Malthinus (s. str.) rifbjergi, 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 : 20

Malthinus (s. str.) rifbjergi n. sp.

( Fig. 14 )

Holotype. Male, in Baltic amber, accession No. ALDC0510 /ALD. Ba.Can. 24

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. Fossil records of Malthinus are known from Baltic amber as various specimens at the generic level ( Fanti 2017a) and only one described species, M. danieli Kuśka & Kania, 2010 . Malthinus rifbjergi n. sp. differs in the brown legs, pronotum and elytra and the yellow head (pronotum yellow with a longitudinal black spot on the basal half, tibiae yellow-brown and femora dark in M. danieli ) ( Kuśka & Kania 2010). Furthermore, the new species has a different length of antennomeres, the second article being as long as third, and fourth and fifth articles longer, while in M. danieli the second is shorter and the antennomeres III-XI are subequal in length. The body length of M. danieli is 3.2 mm, while M. rifbjergi n. sp. is 4.0 mm.

Description. Adult, winged, slender. Female, defined on the basis of the short antennae and large last ventrite. Body length 4.0 mm. Head yellow and pronotum, elytra, antennae and legs brown. Head completely exposed, strongly triangular behind eyes, wider than pronotum, very wrinkly and equipped with impressed punctation. Eyes large, round, convex. Maxillary palps 4-segmented, with palpomeres unequal in length, with the terminal globular, elongated and distally pointed. Labial palps 3-segmented with the last segment globular and pointed. Antennae 11-segmented, filiform, surpassing the half of elytra; scape very elongated, club-shaped and enlarged at apex; pedicel ~1.5 times shorter than scape; antennomeres III-VI as long as pedicel; antennomeres VII-X slightly shorter than III; antennomere XI as long as III, slightly enlarged from middle to apex which is slightly pointed; all antennomeres equipped with many short setae. Pronotum transverse, slightly narrowed anteriorly, equipped with scattered pubescence, apical and basal margins straight and strongly bordered; sides sinuous; angles slightly rounded; surface not flat. Scutellum short and rounded. Elytra slightly narrower than head, wider than pronotum, short and not covering the last abdominal segments, parallel-sides, slightly narrowed from half length; apex strongly rounded; surface covered with impressed punctation ordered in lines and equipped with setae; apex without yellow rounded marks. Posterior wings dark, long and very surpassing the elytra and the abdominal segments. Sternum and abdominal segments pubescent; last tergite very short and rounded at apex. Legs slender; coxae massive; trochanters elongated; femora very enlarged; tibiae cylindrical, thin, longer than femora. Tarsal formula 5-5-5; tarsomere I long and ~2 times longer than second; tarsomere III short, tarsomere IV bilobed; tarsomere V slender; claws simple.

Etymology. This new species is named in memory of the Danish writer Klaus Rifbjerg (Copenhagen, 15 December 1931 - Copenhagen, 4 April 2015).

Syninclusions. Wood remains, oak inflorescence, stellate trichomes, some Diptera ( Empididae and other undetermined family).

Remarks. The amber piece measures 19.5 x 14.5 x 9 mm and weighs 2.4 grams. The inclusion is complete and well visible.

Figures

Fig. 14. Malthinus rifbjergi n. sp. in Baltic amber. A: Holotype, dorsal view, bar = 1.0 mm; B: Holotype, detail of head and pronotum, bar = 500 μm.