Furcembolus martensi 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 : 270

Furcembolus martensi Jiang & Li spec. nov.

Figs 3 , 7–8 , 11B

Type material. MYANMAR: Kachin State: Holotype: male (IZCAS-Ar42321Fo), Late Cretaceous amber from Hukawng Valley . No biotic syninclusions.

Material studied for comparison. F. longior ( Fig. 11A , SEABRI-Ar003), Late Cretaceous amber from Hukawng Valley. No biotic syninclusions.

Etymology. The specific name is dedicated to Prof. Dr. Jochen Martens; noun (name) in genitive case.

Diagnosis. The embolus apophysis of this species is similar to Furcembolus longior (see Wunderlich 2017: 131, figs 80–81, photo 62), but can be distinguished by palpal tibia without apophysis and egg-shaped in lateral view, by the length of the embolus, by the shape of embolus, and the shape of carapace ( Figs 7 , 11B ). The embolus of F. longior has a triangular apophysis near its tip. Both cephalic region and the lateral of thoracic region of F. martensi spec. nov. are raised, while only the cephalic region of F. longior is raised.

Description. Male (holotype): Total length 3.54, carapace 1.56 long, 0.85 wide, opisthosoma 1.98 long, 1.28 wide. Left palp: 1.36 (0.59 + 0.21 + 0.56), left leg I: 9.66 (2.69 + 0.41 + 3.22 + 2.53 + 0.81), leg II: 6.30 (1.68 + 0.42 + 1.80 + 1.71 + 0.69), leg III: 4.61 (1.25 + 0.45+ 1.04 + 1.38 + 0.49), leg IV: 5.52 (1.52 + 0.31 + 1.64 + 1.41 + 0.64); right palp: 1.26 (0.70 + 0.17 + 0.39), right leg I: 9.63 (2.84 + 0.45 + 2.97 + 2.53 +0.84), leg II: 6.56 (1.87 + 0.45 + 1.88 + 1.68 + 0.68), leg III: – (– + – + –+ 1.05 + 0.55), leg IV: – (1.86 + 0.32+ 1.62 + – + –). Eyes: diameter ALE 0.04, diameter AME 0.13, diameter PLE 0.05, distance ALE-PLE not visible, distance AME-AME 0.08. Habitus as in Figs 8D–E . Colour in amber: body and legs dark brown. Prosoma ( Figs 8A–B, D–E ): carapace finely granulated, margin distinctly serrated, cephalic part of carapace clearly highest in its posterior portion; six eyes ( Fig. 8B ) almost ovoid, AME> PLE> ALE; clypeus vertical anteriorly; chelicerae with two tiny teeth, anterior surface not visible; labium triangular, distally obtuse; sternum ( Fig. 8A ) rough, marginally rugose. Leg slender, with distinctly serrate setae. Opisthosoma ( Figs 8D–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 7 , 11B ): femur approximately 3 times longer than patella, curved and rugose at middle part of ventral surface; patella short; tibia swollen, approximately 5 times as wide as femur, without apophysis; cymbium small and compressed; bulb long, proximal slightly swollen; embolus originates from the apex of oval palpal bulb, bending outwards in the middle and inwards on the distal part; embolus with a flat apophysis.

Figures

FIGURES 3A–D. Furcembolus chuandiani spec. nov., holotype male. A–B Right embolus, arrow points at tip of embolus (A dorsal, B retrolateral). C Right palp, retrolateral. D Left palp, retrolateral. Scale bars: A: 0.20 mm, B: 0.10 mm, C–D: 0.50 mm. B—bulb, Cy—cymbium, E—embolus, Fe—femur, Pa—patella, Ti—tibia.

FIGURES 7A–D. Furcembolus martensi spec. nov., holotype male. A, C–D Left palp (A dorsal, C prolateral, D retrolateral). B Embolus of the left palp, dorsal. Scale bars: A, C–D: 0.50 mm; B: 0.10 mm. B—bulb, Cy—cymbium, E—embolus, EA—embolus apophysis, Fe—femur, Pa—patella, Ti—tibia.

FIGURES 8A–E. Furcembolus martensi spec. nov., holotype male. A Prosoma, ventral. B Carapace, lateral. C Leg claws, lateral view, asterisks indicate the serrate setae present on tarsus. D–E Habitus, lateral. Scale bars: A–B: 0.50 mm; C: 0.10 mm; D–E: 1.00 mm. ALE—anterior lateral eye, AME—anterior median eye, En—endite, Lb—labium, PME—posterior lateral eye.

FIGURES 11A–B. †Furcembolus spp., left male palp. A Furcembolus longior (SEABRI-Ar003), retrolateral. B Furcembolus martensi spec. nov. (IZCAS-Ar42321Fo), retrolateral. Scale bars: 0.20 mm.