Liphistius platnicki Schwendinger & Huber, sp. nov.
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 platnicki

description: Liphistius platnicki Schwendinger & Huber, sp. nov.
Figs 1, 2C, 23-24
Holotype: MHNG-ARTO-0028361 (sample MT-14/25); male (matured 1.VIII.2016); Myanmar, Shan State, N of Lashio, near Loi Kan Village (23°05’23”N, 97°47’02”E), 1140 m; 10.VI.2014; leg. P.J. Schwendinger & S. Huber.
Paratypes: MHNG-ARTO-0028362 to MHNGARTO-0028366, BRCM (sample MT-14/25); 6 males (matured 10.IX.2015; 26.V.2016; 2.VII.2016; 3.VII.2016; 26.VII.2016; 8.VIII.2016); collected together with the holotype. – BRCM, MHNGARTO-0028369 to MHNG-ARTO-0028377 (sample MT-14/25); 10 female paratypes (allotype, MHNGARTO-0028377, last moulted 10.III.2021); collected together with the holotype.
Etymology: We name this species in honour of the renowned American arachnologist Norman I. Platnick
(1951-2020) who, together with Walter C. Sedgwick, revised and properly defined the genus Liphistius in 1984 and described several species (also from Myanmar) in this genus. Initially we wanted to name after him the species that he misidentified as L. birmanicus and that he described and illustrated from both sexes in much detail, but that meanwhile was named L. pyinoolwin in 2021.
Diagnosis: Medium-sized, mostly brown species with indistinctly annulated legs in females (but not in males). Most similar to L. nabang. Males different by distal contrategular edge in distal view without a prodorsal protrusion (Fig. 23A, E-F, I; present in L. nabang, Yu et al., 2021: fig. 3B) and with a narrowly rounded apex (Fig. 23 E-G; pointed in L. nabang, Yu et al., 2021: fig. 3B); proximal edge of tegulum widely rounded (Fig. 23 J-L; angular in L. nabang, Yu et al., 2021: fig. 3A); paracymbium without retrolateralproximal heel (Fig. 23A; present in L. nabang, Yu et al., 2021: fig. 3E). Females distinguished from those of L. nabang by poreplate anteriorly wider than posteriorly (in L. nabang anteriorly narrower than posteriorly or equally wide), its anterior margin more strongly invaginated (in L. nabang slightly invaginated to arched); posterior stalk relatively longer and slightly constricted in anterior portion, without “bulging margins” between poreplate and posterior stalk (in L. nabang transition between poreplate and posterior stalk very wide and carrying widely separated “bulging margins”); posterior part of genital atrium not strongly curved ventrad (Fig. 24 cf. Yu et al., 2021: fig. 4).
Description of male (holotype): Colour in alcohol (darker in life): Mostly light brown. Carapace with slightly darkened, large, orchid-shaped pattern on pars thoracica; eye mound black. Chelicerae cream-coloured proximally, light brown distally. Ventral side of palps and legs slightly lighter than dorsal side; most of ventral side of palpal coxae and leg tarsi cream-coloured. Legs and palps mostly light brown, without annulations; palpal tarsus and sclerotised parts of palpal organ dark brown. Membranous cuticle of opisthosoma creamcoloured and finely mottled with grey. Sternites of opisthosoma slightly darker than membranous cuticle; tergite I entirely dark brown, tergites II-VI mostly light yellow-brown, with darker spots laterally and on
► posterior margin, tergites VII-X light yellow-brown medially and dark brown laterally.
Setae on carapace: Several small setae around eye mound, including one closely spaced enlarged pair side by side behind eye mound; few small setae on lateral margins of carapace and on coxal elevations; 1 enlarged seta on each posterolateral corner; no setae on posterior margin; 2 small setae anterior to fovea.
Cheliceral teeth: 12 small teeth of different sizes on promargin of each cheliceral groove.
Scopula: Only distally divided by median stripe on all tarsi; quite weak on tarsus I, only slightly denser on other tarsi; covering distal 5/6 of tarsi I-III, distal 4/5 of tarsus IV.
Tarsal claws: Paired claws with 3 teeth on tarsus I, 3-4 on tarsus II, 4 on tarsus III, 5-6 on tarsus IV; unpaired claw with 1-2 (mostly 2) denticles on tarsi I-III, 1 and 3 on tarsus IV.
