced receptacles (Fig. 9D-N cf. Fig. 5E-O, 13F-P).

Description: MALE (holotype). Colour in alcohol (darker in living spider): Carapace dark reddish brown; area between eyes almost black (Fig. 8A). Dorsal side of chelicerae and legs mostly dark brown, except for slightly lighter coxae, trochanters, tarsi and distal part of metatarsi; palp mostly greyish brown, its tibia dorsally slightly lighter. Ventral side of leg coxae, sternum and labium light brown. Palpal coxa light orange-coloured throughout. Opisthosoma dorsally dark grey, speckled with light spots, with two lighter median patches in anterior half; ventrally mostly light brown, except for cream-coloured genital area and light orange-coloured PLS.

Morphology and measurements: Body 10.73 long. Carapace 4.57 long, 4.03 wide, densely covered with relatively large wart-like hair bases (Fig. 8A); the corresponding hairs tiny; only a single strong short bristle on anterior carapace margin, in front of ALE. Eight eyes on bipartite mound, with a saddle between AME and main eye group; entire eye group 0.89 long, 0.86 wide; ALE and AME separated by 0.22. MOQ 0.47 long, 0.58 wide. Eye diameters: AME 0.27, ALE 0.26, PME 0.20, PLE 0.27. Several fine transversal wrinkles to left and right of anterior half of eye mound. Pars cephalica slightly and evenly arced, its posterior zone without a boss, at same level as eye mound in lateral view. Fovea slightly procurved, 0.88 wide, occupying 23% of carapace width at that point. Proximal article of chelicera 1.64 long; ventral groove with five strong and two weak teeth on pro- and retromargin; fang claw with sharp, straight proventral keel and with serrate retroventral keel; rastellum on long and narrow process, composed of 11/12 short, thick spines and several weaker and more pointed spines. Palpal coxa 1.67 long, 0.90 wide, without recognizable spinules (but several bristles in prolateral half clearly shorter than others). Labium 0.66 long, 0.88 wide, without spinules (but four bristles shorter than others). Sternum 2.46 long, 2.25 wide; labio-sternal suture and two pairs of free sternal sigilla shallow and rather indistinct (Fig. 8B).

Palp 6.90 long (2.41 + 1.31 + 2.19 + 0.99). Tibia moderately incrassate, 1.01 wide, retrolaterally with a curved band of 33/38 spines of various lengths in distal half (Fig. 8D). Tarsus short, distally with two short lobes and one dorsal spine. Palpal organ typical for the genus (Fig. 8C-D); apex of embolus with a distinct, laterad-directed tooth proximal to a shallow notch (Fig. 8E-F). Legs 3214. Leg I 13.25 long (4.11 + 2.16 + 2.74 + 3.01 + 1.23); leg II 11.44 long (3.59 + 1.81 + 2.27 + 2.57 + 1.20); leg III 9.77 long (2.74 + 1.70 + 1.56 + 2.46 + 1.31); leg IV 13.95 long (3.92 + 2.00 + 3.07 + 3.37 + 1.59). Leg tarsi with a weak ventral pseudoscopula: in distal half of tarsus I, in distal four-fifth of tarsi II-III, essentially none on tarsus IV (only few scopuliform hairs in an irregular median row in distal three-fourths). Leg I: metatarsus with a distinct prolateral knee (Fig. 8G); tibia incrassate (1.26 wide; tibia II in comparison only 0.74 wide), carrying a prolateral-distal mating clasper complex composed of: 1) a stout distal spur carrying a relatively wide, distad-directed megaspine; 2) a smaller subdistal spur carrying a short, wide, pointed megaspine; 3) a wart-like tubercle without smooth, shiny surface between both spurs. No prodorsal-distal process in mating clasper (Figs 3C, 8H). Leg tarsus II slightly spindle-shaped. Relatively large hair bases dorsally on chelicerae, palpal trochanter to tibia, and on trochanters, femora and tibiae, as well as ventrally on all femora and on tibia I of legs (Fig. 8H); hair bases less pronounced dorsally on leg patellae, indistinct on all metatarsi and tarsi.

Spines: Palp: femur p2 (one long and one short spine distally); patella, 0; tibia r33/38; tarsus d1. Leg I: patella, 0; tibia p2 (megaspines) + 1, r8/9; metatarsus p7, r7/8; tarsus p3, r3/4. Leg II: patella, 0; tibia p4, v6/7; metatarsus p6, r5; tarsus p1/2, r2. Leg III: patella d3, p4/6; tibia p5/7, r3/4, v6/7; metatarsus d9, v8/9; tarsus p0/2, r1/2. Leg IV: patella p7/8; tibia v6/7 (all long and weak); metatarsus v7 (all long and weak); tarsus v10/11.

Trichobothria as in male of previous species. Paired leg claws with one large and rarely one small proximal denticle; unpaired leg claws bare.

Opisthosoma oval, 4.22 long, 3.31 wide, densely covered with short dark hairs and few longer interspersed hairs in posterior zone of ventral side. PMS 0.38 long, without macro-spigots; PLS 1.12 long: proximal article 0.57, without macro-spigots; median article 0.27, with four macro-spigots; distal article 0.28, with one macro-spigot. FEMALE (allotype): Colour in alcohol (darker in living spider): Dorsal side of prosoma uniformly brown, except for slightly darker chelicerae; ventral side of prosoma slightly lighter than dorsal side. Dark pigment around AME and behind ALE and PLE (Fig. 9A). Palpal coxae, labium, sternum and ventral side of chelicerae more reddish than ventral side of legs. Opisthosoma dorsally dark greyish brown, more densely speckled than in male, ventrally lighter greyish, except for darkened epigynal area (Fig. 9C) and light brown spinnerets.

Morphology and measurements: Body 16.14 long. Carapace 5.37 long, 4.53 wide, smooth, with few very thin hairs on pars thoracica; slightly stronger ones on lateral carapace margin; long and strong bristles on, in front and behind eye mound and about half way back to fovea, one pair among them very long. Entire eye group 1.07 long, 1.08 wide; ALE and AME separated by 0.38. MOQ 0.49 long, 0.68 wide. Eye diameters: AME 0.27, ALE 0.24, PME 0.17, PLE 0.29. No wrinkles lateral to eye mound. Posterior zone of pars cephalica with a pronounced boss, clearly higher than eye mound in lateral view. Fovea strongly procurved, with angles between posterior and lateral parts (Fig. 9A), 0.93 wide, occupying 21% of carapace width at that point. Proximal article of chelicera 2.29 long, stronger than in male; ventral groove with 7/8 teeth (mostly strong, two smaller ones on left side) on promargin and 6/8 teeth (most of them strong, one small on left side) on retromargin; rastellum on long and narrow process, composed of 14/15 short, thick spines (stronger than in male) and several weaker and more pointed spines. Palpal coxa 2.02 long, 1.25 wide, with more than 50 spinules of various sizes spread over almost entire ventral surface, the strongest ones in prolateral half. Labium 0.90 long, 1.09 wide, carrying four strong spinules. Sternum 3.11 long, 2.78 wide; labio-sternal suture and sternal sigilla quite inconspicuous, as in male (Fig. 9B).

Palp 8.56 long (2.89 + 1.96 + 1.77 + 1.94); tarsus slightly spindle-shaped; tibia dorsally with a moderately pronounced subdistal pseudosegmentation.

Legs 2314. Leg I 9.98 long (3.22 + 2.18 + 2.13 + 1.58 + 0.87); leg II 8.91 long (2.73 + 1.96 + 1.77 + 1.47 + 0.98); leg III 9.44 long (2.51 + 2.13 + 1.53 + 1.99 + 1.28); leg IV 12.54 long (3.35 + 2.51 + 2.62 + 2.64 + 1.42). Leg tarsi without pseudoscopula; metatarsi I-II not spindle-shaped (unlike in female of T. birmanicus sp. nov.).

