Dicranopalpus ramiger (C. L. Koch & Berendt, 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 : 57

Dicranopalpus ramiger (C. L. Koch & Berendt, 1854)

Dicranopalpus ramiger: Perkovsky et al. (2010a: 121 , fig. 6D; 126, fig. 9B, Rovno amber)

Figs 15–17

Material examined. UKRAINE: SIZK K-1151 (jointly with SIZK K-1150, and SIZK K-1152–1158), SIZK K- 9767. All from Rovno amber, Rovno Oblast (Region), Sarny District, Klesov, Pugach quarry; late Eocene. Syninclusions: SIZK K-1150, female Theridiidae (Araneae) ; Auchenorrhyncha (Cicadinea); SIZK K-9767: stellate hairs/trichomes; SIZK K-9768: Сollembola, Entomobryomorpha; SIZK K-9769, incertae sedis ; SIZK K-1151, Diptera : Dolichopodidae ; SIZK K-1152: Cecydomyiidae (Lеdomyia sp.); SIZK K-11533, Araneae , juv.; SIZK K-1154, Acari : Cunaxidae (Cunaxinae) ( Sergeenko et al. 2013); SIZK K-1155, Auchenorrhyncha: Fulgoroidea; Diptera : Nematocera; SIZK K-1156, Hymenoptera : Scelioninae ; SIZK K-1157, Diptera : Tipuloidea; SIZK K-1158: female of Culicoides (Ceratopogonidae) ( Sontag & Szadziewski 2011).

Description. SIZK K-1151 ( Figs 15–16 ) is near the edge of the amber piece: part of the opisthosoma is concealed by an air bubble. During the processing of the amber piece, the front part of the prosoma was sawn off together with part of the limbs. However, the specific shape of the ocular tubercle and the structure of the remaining patellar and tibial apophyses of the pedipalps ( Fig. 16 ) clearly indicate the generic affiliation of this fossil. Body length: 1.125, abdomen width: 0.87. Ocular tubercle width: 0.25, diameter of each lens 0.11. Appendage lengths: palpal tarsus length: 0.52, tarsus ends with claw; tibial apophysis length: 0.1; tibial apophysis maximum width: 0.07. The other palpal/limbs segments cannot be measured correctly.

SIZK K-9767 ( Fig. 17 ) with L: 1.12–1.25; abdomen width: 0.88; Appendage lengths: Palps with article lengths of: Fe: 0.56; Pa: 0.18; patellar apophysis length: 0.28; Ti: 0.42–0.43; tibial apophysis length: 0.1; Ta: 0.77–0.78. Legs femur length: Fe I: 2.15–2.25; Fe II: 4.85; Fe III: 2.35; Fe IV: 3.35.

Remarks. In extant forms of this genus, the tibial apophysis/protuberances of the pedipalps are usually more prominent in juveniles and females than in males. An apophysis is present on the pedipalpal tibia in these fossil specimens too ( Figs 16–17 ), see also Dunlop & Mitov (2009: fig. 19). This combined with their small size indicates that, as in extant Dicranopalpus , these are most likely either juveniles ( Staręga 2002)—see also photos of juvenile Dicranopalpus in Duinen (2020) —or subadults (most likely female) of relatively small-bodied species (body length in the range of 1.1–3.6). Comparative modern examples would be, e.g., Dicranopalpus angolensis (Lawrence) from Angola in Africa, or D. larvatus (Canestrini) and D. brevipes Marcellino , both from Italy ( Lawrence, 1951: 40–42, figs 3–4; Wijnhoven & Martens 2019: fig. 4; Wijnhoven et al. 2020: fig. 4).

Dicranopalpus ramiger has been previously recorded from Baltic and Bitterfeld amber ( Table 1 ) and was the only harvestman species previously reported from Rovno amber ( Perkovsky et al. 2010a). Interestingly, its modern relative Dicranopalpus ramosus Doleschall appears to be in the process of moving northwards from its Mediterranean origins ( Wijnhoven & Prieto 2015, and literature therein), and is thus reclaiming areas where the fossil record indicates the genus formerly occurred. Noordijk et al. (2007) noted that the living species D. ramosus is primarily scansorial on trees and shrubs. If the amber species had a similar lifestyle to the modern counterpart this might explain the frequency with which these animals tended to become trapped in resin. In northern European amber collections it is usually the predominant harvestman species (see Mitov et al. 2021).

Figures

FIGURES 15–17. Dicranopalpus ramiger (C. L. Koch & Berendt, 1854) from Rovno amber (Klesov, Pugach quarry, Ukraine), late Eocene. 15 SIZK K-1151, detail of body and legs, dorso-lateral view. 16 SIZK K-1151, detail of left pedipalp (sawn off), showing the distal part of patellar apophysis (black arrow) and the tibial apophysis (white arrow). 17 SIZK K-9767, detail of the body and limbs (view from back); note the long patellar (black arrow) and short tibial (white arrow) apophyses characteristic for the genus. Scale bars: 15, 17: 1 mm; 16: 0.1 mm.