Palp: Tibial apophysis short, triangular and basally wide in ventral view, not set back from distal margin of tibia (Fig. 23C), carrying 4 long apical megaspines, the ventral 3 distinctly longer than the dorsal one; dorsal to apophysis a quite long spine on a slightly elevated base (Fig. 23 CD). Palpal tarsus with a pronounced subdistal suture on ventral side (Fig. 23A) and with a widely but shallowly invaginated distal margin (Fig. 23 H-I). Paracymbium moderately deep (Fig. 23B), in ventral view clearly longer than wide, with a distinctly conical distal side, without a retrolateral-proximal heel (Fig. 23A); cumulus distinctly elevated, unpigmented on its retroventral side, carrying a group of 5 long, strong bristles (Fig. 23 A-B). Subtegulum without apophysis (Fig. 23A, J). Tegulum wide, axeblade-shaped; its distal margin elevated, developed as a short, wide keel with a quite straight margin (Fig. 23 I-J, M); its proximal edge widely rounded and finely dentate, straight (not bent proximad) and strongly protruding from surface of palpal organ (Fig. 23 I-J, M). Pigmented bridge between tegulum and contrategulum on retrodorsal side of palpal organ well developed (Fig. 23J). Contrategulum with moderately developed, conical proventral process (Fig. 23E, showing paratype); essentially only a single strong wrinkle on prolateral surface and a very indistinct proximal ledge on retrodorsal side (Fig. 23 H-J, see also Fig. 23F, K for paratype); distal edge of contrategulum narrow and evenly arched, without protrusion prodorsally; dorsal apex of contrategulum quite long and very narrowly rounded (Fig. 23I, see also Fig. 23 E-G for paratype). Para-embolic plate short, about as long as retroventral edge of embolus complex and not clearly separated from it by an invagination (Fig. 23A). Membranous prolateral-proximal zone of embolus complex not swollen (Fig. 23 A; swollen in L. cupreus sp. nov., Fig. 21A); embolus proper narrowly divided, its sclerotised part strengthened by 3 longitudinal ribs reaching apex and carrying denticles distally (Fig. 23J, see also Fig. 23 E-F, K for paratypes); membranous part of embolus proper distinctly shorter than sclerotised part, at its base a short, weakly pigmented area with only a few longitudinal wrinkles and with a very narrow and concave distal margin; embolic folds short (Fig. 23H).
Measurements: Total length 13.12; CL 5.45, CW 4.93; opisthosoma 5.56 long, 3.82 wide; eye mound 0.90 long, 0.96 wide; palpal coxa 1.91 long, 1.19 wide; labium 0.40 long, 0.95 wide; sternum 2.70 long, 1.91 wide (0.95 on ventral surface); palp 9.14 long (2.74 + 1.67 + 3.18 + 1.55); leg I 16.10 long (4.41 + 2.23 + 3.34 +3.97 + 2.15); leg II 17.01 long (4.45 + 2.23 + 3.46 + 4.49 + 2.38); leg III 19.12 long (4.77 + 2.23 + 3.78 + 5.52 + 2.82); leg IV 23.48 long (5.80 + 2.38 + 4.77 + 7.03 + 3.50).
Description of female (allotype): Colour in alcohol (darker in life, as in Fig. 2C): Mostly as in male, but generally darker, distal part of chelicerae much darker. Legs and palps with indistinct annulations, i.e. faint and broken light median rings on all tibiae of legs and palps, plus on metararsi of legs II-IV, and very faint on tarsi II-IV; a faint light proximal ring on all leg metatarsi. Membranous cuticle of opisthosoma more distinctly mottled with grey-brown than in male; tergites II-VI with much larger dark portions, extending from anterior to posterior margins, leaving rather small paramedian pairs of longitudinal bands.
Setae on carapace: Slightly more than in the holotype; pair of stiff bristles in front of eye mound much larger; pair of enlarged setae behind eye mound situated behind each other (in male side by side); 5 small setae anterior to fovea.
Cheliceral teeth: 12 strong teeth on promargin of each cheliceral groove.