Spines: Palp: femur p2 (one long and one short spine distally); patella p1; tibia p14/18, r17; tarsus p19, r18/19, v3. Leg I: patella, 0; tibia p15/16, r18/21; metatarsus p16/17, r15/17; tarsus p7/8, r6, v3. Leg II: patella, 0; tibia p8/10, r10/12; metatarsus p10/14, r9/11; tarsus p6, r4/5, v2/3. Leg III: patella d2/3, p16; tibia p7/8, r4, v3 (quite long and weak); metatarsus d13/17, v4/5; tarsus v2/3. Leg IV: patella p20; tibia v4/5 (quite long and weak); metatarsus v10/11; tarsus v12/14. A cluster of 15/16 spinules dorso-distally on leg tibia I; on tibia II 22/28 spicules in a dorso-distal cluster extending backward in a narrow band and further in a single row to midpoint of article; a dorso-distal cluster of seven spinules on palpal tibia.

Trichobothria as in females of previous species. Paired leg claws with one large subproximal denticle and on some (anterior) legs additionally with one small denticle; unpaired leg claws bare. Palpal claw with one large and one small denticle.

Opisthosoma oval, 7.36 long, 4.96 wide; with several long hairs interspersed between many short hairs, even longer hairs on ventral side. PMS 0.53 long, without macro-spigots; PLS 1.63 long: proximal article 0.83, without macro-spigots; median article 0.41, with six macro-spigots; distal article 0.39, with one macro-spigot. Vulva (of paratypes; Fig. 9D-N): Receptacles relatively long and relatively close to each other; receptacular heads not much wider than receptacular stalks; vulva essentially indistinguishable from vulvae of T. birmanicus sp. nov. (see Fig. 7F-P).

Variation: In males (n = 7) the carapace length ranges 3.77-4.74, the corresponding width ranges 3.31-4.25. The largest female (n = 10) has a 5.26 long and 4.42 wide carapace; in the smallest reproductive female (with an egg case) it is 4.29 and 3.57, respectively. The subdistal embolic tooth is distinct in five males examined (Fig. 8E-F), rather indistinct in two males. Male paratype MHNG-ARTO-28949 has 2/3 megaspines on the distal spur of the tibia I mating clasper and 4/5 megaspines on the subdistal spur (Fig. 8I-J) whereas all other males have only a single megaspine on each spur (Figs 3C, 8H), as do all males of all other congeneric species examined. Therefore surplus megaspines on the coupling spurs is clearly an aberration. In the smallest male (MHNG-ARTO-28951) both metatarsi I have a more pointed prolateral knee than in other males. Females possess 3-11 pronounced spinules of various sizes on their labium; males have 0-4 more or less distinctly developed labial spinules. The AME are equally large to distinctly larger than the PLE in males (Fig. 8A); in all females the AME are slightly smaller than the PLE (Fig. 9A). In all specimens examined the PMS lacks macro-spigots; so does the proximal article of the PLS, except for a single female which carries a single macro-spigot on one side; the median article of the PLS has 3-7 macro-spigots; the distal article has a single macro-spigot in all specimens examined. The pseudoscopula in males shows little intraspecific variation: covering the distal two-thirds of tarsus I in four males, the distal half in three males (including the holotype); one male has slightly more scattered scopuliform hairs on tarsus IV than the others. In all females there are two prolateral-distal spines on the palpal femur: one always long and strong, the other always shorter and usually also weaker (as it is the case in all females of T. birmanicus sp. nov.); only in the allotype is it as strong as the longer spine. Variation in vulva morphology is shown in Fig. 9D-N.

Distribution: The new species is only known from the type locality, close to the Andaman coast of the northern part of southern Myanmar (Fig. 1A).

Biology: Habitat: All spiders were collected from the steep soil banks of a rural road fringed with planted trees.

Burrow structure: Burrows in the field were more or less straight and unbranched, up to 3 cm long (in captivity up to 4 cm), without a soil pellet, closed by a quite thick (slightly cork-shaped) door. In males (all matured in captivity) doors were 0.6-0.8 cm long and 0.7-0.9 cm wide. The largest burrow (of a female) had a door 1.1 cm long and 1.2 cm wide. All burrows were lined with a dense layer of silk.

Phenology: Males matured in captivity in early May, about 10.5 months after being captured, and in early to late March, about 21 months after being captured. In mid-June one fresh egg case was extracted from the burrow of a female. Another female laid eggs in its transport vial the day after being captured. These eggs were subsequently eaten by their mother.

Egg case: The extracted and preserved egg case is 1.0 cm long, 0.75 cm wide and 0.5 cm high, white on its upper surface, brown elsewhere (as in T. birmanicus sp. nov., Fig. 2K-L). It contains 45 undeveloped (and thus newly laid) eggs.

Idiops sp. – Schwendinger, 1996: 578 (mentioned as an additional species occurring in Thailand).

Holotype: MHNG-ARTO-28965, sample TH-11/17; male (matured 1.IV.2014); Nakhon Nayok Prov. & Distr., Salika W.F., 14°19'N, 101°15'E, 100 m; 18.XII.2011; leg. P.J. Schwendinger & K. Hongpadharakiree.

Paratypes: MHNG-ARTO-28966-28968, sample TH-11/17; 3 males (matured 4.III.2014; 3.IV.2014; mid-IV.2014); collected together with the holotype. – MHNG-ARTO-28969-28972, sample TH-11/17; 4 females (including allotype MHNG-ARTO-28969); collected together with the holotype. – THNHM; 1 male (matured 18.XII.2014); collected together with the holotype. – THNHM; 1 female; Salika W.F.; 2010; leg. K. Hongpadharakiree. – MHNG-ARTO-28973-28976, sample TA-22/09; 4 males (matured 8.I.2014; 15.II.2015; 17.II.2015; 27.II.2015); Thailand, Chanthaburi Prov., Khao Khitchakut Distr., near Krathing W.F., 12°50'N, 102°07'E, 45 m; 5.IX.2013; leg. P.J. Schwendinger. – MHNG-ARTO-28977-28980, sample TA-22/09; 4 females; same data. – THNHM; 1 female; near Krathing W.F., 12°50'N, 102°08'E, 250 m; 28.X.2010; leg. K. Hongpadharakiree. – MHNGARTO-28981, MHNG-ARTO-28995-28996, sample TH-09/10; 1 male (matured beginning of I.2009), 2 females; Thailand, Nong Khai Prov., Bung Kla Distr., Phu Wua, 18°14'N, 103°58'E, 390 m, 13./14.VI.2013; leg. P.J. Schwendinger. – MHNG-ARTO-28997-28999, sample MT-19/05; 3 males (matured 19.III.2015; 1.IV.2015; 10.V.2015); Myanmar, Tanintharyi Region, Dawei, near Myaw Yit Pagoda, 14°05'N, 98°05'E, 5-20 m; 21.VI.2013; leg. P.J. Schwendinger. – MHNGARTO-29000-29002, sample MT-19/05; 3 females; same data as for previous specimens.

Etymology: “Sayam” is the Thai word for “Siam”. Latinized adjective.

Diagnosis: Males are distinct from males of all other species treated here by having a mating clasper complex with a wart-like tubercle carrying a shiny black cap (Figs 3D, 10L-O) and a relatively narrow distal spur carrying a dorsad-directed instead of distad-directed megaspine (Figs 3D, 10I-O); carapace with warty surface (Fig. 10A-B), but warts smaller and more widely spaced than in T. tenuis sp. nov. (Fig. 8A); prolateral knee of metatarsus I strongly developed (Fig. 10I-K); embolus with a distinct subdistal notch and tooth (Fig. 10F-H). Females with receptacles quite close to each other and having rather small heads (Fig. 11F-O); different from those of T. crassus comb. nov. (with distinctly larger receptacular heads; Fig. 3H), T. pylorus comb. nov. and T. inermis sp. nov. (receptacles more widely separated from each other; Fig. 5G-O and Fig. 13F-P), but essentially indistinguishable from receptacles of females of other species treated here.

