Allomedmassa Dankittipakul & Singtripop, 2014

Jin, Chi, Zhang, Hongli & Zhang, Feng, 2019, First records of the corinnid genera Allomedmassa Dankittipakul & Singtripop, 2014 and Medmassa Simon, 1887 from China, with the description of a new genus (Araneae: Corinnidae), Zootaxa 4585 (3), pp. 459-477 : 460-465

publication ID	https://doi.org/ 10.11646/zootaxa.4585.3.3
publication LSID	lsid:zoobank.org:pub:1BA367F9-0A0D-4CC6-9D94-D947459723BA
persistent identifier	https://treatment.plazi.org/id/03D287C6-FF96-7431-87B9-FB4CFD114C26
treatment provided by	Plazi
scientific name	Allomedmassa Dankittipakul & Singtripop, 2014
status

Treatment

Allomedmassa Dankittipakul & Singtripop, 2014 View in CoL View at ENA (ǖflđffl)

Allomedmassa Dankittipakul & Singtripop 2014: 17 View in CoL .

Type species: Allomedmassa mae Dankittipakul & Singtripop 2014 , by original designation.

Diagnosis. Allomedmassa resembles the genus Medmassa in having a U-shaped sperm duct in the male palp and by the absence of morphological adaptations to ant-mimicry, but can be distinguished from it by: 1) carapace oval and obviously convex ( Figs 2A View FIGURE 2 , 3A View FIGURE 3 , 5A View FIGURE 5 ), whereas it is almost around and flat in Medmassa ( Fig. 8A View FIGURE 8 ); 2) AER straight in frontal view ( Figs 2D View FIGURE 2 , 3D View FIGURE 3 , 5D View FIGURE 5 ), whereas it is obviously procurved in Medmassa ( Fig. 8D View FIGURE 8 ); 3) male palpal tibia wider than long and with numerous bristles ( Figs 2 View FIGURE 2 E–G), whereas it is longer than wide and without bristles in Medmassa ( Figs 8 View FIGURE 8 E–H); 4) the ventral furrow of the cymbium is closed off distally ( Fig. 10F View FIGURE 10 ), whereas it continues to be open to the distal end of the cymbium in Medmassa ( Figs 8E, F View FIGURE 8 ); 5) RTA is positioned ventrally and proximally on the tibia ( Figs 2G View FIGURE 2 , 3G View FIGURE 3 , 5G View FIGURE 5 ), whereas it is more retrolateral and distally located in Medmassa ( Figs 8 View FIGURE 8 F–H); 6) RTA simple and sharply pointed ( Figs 2G View FIGURE 2 , 3G View FIGURE 3 , 5G View FIGURE 5 ), whereas it is more complex in Medmassa , with one or more branches, usually blunt and forked ( Figs 8 View FIGURE 8 F–H); 7) embolus thick and S-shaped ( Figs 2F View FIGURE 2 , 3F View FIGURE 3 , 5F View FIGURE 5 ), whereas it is slender and spiniform in Medmassa ( Fig. 8F View FIGURE 8 ; Deeleman-Reinhold 2001: fig. 545); 8) COs of female genitalia large and clearly separated ( Figs 6E, F View FIGURE 6 ; Dankittipakul & Singtripop 2014: fig. 18), whereas they are mostly small, closely-situated openings in Medmassa ( Deeleman-Reinhold 2001:fig. 553; Haddad & Bosselaers 2010: figs 8– 10); 9) spermathecae small and reniform ( Fig. 6F View FIGURE 6 ; Dankittipakul & Singtripop 2014: fig. 19), whereas they are large, and round or oval in Medmassa ( Deeleman-Reinhold 2001: fig. 554; Haddad & Bosselaers 2010: fig. 11).

Allomedmassa also resembles the new genus Paramedmassa gen. nov. described in this paper. See the diagnosis part of Paramedmassa gen. nov. below for details.

Description. Medium to large-sized (10–15 mm), dark, non-ant-mimicking spiders ( Fig. 1 View FIGURE 1 ). Carapace black, obviously convex, with rough surface, highest before fovea; thoracic region almost round and cephalic region very long and parallel-sided; widest at coxae II, gradually narrowing backwards, strongly concave at posterior margin before pedicel ( Figs 2A View FIGURE 2 , 3A View FIGURE 3 , 4A View FIGURE 4 , 6A View FIGURE 6 ); cephalic region long, with parallel lateral edges; radial and cervical grooves indistinct; fovea longitudinal, short. AER straight in frontal view, PER straight or slightly procurved in dorsal view ( Figs 2 View FIGURE 2 C–D, 3C–D); AME largest, ALE smallest. MOA almost square. Clypeus height narrower than diameter of AME. Chilum present, single, triangular, sclerotized and brown ( Fig. 2D View FIGURE 2 ). Chelicerae same color as carapace, concave at distal end dorsally in male ( Figs 2D View FIGURE 2 , 3D View FIGURE 3 , 4D View FIGURE 4 ); promargin with three and retromargin with four to seven teeth, left retromargin tends to have smaller teeth than right retromargin. Endites and labium dark brown, longer than wide. Sternum brown, shield-shaped, longer than wide, precoxal triangles and intercoxal sclerites present. Legs reddish to dark brown; anterior tibiae with four pairs of ventral spines (subject to tibia I); metatarsi III–IV ventrally with distal preening brush; leg formula 4123. Abdomen oval, dark grey to dark brown, with narrow anterior dorsal scutum in male, posteriorly with several light grey chevrons; epigastric sclerite weakly sclerotized, post-epigastric sclerite and ventral sclerite absent, inframamillary sclerite small.