Claws: Left palpal claw with 2 denticles, right claw with 3 denticles. Paired tarsal claws of legs I-II with 3 teeth, of leg III with 4 teeth, of leg IV with 3-4 teeth; unpaired claws of leg I with 3 denticles, of leg II with 3-4 denticles, of leg III with 2 denticles, of leg IV with 1-2 denticles. All tarsi without scopula.
Vulva (Fig. 24C, F): Membranous uterus externus with a small but distinct pair of lateral pockets (see Fig. 24G for another female). Vulval plate slightly longer than wide, with a few hairs on lateral folds. Poreplate with widely and quite deeply invaginated anterior margin carrying a
.
►
fairly large and widely separated pair of vesicle clusters (corresponding to anterior lobes); anterolateral processes on each side of poreplate small, composed of only one vesicle (on one side) or a few vesicles (on other side). CDO small; receptacular cluster racemose, slightly longer than wide, not reaching anterior margin of poreplate, very deep (Fig. 24F). Posterior stalk quite long, wider than poreplate, with a slight constriction at transition from poreplate to posterior stalk; axe-blade-shaped, anteriorly narrower than posteriorly, with a widely arched posterior margin (Fig. 24C).
Measurements: Total length 18.56; CL 6.68, CW 5.84; opisthosoma 8.62 long, 6.92 wide; eye mound 0.97 long, 1.00 wide; palpal coxa 2.42 long, 1.55 wide; labium 0.64 long, 1.55 wide; sternum 3.54 long, 2.34 wide (1.43 on ventral surface); palp 10.61 long (3.38 + 2.03 + 2.54 + 2.66); leg I 13.59 long (4.21 + 2.42 + 2.74 + 2.70 + 1.52); leg II 14.06 long (4.21 + 2.46 + 2.74 + 2.98 + 1.67); leg III 15.30 long (4.25 + 2.54 + 2.94 + 3.66 + 1.91); leg IV 21.09 long (5.68 + 2.82 + 4.17 + 5.76 + 2.66).
Variation: For carapace measurements and prefoveal setae counts see Table 1. All specimens have both AME well developed. In four specimens the prefoveal setae are situated relatively far away from the fovea. Most females have two enlarged bristles behind the eye mound, one specimen has only one. In most males the scopula covers 5/6 of the ventral side of tarsi I-III and 4/5 of tarsus IV, in one male it covers 4/5 of tarsus I. Variation in details of the male palp is given in Fig. 23. None of the males has a prodorsal protrusion at the base of the distal contrategular edge (present in L. nabang and L. cupreus sp. nov.). The apex of the proventral contrategular process is narrowly rounded or obliquely truncate (Fig. 23E) in distal view. All males have a distinctly elevated distal tegular edge which is dentate (Fig. 23 K-L) or quite smooth (Fig. 23J). All males examined have three ridges reaching the apex of the sclerotised embolus part. The lightly pigmented area at the base of the membranous embolus part has wrinkles that are more or less strongly inclined, in some specimens being almost horizontal. In small females the annulations (light median rings) on the legs and palps are more pronounced than in the allotype (the largest female examined). Variation in the shape of the vulval plate is shown in Fig. 24: the lateral folds carry no or only very few hairs; the anterior margin of the poreplate is slightly to deeply invaginated, widely concave to straight; the anterior lobes (vesicle clusters) are narrow to wide; the anterolateral processes are small and composed of one to only a few vesicles; the receptacular cluster is small to medium-sized, always racemose, never reaching the anterior poreplate margin; the posterior stalk is axe-blade-shaped to almost elliptical.
Relationships: The new species appears most closely related to L. nabang + L. cupreus sp. nov. with which it shares characters explained further below (see Discussion - Relationships). These three species form the most distinct subgroup within the birmanicus -group.
Distribution: This species is only known from the type locality near Lashio, about 17 km north of the type locality of L. cupreus sp. nov. (Fig. 1).
Biology: No mature spiders and no egg cases were found at the type locality, but the dates at which males matured in captivity (especially the first date after capture) indicate that this species has a phenology very similar to other congeneric species in Myanmar and northern Thailand.
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 416-420, DOI: 10.35929/RSZ.0083, http://zenodo.org/record/7761487