Description: MALE (holotype). Colour in alcohol (darker in living spider; see Fig. 2I for male paratype): Carapace reddish brown, with darkened area around eye mound continuing as two dark parallel, posteriorly narrowing bands back to fovea; areas between ALE and main eye group almost black, both separated by a light transversal band (Fig. 10B). Dorsal side of chelicera, palpal tibia and tarsus, all leg trochanters, tarsus II and metatarsus II, and tarsi III-IV entirely light brown, distal zone of tibia I and proximal half of metatarsus I darkened, other limb articles dorsally light brown, with three dark longitudinal stripes. Leg coxae, labium and sternum light orange-coloured; palpal coxae and ventral side of limbs slightly darker. Fang claw and sclerites of palpal organ dark brown. Opisthosoma dorsally dark grey, densely speckled with light spots, with two lighter median patches in anterior half; ventrally mostly light grey, except for light orange-coloured genital area, booklung covers and spinnerets.

Morphology and measurements: Body 15.32 long. Carapace 5.71 long, 5.13 wide, quite densely covered with relatively small wart-like hair bases (Fig. 10A-B); corresponding hairs mostly short and weak, longest and adpressed halfway between eye mound and fovea; only a single strong, short median bristle in front of ALE and three such bristles in front of AME. Eight eyes on bipartite mound, with a saddle between ALE and main eye group; entire eye group 1.12 long, 1.24 wide; ALE and AME separated by 0.28. MOQ 0.61 long, 0.83 wide. Eye diameters: AME 0.38, ALE 0.33, PME 0.22, PLE 0.39. Several fine transversal wrinkles to left and right of anterior half of eye mound. Posterior zone of pars cephalica with a moderate boss, slightly lower than eye mound in lateral view. Fovea slightly procurved, 0.97 wide, occupying 19% of carapace width at that point. Proximal article of chelicera 2.21 long; ventral groove with seven teeth on each margin, 1/2 of them on promargin rather small, one on retromargin small; fang claw with sharp, straight proventral keel and with serrate retroventral keel; rastellum on long and narrow process, composed of 14/16 short, thick spines and several weaker and more pointed spines. Palpal coxa 2.08 long, 1.17 wide, with about 20 very short (shorter than those on labium) spinules, most of them not thicker than nearby bristles. Labium 0.78 long, 1.04 wide, with four short, weak spinules (only little thicker than nearby bristles). Sternum 2.92 long, 2.99 wide; labio-sternal suture distinct and relatively long, it and sigilla of same colour as other parts of sternum (Fig. 10C).

Palp 9.05 long (3.05 + 1.82 + 2.95 + 1.23). Tibia moderately incrassate, 1.36 wide, retrolaterally with a curved band of 31 spines of various lengths in distal half (Fig. 10E). Tarsus short, distally with two short lobes and one dorsal spine. Palpal organ typical for the genus (Fig. 10D-E); apex of embolus with a distinct tooth proximal to a relatively deep notch (Figs 10F-G).

Legs 3214. Leg I 16.36 long (4.94 + 2.86 + 3.21 + 3.86 + 1.49); leg II 14.15 long (4.35 + 2.24 + 2.95 + 3.18 + 1.43); leg III 12.56 long (3.64 + 2.21 + 2.01 + 3.08 + 1.62); leg IV 16.82 long (4.74 + 2.53 + 3.73 + 4.03 + 1.79). Leg tarsi with a ventral pseudoscopula: in distal half of tarsus I, in distal four-fifth of tarsi II-III, developed as a relatively wide median band in distal two-thirds of tarsus IV. Leg I: metatarsus curved in proximal half, halfway on prolateral side with a pronounced knee (Fig. 10I); tibia distinctly incrassate (1.72 wide; tibia II in comparison only 0.97 wide), carrying a prolateral-distal mating clasper complex composed of: 1) a relatively narrow distal spur carrying a dorsad-directed megaspine; 2) a smaller subdistal spur carrying a short, wide, pointed megaspine; 3) a wart-like tubercle with a black, smooth and shiny cap between both spurs; no prodorsal-distal process present (Figs 3D, 10L-M). Leg tarsus II slightly spindle-shaped; tarsus III indistinctly so. Slightly enlarged hair bases on leg tibiae I-II; these indistinct on other limb articles.

Spines: Palp: femur p2 (one long and one short spine distally); patella, 0; tibia r31; tarsus d1. Leg I: patella, 0; tibia p2 (megaspines) + 1/2, r11; metatarsus p7, r11/13; tarsus p5/6, r4/5. Leg II: patella, 0; tibia p5, r3/4, v5 (plus 3 long, strong bristles); metatarsus p12, r7/9; tarsus p5, r4. Leg III: patella d3, p12; tibia d10/11, v5/7; metatarsus d11/13, p3, v6/9; tarsus p3, r2. Leg IV: patella p17/19; tibia p3, v8/10 (all long and weak); metatarsus p3, v10 (all long and weak); tarsus p2/3, r1/3, v8/10. Trichobothria as in males of previous species. Paired leg claws with a large subproximal denticle, on anterior legs often additionally with a small denticle; unpaired leg claws bare.

Opisthosoma oval, 6.69 long, 4.81 wide, covered with a mixture of short and medium-sized dark hairs; some even longer bristles on ventral side. PMS 0.49 long, without macro-spigots; PLS 1.45 long: proximal article 0.77, without macro-spigots; median article 0.38, with 5/6 macro-spigots; distal article 0.30, with one macro-spigot. FEMALE (allotype): Colour in alcohol (darker in living spider): Dorsal side of prosoma mostly light orange-brown, except for slightly darker chelicerae; area between eyes much darker (Fig. 11A). Ventral side of prosoma mostly light orange-coloured, except for slightly darker labium and palpal coxae, and distinctly darker chelicerae (Fig. 11B). Fang claws dark brown. Three indistinct dark longitudinal stripes on femora and patellae. Opisthosoma dorsally dark greyish brown, densely speckled as in male, with an indistinct light median patch in anterior half; ventrally mostly lighter greyish, except for dark orange-coloured epigynal area and light orange-coloured booklung covers and spinnerets (Fig. 11C-D).

Morphology and measurements: Body 18.25 long. Carapace 5.58 long, 4.87 wide, smooth, with few short hairs on lateral margins; stronger (but not longer) bristles in front of ALE, in front of AME and on posterior margin of eye mound; longer bristles between eye mound and fovea, one very long pair at about midway. Entire eye group 1.11 long, 1.19 wide; ALE and AME separated by 0.39. MOQ 0.53 long, 0.74 wide. Eye diameters: AME 0.27, ALE 0.31, PME 0.20, PLE 0.33. No wrinkles lateral to eye mound. Posterior zone of pars cephalica with a distinct boss, slightly higher than eye mound in lateral view. Fovea distinctly procurved, with indistinct angles between posterior and lateral parts (Fig. 11A), 0.88 wide, occupying 19% of carapace width at that point. Proximal article of chelicera 2.53 long, stronger than in male; ventral groove with 6/8 teeth (most of them strong; one small on right side, three small on left side) on promargin, and 9/10 teeth (most of them strong; four small on right side, three small on left side) on retromargin; rastellum on long and narrow process, composed of 19/20 short, thick spines (stronger than in male) and several weaker and more pointed spines. Palpal coxa 2.21 long, 1.36 wide, with about 60 spinules of various sizes spread over almost entire ventral surface, the strongest ones in prolateral half. Labium 0.91 long, 1.10 wide, carrying three strong plus two weak spinules. Sternum 3.18 long, 2.99 wide; labio-sternal suture and sternal sigilla quite inconspicuous (Fig. 11B).

Palp 9.26 long (3.12 + 2.05 + 2.01 + 2.08); tarsus slightly spindle-shaped; tibia dorsally with a weakly pronounced subdistal pseudosegmentation.

Legs 3214. Leg I 10.46 long (3.38 + 2.34 + 2.14 + 1.66 + 0.94); leg II 9.68 long (3.05 + 2.18 + 1.82 + 1.59 + 1.04); leg III 9.42 long (2.50 + 2.05 + 1.46 + 1.98 + 1.43); leg IV 13.48 long (3.77 + 2.63 + 2.79 + 2.73 + 1.56). Leg tarsi without pseudoscopula; metatarsi I-II indistinctly spindle-shaped.