Palpal tibia short, longer than wide, ventral surface flat, covered with numerous bristles; prolateral tubercle digitiform; RTA located far away from cymbium base, with sharp apex, pointed ventrally. Cymbium elongate, without dorsal chemosensory patch. Tegulum oval, with no structures except embolus; round basally, always bulging on retrolateral side, gradually narrowed apically; sperm duct thick, U-shaped. Embolus thick and long, Sshaped, sharply pointed, directed retrolaterally; base to middle part often with modifications.

Epigynal region heavily sclerotized. Copulatory openings elliptical, large, situated medially, clearly separated. Vulva: copulatory ducts long, heavily sclerotized, thick-walled, anteriorly thick and posteriorly slender, running parallel forward, then bending medially and extending backwards; accessory glands small, digitiform, located at middle part of copulatory ducts; spermathecae small, transverse reniform, situated posteriorly, close to each other; fertilization ducts short; two fixed sclerites present, connected to basal portion of fertilization ducts and posterior margin of epigyne.

Composition. Five species: Allomedmassa mae Dankittipakul & Singtripop, 2014 , A. deelemanae Dankittipakul & Singtripop, 2014 , A. bifurca sp. nov., A. crassa sp. nov. and A. matertera sp. nov..

Distribution. Northern Thailand and southwestern China.

Remarks. There were three species in the genus when it was established by Dankittipakul & Singtripop (2014). In addition to the type species, Allomedmassa day is also distributed in China, but it is transferred to the new genus Paramedmassa gen. nov. according to the specimen examined in this paper. Allomedmassa deelemanae was not found in China, and due to the lack of research materials it was not studied here, and is provisionally placed in the genus.

In a recent phylogenetic analysis carried out by Wheeler et al. (2017), Allomedmassa was suggested as the sister group to Castianeirinae. However, their analysis was problematic as it did not include Medmassa . If it had included a broader taxon set, then Medmassa , Messapus and Allomedmassa may have formed a clade of their own. Considering that they do not fit the bill to be considered castianeirines, particularly the well-developed RTA and large, non-ant-mimicking body, we think that with more data these three genera and Paramedmassa could form a subfamily of their own.

Allomedmassa mae Dankittipakul & Singtripop, 2014 View in CoL (母异介蛛)

Figs 1 View FIGURE 1 , 2 View FIGURE 2

Allomedmassa mae Dankittipakul & Singtripop, 2014: 19 View in CoL View Cited Treatment , figs 1–6, 9–12, 15–19.

Material examined. CHINA: Yunnan Province: 1♂, Xishuangbanna, Menghai County, Xiding Township , Babinglaozhai Village (21°55.9512′N, 100°8.7594′E), 1715 m a.s.l., 26 July 2018, leg. Chi Jin. GoogleMaps

Diagnosis. This species can be distinguished from other congeners by 1) male palpal ventral surface distinctly elevated, forming a hump ( Fig. 2E View FIGURE 2 ); 2) embolus lacking any modifications ( Fig. 2F View FIGURE 2 ); 3) copulatory ducts of the female genitalia are extremely wide ( Dankittipakul & Singtripop 2014: 22, figs 12, 19).

Description. Male ( Figs 1 View FIGURE 1 , 2 View FIGURE 2 ). Total length 10.71; carapace 5.52 long, 4.51 wide, width/length = 0.82; abdomen 5.19 long, 3.33 wide. Body colouration as in genus description. Diameters of eyes: AME 0.42, ALE 0.26, PME 0.27, PLE 0.35. Eye interdistances: AME–AME 0.26, AME–ALE 0.14, ALE–ALE 1.31, PME–PME 0.42, PME–PLE 0.41, PLE–PLE 1.64, ALE–PLE 0.18. OAW 1.97, CRW 2.80, OAW/CRW = 0.70. CRW:/carapace width = 0.62. MOA 0.90 long, front width 0.90, back width 0.85. Clypeus height 0.36, 0.86 times AME diameter. Chelicerae with three promarginal teeth, four or five retromarginal teeth. Labium 1.50 long, 0.81 wide. Sternum 2.57 long, 2.20 wide. Measurements of legs: I 17.34 (5.02 + 2.09 + 4.27 + 3.84 + 2.12), II 16.00 (4.70 + 1.96 + 3.86 + 3.78 + 1.70), III 14.30 (4.15 + 1.81 + 3.24 + 3.40 + 1.70), IV 17.55 (4.65 + 1.97 + 4.21 + 5.04 + 1.68). Leg formula: 4123. Leg spination: femora I–II pl 1 do 2, III–IV pl 1 do 3 rl 1; tibiae I–II plv 4 rlv 4, III pl 2 rl 2 plv 1 rlv 1, IV pl 2 rl 2 plv 2 rlv 1; metatarsi I–II plv 2 rlv 2, III pl 1 rl 1 plv 2 rlv 2 vt 3, IV pl 2 rl 2 plv 2 rlv 2 vt 3.

