Liphistius birmanicus Thorell 1897
Creators: name: Schwendinger, Peter J.
name: Huber, Siegfried
name: Lehmann-Graber, Christina
name: Ono, Hirotsugu
name: Aung, Mu Mu
name: Hongpadharakiree, Komsan
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Liphistiidae
Liphistius
Liphistius birmanicus

description: The birmanicus -group
When this species group was defined by Schwendinger in 1998 it contained only three species (L. birmanicus, L. lordae and L. lahu). As four additional species were added later and five are newly described here, a refined diagnosis and description of this group is necessary and given in the following.
Diagnosis: Essentially distinguished by the following four characters: (1) Contrategular area below (proximal of) tegulum completely unpigmented (e.g. Figs 8F, H-I, 13F-G, 21K, M, 23L-M). In males of all other species groups this area is more or less extensively pigmented. (2) A more or less distinct (least so in L. platnicki sp. nov., Fig. 23F) proximal ledge on retrodorsal side of contrategulum (e.g. Fig. 4 A-C, G). A similar ledge is present only in L. desultor Schiödte, 1849, but there it is situated medially, not proximally, and its most prominent part is on the proventral side, not on the retroventral side (Schwendinger et al., 2019: fig. 5F-G, I-K). (3) Embolus proper narrowly divided, with a longer sclerotised part and a distinctly shorter membranous part lying close to each other (e.g. Fig. 4 C-D, G). This is also found in the bristowei - (e.g. Schwendinger, 1990: figs 57-59), malayanus - (e.g. Schwendinger, 2017: fig. 3B, D, F, H), tioman -, linang - and batuensis -group, whereas in the trang - group the embolus is widely divided, with both parts clearly apart from each other (Schwendinger, 1990: figs 60-62; Schwendinger, 2017: fig. 3A, C, E, G). (4) Poreplate with a pair of more or less developed (least so in L. nabang and L. cupreus sp. nov., Yu et al., 2021: fig. 4 and Fig. 22) anterior lobes (e.g. Fig. 5). The females of several species in the malayanus -, tioman -, linang - and batuensis -group also have pronounced anterior lobes on their poreplates, but these co-occur with either a very large receptacular cluster, a very large CDO or a reduced sclerotisation of the posterior part of the poreplate and/or of the posterior stalk (see various illustrations in Schwendinger, 2017).
Additions to description: Medium-sized to very large species (CL of males 4.92-12.67, CW 4.56-11.47). All males and the females of most species with a brown to almost black body colouration, often with annulated legs (Figs 2, 3 A-D); only in L. birmanicus and L. hpruso females with yellow or orange-coloured areas on carapace and proximal portions of legs and palps (Fig. 3 E-I). Males with medium-sized tibial apophysis, triangular in ventral view, usually not much set back from distal margin of palpal tibia (e.g. Fig. 6K, N; except in L. tung sp. nov., Fig. 8B), carrying four long tapering apical megaspines (e.g. Fig. 4F). Paracymbium rather short, moderately deep, with indistinctly conical, almost plane distal side (e.g. 4H-J), or with distinctly conical distal side (only in L. cupreus sp. nov., L. platnicki sp. nov. and L. nabang, Figs 21A, 23A, Yu et al., 2021: fig. 3D-F), and with (e.g. Fig. 6L) or without (e.g. 10A) a retrolateralproximal heel; the latter widely (e.g. Figs 4 H-I, 15G) or narrowly rounded (e.g. Figs 6L, 19F), in L. lordae heel protruding proximally (Fig. 17G), in all other cases retrolaterally (e.g. Fig. 6J, L-N); cumulus not or only indistinctly elevated (e.g. Fig. 4 H-J), or distinctly elevated (only in L. cupreus sp. nov., L. platnicki sp. nov. and L. nabang, Figs 21B, 23 A-B, Yu et al., 2021: fig. 3D-F), carrying several long, strong bristles. Ventral side of palpal tarsus with a distinct subdistal suture (Figs 21A, 23A), with a subdistal trench or without any depression there; distal margin of palpal tarsus widely but shallowly invaginated (e.g. Fig. 4G). Subtegulum with (e.g. Fig. 10A, G) or without (e.g. Fig. 21A, K, M) a small apophysis, never with a large one. Tegulum well-developed and wide; its distal margin not elevated in most species (e.g. Fig. 8 F-G), only in L. nabang and L. platnicki sp. nov. distinctly elevated into a short wide keel (Yu et al., 