Spines: Palp: femur p2 (one long and one short spine distally), patella p1; tibia p19, r16/18; tarsus p17/18, r18/19, v4/5. Leg I: patella, 0; tibia p18/19, r17/19; metatarsus p16/18, r14/15; tarsus p7/8, r7, v3. Leg II: patella, 0; tibia p10, r10/12; metatarsus p13/14, r9/8; tarsus p7/8, r3, v3. Leg III: patella d3, p14/15; tibia d10/16, p1, v2 (quite long and weak); metatarsus d12/14, v6/8; tarsus v5/6. Leg IV: patella p13/15; tibia p1, v4 (quite long and weak); metatarsus v11; tarsus v12. A cluster of 13 spinules dorso-distally on leg tibia I; on tibia II 16/17 spicules in a dorso-distal cluster extending backward in a narrow band in distal fourth of article; a dorso-distal cluster of five spinules on palpal tibia. Trichobothria as in females of previous species. Paired leg claws with a large subproximal denticle and on some (anterior) legs additionally with a small denticle; unpaired leg claws bare. Palpal claw with one large and one small proximal denticle.

Opisthosoma oval, 8.25 long, 5.23 wide; with a mixture of short and medium-long dark hairs dorsally, ventrally with a few long hairs in genital area and on booklung covers. PMS 0.57 long, without macro-spigots; PLS 1.49 long: proximal article 0.77, without macro-spigots; median article 0.39, with six macro-spigots; distal article 0.33, with one macro-spigot (Fig. 11D-E).

Vulva (of paratypes; Fig. 11F-O): Receptacles relatively long and close to each other; receptacular heads not much wider than receptacular stalks; vulva essentially indistinguishable from vulvae of T. birmanicus sp. nov. (Fig. 7F-P) and T. tenuis sp. nov. (Fig. 9D-N).

Variation: In males (n = 10) the carapace length ranges 5.78-6.30, the corresponding width 4.48-5.65. The largest (n = 15) conspecific female (in THNHM) has a 9.21 long and 7.76 wide carapace. The dark spots on the carapace of the female allotype (Fig. 11A) are not pigment in the cuticle, but thin particles, shaped like tiny paper shreds, attached to the surface of the cuticle. These particles presumably are fragments of only partly dissolved endocuticle left over from the discarded last exuvia; they can be removed with a brush. The presence of such particles is fairly common: they were also found in nine other T. sayamensis sp. nov. females from all localities, in females of at least two other Titanidiops species, and in other mygalomorph and mesothelid specimens with a mostly glabrous carapace. Males have up to four weak spinules on their labium; females 3-10 strong spinules. The number of spines on the retrolateral side of the palpal tibia of males ranges 20-40. The prolateral median knee in the metatarsus I of males is expressed either as a spike (Fig. 10K), as an apically pointed cone (Fig. 10J), or as an apically rounded cone (Fig. 10I). All males have a small wart-like tubercle with a shiny black cap in the mating clasper complex, but that is rather difficult to see in specimens where the nearby cuticle is dark (Fig. 10L-M versus Fig. 10N-O). The expanse of the pseudoscopula on leg tarsi of males is quite variable: mostly in the distal half of tarsus I, in a male from Myaw Yit shorter (in distal two-fifths); in distal two-thirds to four-fifths on tarsi II-III; in a quite wide median band in distal two-thirds to three-fourths on tarsus IV. Most specimens lack marco-spigots on the PMS and on the proximal article of the PLS, only the largest female has there 0/1 and 0/3 macro-spigots, respectively; the number of such spigots on the median article of the PLS ranges 3-10; the distal article always carries a single macro-spigot. Variation in vulva morphology is shown in Fig. 11F-O.

Distribution: This species has a wide geographical distribution, ranging from southern Myanmar through central and south-eastern to north-eastern Thailand (Fig. 1A).

Biology: Habitat: Spiders were collected from sloping soil without vegetation beneath tree roots and water pipes in trails, from earth banks on the sides of a footpath, and from the banks of old trenches (at Myaw Yit); all in shady places within forests, never in sun-exposed places.

Burrow structure: All burrows inspected were unbranched and more or less straight, up to six centimetres long in females, up to 3.5 cm in males, without a soil pellet, closed by moderately thick doors. In males (all matured in captivity) doors were 0.85-1.25 cm long and 0.9-1.35 cm wide. The largest burrow (belonging to a female) had a door 1.3 cm long and 1.4 cm wide. All burrows were lined with a relatively thin layer of silk; prey remnants were stored at the bottom of the burrows. Phenology: Males matured in captivity between early January and early May; those from Myaw Yit a bit later in the year than males from Thailand, but they were also in captivity for a longer period of time (about 2-3 years versus 0.5-2.5 years in Thai specimens). No egg cases were found in the field or constructed by spiders in captivity.

Holotype: MHNG-ARTO-29018, sample MT-19/01; male (matured 9.IX.2015); Thailand, Chumphon Prov., Lang Suan Distr., Ban Bang Nam Jued, 9°59'N, 99°09'E, 5 m, 13./14.VI.2013; leg. P.J. Schwendinger.

Paratypes: MHNG-ARTO-29019-29021, sample MT-19/01; 3 males (matured 29.IX.2013; 7.IX.2015; 13.X.2013); collected together with the holotype. – MHNG-ARTO-29022-29029; 8 females; collected together with the holotype. – MHNGARTO-29030-29031, sample TH-06/04; 1 male (matured end of IX.2007), 1 female; Thailand, Krabi Prov. & Distr., Ban Laem Pho, near Gastropod Fossil Beach, 8°02'N, 98°53'E, 1 m; 15./17.IX.2006. – MHNG-ARTO-29032-29034, sample TH-08/09; 1 male (matured 8.VIII.2011), 2 females; same locality as for previous specimens; 15./16.VI.2008. – MHNGARTO-29035-29036, sample TH-09/04; 1 male (matured 11.VI.2009), 1 female; Thailand, Krabi Prov., Khlong Thom Distr., Khao Phra - Bang Khram, 7°54'N, 99°16'E, 80 m; 2./3.VI.2009. All specimens leg. P.J. Schwendinger.

Other material: MHNG; 1 juvenile; collected together with the holotype.

Etymology: The Latin adjective “inermis” means “unarmed”, referring to the absence of a mating clasper in males of this species.

Diagnosis: Males of the new species differ from those of all congeners by lacking a mating clasper on tibia I (Figs 3A, 12N-T); they are further distinguished from congeneric males, except those of T. pylorus comb. nov., by having a smooth carapace without wart-like hair bases (Fig. 12A-B), a row of dorsal spines on leg and palp femora, a row of 3-7 denticles on their paired leg claws, and by lacking a subdistal embolic notch (Fig. 12H-M). Females are distinguished from those of other species treated here by having wide bands of tiny spinules on coxae I-II (Fig. 13D-E) and a pronounced heel on the retrolateral-distal corner of their coxa IV (Fig. 13C); they additionally differ from congeneric females, except for those of T. pylorus comb. nov., by a vulva with widely spaced receptacles (Fig. 13F-P).

Description: MALE (holotype). Colour in alcohol (darker in living spider; Fig. 2J): Carapace mostly brown, slightly more reddish on pars cephalica; irregular dark patches on pars thoracica (but see Variation) and three dark longitudinal bands (narrowing posteriorly) on pars cephalica; black rings around ALE, AME and PLE (Fig. 12A). Chelicerae, palps and legs mostly brown, except for lighter palpal tibia, leg tarsi, entire metatarsi III-IV and distal part of metatarsi I-II, and except for darker lateral parts of palpal tarsus. Ventral side of prosoma (except for chelicerae) mostly slightly lighter than dorsal side; rastellum and fang claw dark brown. Opisthosoma dorsally dark grey-brown, speckled with small light spots, with two indistinct lighter patches in anterior half; ventral side mostly light greyish brown, except for cream-coloured genital area, booklung covers and spinnerets.

