Sabacon claviger ( Menge, 1854 )

Mitov, Plamen G., Perkovsky, Evgeny E. & Dunlop, Jason A., 2021, Harvestmen (Arachnida: Opiliones) in Eocene Rovno amber (Ukraine), Zootaxa 4984 (1), pp. 43-72 : 59

Sabacon claviger ( Menge, 1854)

Figs 18–21

Material examined. UKRAINE: SIZK K-7898, from Rovno amber, Rovno Oblast (Region), Sarny District, Klesov, Pugach quarry; late Eocene. Syninclusions: stellate hairs/trichomes; Isopoda (Oniscoidea) .

Description. SIZK K-7898 ( Figs 18–19 ) has a deformed body (L: 1.5), prosoma width: 1.0. Carapace smooth, with only a few setae. Opisthosomal dorsum ornamented by regular rows of black thorns ( Fig. 19 ). Venter: surface of all coxae, genital operculum and sternites with a black spine-like setae; ocular tubercle: length 0.25, and width 0.375. Appendage article lengths: chelicerae: basal segment: 0.25, distal segment: 0.67, movable digit: 0.3; pedipalps: Fe: 0.62, Pa: 0.57, Ti: 0.92, Ta: 0.37; Leg I: Fe: 1.0, Pa: 0.5, Ti: 1.12, Mt: 1.45, Ta: 1.55; Leg II: Fe: 1.7, Pa: 0.62, Ti: 1.97, Mt: 2.32, Ta: 3.2; Leg III: Fe: 1.0, Pa: 0.42, Ti: 1.0, Mt: 1.62; Leg IV: Fe: 0.92, Pa: 0.45; part of the segments could not be measured correctly. Pedipalps inflated ( Figs 20–21 ), trochanter, femur and patella with scattered spine-like setae; tibia and tarsus throughout with dense brush-like setae—probably plumose glandular as in modern species, see Wolff et al. (2016) —ventro-distally, tibia with a long seta ( Fig. 20 : arrow). All leg articles with black, scattered spine-like setae; patellae, tibiae, metatarsi and tarsi with short setae; tarsi ending with a single claw.

Remarks. The Eocene localities fit into the present range of Sabacon , namely SW Europe, Siberia, Russia (Primorye Province), the Himalayas, India, China, Japan, Korea and North America (see Staręga 2002; Martens 2015). It is noteworthy that the shape of the palpal tibia and tarsus in Sabacon claviger ( Figs 20–21 ) is closest to that of males of European members of the genus (i.e., Sabacon viscayanum ramblaianum Martens and Sabacon altomontanum Martens ; e.g., Martens 1983: figs 32, 48).

Figures

FIGURES 18–21. Sabacon claviger (Menge, 1854), SIZK K-7898, from Rovno amber (Klesov, Pugach quarry, Ukraine), late Eocene. 18 Detail of the body and limbs, dorsal view. 19 Detail of the body and limbs (view from back), showing the opisthosomal dorsum ornamented by regular rows of black thorns (arrowed). 20 Detail of the left pedipalp in ventro-ectal view, showing tibia and tarsus throughout with dense brush-like setae and the tibial long seta (arrowed). Part of the palpal setae are not visible due to amber aberrations—compare with Fig. 21. 21 Detail of the right pedipalp, showing the tibia and tarsus, closer ectal view. Scale bars: 18–19: 1 mm; 20: 0.5 mm; 21: 0.3 mm.