Liphistius nabang Yu, Zhang & Zhang, 2021

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, Revue suisse de Zoologie 129 (2), pp. 375-424 : 421

Liphistius nabang Yu, Zhang & Zhang, 2021

Liphistius nabang Yu, Zhang & Zhang, 2021: 36-40 , figs 1-4 (description of males and females).

Types: MHBU-ARA-00020000 to MHBU-ARA-00020004; male holotype, 1 male and 3 female paratypes; China, Yunnan Province, Yingjiang County, Nabang (24°45’07.64”N, 97°33’47.02”E and 24°45’27.13”N, 97°33’52.86”E), 265-283 m; 2.VIII.2019 and 2.X.2019; leg. Q. Ji and K. Yu, C. Zhang & S.Y. Zhang. Types not examined; no additional material available.

Diagnosis: Distinguished by the following combination of characters: tegulum somewhat triangular in shape, with distinctly elevated distal edge and V-shaped proximal edge; distal contrategular edge with widely rounded prodorsal protrusion and pointed apex; paracymbium with retrolateral-proximal heel; cumulus distinctly elevated ( Yu et al., 2021: fig. 3); vulval plate strongly bent ventrad in proximal part; poreplate with reduced anterior lobes and without anterolateral processes; posterior stalk short, wider than poreplate; a pair of lateral “bulging margins” between poreplate and posterior stalk ( Yu et al., 2021: fig. 4).

Additions to description and taxonomic remarks: This species is most similar and probably very closely related to L. cupreus sp. nov. and L. platnicki sp. nov., which are also geographically the closest congeners. Liphistius nabang shares with these two species a number of characters which are taxonomically more or less important. These are: an enlarged spine on an elevated base dorsal of the tibial apophysis ( Yu et al., 2021: fig. 3D; Figs 21 C-D, 23C-D), a relatively long and narrow paracymbium with a distinctly conical distal side and a distinctly elevated cumulus ( Yu et al., 2021: fig. 3D-F; Fig. 21 A-B; Fig. 23 A-B), a more or less distinctly elevated distal edge of the tegulum ( Yu et al., 2021: fig. 3A-B, D-E; Fig. 21K ; Fig. 23 I-M; absent in some males of L. cupreus sp. nov., Fig. 21M ) and a reduced proximal ledge on the dorsal side of the contrategulum ( Yu et al., 2021: fig. 3A-B; Figs 21 E-F, H-I, K-N, 23F, I-K) in males, plus a similar vulval plate with more or less strongly reduced anterior poreplate lobes and with a wide (at least as wide as poreplate) posterior stalk in females ( Yu et al., 2021: fig. 4; Figs 22 , 24 ). It is not clear from the original description and illustrations if L. nabang also shares with these two new species a pronounced subdistal suture on the ventral side of the palpal tarsus. Liphistius nabang differs from these two similar species by possessing a rather triangular tegulum ( Yu et al., 2021: fig. 3A cf. Figs 21K , 23 J-L) and a retrolateral-proximal heel on the paracymbium ( Yu et al., 2021: fig. 3E; absent in L. cupreus and L. platnicki sp. nov., Figs 21A , 23A ) in males, as well as by a wider posterior stalk and a shallowly invaginated or slightly arched distal poreplate margin (instead of always invaginated, in most cases more deeply so than on L. nabang ) ( Yu et al., 2021: fig. 4 cf. Figs 22 , 24 ). The widely separated lateral pair of “bulging margins” of L. nabang , situated on the ventral side of the vulval plate between the poreplate and the posterior stalk ( Yu et al., 2021: fig. 4), is a structure that we have not observed in any other congeners and which appears to be autapomorphic. We assume that these “bulging margins” are exceptionally widely separated, thickened posterior poreplate margins.

CL and CW of the male holotype are given as 4.89 and 5.11 ( Yu et al., 2021: 37; no measurements are given for the male paratype), which suggests that this structure is wider than long, something we have not observed in any other Liphistius species. This odd ratio is not evident from the corresponding photo ( Yu et al., 2021: fig. 2A), where the carapace looks clearly longer than wide. If measured in a position with the anterior and posterior carapace margin at the same focal plane, the measurements are probably different.

Although not mentioned in the original description of L. nabang , photos of the male holotype and of a female paratype therein ( Yu et al., 2021: fig. 2A-B) indicate that prefoveal setae are missing in both sexes. Within the birmanicus -group this unusual lack (if confirmed) is only shared with the closely related L. cupreus sp. nov.