Morphology and measurements: Body 11.99 long. Carapace (Fig. 12A) 4.38 long, 3.64 wide, smooth, without wart-like hair bases. Few short, strong bristles on and in front of ALE, on lateral carapace margins and on coxal elevations of pars thoracica, many bristles in a triangular area anterior of posterior carapace margin; two longitudinal rows of strong bristles running from eye mound to fovea, one pair in the middle distinctly longer and stronger than others. Eight eyes on bipartite mound, with a saddle between ALE and main eye group; entire eye group 0.96 long, 0.98 wide; ALE and AME separated by 0.23. MOQ 0.60 long, 0.69 wide. Eye diameters: AME 0.35, ALE 0.27, PME 0.20, PLE 0.24. Several fine transversal wrinkles to left and right of anterior half of eye mound. Pars cephalica slightly and evenly arced, its posterior zone without a boss, distinctly lower than eye mound in lateral view. Fovea moderately procurved, 0.71 wide, occupying 21% of carapace width at that point. Proximal article of chelicera 1.43 long; ventral groove with seven teeth (1/2 of them small) on promargin and 5/6 teeth (1/2 of them small) on retromargin; fang claw with sharp, straight proventral keel and with serrate retroventral keel; rastellum on long and narrow process, composed of ten short, thick spines and several weaker and more pointed spines. Palpal coxa 1.53 long, 0.91 wide, without spinules. Labium 0.52 long, 0.78 wide, also without spinules. Sternum 2.47 long, 2.11 wide; labio-sternal suture relatively deep, it and sigilla (two pairs, as in all other congeners) of same colour as other parts of sternum (Fig. 12C).

Palp 8.08 long (2.86 + 1.30 + 2.95 + 0.97). Tibia moderately incrassate, 1.17 wide, retrolaterally with a curved band of only 9/11 spines of various lengths in distal half (Fig. 12G). Tarsus short, distally with two short lobes and one strong and one weak dorsal spine. Palpal organ typical for the genus (Fig. 12F-G); apex of embolus with a distinct tooth but without a notch (Figs 12H-I).

Legs 3214. Leg I 16.07 long (4.87 + 2.24 + 3.70 + 3.34 + 1.92); leg II 13.06 long (4.03 + 1.82 + 2.66 + 2.86 + 1.69); leg III 11.37 long (2.86 + 1.69 + 1.79 + 3.08 + 1.95); leg IV 16.67 long (4.22 + 2.18 + 3.77 + 4.29 + 2.21). Leg tarsi with a ventral pseudoscopula: very thin in distal two-thirds to three-fourth of tarsus I, thin in distal five-sixth of tarsus II, much denser and covering almost entire ventral side of tarsi III-IV. Leg I: metatarsus unmodified (Fig. 12N); tibia also unmodified and not incrassate (0.71 wide; tibia of shorter leg II in comparison 0.62 wide), without a mating clasper complex but instead with 2/3 prolateral-distal spines (Fig. 12N-P) and with a well-developed prolateral-distal slit organ (Figs 3A, 12T). All leg tarsi slightly spindle-shaped in their proximal half, cylindrical in distal half.

Spines: Palp: femur d1/2; patella, 0; tibia r9/11; tarsus d2 (one of them weak). Leg I: femur d6; patella v2 (long); tibia p3/4 (2/3 of them distally), r3/4, v7/9; metatarsus p4/5, r4/7, v6/8; tarsus p3, r3. Leg II: femur d5/6; patella v2 (long); tibia v8/9; metatarsus p4, v8; tarsus p4, r2/4. Leg III: femur d5/6; patella d3/4, p13/14; tibia p10, r6, v6/8; metatarsus d8/9, p1/2, r1, v9/10; tarsus p4/5, r3. Leg IV: femur d4/5; patella p11/12; tibia v6/7 (long); metatarsus v9; tarsus p5/7, r1/2. Leg coxa II with a broad longitudinal band of minute spinules (less distinct than in conspecific females); spinules on coxa I barely discernible.

Trichobothria as in males of other species. Paired leg claws with a row of 4-7 denticles on legs I-II, 3-5 on legs III-IV; on legs II-IV subproximal denticle usually larger than others; unpaired leg claws bare.

Opisthosoma oval, 5.42 long, 3.57 wide, mostly covered with short dark hairs, in posterior zone and on ventral surface also with longer hairs. Epiandrous spigots weakly spiniform (see Fig. 12E for more strongly spiniform spigots in male paratype). PMS 0.42 long, carrying one macro-spigot; PLS 1.11 long: proximal article 0.61, with one macro-spigot; median article 0.30, with four macro-spigots; distal article 0.20, with one macro-spigot.

FEMALE (allotype): Colour in alcohol (darker in living spider): Carapace mostly brown, slightly darkened between ALE and main eye group; black pigment around entire ALE and AME and around most of PLE and PME. Dorsal side of chelicerae, palps and legs slightly darker than carapace. Sternum and coxae I-II brown, coxae III-IV lighter; labium, palpal coxae and ventral side of chelicerae reddish brown; fang claws dark brown. Opisthosoma dorsally dark greyish brown, densely speckled with small light spots, with two light median patches in anterior half; genital area, booklung covers and spinnerets light brown, area between posterior booklung covers light greyish brown, posterior half of ventral side cream-coloured.

Morphology and measurements: Body 19.22 long. Carapace 6.46 long, 4.97 wide, smooth, with few very thin but relatively long hairs all over carapace, densest in posterior zone; medium-long bristles in front of ALE and between PME; two pairs of long bristles in anterior half of area between eye mound and fovea; a single very long bristle between AME. Entire eye group 1.27 long, 1.47 wide; ALE and AME separated by 0.60. MOQ 0.55 long, 0.80 wide. Eye diameters: AME 0.28, ALE 0.29, PME 0.22, PLE 0.35. No wrinkles lateral to eye mound. Pars cephalica moderately and evenly arced, its posterior zone at same level as eye mound in lateral view. Fovea distinctly procurved (Fig. 13A), 0.97 wide, occupying 21% of carapace width at that point. Proximal article of chelicera 2.53 long, stronger than in male; ventral groove with 5/6 large plus 1/2 small teeth on promargin and four large plus 1/2 small teeth on retromargin, and with two additional very small teeth between both rows; rastellum on long and narrow process, composed of 16/17 short, thick spines (stronger than in male) and several weaker and more pointed spines. Palpal coxa 2.66 long, 1.49 wide, with about 100 spinules of various sizes spread over almost entire ventral surface, in prolateral half stronger than in retrolateral half, the strongest ones in prolateral-proximal and in prolateral-distal corner (Fig. 13B). Labium 0.97 long, 1.23 wide, carrying two strong spinules. Sternum 3.64 long, 3.25 wide; labio-sternal suture relatively deep, of same colour as indistinct sigilla and as other parts of sternum (Fig. 13B).

Palp 10.53 long (3.51 + 2.21 + 2.34 + 2.47); tarsus slightly spindle-shaped; tibia dorsally with a pronounced, light-coloured subdistal pseudosegmentation.

Legs 3214. Leg I 11.69 long (3.77 + 2.47 + 2.40 + 1.95 + 1.10); leg II 10.62 long (3.64 + 2.27 + 1.92 + 1.69 + 1.10); leg III 10.29 long (2.79 + 2.27 + 1.46 + 2.08 + 1.69); leg IV 13.50 long (3.60 + 2.99 + 2.73 + 2.69 + 1.49). Leg tarsi without pseudoscopula. Leg coxa IV with a pronounced heel on retrolateral-distal corner (Fig. 13C). Spines: Palp: femur p2; patella p1; tibia p20/21, r18/23; tarsus p24, r23/27, v4. Leg I: patella p2/0; tibia p14, r15/16; metatarsus p19/20, r20; tarsus p8, r9, v3/4. Leg II: patella, 0; tibia p7, r4; metatarsus p17/18, r7; tarsus p6, r3, v3/4. Leg III: patella d2, p17/19, r1/3; tibia p18/20, r13/15, v2 (long and weak); metatarsus p11/13, r9/10, v7/8; tarsus r0/1, v6/7. Leg IV: patella p22/24; tibia v3/4 (long and weak); metatarsus v7; tarsus r1, v14/16. No cluster of spinules dorso-distally on tibiae I-II or on palpal tibia. Leg coxa II with a broad longitudinal band of tiny denticles (as thick as nearby bristles but much shorter) in retrolateral half (Fig. 13E); coxa I equally so, but spinules less distinct (Fig. 13D).