2021: fig. 3A-B, D-E and Fig. 23 I- M); proximal margin of tegulum with a wide, finely to coarsely dentate edge, in most species more or less bent and overhanging the unpigmented membranous contrategular area below it (e.g. Fig. 6F) or adpressed to it (e.g. Fig. 10B), only in L. platnicki sp. nov. straight and strongly salient (Fig. 23M). Pigmented bridge between tegulum and contrategulum on retrodorsal side of palpal organ well developed. Contrategulum carrying a medium-sized, more or less conical proventral process with a rounded (e.g. Fig. 4 A-C) or widely truncate apex (Fig. 17A, C), in most species at a roughly 45-90° angle to the axis of the palpal organ (e.g. Fig. 4G), in L. birmanicus and L. pinlaung distaddirected, almost parallel to axis of palpal organ (Figs 13D, F, 15C, E); distal edge of contrategulum narrow (e.g. Fig. 21E) to wide (e.g. Fig. 19A), its prolateral part with a more (e.g. Fig. 6I) or less (e.g. Fig. 4G) elevated keel, its prodorsal part evenly arched (e.g. 4A-C), or with an angular (in L. cupreus sp. nov., Fig. 21A, E-F, H-I) or arched protrusion (in L. nabang, Yu et al., 2021: fig. 3B); retrodorsal side of contrategulum with a pronounced (e.g. Fig. 4 A-C, G) or rather small (only in L. cupreus sp. nov., L. platnicki sp. nov. and L. nabang, Figs 21 E-F, H-I, N, 23F, H-I, Yu et al., 2021: fig. 3A-B) proximal ledge; contrategular area proximal of tegulum completely unpigmented (e.g. Fig. 8 F-I). Para-embolic plate short in most species, with (e.g. Fig. 6 F-H) or without (e.g. Fig. 4 C-D) a slight indentation between it and keel-shaped retroventral edge of embolus complex; in L. tung sp. nov. and L. ferox sp. nov. para-embolic plate long and tounge-shaped (Figs 8A, I-H, 10A-D). Retrolateral margin of embolus complex unpigmented and overhanging distal margin of tegulum (e.g. Fig. 8 F-G); prolateral margin of embolus complex with a lobate protrusion in L. pyinoolwin (Fig. 19 A-B), unmodified in all other species of the group. Embolus proper narrowly divided; its sclerotised part strengthened by 2-6 ribs reaching apex; only in L. ferox sp. nov. with 2 ribs, one of them carrying a triangular distal protrusion (Fig. 10 E-H); in distal view retrolateral side of sclerotised embolus part rounded and concave in most species, only in L. ferox sp. nov. angular (Fig. 10H); membranous part of embolus proper distinctly shorter than sclerotised part, at its base a more or less strongly pigmented area with longitudinal or inclined wrinkles (e.g. Figs 6I, 13D). Females with lateral folds of vulval plate well developed, glabrous or carrying few to several hairs; no hairs in genital atrium, and only exceptionally a single hair on poreplate or on posterior stalk (Figs 16I, 18E). Poreplates mostly wider than long (with only very few exceptions, e.g. Fig. 22N), with a more or less strongly invaginated anterior margin (slightly arched only in one documented female of L. nabang, Yu et al. 2021: fig. 4E-F) carrying a pair of anterior lobes ranging from large and wide (in L. lordae, Fig. 18) to small and reduced to 1-2 clusters of vesicles (in L. cupre us sp. nov., Fig. 22 and L. nabang, Yu et al., 2021: fig. 4); lateral margins of poreplate ventrally with (e.g. Fig. 7) or without small, knob-shaped anterolateral processes (e.g. Fig. 5); CDO mostly small (e.g. Fig. 5A), slightly larger only in L. tung sp. nov. (Fig. 9A, C, E), distinctly larger only in juveniles (Fig. 9G), mostly rounded (e.g. Fig. 5A, D), rarely slit-like (Fig. 14D); receptacular cluster always racemose (never digitiform as in some trang -group species), moderately large, only in a few females slightly surpassing anterior margin of poreplate (e.g. Figs 5 A-B, 18D, G-H). Poreplate and posterior stalk always fully sclerotised and connected to each other. The latter ranging from very short (e.g. Fig. 22K) to quite long (e.g. Fig. 9C and Aung et al., 2019: fig. 3B-E), and from much narrower than poreplate (e.g. Fig. 20) to distinctly wider than poreplate (e.g. Fig. 24D and Yu et al., 2021: fig. 4C-F), from widely eliptically (e.g. Fig. 9A) to quadrangular (e.g. Fig. 14B) and axe-blade-shaped (e.g. Fig. 16A), with a short and indistinct (e.g. Figs 22, 24) to long and
pronounced (e.g. Fig. 20 F-G) constriction in its anterior part.
