Electrolichas circumbalticus, Alekseev, Vitalii I. & Jäch, Manfred A., 2016

Alekseev, Vitalii I. & Jäch, Manfred A., 2016, Electrolichas circumbalticus gen. et sp. nov. (Coleoptera: Byrrhoidea: Ptilodactylidae) from Baltic amber, the first anchytarsine toed-winged beetle described from Europe, Zootaxa 4136 (3), pp. 593-599 : 595-597

Electrolichas circumbalticus sp. nov.

( Figs. 1–5 )

Material examined. Holotype No. 1141-1 [ CCHH], adult, male (ramose antennae), almost complete (left protarsus lacking), included in medium-sized elongate yellow amber piece with approximate dimensions: 42 × 25 × 9 mm. The ventral part of the beetle is partially obscured by milky foam. Syninclusions are represented by four specimens of Diptera ( Sciaridae male, Psychodidae male, Chironomidae male and female), one specimen of Hymenoptera (Scelionidae) , two specimens of Hemiptera (Coccina crawler, Aphidina nymph), Acari, numerous fagacean stellate hairs and pollen of different conifers.

Type strata. Baltic amber, Upper or mid-Eocene.

Type locality. Yantarny settlement (formerly Palmnicken), Sambian (Samland) Peninsula, Kaliningrad Region, Russia.

Diagnosis. As stated for the new genus.

Description. Habitus. Body length 8.25 mm; width (at elytral humeri) 2.5 mm. Elongate, moderately densely punctate and pubescent, entirely dark brown.

Head. Subquadrate; almost indistinctly punctate. Eyes entire, finely facetted, without interfacetal setae, strongly protuberant. Labrum transverse, slightly sinuate anteriorly, with antero-lateral setal tufts. Terminal segment of maxillary palps cylindrical, ratio of palpomeres 2–4: 5.0: 3.0: 6.0. Antennal insertions exposed in dorsal view, widely separated. Antennae pectinate, long (when posteriorly extended reaching beyond middle of elytra), with non-articulated rami. Antennomeres 1–2 simple and cylindrical, antennomeres 3–10 uniramose, triangular process of antennomere 3 shortest. Ratio of antennomere lengths: 7.0: 4.0: 10.0: 10.0: 10.0: 10.0: 10.0: 10.0: 10.0: 10.0: 13.0.

Thorax. Pronotum transverse (in dorsal view about 0.55 times as long as its median length); broadest at base, narrowed and rounded anteriorly. Anterior margin of pronotum almost semicircular. Lateral pronotal margin very narrowly explanate. Posterior angles of pronotum more or less acute. Pronotal basal margin weakly bisinuate and finely crenulate, medially with shallow rounded emargination, which is, on each side, bordered by a tooth-like process. Prosternum with a process fitting into cavity of mesoventrite. Prosternal process narrow, keeled, narrowly rounded at apex. Mesoventral keel absent. Scutellum weakly cordiform, anterior margin more or less straight, without median notch or excision. Elytra subparallel-sided, almost as broad as pronotum basally, not striate, moderately convex, irregularly punctate, about 2.1 times as long as their combined widths and 5.0 times as long as pronotum. Elytral punctures unisetose, distinct, round, separated by 2–3 times of a puncture diameter. Pubescence of elytra short (as on pronotum), becoming gradually longer towards apex; setae on elytral apices almost twice as long as on base. Epipleura present, widest at humeral area; reaching first ventrite.

Legs. Pro- and mesocoxae conical. Metacoxae very narrowly separated, transverse. Femora and tibiae slender. Tibiae with two acute apical spurs. Tarsi ( Fig. 3–4 ) not pseudotetramerous, proportional lengths of metatarsomeres: 1.5: 1.2: 1.2: 1.1: 1.5, flashy pads on apex of first tarsomere (not distinctly bilobed) as well as on tarsomeres 2–4 (distinctly bilobed). Claws simple, acute, long, symmetrical.

Abdomen. With five ventrites. Ratio of ventrite lengths: 3.0: 4.0: 3.0: 3.0: 3.4. Fifth ventrite simple, entire, without emargination apically.

Etymology. The specific epithet is toponymic and refers to the region of the specimen’s origin. It is formed after the Latin “circum” (around, in vicinity) and the Medieval Latin “balticus” (Baltic). Remarks. The area of the mouthparts is indistinct in the holotype. Genitalia internal and obscured in this specimen. Metathoracic wings not visible. The monochrome dark body color of the specimen could be a result of the fossilization in amber.

Figures

FIGURES 1 – 2. Electrolichas circumbalticus gen. et sp. nov., holotype, habitus: 1) dorsal view; 2) ventro-lateral view.

FIGURES 3 – 5. Electrolichas circumbalticus gen. et sp. nov., holotype: 3) pro-, meso- and metatarsi, ventral view; 4) metatarsus dorso-lateral view; 5) reconstruction of habitus, dorsal view.