Gramboale prutenorum, Alekseev & Tomaszewska, 2018

Alekseev, Vitalii I. & Tomaszewska, Wioletta, 2018, New handsome fungus beetles (Coleoptera: Coccinelloidea: Anamorphidae, Endomychidae) from European amber of the Upper Eocene, Palaeontologia Electronica (6 A) 21 (1), pp. 1-23 : 3-5

Gramboale prutenorum sp. nov.

Figure 1

zoobank.org/ 9222D44D-A06C-4458-A4F0-D3F31BBCE428

Type material. Holotype: No. 1799-1 [ CCHH]. Presumably male. The beetle inclusion is preserved in a polished piece of transparent amber with a yellowish shade. The small amber piece is embedded in a block of polyester resin (total measurements are: 14 x 7 x 6 mm). Syninclusions absent. Left half of the beetle is obscured by milky foam in the surrounding amber.

Type strata. Baltic amber. Eocene.

Type locality. Russia, Kaliningrad region, the Sambian (Samland) peninsula, Yantarny settlement (formerly Palmnicken) .

Etymology. The species name is derived from the Latin name of the West Baltic tribe Pruteni or Prutheni (Prussians). The epithet is a noun in plural form and in genitive case.

Diagnosis. As stated for new genus.

Description. Body length = 3.4 mm; width (at widest point in the middle part of elytra) = 1.8 mm; height = 1.38 mm. Rounded, convex habitus; dorsal surface shiny and glabrous; body including appendages uniformly black.

Head wide, retracted into prothorax up to surface of compound eyes, punctate, finely shagreened; puncture diameters are 0.5 times that of one compound eye facet; width of interspaces 1.0– 3.0 times puncture diameter. Punctation on frons slightly sparser than on clypeus. Fronto-clypeal suture present. Eyes rounded, slightly prominent. Antennae relatively long, extending to base of elytra, composed of 11 antennomeres with conspicuous, pubescent club composed of three antennomeres; antennomere 1 obovate. Terminal maxillary palpomere as long as antennomere 2, obconical. Terminal labial palpomere pointed, rounded-triangular; penultimate palpomere subcylindrical.

Pronotum convex, transverse, 0.47 times as long as wide; with rounded posterior and anterior angles; finely bordered laterally. Posterior margin of pronotum weakly bisinuate, anterior margin weakly concave. Pronotum finely shagreened anteriorly, coarsely and moderately densely punctate, with width of interspaces 1.5–2.0 times puncture diameter laterally and with width of interspaces 3.0–4.0 times puncture diameter medially. Prosternal process wide. Procoxal cavities open externally, closed internally. Mesoventrite with intercoxal process rounded and prominent anteriorly between mesocoxae.

Elytra rounded, convex, shiny, glabrous, with weak humeri, punctate-striate. Punctures (rounded on elytral disc and oval laterally), forming regular or almost regular rows or shallow furrows. Sutural striae indistinct. Scutellum visible, weakly transverse, rounded posteriorly. Epipleura well developed, almost reaching apex of elytra. Hind wings not apparent.

Meso- and metacoxae widely separated (by distance equal almost two times and three times longitudinal coxal diameter, respectively). Mesocoxal cavities closed laterally. Abdomen with five ventrites; ventrite 1 as long as two following ventrites combined. Ventrites 2, 3, and 4 subequal in length. Apex of terminal ventrite widely rounded. Postcoxal lines on ventrite 1 absent. Thoracic punctation dense and large, abdominal punctation (especially on ventrites 2–5) sparser and distinctly smaller.

Femur subclavate; meso- and metafemur with shallow groove on inner margin. All tibiae simple (without angulations or projections), weakly curved, covered with short pubescence. Tarsal formula 4-4-4. Tarsi long, with simple cylindrical segments, pubescent (tarsomere 1 bearing tuft of very dense and long setae ventrally). Tarsomere 4 as long as tarsomeres 1–3 combined. Tarsal claws long (0.3 x as long as tarsomere 4), curved, symmetrical, toothed basally.

Remarks. The holotype is most likely a male, based on the presence of modifications on the legs in the form of tufts of setae on tarsomere 1. Genitalia are internal and obscured in this specimen, and are generally impossible to differentiate in specimens embedded in amber.

Figures

FIGURE 1. Gramboale prutenorum gen. et sp. nov. (No. 1799-1 [CCHH], holotype) (Anamorphidae) from Baltic amber. 1-3, Habitus in lateral (1), dorsal (2), and ventral (3) views. 4, A reconstruction of the habitus in ventral view.