Species included (n = 12): Liphistius birmanicus Thorell, 1897 (Myanmar), L. cupreus sp. nov. (Myanmar), L. ferox sp. nov. (Myanmar), L. hpruso Aung et al., 2019 (Myanmar), L. lahu Schwendinger, 1998 (Thailand), L. lordae Platnick & Sedgwick, 1984 (Myanmar), L. metopiae sp. nov. (Thailand), L. nabang Yu et al., 2021 (China), L. pinlaung Aung et al., 2019 (Myanmar), L. platnicki sp. nov. (Myanmar), L. pyinoolwin Xu et al., 2021 (Myanmar), L. tung sp. nov. (Myanmar).
Distribution: All species known so far occur in the mountainous area that lies roughly between the Ayeyarwady (= Irrawaddy) River in the west, the Mekong River in the east and the Thai-Burmese border in the south (Fig. 1). At least two of these species (L. lahu and L. ferox sp. nov.) occur together with or very close to species of the bristowei -group.
Key to the species:
1 Males (unknown for L. hpruso) ............................................................................................................................ 2
- Females................................................................................................................................................................ 12
2(1) Proventral process of contrategulum strongly distad-directed, almost parallel to axis of palpal organ (Figs 13D, F, 15C) .................................................................................................................................................................. 3
- Proventral process of contrategulum inclined from axis of palpal organ at an angle of roughly 45-90° (Figs 4G, 6I, 8I, 10F, 17E, 19C, 21N, 23H) ......................................................................................................................... 4
3(2) Large spiders (CL and CW of males 7.79-9.30 and 7.29-8.48, respectively); paracymbium without retrolateralproximal heel (Fig. 13H) ............................................................................................... L. birmanicus (Myanmar)
- Medium-sized spiders (CL and CW of males 4.92-6.27 and 4.56-5.40, respectively); paracymbium with retrolateral-proximal heel (Fig. 15G) ........................................................................................... L. pinlaung (Myanmar)
4(2) Para-embolic plate much longer than retroventral edge of embolus complex (Figs 8A, H-I, 10A-D ................. 5
- Para-embolic plate as long as or only slightly longer than retroventral edge of embolus complex (Figs 4D, 6F, 13E, 15D, 17D, 19D, 21A, 23A) .......................................................................................................................... 6
5(4) Medium-sized spiders (CL and CW of males 6.30-6.70 and 5.70-6.26, respectively); sclerotised part of embolus proper strengthened by 3 longitudinal ribs reaching the apex, none of them with an angular distal protrusion (Fig. 8A, C-D, F-I); proximal edge of tegulum salient, distinctly protruding from surface of palpal organ (Fig. 8 H-J); tibial apophysis distinctly set back from anterior margin of tibia (Fig. 8B) ................ L. tung sp. nov. (Thailand)
- Very large spiders (CL and CW of males 11.47-12.67 and 10.45-11.47, respectively); sclerotised part of embolus proper strengthened by only 2 longitudinal ribs reaching the apex, one of them carrying an angular distal protrusion (Fig. 10 E-H); proximal edge of tegulum adpressed to surface of palpal organ (Fig. 10B); tibial apophysis only slightly set back from anterior margin of tibia (Fig. 10J) ................................. L. ferox sp. nov. (Myanmar)
6(4) Cumulus distinctly elevated (Figs 21B, 23B, Yu et al., 2021: fig. 3D-F); paracymbium with distinctly conical distal side (21A, 23A, Yu et al., 2021: fig. 3D-F); proximal ledge on retrodorsal side of contrategulum indistinct or small (Figs 21 E-F, H-I, L-N, 23F, H-I) ............................................................................................................ 7
- Cumulus not or only slightly elevated (Figs 4 H-J, 6J, L-N, 17G, 19E-F); paracymbium with indistinctly conical, almost plane distal side (Figs 4 H-J, 6J, L-N, 17G, 19E-F); proximal ledge on retrodorsal side of contrategulum pronounced (Figs 4 A-C, 6A-D, 17A, C, 19A) ..................................................................................................... 9
7(6) Distal edge of contrategulum evenly rounded, without a prodorsal protrusion in distal view (Fig. 23 E-F); distal margin of tegulum distinctly elevated, developed as a short and wide keel (Fig. 23 I-M); paracymbium without a retrolateral-proximal heel (Fig. 23A) ................................................................... L. platnicki sp. nov. (Myanmar)