Variation: See Yu et al., 2021: 37, 40. For carapace measurements see Table 1 .

Distribution: This species is known only from the type locality, which lies at low altitudes right at the border between the Yunnan Province of China and the Kachin State of Myanmar. It presumably occurs on both sides of the border.

Figures

Fig. 21. Liphistius cupreus sp. nov., palps of three males; holotype (A-D, H-J, L-N), paratype matured end VI.2018 (E-G), paratype matured mid VI.2018 (K). (A) Left tarsus and palpal organ, ventral view. (B) Left paracymbium and distal margin of tibia, retrolateral view. (C) Distal part of left tibia, ventral view. (D) Same, retrolateral and slightly proximal view. (E) Left palpal organ, distal view (dorsal side up). (F) Dorsal part of left contrategulum and embolus proper, distal and slightly ventral view. (G) Dorsal part of left contrategulum, distal and slightly dorsal view. (H) Left contrategulum, distal and slightly ventral view. (I) Right contrategulum, same view. (J) Part of left palpal organ, retroventral view; slightly bent proximal edge of tegulum indicated by arrow. (K) Right palpal organ, retrolateral and slightly distal view. (L) Left palpal organ and distal margin of tarsus, dorsal and slightly proximal view. (M) Left palpal organ, retrolateral and slightly distal view. (N) Left palpal organ and distal margin of tarsus, prodorsal and slightly proximal view. Scale lines 1.0 mm (A-B, E-N; C-D). Abbreviation: a - angular prodorsal protrusion at base of distal edge of contrategulum.

Fig. 23. Liphistius platnicki sp. nov., palps of three males; holotype (A-D, H-J, M), paratype matured 26.VII.2019 (E-G), paratype matured 8.VIII.2016 (K-L). (A) Left tarsus and palpal organ, ventral view. (B) Left paracymbium and distal margin of tibia, retrolateral view. (C) Distal part of left tibia, ventral view. (D) Same, retrolateral and slightly proximal view. (E) Left palpal organ, distal view (dorsal side up). (F) Dorsal part of left contrategulum and embolus proper, distal and slightly ventral view. (G) Dorsal part of left contrategulum, distal and slightly dorsal view. (H) Left palpal organ and distal margin of tarsus, prodorsal and slightly proximal view. (I) Same, dorsal and slightly proximal view. (J) Same, retrolateral and slightly distal view. (K) Left palpal organ, retrolateral view. (L) Tegulum and nearby parts of right palpal organ, same view. (M) Part of left palpal organ, retroventral view; elevated distal edge of tegulum indicated by short arrow, straight, salient proximal tegular edge indicated by long arrow. Scale lines 1.0 mm (A-B; C-D; E-M).

Fig. 22. Liphistius cupreus sp. nov., vulval plates of ten females (all taken from exuviae), dorsal view (E with uterus externus attached, H, K, N), ventral view (A-D, I-J, L-M, O), ventral and slightly anterior view (P), posterior view (G), and isolated uterus externus (F). (A) Moult of 10.II.2019. (B) Moult of 12.V.2020. (C) Moult of 5.VII.2019. (D-F) Moult of 22.XI.2020. (G) Moult of VI.2019. (H-I) Moult of 13.II.2021. (J) Allotype; moult of 19.I.2019. (K-L) Moult of 14.II.2021. (M) Moult of 1.V.2021. (N-P) Moult of 23.X.2021. Arrows indicating paired lateral pockets of membranous uterus externus. Scale lines 1.0 mm.

Fig. 24. Liphistius platnicki sp. nov., vulval plates of ten females (all from exuviae), dorsal view (A, D, K, O), ventral view (B-C, E, H-J, L-N, P), anterior view (F), and isolated uterus externus (G). (A-B) Moult of 29.I.2021. (C, F) Moult of 10.III.2021 (al- lotype). (D-E) Moult of 25.IV.2020. (G, N) Moult of 14.X.2021. (H) Moult of 14.V.2020. (I) Moult of 20.XI.2021. (J) Moult of 13.X.2021. (K-L) Moult of 2.IV.2021. (M) Moult of 7.I.2021. (O-P) Moult of 3.X.2021. Arrows indicating paired lateral pockets of membranous uterus externus. Scale lines 1.0 mm