Trichobothria as in females of other species. Palpal claw and paired leg claws with only one large subproximal denticle, on some limbs additionally with a small denticle; unpaired leg claws bare.

Opisthosoma oval, 9.42 long, 6.30 wide; with a mixture of short and medium-long dark hairs dorsally and ventrally. PMS 0.77 long, with one macro-spigot; PLS 1.69 long: proximal article 0.85, with three macro-spigots; median article 0.53, with 5/6 macro-spigots; distal article 0.31, with one macro-spigot.

Vulva (of paratypes see Fig. 13F-P): Receptacles relatively long and widely separated from each other; receptacular heads not much wider than receptacular stalks; essentially indistinguishable from vulva of T. pylorus comb. nov. (Fig. 5E-O).

Variation: In males (n = 7) the carapace length ranges 4.42-4.94, the corresponding width 3.44-4.09. The largest conspecific female (n = 12) has a 7.24 long and 5.97 wide carapace. The smallest and the largest male, as well as the largest female examined are all from the type locality. The subdistal embolic tooth is distinct in all males from the type locality (Fig. 12H-I), indistinct (Fig. 12J-K) to absent (Fig. 12L-M) in males from the other two localities; all males lack a subdistal embolic notch. Tibia I and metatarsus I are unmodified in all males (Fig. 12N-S). Instead of a mating clasper there are 1-3 strong spines prolaterally-distally on tibia I of all males: only one spine on both sides in the two males from Ban Laem Pho, 2-3 spines in males from the other two localities (three spines on both sides in the male from Khao Phra - Bang Khram). All males have a row of dorsal spines on the femora of legs and palps; in males from the type locality these spines are slightly more pronounced than in males from the other two localities. The pseudoscopula in males varies in expanse only on tarsus I, covering the distal two-thirds to four-fifths of the ventral side; on other legs there is no variation. All males have a row of 3-7 denticles on their paired tarsal claws. Females possess 1-3 large plus 0-2 small spinules on their labium; most males have no labial spinules, only one male from Ban Laem Pho has two anterior bristles with incrassate bases (i.e. spinules with a filiform apex, these are also present on palpal coxae; Fig. 12D). The AME are clearly larger than the PLE in all males examined; in all females they are distinctly smaller. All females carry a single, very long bristle between their AME. All females have a wide band of tiny spinules on coxae I-II; in females from the type locality these bands are slightly wider than in females from other localities. In all males examined the PMS carry one macro-spigot, in conspecific females 0-2 macro-spigots (one female from Ban Laem Pho with none on one side, one on the other; two females from the type locality and from Khao Phra - Bang Khram with two on both sides). Males have one macro-spigot on the proximal article of the PLS, 3-5 on its median article, and mostly one (one male from the type locality with none on one side) on its distal article. Females have 1-4 macro-spigots on the proximal article of the PLS, 4-8 on its median article, and 1-2 on its distal article. Variation in vulva morphology is shown in Fig. 13F-P.

Distribution: This species is known from three localities in southern Thailand: the type locality on the east coast, the other two localities further south, on the west coast (Fig. 1A). The latter two localities are only a few kilometres away from the mainland locality of T. insularis sp. nov.

Biology: Habitat: All spiders were collected from shaded soil banks. Two localities are near the coast: the type locality is an overgrown road side at the foot of a hill covered with the remnant patch of a primary evergreen forest, about 100 m away from the coast; at Ban Laem Pho the spiders were found right above the rocky shore (Fig. 2M). At Khao Phra - Bang Khram spiders were found on the side of a rural road near a primary forest several kilometres away from the coast. Burrow structure: All burrows were more or less straight and unbranched, up to 8.5 cm long, closed by a moderately thick door, and equipped with a soil pellet about 2 cm below the entrance. In males (all matured in captivity) doors were 0.8-0.9 cm long and 1.0-1.1 cm wide. The largest burrow (of a female) had a door 1.6 cm long and 1.9 cm wide. Some burrows at the type locality (but not elsewhere) had a small knob (like a door knob) in the centre of the outer side of their door. The largest soil pellet was 1.4 cm long, 1.4 cm wide and 1.9 cm high. Soil pellets from all three localities had the same overall shape as soil pellets of T. pylorus comb. nov. (see Fig. 2B-C), but are distinguished from them by a more or less wide, circular depression in the upper part of the frontal side (see Fig. 2D-G). This depression was usually uncovered, except for a single case in which a fine sheet of silk, with a central hole, was spun over the depression. Phenology: Males matured in captivity between early June and mid-October. One male matured (on 11.VI.) only eight days after being captured; the male that matured in mid-October was collected four months earlier. The presence of an empty egg case in the field at the beginning of June, but none in mid-June and in mid-September, suggests that mating starts in June and eggs are laid after mid-September; the spiderlings hatch and leave the burrow of the mother before June.

Egg cases: At the beginning of June an old empty egg case was found in the burrow of a female at Khao Phra - Bang Khram. It was 2.5 cm long, 1.5 cm wide and 0.7 cm high, of the same shape and colouration as in T. birmanicus sp. nov. (Fig. 2K-L).

Holotype: MHNG-ARTO-29003, sample TH-07/11; male (matured end of IV.2008); Thailand, Phang Nga Prov., Ko Yao Distr., Ko Yao Yai, west of Ban Hin Kong, 8°02'N, 98°35'E, 60 m; 18.VII.2007; leg. P.J. Schwendinger.

Paratypes: MHNG-ARTO-29004-29006, sample TH-07/11; 3 males (matured 9.IV.2009; 8.VII.2009; 3.IV.2010); collected together with the holotype. – MHNG-ARTO-29007-29010, sample TH-07/11; 4 females; collected together with the holotype. – THNHM, sample TH-06/10; 1 male (matured 19.IV.2007); from the type locality; 25.IX.2006. – MHNG-ARTO-29011-29014; 4 females (including allotype MHNG-ARTO-29011; same data as for previous specimen. – MHNG-ARTO-29015, sample TH-06/08; 1 male (matured beginning of IV.2007); Thailand, Phang Nga Prov., Ko Yao Distr., Ko Yao Noi, 8°09'N, 98°38'E, 60 m; 22.IX.2006. – MHNGARTO-29016, sample TH-09/06; 1 male (matured 18.III.2010); Thailand, Krabi Prov. & Distr., Thab Khaek - Hang Nak Hill Nature Trail, 80 m; 6.VI.2009. – MHNG-ARTO-29017, sample TH-08/07; 1 female; Thailand, Krabi Prov. & Distr., Thab Khaek - Hang Nak Hill Nature Trail, 8°06'N, 98°45'E, 50-80 m; 13./19. VI.2008. All specimens leg. P.J. Schwendinger.

Other material examined: MHNG-ARTO-29037-29042, sample IND-08/02; 6 males (matured 29.X.2009; 2.XI.2009; 10.XI.2009; 18.XI.2009; 5.I.2010; 10.I.2010); Indonesia, Bangka Belitung Island Prov., Pulau Belitung, Gunung Tajam, near Gurok Beraye W.F., 2°47'S, 107°52'E, 150 m; 20.IX.2008. – MHNG-ARTO-29043-29047, sample IND-08/02; 5 females; same locality and date as for previous specimens. – MHNG; 1 juvenile male; same data. All specimens leg. P.J. Schwendinger.

Etymology: The epithet is a Latin adjective (insularis = of or from an island) that refers to the occurrence of this species on islands.

Diagnosis: Similar to T. tenuis sp. nov., different in larger body size. Males distinguished from those of T. tenuis sp. nov. by wart-like hair bases on pars cephalica of carapace relatively smaller and more widely spaced (Figs 14A, 15A cf. Fig. 8A); hair bases on tibiae less distinctly wart-like; a prolateral distal spine present on femora I-II of some males (absent in all T. tenuis sp. nov. males); tibia I with a small prodorsal-distal process near mating clasper (Figs 3E-F, 14H-J, 15B-D; absent in T. tenuis sp. nov., Figs 3C, 8H-J); prolateral knee of metatarsus I less pronounced (Figs 14G, 15E cf. Fig. 8G). Vulvae of females different from vulva of holotype of T. crassus comb. nov. by having distinctly smaller receptacular heads (Figs 16E-M, 17 cf. Fig. 3H), and from vulvae of T. pylorus comb. nov. and T. inermis sp. nov. by receptacles closer to each other (Figs 16E-M, 17 cf. Figs 5E-O and 13F-P), but indistinguishable from females of other species treated here.

