Palmnickeneoceras ejersboi, 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 : 15-16

Palmnickeneoceras ejersboi n. sp.

( Fig. 10 )

Holotype. Sex undetermined, in Baltic amber, accession No. ALDC0392 /ALD. Ba.Can. 17

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. Palmnickeneoceras ejersboi n. sp. is distinguishable by the palps elongated and slightly securiform, and by the shape of antennae, unknown in any other fossil species. The other fossil genera of the same lineage show more antennomeres. Furthermore, extant and fossil members of the subfamily Malth in inae with long elytra, Malthinus (Indomalthinus) Brancucci in Wittmer & Brancucci, 1978, Inmalthodes Pic, 1938 , Macrocerus Motschulsky, 1845 , Mimomalthinus Pic, 1931 , Mantimalthinus Fanti & Castiglione, 2017 and Kuskaella Fanti & Kupryjanowicz, 2017 - show a different surface of elytra, different palps or a different pronotal shape ( Fanti & Castiglione 2017; Fanti & Kupryjanowicz 2017).

Description. Adult, winged, robust habitus. Sex undetermined (last sternites are not well visible). Body length 5 mm. Pronotum reddish - orange, elytra dark brown Ʊ blackish, antennae and legs testaceous - brown. Head pale brown, as large as pronotum. Eyes small and elongatedsubspherical, interocular dorsal distance ~4.2 times greater than eye diameter. Mandibles small, little visible but seemingly without tooth. Maxillary palpomeres unequal with last segment very elongated and slightly securiform, without appendix at apex. Antennae inserted near and on the inner part of the eyes, long, reaching the apical th ird of the elytra, 11-segmen ted, covered with dense and very short setae; scape elongated and cylindrical; pedicel very short and about six times shorter than scape; antennomeres III-V dilated; antennomere VI rectangular; antennomeres VII-XI filiform, antennomeres XI extremely elongated, much more than scape. Pronotum strongly transverse, parallel-sided; basal margin very slightly bordered; surface smooth with some small setae. Scutellum wide at base and elongated at apex, that is roundish. Elytra slightly wider than pronotum with rugose surface and numerous setae, elongated, covering the last abdominal segments; apex slightly roundish. Posterior wings covered by elytra. Sternum and abdominal segments dark brown and covered with numerous setae. Legs equipped with numerous short setae; coxae small and short; trochanteres elongated and roundish; profemora curved, very dilated and cylindrical, meso- and metafemora slender and longer; tibiae cylindrical very thin and long. Tarsi 5-segmented; first tarsomere slightly elongated; second tarsomere about one-half as long as the first, third tarsomere very small and bilobed at sides; fourth triangular; fifth long and scale-shaped; claws simple, long and robust.

Etymology. The species is named in memory of the Danish journalist and writer Jakob Ejersbo (Rødovre, 6 April 1968, Aalborg, 10 July 2008).

Syninclusions. Numerous stellate trichomes and wood remains (also botanical masses and pollen grains), pyrite, one Trichoptera, two Diptera , one mite.

Remarks. The piece of amber of rectangular shape, measures 24 x 10 x 5 mm. The left antenna is folded along the body, the antennomeres VIII-X are not well visible and even all legs are curled up. It is not possible to observe if the claws have a tooth at the base.

Figures

Fig. 10. Palmnickeneoceras ejersboi n. gen. et n. sp. in Baltic amber. A: Holotype, dorsal view, bar = 500 μm; B: Holotype, ventral view, bar = 500 μm; C: Holotype, detail of antennae, bar = 500 μm; D: Holotype, dorsal view, bar = 1.0 mm.