- Distal edge of contrategulum with an angular or arched prodorsal protrusion in distal view (Fig. 21A, E-F, H-I, L, Yu et al., 2021: fig. 3B); distal margin of tegulum distinctly, indistinctly or not elevated (Fig. 21 K, M, Yu et al., 2021: fig. 3A-B, D-E); paracymbium with or without a retrolateral-proximal heel (Yu et al., 2021: fig. 3E, Fig. 21A) ...................................................................................................................................................................... 8
8(7) Distal edge of contrategulum with an angular prodorsal protrusion (Fig. 21A, E-F, H-I, L) and with a narrowly rounded dorsal apex (Fig. 21 E-G); distal edge of tegulum not or only indistinctly elevated (Fig. 21K, M); paracymbium without a retrolateral-proximal heel (Fig. 21A) .................................... L. cupreus sp. nov. (Myanmar)
- Distal edge of contrategulum with an arched prodorsal protrusion and with a pointed dorsal apex (Yu et al., 2021: fig. 3B); distal edge of tegulum distinctly elevated, developed as a short, wide keel (Yu et al., 2021: fig. 3A-B, D-E); paracymbium with a retrolateral-proximal heel (Yu et al., 2021: fig. 3E) ...................... L. nabang (China)
9(6) Proventral process of contrategulum very wide, with widely truncate apex in distal view (Fig. 17A, C); heel of paracymbium protruding proximally (Fig. 17G) ................................................................... L. lordae (Myanmar)
- Proventral process of contrategulum conical, with narrowly rounded or narrowly and obliquely truncate apex in distal view (Figs 4 A-C, 6A-D, 19A); heel of paracymbium protruding retrolaterally (Figs 4 H-J, 6J, L-N, 19E-F) ............................................................................................................................................................................. 10
10(9) Retrolateral-proximal heel of paracymbium carrying 2-3 enlarged spicules (Fig. 19 E-F); base of embolus complex with a lobate prolateral protrusion in distal view (Fig. 19 A-B) ............................ L. pyinoolwin (Myanmar)
- Retrolateral-proximal heel of paracymbium without enlarged spicules but normal spicules or stiff bristles instead (Fig. 4 H-J, 6J, L-N); base of embolus complex without prolateral protrusion in distal view (Fig. 4C, 6A) ..... 11
11(10) Depth/length ratio of tibial apophysis of palp ~ 1.4 (Fig. 4F); retrolateral-proximal heel of paracymbium widely rounded (Fig. 4 H-J); prolateral part of distal edge of contrategulum indistinctly elevated (Fig. 4E, G); no invagination between para-embolic plate and retroventral edge of embolus complex (Fig. 4 C-D) ... L. lahu (Thailand)
- Depth/length ratio of tibial apophysis of palp ~ 2.2 (Fig. 6O); retrolateral-proximal heel of paracymbium narrowly rounded (Fig. 6J, L-N); prolateral part of distal edge of contrategulum distinctly elevated (Fig. 6 H-I); a shallow invagination between para-embolic plate and retroventral edge of embolus complex (Fig. 6 F-H) ........................ ............................................................................................................................... L. metopiae sp. nov. (Thailand)
12(1) Portions of carapace, legs and palps of females and of last immature instars of males orange-coloured (Fig. 3 EI) ......................................................................................................................................................................... 13
- Body and legs uniformly dark, or body brown and legs more or less distinctly annulated (Figs 2, 3 A-C) ....... 14
13(12) Large spiders (CL and CW of females up to 14.73 and 13.27, respectively); posterior stalk of vulval plate usually wider than long or rarely as wide as long, its posterior margin usually straight, rarely widely rounded (Fig. 14) ........................................................................................................................................ L. birmanicus (Myanmar)
- Medium-sized spiders [CL and CW of female holotype (fully grown?) 7.02 and 6.16, respectively]; posterior stalk of vulval plate clearly longer than wide, its posterior margin narrowly rounded or angular (Aung et al., 2019: fig. 3B-E) .................................................................................................................... L. hpruso (Myanmar)
14(12) Very large spiders (CL and CW in females up to 18.32 and 16.61, respectively); anterior lobes of poreplate folded ventrad (Figs 11-12); body and legs uniformly very dark, without annulations (Fig. 3 A-B) ................................. ..................................................................................................................................... L. ferox sp. nov. (Myanmar)
- Medium-sized spiders [CL and CW in females up to 8.50 and 7.90, respectively (for L. lordae)]; anterior lobes of poreplate not folded ventrad (Figs 5, 7, 9, 16 A-J, 18, 20, 22, 24, Yu et al., 2021: fig. 4); body brown to dark, legs annulated or not .................................................................................................................................................. 15