Palp as illustrated ( Figs 2 View FIGURE 2 E–G). Tibia with ventral surface distinctly elevated to form hump; RTA located near ventral hump, slightly curved. Tegulum basally round, slightly convex on retrolateral side; sperm duct visible along entire length. Embolus S-shaped in ventral view, without modifications.

Female not examined.

Distribution. China (Yunnan), Thailand (Chiang Mai, Mae Hong Son) ( Fig. 12 View FIGURE 12 ).

Allomedmassa bifurca sp. nov. (二歧异介蛛)

Figs 3 View FIGURE 3 , 4 View FIGURE 4 A–C

Type material. Holotype: GoogleMaps ♂, CHINA: Guangxi Zhuang Autonomous Region: Nanning City, Liangjiang Township GoogleMaps , Daming Mountain GoogleMaps , Luoyuewang GoogleMaps temple (23°28.605′N, 108°26.410′E), 1484 m a.s.l., 24 May 2011, leg. Yingnan Wang. Paratypes: 1♂, same data as holotype GoogleMaps .

Etymology. The specific name is a Latin adjective meaning "bifurcate". It refers to the embolus with a branch dorsally.

Diagnosis. The new species resembles A. crassa sp. nov. in both having the ventral surface of male palpal tibia lacking a hump, and having modifications on the embolus, but can be distinguished from it by: 1) embolus is more slender ( Figs 3F View FIGURE 3 , 4B View FIGURE 4 ) than that of A. crassa sp. nov. ( Figs 4E View FIGURE 4 , 5F View FIGURE 5 ); 2) embolus with a branch dorsally ( Figs 3F View FIGURE 3 , 4B View FIGURE 4 ), whereas it lacks a branch in A. crassa sp. nov. ( Figs 4E View FIGURE 4 , 5F View FIGURE 5 ); 3) tegulum slightly convex on retrolateral side ( Figs 3F View FIGURE 3 , 4B View FIGURE 4 ), whereas it strongly convex in A. crassa sp. nov. ( Figs 4E View FIGURE 4 , 5F View FIGURE 5 ). Female unknown.

Description. Male ( Figs 3 View FIGURE 3 A–D). Total length 12.14–14.14 (n=2). Holotype: body 14.14 long; carapace 6.92 long, 5.78 wide, width/length = 0.84; abdomen 7.22 long, 3.90 wide. Body colouration as in genus description. Diameters of eyes: AME 0.47, ALE 0.29, PME 0.37, PLE 0.37. Eye interdistances: AME–AME 0.27, AME–ALE 0.20, ALE–ALE 1.55, PME–PME 0.45, PME–PLE 0.58, PLE–PLE 2.17, ALE–PLE 0.15. OAW 2.60, CRW 3.62, OAW/CRW = 0.72. CRW/carapace width = 0.52. MOA 1.10 long, front width 1.17, back width 1.19. Clypeus height 0.40, 0.85 times AME diameter. Chelicerae with three promarginal teeth, six or seven retromarginal teeth.

Labium 1.20 long, 0.95 wide. Sternum 3.40 long, 2.81 wide. Measurements of legs: I 23.81 (6.40 + 3.00 + 5.78 +5.64 + 2.99), II 23.01 (6.20 + 2.87 + 5.54 + 5.43 + 2.97), III 19.28 (5.33 + 2.24 + 4.48 + 4.76 + 2.47), IV 24.55 (6.48 + 2.67 + 5.72 + 7.10 + 2.58). Leg formula: 4123. Leg spination: femora I–II pl 1 do 2, III–IV pl 1 do 3 rl 1; tibiae I–II plv 4 rlv 4, III pl 2 rl 2 plv 1 rlv 1, IV pl 2 rl 2 plv 2 rlv 1; metatarsi I–II plv 2 rlv 2, III pl 1 rl 1 plv 2 rlv 2 vt 3, IV pl 2 rl 2 plv 2 rlv 2 vt 3.

Palp as illustrated ( Figs 3 View FIGURE 3 E–G, 4A–C). Tibia with ventral surface flat and slanting, not forming hump; RTA short, slightly curved. Tegulum slightly flattened basally, slightly convex on retrolateral side; sperm duct visible for most its length, hidden near base of embolus. Embolus slender, S-shaped in ventral view, with fine dorsal branch near tip, originating from base of embolus and shorter than embolus.

Distribution. China (Guangxi) ( Fig. 12 View FIGURE 12 ).