Dicristatus minutus, Irfan & Wang & Zhang, 2023

Irfan, Muhammad, Wang, Lu-Yu & Zhang, Zhi-Sheng, 2023, Survey of Linyphiidae spiders (Arachnida: Araneae) from Wulipo National Nature Reserve, Chongqing, China, European Journal of Taxonomy 871, pp. 1-85 : 9-13

Dicristatus minutus gen. et sp. nov. (微二叉蛛)

urn:lsid:zoobank.org:act:5C8B2773-385A-4E81-AC05-6A9A922C0075

Figs 4–6

Differential diagnosis

Dicristatus minutus gen. et sp. nov. can be diagnosed by the lower projection of dorsal tibial apophysis with seven teeth and the upper projection with six teeth; anterior radical process comma-shaped in retrolateral view in male palp. Dorsal plate outline anteriorly V-shaped in epigyne.

Etymology

The epithet is derived from the Latin adjective ‘ minutus ’ meaning ‘minute’ and referring to the very small embolus, completely covered by the distal suprategular apophysis in male palp ( Fig. 4B, 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-04-01 .

Paratypes

CHINA • 1 ♀; same collection data as for holotype; SWUC-T-LIN-04-02 • 1 ♀; Chongqing, Wushan County, Guanyang Town, Zhuxian Township Miaotang ; 31°21′39.92″ N, 110°06′07.50″ E; elev. 1065 m; 19 Jul. 2021; Z. S. Zhang, L.Y.Wang and T.Y. Ren leg.; SWUC-T-LIN-04-03 .

Description

Male (holotype, Figs 4 , 6A ) MEASUREMENTS. Total 1.61 long; carapace 0.79 long, 0.60 wide; abdomen 0.98 long, 0.62 wide. Eye sizes and interdistances: AME 0.03, ALE 0.07, PME 0.07, PLE 0.07, AME–AME 0.02, PME–PME 0.07, AME–ALE 0.03, PME–PLE 0.04, ALE–ALE 0.24, PLE–PLE 0.27, ALE–PLE 0.01, AME– PME 0.05.

CEPHALOTHORAX. Carapace yellow; cephalic region slightly elevated; fovea, cervical and radial grooves distinct. Clypeus 0.15 high.

CHELICERAE. With six promarginal and five retromarginal teeth.

LEG MEASUREMENTS. Legs long, yellow, covered with fine spines. Length of legs: I 2.56 (0.69, 0.88, 0.56, 0.43), II 2.28 (0.61, 0.78, 0.52, 0.37), III 1.94 (0.55, 0.62, 0.44, 0.33), IV 2.52 (0.72, 0.85, 0.58, 0.37). Leg formula I-IV-II-III. TmI 0.29 and TmIV absent. Tibial spine formula: 2-2-1-1.

ABDOMEN. Oval, light gray to green, densely covered with fine spines, ventral side light gray.

PALP ( Fig. 4 ). Patella short, medially grooved. Tibia with one retrolateral and one dorsal trichobothria, retrolateral tibial apophysis absent; dorsal tibial apophysis large, tongue-shaped in ventral view, retrolateral margin with a row of comb macrosetae, ventrally with a pair of comb-shaped projections; lower projection with seven teeth and upper projection with six teeth; cymbial retrobasal process with a small projection, extending retrolaterally, covering basal part of paracymbium; paracymbium J-shaped, distal arm tip with an indent; protegulum small; suprategulum with a sharp median tooth of distal suprategular apophysis; distal suprategular apophysis robust, distally bifurcated, completely covering the embolus. Embolic division: tailpiece foot-shaped; anterior radical process comma-shaped in retrolateral view, strongly sclerotized, outer surface serrated; embolic membrane reduced, curved with pointed end; embolus black, strongly sclerotized, minute with pointed end, hardly visible on undissected palp.

Female (paratype, SWUC-T-LIN-04-02, Figs 5 , 6B )

MEASUREMENTS. Total 1.82 long; carapace 0.82 long, 0.56 wide; abdomen 1.27 long, 0.67 wide. Eye sizes and interdistances: AME 0.04, ALE 0.07, PME 0.05, PLE 0.08, AME–AME 0.02, PME–PME 0.05, AME–ALE 0.02, PME–PLE 0.03, ALE–ALE 0.23, PLE–PLE 0.28, ALE–PLE 0.01, AME–PME 0.06.

CEPHALOTHORAX. Same as in male. Clypeus 0.11 high.

CHELICERAE. With six promarginal and five retromarginal teeth.

LEG MEASUREMENTS. Legs long, yellow, covered with fine spines. Length of legs: I 2.31 (0.66, 0.84, 0.49, 0.32), II 2.13 (0.61, 0.72, 0.46, 0.34), III 1.84 (0.53, 0.63, 0.39, 0.29), IV 2.40 (0.68, 0.84, 0.49, 0.39). Leg formula IV-I-II-III. TmI 0.39 and TmIV absent. Tibial spine formula: 2-2-1-1.

ABDOMEN. Same as in male.

EPIGYNE ( Fig. 5 ). Ventral plate wider than long; copulatory ducts forming a broad loop outside ventral plate, extending posteriorly above the epigastric furrow; copulatory openings situated mid-ventrally in the inner margin loop of copulatory ducts; dorsal plate heart-shaped, longer than wide, posterior margin round, with a deep depression at center. Vulva: spermathecae round, antero-laterally positioned, pointing away from each other. Fertilization ducts antero-mesally oriented.

Distribution

Known from type locality.

Figures

Fig. 4. Dicristatus minutus gen. et sp. nov., ♂ holotype (SWUC-T-LIN-04-01), left palp. A. Prolateral view. B. Retrolateral view. C. Dorsal view. D. Ventral view.

Fig. 5. Dicristatus minutus gen. et sp. nov., ♀ paratype (SWUC-T-LIN-04-02). A, C–D. Epigyne, ventral view. B. Epigyne, lateral view. E. Vulva, dorsal view.

Fig. 6. Dicristatus minutus gen. et sp. nov., habitus, dorsal view. A. Holotype, ♂ (SWUC-T-LIN-04-01). B. Paratype, ♀ (SWUC-T-LIN-04-02).