15(14) Posterior stalk as wide as or wider than poreplate; anterior lobes of poreplate reduced to 1-2 clusters of vesicles on each side (Figs 22, 24, Yu et al., 2021: fig. 4) ............................................................................................... 16
- Posterior stalk narrower than poreplate; anterior lobes of poreplate fully developed (Figs 5, 7, 9, 16 A-J, 18, 20) ............................................................................................................................................................................. 18
16(15) Ventral side of vulval plate with a widely separated pair of “bulging margins” laterally between poreplate and posterior stalk; posterior part of genital atrium strongly curved ventrad (Yu et al., 2021: fig. 4) ........................... .................................................................................................................................................... L. nabang (China)
- “Bulging margins” absent; posterior part of genital atrium not strongly curved ventrad .................................. 17
17(16) Anterior margin of poreplate with 1-2 rather small clusters of vesicles on each side; lateral margins of poreplate without anterolateral processes; posterior stalk much shorter than poreplate (Fig. 22); prefoveal setae on carapace absent ..................................................................................................................... L. cupreus sp. nov. (Myanmar)
- Anterior margin of poreplate with only one rather large cluster of vesicles on each side; lateral margin of poreplate with a small knob-shaped anterolateral process on each side; posterior stalk almost as long as poreplate (Fig. 24); prefoveal setae present .................................................................................. L. platnicki sp. nov. (Myanmar)
18(15) No knob-shaped anterolateral processes on ventral side of poreplate (Figs 5, 9, 18) ........................................ 19
- Each lateral side of poreplate ventrally with a knob-shaped anterolateral process (Figs 7, 16 A-J, 20) ............ 21
19(18) Anterior lobes of poreplate very wide and continuous with lateral poreplate margins, no step between them step (Fig. 18); no annulations on legs and palps ........................................................................... L. lordae (Myanmar)
- Anterior lobes of poreplate mostly rather narrow, with a more or less distinct step between them and lateral poreplate margins (Figs 5, 9); legs and palps with or without annulations ............................................................... 20
20(19) Step between anterior lobes and lateral margins of poreplate pronounced; length of posterior stalk clearly more than half of poreplate length (Fig. 9); legs and palps not annulated .......................... L. tung sp. nov. (Myanmar)
- Step between anterior lobes and lateral margins of poreplate rather indistinct; length of posterior stalk less than or little more than half of poreplate length (Fig. 5); legs and palps annulated ......................... L. lahu (Thailand)
21(18) Posterior stalk of vulval plate clearly longer than wide or only slightly wider than long, its anterior portion with a long constriction (Fig. 20; Xu et al., 2021: figs 5-7) .................................................. L. pyinoolwin (Myanmar)
- Posterior stalk of vulval plate clearly wider than long, its anterior portion with a short constriction (Figs 7, 16 A-J; Aung et al., 2019: fig. 5) .................................................................................................................................... 22
22(21) Anterior margin of poreplate mostly with a deep and narrowly U-shaped invagination between anterior lobes (indistinct in Fig. 7E); posterior stalk of vulval plate small in comparison with poreplate (Fig. 7); legs and palps annulated .............................................................................................................. L. metopiae sp. nov. (Thailand)
- Anterior margin of poreplate with a less deep, more widely U-shaped or widely V-shaped invagination between anterior lobes; posterior stalk of vulval plate distinctly larger in comparison with poreplate (Fig. 16 A-J, Aung et al., 2019: fig. 5); legs and palps not annulated .................................................................. L. pinlaung (Myanmar)
description: Published as part of Schwendinger, Peter J., Huber, Siegfried, Lehmann-Graber, Christina, Ono, Hirotsugu, Aung, Mu Mu & Hongpadharakiree, Komsan, 2022, A taxonomic revision of the Liphistius birmanicus-group (Araneae: Liphistiidae) with the description of five new species, pp. 375-424 in Revue suisse de Zoologie 129 (2) on pages 376-380, DOI: 10.35929/RSZ.0083, http://zenodo.org/record/7761487