Rhagonycha (s. str.) nielsenae, Fanti & Damgaard, 2018

Fanti, Fabrizio & Damgaard, Anders Leth, 2018, Fossil soldier beetles from Baltic amber of the Anders Damgaard amber collection (Coleoptera Cantharidae), Baltic Journal of Coleopterology 18 (1), pp. 1-32 : 18-19

Rhagonycha (s. str.) nielsenae n. sp.

( Fig. 12 )

Holotype. Female, in Baltic amber, accession No. ALDC0053 /ALD. Ba.Can. 4

Type locality. Russia, Kaliningrad Region, Sambian Peninsula, amber quarry near Yantarny (previously known as Palmnicken).

Type horizon. Middle Eocene (Lutetian) (47.8- 41.2 MY) to Late Eocene (Priabonian) (37.8- 33.9 MY).

Differential diagnosis. Only two species of Rhagonycha are actually known from amber deposits: Rh. kryshtofovichi ( Yablokov-Khnzorian, 1960) , which differs from Rh. nielsenae n. sp. in larger size (7 mm) and different length of the antennomeres, and Rh. sucinobaltica Poinar & Fanti, 2016 , which differs in the blackish-dark brown colour, the pronotum with much more concave sides and in th e differ en t last abdomin al segmen t ( Yablokov-Khnzorian 1960; Kazantsev 2013; Poinar & Fanti 2016). Other members of the genus Rhagonycha are known from Eocene of Florissant ( USA), Miocene of Oeningen ( Germany) and Radoboj ( Croatia), and from Pliocene of Lac Chambon, France ( Fanti 2017a). All show different colour and body size. Description. Adult, winged. Female, defined on the basis of the short antennae, massive habitus and on the large last ventrite. Body length ~ 3.3 mm; elytra 2.5 mm. Entirely dark brown except for the black head. Head completely exposed, elongated, pubescent. Eyes large and roundish, interocular ventral distance about two times greater than eye diameter. Mandibles not visible. Maxillary palps 4-segmented with the last palpomere elongated-securiform and stout. Labial palps 3-segmented with the last segment securiform. Antennae filiform, 11-segmented, short and slightly surpassing the humeral zone of elytra, equipped with short setae; scape robust, long and cylindrical; pedicel short, one-third as long as scape; antennomere III similar in length to the pedicel; antennomeres IV-VI very elongated and subequal in length; antennomeres VII-XI subequal in length, shorter and more robust than the previous. Pronotum trapezoidal, slightly wider than long and larger than head, equipped by a dense short pubescence and small punctation, large at base and gradually steadily narrower towards the apex; basal angles strongly rounded; apical margin bordered. Scutellum strongly rounded and pubescent. Elytra elongated and covering the last abdominal segments, stout, very slightly broader than base of pronotum, parallel-sided; apex narrow and slightly rounded; surface equipped with many setae. Posterior wings completely covered by elytra. Sternum dark brown, trapezoidal, equipped with scattered setae; ventrites short and wide with the last rounded and large. Legs short and pubescent; coxae massive; trochanters elongated with rounded apex; femora robust; tibiae thin, cylindrical, as long as femora. Tarsi 5-segmented; first segment slightly elongated; second and third shorter than first and straight at apex; fourth segment slightly bilobed at sides; fifth thin and elongated; claws bifid but not well visible.

Etymology. This new species is named in memory of Nielsine Mathilde Nielsen (Svendborg, 10 June 1850 - Copenhagen, 8 October 1916), the first female academic and physician in Denmark.

Syninclusions. Wood remains.

Remarks. The amber piece is yellow and quite flattened and measures around 15 x 9 mm. The inclusion is complete with the ventral side not optimally visible, and dorsally covered with a superficial cotton-like emulsion.

Figures

Fig. 12. Rhagonycha nielsenae n. sp. in Baltic amber. A: Holotype, dorsal view, bar = 500 μm; B: Holotype, ventral view, bar = 500 μm; C: Holotype, detail of pronotum, bar = 100 μm; D: Holotype, detail of sternum, bar = 200 μm.