Diplocephalus circularis Irfan, Zhang & Peng, sp. n.
Creators: name: Irfan, Muhammad
name: Zhou, Gu-Chun
name: Peng, Xian-Jin
name: Zhang, Zhi-Sheng
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Linyphiidae
Diplocephalus
Diplocephalus circularis

description: Diplocephalus circularis Irfan, Zhang & Peng, sp. n.
(vä双头e)
Figures 53–57, 307, 312, 315
Types. Holotype ♂, CHINA, Hubei Prov.: Badong Co., Yanduhe Town, Songziyuan Vill., 31.35278°N, 110.39937°E, 1836 m, 27.IV.2016, W. Liu et al. leg. Paratypes: 16♂ 13♀, with same data as for holotype; 6♂ 9♀, Badong Co., Yanduhe Town, Songziyuan Vill., 31.33400°N, 110.42625°E, 1340 m, 28.IV.2016, W. Liu et al. leg.; 1♂, Badong Co., Yanduhe Town, Songziyuan Vill., 31.3406°N, 110.4131°E, 1320 m, 24.IV.2016, W. Liu et al. leg.; 5♀, Enshi Co., Xingdou MNNR, 30.04166°N, 109.13377°E, 1253 m, 18.V.2017, G.C. Zhou et al. (HNU–HB– IV–1710); Hunan Prov.: 1♂, Shaoyang City, Suining Co., Zhaishi Town, Tieshanlin Vill., Huangshan NNR, 26.37646°N, 110.10573°E, 1129 m, 26.X.2017, G.C. Zhou (HNU–HN– IV–1759); Chongqing: 1♀, Youyang Co., Taohuayuan Scenic Spot, 28.85096°N, 108.75037°E, 995 m, 23.VII.2017, M. Irfan & G.C. Zhou (HNU–CQ– IV–1718).
Etymology. The specific epithet is derived from the Latin adjective “circularis ” meaning “circular” and referring to the curved anterior terminal apophysis in male palp.
Diagnosis. The male of Diplocephalus circularis sp. n. resembles that of D. crassilobus in having the similar cephalic lobe in male (Figs 57A–C; Millidge 1979, figs 50–56), but can be distinguished by the embolus forming a complete 360° circle in D. circularis sp. n. (Figs 53A– C, 54A, B, 55A–C; vs. spindle-shaped); dorsal tibial apophysis at apex ventrally with two projections in D. circularis sp. n. (Figs 54C, D; vs. with one projection). The female of D. circularis sp. n. resembles those of D. parentalis in having similar ventral plate and fissure in epigyne (Figs 56A–D; Song and Li, 2010, figs 10G, 11A, B), and can be distinguished by the spermathecae Ushaped, pointing towards the anterior margin of epigyne in D. circularis sp. n. (Figs 56B, D; vs. J-shaped, pointing towards the posterior margin of epigyne).
Description. Male (holotype, Figs 57A–C): Total length: 1.53. Carapace 0.71 long, 0.57 wide, cephalic region with cephalic lobe 0.27 high, yellow, fovea, cervical and radial grooves distinct. Clypeus 0.24 high. Chelicerae with three promarginal and four retromarginal teeth. Sternum longer than wide, yellowish with microsetae. Eye PMEs presents on the cephalic lobe, AER recurved, PER procurved. Eye sizes and interdistances: AME 0.05, ALE 0.04, PME 0.05, PLE 0.04, AME–AME 0.01, PME–PME 0.08, AME–ALE, 0.06, PME–PLE 0.12, AME–PME 0.12, ALE–ALE 0.28, PLE–PLE 0.27, ALE–PLE 0.01. Length of legs: I 1.9 (0.55, 0.64, 0.42, 0.29), II 1.75 (0.53, 0.56, 0.39, 0.27), III 1.54 (0.46, 0.48, 0.34, 0.26), IV 1.96 (0.36, 0.63, 0.44, 0.26). Tibial spine formula: 2-2-1-1. TmI 0.19 and TmIV absent. Opisthosoma 0.99 long, 0.72 wide, oval, dark brown to black.
Palp (holotype, Figs 53A–D, one of the paratype, Figs 54A–D): Femur unmodified, as long as patella and tibia. Patella shorter than tibia, ventrally grooved. Tibia dorsally with broad, long dorsal tibial apophysis, retrolateral margin with a row of thick setae, apex with two projections extending retrolaterally with teeth. Cymbium unmodified, conical, distal end broad; paracymbium (PC) L-shaped, distal arm tip hook-shaped with blunt end; tegulum (T) with well developed protegulum (PT), protruding above the apex of cymbium; distal suprategular apophysis (DSA) sclerotized, basal part broad, distal end needle-like with pointed end. Tailpiece (TP) of embolic division long, curved with blunt tip; embolic membrane (EM) long, with broad end; embolus (E) long, highly sclerotized, forming a tranvers circular at the apex.
Variation (one of the paratype palp, Figs 55A–D): Distal long arm of distal suprategular apophysis with a tooth. All the other morphological and genital characters are similar to the male holotype.
Female (paratype, Figs 57D–F): Total length: 1.56. Carapace 0.66 long, 0.55 wide, cephalic region slightly elevated, yellow, fovea, cervical and radial grooves distinct. Clypeus 0.14 high. Chelicerae with 4 promarginal and 6 retromarginal teeth. Sternum longer than wide, yellowish with microsetae. Eyes: AER recurved, PER procurved. Eye sizes and interdistances: AME 0.03, ALE 0.04, PME 0.04, PLE 0.04, AME–AME 0.02, PME–PME 0.04, AME–ALE, 0.04, PME–PLE 0.03, AME–PME 0.05, ALE–ALE 0.22, PLE–PLE 0.23, ALE–PLE 0.01. Length of legs: I 1.75 (0.54, 0.59, 0.33, 0.29), II 1.68 (0.50, 0.54, 0.34, 0.30), III 1.37 (0.46, 0.40, 0.27, 0.24), IV 1.77 (0.57, 0.61, 0.35, 0.24). Tibial spine formula: 2-2- 1-1. TmI 0.17 and TmIV absent. Opisthosoma 1.14 long, 0.78 wide, oval, dark brown to black.
Epigyne (Figs 56A–D): Epigynal plate more than two times wider than long, medially with a long fissure (F); ventral plate (VP) with copulatory openings (CO) anteriorly; dorsal plate (DP) somewhat quadrate, postrior end round, completly covered by ventral plate in ventral view; copulatory ducts (CD) enclosed in a slightly sclerotized capsule. Spermathecae (S) present anterolaterally, spaced by two diameters. Fertilization ducts (FD) present dorso mesally.
Distribution. Known only from the type localities (Chongqing, Hubei and Hunan Provinces, Figs 307, 312, 315).
description: Published as part of Irfan, Muhammad, Zhou, Gu-Chun, Peng, Xian-Jin & Zhang, Zhi-Sheng, 2025, Survey of Linyphiidae spiders (Arachnida: Araneae) from some Oriental Regions of China, pp. 1-248 in Megataxa 15 (1) on pages 43-46, DOI: 10.11646/megataxa.15.1.1, http://zenodo.org/record/14985176