Stemonyphantes bifurcus sp. nov. (叉冠蛛)

urn:lsid:zoobank.org:act: 79E6DE86-42CB-453B-B116-8B35347D28D6

Figs 46, 48A

Differential diagnosis

The new species resembles Stemonyphantes lineatus (Linnaeus, 1758) in having the similar paracymbium (Fig. 46B; Hormiga et al. 2021: fig. 8a) but can be distinguished by the radix with bifurcated anterior radical process (Fig. 46A); tegulum with three anterior tegular process (Fig. 46A–B, D).

Etymology

The epithet is derived from the Latin adjective ‘ bifurcus ’ meaning ‘bifurcate’ and referring to the distal end of radix being bifurcated with two radical processes in male palp (Fig. 46A–B, D).

Type material

Holotype CHINA • ♂; Chongqing, Wushan County, Guanyang Town, Zhuxian Township, Putao Village; 31°15′26.72″ N, 110°4′34.11″ E; elev. 1542 m; 6 Oct. 2020; L.Y. Wang, X.W. Zhou, T.Y. Ren, J.X. Zhao and L. Xiao leg.; SWUC-T-LIN-19-01.

Paratype CHINA • 1 ♀; Wushan County, Guanyang Town, Zhuxian Township, Putao Village; 31°16′8.98″ N, 110°4′34.11″ E; elev. 1445m; 6 Oct. 2020; L.Y. Wang, X.W. Zhou, T.Y. Ren, J.X. Zhao and L. Xiao leg.; SWUC-T-LIN-19-02.

Description

Male (holotype, Figs 46, 48A)

MEASUREMENTS. Total 3.57 long; carapace 1.95 long, 1.21 wide; abdomen 1.88 long, 1.43 wide. Eye sizes and interdistances: AME 0.13, ALE 0.13, PME 0.12, PLE 0.12, AME–AME 0.08, PME–PME 0.08 AME–ALE 0.04, PME–PLE 0.11, ALE–ALE 0.61, PLE–PLE 0.64, ALE–PLE 0.02, AME–PME 0.11.

CEPHALOTHORAX. Carapace yellow, cephalic region slightly elevated; fovea, cervical and radial grooves distinct. Clypeus 0.28 high.

CHELICERAE. With four promarginal and three retromarginal teeth.

LEG MEASUREMENTS. Legs long, yellow, covered with fine spines. Length of legs: I 7.26 (1.96, 2.33, 1.77, 1.20), II 6.66 (1.82, 2.13, 1.62, 1.09), III 5.39 (1.61, 1.71, 1.31,0.76), IV 6.78 (1.77, 2.21, 1.81, 0.99). Leg formula I-IV-II-III. TmI 0.26 and TmIV absent. Tibial spine formula: 2-2-2-2.

ABDOMEN. Oval, grey, dorsally with black and white patches extending laterally, ventral side grey.

PALP (Fig. 46). Patella as long as tibia, slightly curved, dorsally with long thick spine; tibia longer than wide, with two retrolateral and one dorsal trichobothria; ventral tibial apophysis slightly curved with blunt end. Cymbial process broad, D-shaped in ventral view. Paracymbium J–shaped, with thick spines on proximal part. Tegulum with three anterior tegular apophyses, gradually narrow towards distal end with notched tip. Embolic division: radix longer than wide, anterior radical process bifurcated. Embolus long and thin, whip-like.

Female

Unknown.

Distribution

Known from type locality.