Atomaria (Anchicera) perkovskyi, Lyubarsky & Bukejs, 2022

Lyubarsky, Georgy Yu. & Bukejs, Andris, 2022, TwonewfossilspeciesofthegenusAtomariaStephens (Coleoptera: Cryptophagidae) from Eocene European amber with a key to species described from fossil resins, Zootaxa 5188 (3), pp. 283-289 : 286-288

Atomaria (Anchicera) perkovskyi sp. nov.

( Figs 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.

Figures

FIGURES 3–4. Atomaria (Anchicera) perkovskyi sp. nov., No 6832 [MAIG]: 3—habitus, dorsal view; 4—habitus, ventrolateral view. Scale bar = 0.25 mm.