Furcembolus fengzheni Jiang & Li, 2021

Xin, Yafei, Jiang, Tongyao, Yao, Zhiyuan & Li, Shuqiang, 2021, Three new species of the extinct spider genus Furcembolus (Araneae: Pacullidae) from Late Cretaceous Burmese amber, Zootaxa 4984 (1), pp. 258-273 : 269-270

Furcembolus fengzheni Jiang & Li spec. nov.

Figs 1C–D , 5–6 , 10A

Type material. MYANMAR: Kachin State: Holotype: male (IZCAS-Ar42320Fo), Late Cretaceous amber from Hukawng Valley . No biotic syninclusions.

Material studied for comparison. Furcembolus cf. crassitibia ( Fig. 10B , SEABRI-Ar002), Late Cretaceous amber from Hukawng Valley. No biotic syninclusions.

Etymology. The specific name is a patronym in honour of the late Chinese arachnologist Fengzhen Wang (1906–1978) and is a noun (name) in genitive case.

Diagnosis. This species resembles Furcembolus andersoni (see Wunderlich 2008: 582, figs 20–22, photos 75–76) by possessing a long apophysis on embolus, but can be distinguished by the presence of apophysis on the tibia, tibia swollen, the angle of embolus and the sclerotized apophysis of embolus ( Figs 5 , 10A ). In F. andersoni , the tibia is without apophysis. The embolus of F. crassitibia (see Wunderlich 2017: 129, fig. 78) is similar to F. fengzheni spec. nov., but can be distinguished by the angle of embolus. The embolus of F. crassitibia bend twice in a right angle. The embolus of F. fengzheni spec. nov. slightly bending ( Figs 5 , 10A ).

Description. Male (holotype): Total length 3.12, carapace 1.43 long, opisthosoma 1.69 long, 1.14 wide. Left palp not visible, left leg I: 8.46 (2.45 + 0.38 + 2.69 + 2.22 + 0.72), leg II: 5.20 (1.53 + 0.30 + 1.48 + 1.33 + 0.56), leg III: 3.40 (0.88 + 0.31+ 0.91 + 0.85 + 0.45), leg IV: – (1.32 + – + – + – + –); right palp: 1.23 (0.61 + 0.16 + 0.46), right leg I: 8.29 (2.08 + 0.44 + 2.81 + 2.28 +0.68), leg II: 5.20 (1.36 + 0.37 + 1.55 + 1.36 + 0.56), leg III absent, leg IV: 5.32 (1.42 + 0.36+ 1.42 + 1.51 + 0.61). Eyes: diameter ALE 0.06, AME not visible, diameter PLE 0.06. Habitus as in Figs 6D–E . Colour in amber: prosoma and opisthosoma yellow-brown, legs light yellow. Prosoma ( Figs 6A, D–E ): carapace ( Fig. 6A ) finely granulated, margin distinctly serrated, cephalic part of carapace clearly highest in its posterior portion; six eyes almost ovoid, AME> PLE = ALE; clypeus vertical anteriorly, without modifications, 0.31 high; chelicerae without modifiactions; labium triangular, distally obtuse; sternum rough. Leg slender, serrate setae present on metatarsal and tarsal, serration more apparent in tarsal; elongated trichobothria on femur, tibia and metatarsal. Opisthosoma ( Figs 6B, D–E ): oval with 4 or 5 sclerotized lateral plates, smooth, modified by tiny pits, covered with thin setae; ventral scutum rugose. Lateral scutum I reaches the half of margin of pulmonary plate. Spinnerets not visible. Palp ( Figs 5 , 10A ): femur approximately 4 times longer than patella; patella short; tibia swollen, approximately 3 times as wide as femur, with apophysis on the distal; cymbium small and compressed; bulb long, slightly swollen; embolus originates from the apex of oval palpal bulb, bending inwards in the middle; embolus with a sclerotized apophysis.

Figures

FIGURES 1A–D. Ambers pieces containing Furcembolus chuandiani spec. nov., holotype male (A–B) and Furcembolus fengzheni spec. nov., holotype male (C–D) (A, C dorsal; B, D ventral). Scale bars: 10.0 mm.

FIGURES 5A–D. Furcembolus fengzheni spec. nov., holotype male.A–B Right palp, retrolateral. C Embolus of the right palp, prolateral. D Embolus of the left palp, retrolateral. Scale bars:A, C: 0.50 mm; B, D: 0.20 mm. B—bulb, Cy—cymbium, E—embolus, EA—embolus apophysis, Fe—femur, Pa—patella, Ti—tibia.

FIGURES 6A–E. Furcembolus fengzheni spec. nov., holotype male. A Carapace, lateral. B Opisthosoma, lateral. C Leg claws, lateral, asterisks indicate the serrate setae present on tarsus. D–E Habitus, lateral. Scale bars: A, D–E: 1.00 mm; B: 0.50 mm; C: 0.10 mm.

FIGURES 10A–B. †Furcembolus spp., male palp. A Furcembolus fengzheni spec. nov. (IZCAS-Ar42320Fo), right palp, retrolateral. B Furcembolus cf. crassitibia (SEABRI-Ar002), right palp, retrolateral, horizontally flipped. Scale bars: 0.20 mm.