Description: MALE (holotype). Colour in alcohol (darker in living spider): Carapace reddish brown, with darkened area around eye mound continuing as two dark parallel, posteriorly narrowing bands back to fovea; areas between ALE and other eyes almost black (Fig. 14A). Chelicerae, palps and legs mostly brown, except for slightly darker femur to tibia I and proximal three-fourth of metatarsus I, and except for light brown distal half of metatarsi II-IV and entire tarsi II-IV. Ventral side of prosoma (including limbs) slightly lighter than dorsal side. Opisthosoma dorsally dark grey-brown, speckled with light spots, with two faint lighter patches in anterior half; ventrally uniformly light brown.

Morphology and measurements: Body 12.92 long. Carapace 4.71 long, 4.35 wide, covered with relatively small wart-like hair bases (Fig. 14A); corresponding hairs mostly short and weak, longest and adpressed halfway between eye mound and fovea. Eight eyes on bipartite mound, with a saddle between ALE and main eye group; entire eye group 0.83 long, 0.90 wide; ALE and AME separated by 0.22. MOQ 0.42 long, 0.55 wide. Eye diameters: AME 0.26, ALE 0.24, PME 0.15, PLE 0.25. Several fine transversal wrinkles to left and right of anterior half of eye mound. Posterior zone of pars cephalica with a low boss, at same level as eye mound in lateral view. Fovea slightly procurved, 0.75 wide, occupying 18% of carapace width at that point. Proximal article of chelicera 1.82 long; ventral groove with 5/6 teeth on promargin and five teeth (plus two small ones one side) on retromargin; fang claw with sharp, straight proventral keel and with serrate retroventral keel; rastellum on long and narrow process, composed of 8/9 short, thick spines and several weaker and more pointed spines. Palpal coxa 1.69 long, 1.04 wide, with about 30 very short spinules, most of them not thicker than nearby bristles. Labium 0.58 long, 0.84 wide, with three weak spinules (not thicker than nearby bristles). Sternum 2.60 long, 2.34 wide; labio-sternal suture shallow and inconspicuous, it and sigilla of same colour as other parts of sternum (Fig. 14B).

Palp 7.68 long (2.67 + 1.43 + 2.44 + 1.14). Tibia moderately incrassate, 1.14 wide, retrolaterally with a curved band of 30/31 spines of various lengths in distal half (Fig. 14D). Tarsus short, distally with two short lobes and one dorsal spine. Palpal organ typical for the genus (Fig. 14C-D); apex of embolus with a distinct tooth proximal to a relatively deep notch (Figs 14E-F). Legs 3214. Leg I 14.48 long (4.55 + 2.37 + 3.02 + 3.21 + 1.33); leg II 12.70 long (4.03 + 1.95 + 2.63 + 2.76 + 1.33); leg III 10.88 long (3.02 + 1.88 + 1.82 + 2.73 + 1.43); leg IV 15.73 long (4.45 + 2.31 + 3.51 + 3.77 + 1.69). Leg tarsi with a ventral pseudoscopula: in distal half of tarsus I, in distal four-fifth of tarsus II, in distal two thirds to three-fourths of tarsus III, essentially absent from tarsus IV (only a few scattered scopuliform hairs in distal four-fifths). Leg I: metatarsus slightly bent outward, on prolateral side with an indistinct knee below midpoint (Fig. 14G); tibia moderately incrassate (1.17 wide; tibia II in comparison only 0.78 wide), carrying a prolateral-distal mating clasper complex composed of: 1) a stout distal spur carrying a wide, distad-directed megaspine; 2) a smaller subdistal spur carrying a short, wide megaspine; 3) a small, dark, wart-like tubercle with same surface texture as nearby cuticle; 4) a small, conical prodorsal-distal process (Figs 3E, 14H-J). Leg tarsus II indistinctly spindle-shaped. Slightly enlarged hair bases (not as much as in males of T. tenuis sp. nov.) on tibiae of palps and legs, but not on other articles.

Spines: Palp: femur p1; patella, 0; tibia r30/31; tarsus d1. Leg I: patella v3; tibia p2 (megaspines) + 1/4, v9/11; metatarsus p5/6, r8; tarsus p3/4, r3. Leg II: patella v3/4 (weaker than on patella I); tibia p3/5, r4/5, v8; metatarsus p6/7, r7, v2; tarsus p3, r5/7. Leg III: patella d3, p10/11, v1/2; tibia p8/9, r3, v6/9; metatarsus d9/10, p3, v10; tarsus p3, r3. Leg IV: femur p1 (distally); patella p15/16; tibia v7/8; metatarsus v7/8; tarsus p3, v8/9. Trichobothria as in males of other species. Paired leg claws with a large subproximal denticle, on anterior legs often additionally with a small denticle; unpaired leg claws bare.

Opisthosoma oval, 5.26 long, 3.77 wide, mostly covered with short dark hairs, in posterior zone additionally with longer hairs. PMS 0.42 long, without macro-spigots; PLS 1.29 long: proximal article 0.65, without macro-spigots; median article 0.33, with five macro-spigots; distal article 0.31, with one macro-spigot.

FEMALE (allotype): Colour in alcohol (darker in living spider): Dorsal side of prosoma mostly light orange-brown, except for slightly darker carapace and chelicerae; eye mound mostly darkened, black between eyes (Fig. 16A). Ventral side of prosoma slightly lighter than dorsal side; on chelicerae orange-coloured, on labium and sternum light reddish brown (Fig. 16B); rastellum and fang claw dark brown. Opisthosoma dorsally dark greyish brown, densely speckled with small light spots, with two light median patches in anterior half; ventrally mostly cream-coloured, except for darker epigynal area (Fig. 16C).

Morphology and measurements: Body 17.14 long. Carapace 5.94 long, 5.32 wide, smooth, with few short hairs on lateral margins and on both sides of eyes; bristles in front of ALE and of AME; longer bristles only in anterior part of area between eye mound and fovea, posterior-most pair very long. Entire eye group 1.05 long, 1.14 wide; ALE and AME separated by 0.36. MOQ 0.47 long, 0.61 wide. Eye diameters: AME 0.24, ALE 0.26, PME 0.19, PLE 0.28. No wrinkles lateral to eye mound. Posterior zone of pars cephalica with a pronounced boss, slightly higher than eye mound in lateral view. Fovea strongly procurved (Fig. 16A); angles between posterior and lateral parts less distinct than in females of other congeners treated here, 1.23 wide, occupying 24% of carapace width at that point. Proximal article of chelicera 2.92 long, stronger than in male; ventral groove with five strong teeth on pro- and retromargin; rastellum on long and narrow process, composed of 17/20 short, thick spines (stronger than in male) and several weaker and more pointed spines. Palpal coxa 2.27 long, 1.40 wide, with about 70 spinules of various sizes spread over almost entire ventral surface, the strongest ones in prolateral half. Labium 1.04 long, 1.23 wide, carrying two strong spinules. Sternum 3.44 long, 3.05 wide; labio-sternal suture relatively long and deep, of same colour as indistinct sigilla and other parts of sternum (Fig. 16B). Palp 9.60 long (3.18 + 2.14 + 2.14 + 2.14); tarsus slightly spindle-shaped; tibia dorsally with a weakly pronounced subdistal pseudosegmentation.

Legs 2314. Leg I 10.97 long (3.51 + 2.47 + 2.27 + 1.75 + 0.97); leg II 9.81 long (2.99 + 2.21 + 1.95 + 1.62 + 1.04); leg III 10.33 long (2.79 + 2.34 + 1.62 + 2.18 + 1.40); leg IV 14.00 long (3.90 + 2.79 + 2.89 + 2.86 + 1.56). Leg tarsi without pseudoscopula; metatarsus I indistinctly, metatarsus II very indistinctly spindle-shaped.

