Atomaria (Anchicera) perkovskyi, Lyubarsky & Bukejs, 2022

Atomaria (Anchicera) perkovskyi sp. nov.

( Figs 3–4 View FIGURES 3–4 )

Type material. Holotype: collection number No 6832 [ MAIG] (ex coll. Jonas Damzen JDC-10149 R); adult, sex unkown. A complete beetle with partially exposed metathoracic wings is included in a transparent, yellow amber piece with dimensions of 38× 52 mm and a maximum thickness of 15 mm; preserved without supplementary fixation. Ventral side of specimen completely obscured by milky opacity. Syninclusions: four small Nematocera (Diptera) specimens.

Type stratum. Rovno amber, Late Eocene ( Perkovsky et al. 2007) .

Type locality. Rivne Oblast (region), Ukraine .

Description. Measurements: body length (from anterior margin of head to elytral apex along midline) about 1.19 mm, body maximum width across both elytron 0.50 mm; head length 0.16 mm, head maximum width across eyes 0.27 mm; pronotum length 0.30 mm, pronotum maximum width 0.38 mm; elytra length 0.73 mm, elytra maximum width 0.50 mm. Body broadly elongate, moderately arched, slightly convex; integument uniformly darkbrown (as preserved); sparsely covered with semierect pubescence.

Head transverse, about 1.7× as wide as long; coarsely punctate, distance between punctures equal to 0.5-1.0× diameter of one puncture, punctation denser laterally. Compound eyes hemispherical, convex, rather large, with large facets. Antennae inserted close to eyes, under lateral margin of forehead; antennal insertions widely separated; distance between antennal insertions larger than distance between antennae and аnterior margin of eye. Antennae 11-segmented with 3-segmented loose club, slender, short, reaching about to posterior one-third of pronotal length; antennomere 1 subcylindrical, elongate, 1.6× as long as wide; antennomere 2 conical, elongate, 1.5× as long as wide, slightly shorter than antennomere 1; antennomere 3 conical, short, nearly as long as wide, narrower and distinctly shorter than antennomere 2; antennomere 4 nearly as long as wide; antennomere 5 conical, nearly as long as wide, 1.1× as long as wide; antennomeres 6–8 trapezoidal, as long as wide; antennomeres 9–10 trapezoidal, strongly transverse, 1.5× as wide as long; antennomere 11 widely oval, with rounded apex, nearly as long as wide; relative length ratios of antennomeres 1–11 equal to 16:12:7:7:8:5:5:6:8:10:16.

Pronotum transverse, 1.2× as wide as long, slightly narrowed posteriad and anteriad, with maximum width in middle of its length; with slightly convex disc; with finely margined posterior and lateral sides; lateral side borders visible from above only in basal half. Pronotal punctation moderately coarse and dense, distance between punctures equal to 1.5-2.0× diameter of one puncture; puncture diameter slightly smaller than eye facet diameter. Posterior and anterior angles obtuse. Anterior edge weakly sinuate, without excision; posterior edge strongly bisinuate, lobed, with shallow depression and basal pits; lateral edges widely rounded, without callosity and teeth.

Scutellar shield small, oval, strongly transverse, 2.0× as wide as long, covered with fine punctation.

Elytra short-oval, moderately convex, with maximum width about in anterior one-third of its length, 1.5× as long as wide and 2.4 times as long as pronotum length; completely covering the abdomen; lateral sides widely rounded; humeri rounded, slightly prominent. Elytral punctation irregular, moderately coarse and dense; (nearly as pronotal punctation), distance between punctures equal to 1.5-2.0× diameter of one puncture. Epipleura incomplete. Macropterous, metathoracic wings fully developed.

Legs slender, long, relatively similar in shape, finely and densely punctate. Femora elongate-oval, flattened. Pretarsal claws simple, thin.

Etymology. The species is named in honor of our dear colleague Dr. Evgeny E. Perkovsky ( Kiev, Ukraine), leading researcher of inclusions in Rovno amber.

Differential diagnosis. Atomaria perkovskyi sp. nov. can be distinguished from related species by a combination of characters: antennomere 3 short, nearly as long as wide, distinctly shorter than antennomere 2; antennomeres 9 and 10 strongly transverse; antennomere 5 conical, nearly as long as wide, 1.1× as long as wide; pronotum narrowed toward base; lateral side borders of pronotum visible from above only in basal half of its length; and pronotum maximum width in middle of its length. A new species can distinguished from all other extinct Eocene Atomaria representatives using the identification key provided below.