Tonsilla defossa, Xu, Xiang & Li, Shuqiang, 2006

Xu, Xiang & Li, Shuqiang, 2006, A new species of the genus Tonsilla (Araneae: Amaurobiidae) from mountains of Sichuan, China, Zootaxa 1307, pp. 63-68 : 64-67

Tonsilla defossa sp. nov.

Figs 1–12

Type material: Holotype male and 1 female paratype, CHINA: Sichuan Province, Mianning County, Yele Natural Reserve (28.9°N, 102.2°E), 20 October 2005, Xiufeng Zhang, Xiang Xu leg.; 1 male paratype, CHINA: Sichuan Province, Luding County, Hailuogou Glacier Forest Park (29.6°N, 102.0°E), 3 October 2005, Xiufeng Zhang, Xuxiang Xu leg.

Etymology: The specific name is a Latin adjective, meaning “hidden” and referring to the spermathecal heads being hidden by the copulatory ducts.

Diagnosis: The male of this new species is similar to that of T. truculenta Wang & Yin, 1992 but can be distinguished by the broad patellar apophysis, the broad lateral tibial apophysis, the long cymbial furrow which is more than half cymbial length and the fishtail­shaped conductor apex. The female can be separated from other Tonsilla species by the small, anteriorly situated atrium and the hidden spermathecal heads from dorsal view.

Description: Male. Total length 8.6–9.9. Holotype total length 9.9, dorsal shield of prosoma 5.2 long, 3.6 wide; opisthosoma 4.7 long, 3.4 wide. Eyes measurements: AME 0.18; ALE 0.23; PME 0.20; PLE 0.20; AME­AME 0.10; AME­ALE 0.10; ALE­PLE 0.10; PME­PME 0.13; PME­PLE 0.20. Clypeus 0.13. Chelicerae with 3 promarginal teeth and 2 retromarginal ( Fig. 1 ). Leg I longest; leg formula: I, IV, II, III; the measurement of legs is as follows: I: 17.3 (4.6 + 5.7 + 4.5 + 2.5); II: 15.8 (4.2 + 5.0 + 4.2 + 2.4); III: 13.0 (3.7 + 4.0 + 3.5 + 1.8); IV: 17.1 (4.6 + 5.4 + 4.9 + 2.2). Dorsal shield of prosoma brown. Fovea long. Opisthosoma with chevron pattern dorsally. Posterior lateral spinnerets with distal segment shorter than basal one.

Patellar apophysis broad; RTA with distal end not extending beyond tibia; lateral tibial apophysis broad; cymbial furrow longer than half cymbial length; conductor with distal end fishtail­shaped; dorsal apophysis of conductor present; median apophysis broad, spoon­shaped; embolus moderately long, originating prolaterally ( Figs 2–4 , 7–9 ).

Female. Total length 8.2. Dorsal shield of prosoma 3.7 long, 2.4 wide; opisthosoma 4.5 long, 3.0 wide. Eye measurements: AME 0.09; ALE 0.18; PME 0.15; PLE 0.16; AME ­AME 0.10; AME­ALE 0.10; ALE­PLE 0.10; PME­PME 0.13; PME­PLE 0.15. Clypeus 0.13. Chelicerae with 3 promarginal teeth and 2 retromarginal. Leg IV longest; leg formula: IV, I, II, III; the measurement of legs is as follows: I: 9.1 (2.6 + 3.2 + 2.0 + 1.3); II: 8.2 (2.4 + 2.7 + 1.9 + 1.2); III: 7.7 (2.2 + 2.4 + 2.0 + 1.1); IV: 10.6 (2.8 + 3.4 + 3.0 + 1.4).

Epigynal teeth situated anteriorly, moderately separated by slightly less than half atrial width; atrium strongly reduced, situated anteriorly close to epigynal teeth; copulatory ducts large; spermathecae slender and long, widely separated, extending laterally and connecting to copulatory ducts anteriorly; spermathecal heads situated anteriorly, covered by the copulatory ducts from dorsal view ( Figs 5–6 , 10–11 ).

Distribution. China (Sichuan) ( Fig. 12 ).

Figures

FIGURE 12. Collection localities of Tonsilla defossa sp. nov. in mountains of Sichuan, China.

FIGURES 1 – 6. Tonsilla defossa sp. nov., 1. Male cheliceral teeth, lateral view; 2. Pedipalpus, prolateral view; 3. Ditto, ventral view; 4. Ditto, retrolateral view; 5. Epigynum, ventral view; 6. Vulva, dorsal view. Scale bars: 0.5 mm. Abbreviations used in the figures: A = atrium; C = conductor; CD = copulatory duct; CDA = conductor dorsal apophysis; CF = cymbial furrow; E = embolus; ET = epigynal tooth; FD = fertilization duct; LTA = lateral tibial apophysis; MA = median apophysis; PA = patellar apophysis; RTA = retrolateral tibial apophysis; S = spermatheca; ST = subtegulum; T = tegulum; TS = tegular sclerite.

FIGURES 7 – 11. Tonsilla defossa sp. nov., 7. Pedipalpus, prolateral view; 8. Ditto, ventral view; 9. Ditto, retrolateral view; 10. Epigynum, ventral view; 11. Vulva, dorsal view.