Spines: Palp: femur p1; patella p1, r1 (weak); tibia p20, r21/23; tarsus p18/21, r21, v2. Leg I: patella, 0; tibia p16, r22/24; metatarsus p14/15, r19/20; tarsus p6/8, r7/8, v3. Leg II: patella, 0; tibia p9, r13/16; metatarsus p13, r9/12; tarsus p7/8, r4, v3. Leg III: patella d3, p13/14; tibia p11/12, r3/4, v2 (long and weak); metatarsus d11/12, v4; tarsus p1/2, v5/6. Leg IV: patella p18/20; tibia v4 (long and weak); metatarsus v8; tarsus r1, v12/13. A cluster of 10/11 spinules dorso-distally on leg tibia I; 16/17 spicules on tibia II; a dorso-distal cluster of four spinules on palpal tibia.

Trichobothria as in females of other species. Paired leg claws and unpaired palpal claw all with only one large subproximal denticle; unpaired leg claws bare.

Opisthosoma oval, 7.92 long, 5.65 wide; with a mixture of short and medium-long dark hairs dorsally, the longest ones in posterior zone; ventrally with many short hairs and a few long bristles in genital area. PMS 0.68 long, without macro-spigots; PLS 1.65 long: proximal article 0.88, without macro-spigots; median article 0.39, with 6/7 macro-spigots; distal article 0.38, with one macro-spigot.

Vulva (of paratypes see Fig. 16E-M, of females from Belitung Island see Fig. 17): Receptacles relatively long and close to each other; receptacular heads not much wider than receptacular stalks; essentially indistinguishable from vulvae of T. birmanicus sp. nov. (Fig. 7F-P), T. tenuis sp. nov. (Fig. 9D-N) and T. sayamensis sp. nov. (Fig. 11F-O).

Variation: In males (n = 13) the carapace length ranges 4.48-5.45, the corresponding width is 4.09-5.06. The largest conspecific female (from the type locality; out of 14 females examined) has a 6.70 long and 5.71 wide carapace; in the smallest reproductive female (from Belitung Island) it is only 3.96 and 3.38, respectively. There is a wide overlap in measurements of specimens from localities in Thailand and from the locality on Belitung Island. The subdistal embolic tooth and notch are distinct in all males examined (Figs 14E-F, 15H-I). In most males from Thailand the metatarsus I has a weak but distinct prolateral knee (Fig. 14G); in one male from Thailand (from Ko Yao Noi) and in all males from Belitung Island that knee is indistinct (Fig. 15E). The subdistal coupling spur carries a short megaspine that ranges in shape from widely arced to triangular, the latter with a widely to acutely pointed apex. In addition to two coupling spurs with megaspines and a wart-like tubercle without a shiny black cap, all males examined also have a small conical prodorsal-distal process on tibia I (Figs 3E-F, 14H-J, 15B-D). The expanse of the ventral pseudoscopula on leg tarsi I-III of males is quite variable: covering a fourth to half of tarsus I; half to four-fifths of tarsus II; two-fifths to three-fifths of tarsus III; all males lack a pseudoscopula on tarsus IV. Five males from Thailand have one short prolateral spine distally on femur I, all other males have none. Females possess 2-4 large plus 0-4 small spinules on their labium; males have 0-4 weak labial spinules. The AME are equally large to distinctly larger than the PLE (Fig. 14A) in males from Thailand, slightly smaller to slightly larger (Fig. 15A) in males from Belitung Island; in all females examined the AME are slightly to distinctly smaller than the PLE (Fig. 16A). The PMS and the proximal article of the PLS always lack macro-spigots; the median article of the PLS has 3-11 (mostly 4-7) macro-spigots; the distal PLS article always has a single macro-spigot. There is no clear gap in the genital morphology of females from Thailand and Indonesia: in most females from Belitung Island the receptacles are relatively shorter (Fig. 17D-L) than in females from Thailand (Fig. 16E-M), but not so in specimen MHNGARTO-29045 (Fig. 17A-C).

Distribution: This species is known from three localities on the west coast of southern Thailand (two on islands in the Phang Nga Bay and one on the nearby mainland; Fig. 1A), as well as from a locality on the Indonesian island of Belitung (Fig. 1B). The Thai and Indonesian localities are separated by about 1500 km (see also Discussion - The T. insularis sp. nov. disjunction). The mainland locality in Thailand is only a few kilometres away from one of the localities of T. inermis sp. nov.

Biology: Habitat: Spiders were collected from earth banks on the sides of a dirt road, of a footpath and of a stream, all in shady places within primary forests or rubber tree plantations.

Burrow structure: All burrows inspected were straight and unbranched, up to five centimetres long, without a soil pellet, closed by a moderately thick door. In males (all matured in captivity) doors were 0.75-0.95 cm long and 0.85-1.1 cm wide. The largest burrow (of a female) had a door 1.3 cm long and 1.5 cm wide.

Phenology: Males from Thailand matured mostly in April, one male in early July; males from Belitung Island matured between late October and early January. In Thailand two egg cases containing second and third instar spiderlings were found in the field in mid-July, and one egg case containing third instar spiderlings in late September; a fourth female from Thailand built an egg case undetected in captivity and third instar spiderlings emerged from it in early January. On Belitung Island two egg cases containing second and third instar spiderlings were found in the field in late September. The populations in Thailand and in Indonesia have different phenologies. Egg cases: These were 1.1-1.7 cm long, 0.8-1.1 cm wide and 0.5-0.8 cm high, of the same shape and colour as in T. birmanicus sp. nov. (Fig. 2K-L). They contained 26, 61, 69, 91, 104 and 129 spiderlings.

Juveniles: As in other congeneric species threated here, second instar spiderlings are pale, without bristles or spines. They move about clumsily and remain in the egg case. Third instar juveniles are well pigmented, furnished with bristles and weak spines, with the ALE on the anterior carapace margin (Fig. 16D), but not as close to each other as in larger spiders. These spiderlings are agile, remain in the egg case for a few days and then emerge from it to disperse and build their own tiny burrows. No attempts to perform ballooning have been observed.

Remarks: Three females (MHNG-ARTO-29048-29050) were collected by P.J. Schwendinger on Ko Chang [9°49'N, 98°26'E; Thailand, Ranong Prov. (Fig. 1A); different from the larger and better-known Ko Chang in Trat Prov.] which cannot be unequivocally placed in any of the species treated above. The corresponding male is still unknown. Most Titanidiops species in South-east Asia (except for T. pylorus comb. nov. and T. inermis sp. nov., to which these three females clearly do not belong; they also do not construct soil pellets) are difficult to distinguish on the basis of female specimens only. Genital morphology (not illustrated here) and body size indicate that these three females likely belong to T. sayamensis sp. nov.

The SMF houses a single male (SMF 85a; partly desiccated, with three legs detached) which is labelled “Batu-Höhle, leg. Klingel, 15.XI.1961 oder Penang Insel, leg. Klingel, 1.X.1961”. The specimen was found in the collection of Hans Klingel (1932-2019), in a vial together with liphistiid spiders, labelled as originating from either the Batu Caves or from Penang Island. Surprisingly the specimen has a short proximal row of small retromarginal teeth on its cheliceral groove and therefore it either belongs to Idiops (occurring in the Neotropics) or to Ctenolophus (occurring in South Africa), not to Titanidiops. This specimen differs from all Idiops males illustrated in Yamamoto (2013) and in Fonseca-Ferreira et al. (2021) by possessing an unusually long, sigmoid distal coupling spur and a strongly reduced (to a small tubercle without an apical spine) subdistal coupling spur, and by having the prolateral knee of metatarsus I developed as a transversal ridge instead of a cone or mound. Therefore this male presumably belongs to an undescribed species, and we strongly doubt that the ambiguous locality data are correct. If correct, this would be the only known locality of an idiopid species in Peninsular Malaysia, which would not be a big surprise considering the presence of a population of T. insularis sp. nov. on Belitung Island, Indonesia. It would also be the only confirmed occurrence of the genus Idiops or of the genus Ctenolophus in Asia, and that would be a big surprise. However, we strongly believe that this specimen was placed in the wrong vial and was actually collected in the Neotropics, or, more likely, in Africa where Klingel has carried out extensive field work on mammals.