Acroterius hamatus, Irfan & Bashir & Peng, 2021

Irfan, Muhammad, Bashir, Shahida & Peng, Xianjin, 2021, Acroterius gen. nov. (Araneae: Linyphiidae: Linyphiinae) with twelve new species from Yunnan, China, European Journal of Taxonomy 743, pp. 1-53 : 24-28

Acroterius hamatus gen. et sp. nov.

urn:lsid:zoobank.org:act:754D348A-8F5C-47DA-9940-FDCEDD520F56

Figs 19–21 , 38

Differential diagnosis

The new species resembles Acroterius brevis gen. et sp. nov. ( Fig. 8A–D ) in having the posterior median plate extending posteriorly with a parmula, but can be distinguished by: in dorsal view, parmula two times the width of parmula base, with distal part distinctly expanded ( Fig. 19D ), slightly longer than the width of parmula base ( Fig. 19A–D ), but distal part not expanded in A. brevis gen. et sp. nov. In lateral view, anterior wall of epigynal plate projection wider than long ( Figs 19C , 21C ), but longer than wide in A. brevis gen. et sp. nov. ( Fig. 8C ).

Etymology

The species name comes from the Latin adjective ‘ hamatus ’, meaning ‘hook’ and referring to the hookshaped spermathecae in the epigyne.

Type material

Holotype CHINA • ♀; Yunnan Province, Gongshan County, Dulongjiang Township, Kongdang Village ; 27.87961° N, 98.33878° E; alt. 1527 m; 25 Oct. 2004; Guo Tang leg.; HNU-Tang–04–04 .

Paratypes (5 ♀♀)

CHINA – Yunnan Province, Gongshan County • 4 ♀♀; 77 km of new road to Donglongjiang; 27.91034° N, 98.41081° E; alt. 2183 m; 8–9 Nov. 2004; Guo Tang leg.; HNU-Tang–04–09 • 1 ♀; Dulongjiang Township, S/N of Dizhengdang Village along Silalong He; 28.07654° N, 98.32603° E; alt. 1890 m; 28 Oct. 2004; D.H. Kavanaugh leg.; HNU-DHK–2004–059 .

Description

Female (holotype)

MEASUREMENTS AND COLOUR. Total length: 3.43. Carapace 1.41 long, 1.17 wide, cephalothorax brown; clypeus 0.41 high ( Fig. 20A–B ); abdomen 2.01 long, 1.41 wide. Eye sizes and interdistances:

AME 0.06, ALE 0.08, PME 0.07, PLE 0.07, AME–AME 0.04, PME–PME 0.07, AME–ALE 0.09, PME–PLE 0.08, ALE–ALE 0.49, PLE–PLE 0.53, ALE–PLE contiguous.

CHELICERAE. With six promarginal and six retromarginal teeth; reteromarginal teeth long and highly sclerotized protruding beyond fangs.

LENGTH OF LEGS. I = 5.39 (1.74, 1.40, 1.31, 0.94), II = 4.99 (1.42, 1.54, 1.17, 0.83), III = 3.95 (1.18, 1.25, 0.9, 0.62), IV = 4.94 (1.44, 1.53, 1.18, 0.79). Leg formula I–II–IV–III.

EPIGYNE. Parmula 0.53 long, 0.28 wide at base ( Fig. 19A–C ); posterior margin of anterior wall of epigynal plate with projection wider than long on each side ( Fig. 19A–B ). Spermathecae slender, distal part slightly curved, pointing towards posterior margin of epigyne ( Fig. 19D ).

VARIATION IN THE EPIGYNE (HNU-Tang–04–09, Fig. 21A–F ). We noticed in the four out of five female paratypes that the epigynal parmulas are broken at the same point due to unknown reasons. All the other somatic and genitalic characters are found to be similar ( Fig. 21A–D ).

Male

Unknown.

Distribution

China (Yunnan Province, Fig. 38 ).

Figures

Fig. 19. Acroterius hamatus gen. et sp. nov., ♀, holotype (HNU-Tang–04–04). A–B. Epigyne, ventral view. C. Epigyne, lateral view. D. Vulva, dorsal view.

Fig. 20. Acroterius hamatus gen. et sp. nov., ♀, holotype (HNU-Tang–04–04). A. Habitus, dorsal view. B. Habitus, ventral view.

Fig. 21. Acroterius hamatus gen. et sp. nov., ♀, paratype (HNU-Tang–04–09). A–B. Epigyne, ventral view. C. Epigyne, lateral view. D. Vulva, dorsal view. E. Habitus, dorsal view. F. Habitus ventral view.

Fig. 38. Map indicating the type localities of Acroterius absentus sp. nov. (), A. brevis sp. nov. (), A. camur sp. nov. (), A. hamatus sp. nov. (), A. inversus sp. nov. () and A. latus sp. nov. ().

Fig. 8. Acroterius brevis gen. et sp. nov., ♀, paratype (HNU-20040501–2). A–B. Epigyne, ventral view. C. Epigyne, lateral view. D. Vulva, dorsal view.