Amelyris ( Amelyris ) tricarinatus Tshernyshev, Alekseev, Bukejs, Vasilenko, Legalov

Amelyris ( Amelyris) tricarinatus Tshernyshev, Alekseev, Bukejs, Vasilenko, Legalov & Perkovsky, sp. nov.

urn:lsid:zoobank.org:act:

( Figs 11–13 View FIGURES 11–13 )

Type material. Holotype No ISEZh, sch_013, adult, male; Baltic amber. Complete beetle included in right triangular semi-transparent piece of amber with approximate dimensions 25 × 11 × 4 mm, with the beetle located near right angle of the piece. Underside and legs are not well visible due to milky-white coating and opacities in amber matrix. Syninclusions are represented by a few stellate Fagaceae trichomes and many detrital particles.

Locus typicus. Southeastern Baltic Sea coast, the Sambian peninsula, Kaliningrad Oblast .

Stratum typicum. Baltic amber, late Eocene.

Description. Integument unicolorous black (as preserved); dorsal setae brown to black, legs light brown to dark yellow. Body elongate, parallel, flattened dorsally and convex ventrally, very slightly expanded below the middle, with maximum width at about the middle; elytra slightly narrowed towards the apex and rounded, elytral apices closed. Measurements: body length 2.58 mm; body width (in the area of the base of the elytra) 0.8 mm.

Head prognathous, not sculptured, convex, subrounded, not protruding distally and not wider than pronotum at eye level. Compound eyes round-oval, protruding, bare; frons and interocular area evenly convex, without impressions. Surface of head densely punctate, with distinct microsculpture and covered with short, adpressed hairs which, in combination with punctures, give the surface a “cellular” structure as on pronotum. Antennae 11-segmented, short, attached to the head near lower edge of eyes near clypeus, extending over middle but not reaching base of pronotum. Last five antennomeres dilated, forming 5-segmented loose club. Antennomeres 1 and 2 slightly swollen and enlarged, round-oval; 1.5× as long as antennomere 2; antennomere 3 slightly elongated, subcylindrical, slightly narrower and shorter than antennomere 2 and 1.5× as long as antennomere 4; antennomeres 4–10 wide, subtriangular, moniliform, symmetrically dilated; antennomeres 7–11 forming loose club; antennomere 10 subquadrate; antennomere 11 slightly longer and wider than antennomere 10, evenly rounded and flattened at apex.

Pronotum convex, slightly longer than wide, quadrate-rectangular due to straight distal and basal margins and straight upper lateral carina, with slightly rounded angles, laterally with typical double carinate margins: upper carina straight, lower carina rounded, small longitudinal rib present in middle of lateral side between upper and lower carina. Pronotal surface evenly and coarsely punctured and covered with small adpressed hairs; microsculpture distinct; margins of distal and basal sides and upper lateral carinae straight, lower lateral carina widely prominent; all margins smooth without denticles. Pubescence short, curved, sparse, inconspicuous. Disc clearly impressed: at basal angles, near anterior angles, and narrowly along upper carina.

Scutellar shield clearly visible, rectangular, with acute angles and straight lateral sides; distal margin with triangular emargination in middle; surface with small punctures and fine adpressed pubescence; disc not marginate, mat.

Elytra carinate, elongate and parallel, slightly widened near middle, evenly weakly narrowed and rounded towards apex, completely cover abdomen, with closed apices. Bases of elytra slightly wider than pronotum. Humeri small and weakly prominent, distinct, slightly impressed at base, with small, narrow, weakly curved carina. Elytral disc probably dull. Each elytron with five thin and not strongly elevated carinae extending from base to apical part; first carina situated near suture, complete from base to apex; second third carinae not merged at elytral apex; fourth carina begins at base of elytra and continues on outside of humerus and along lateral side to elytral slope; fifth carina strongly attached to epipleura and distinct to end of elytral slope. Surface between carinae with three rows of distinct punctures and developed microsculpture, pubescence short, sparse and small, situated mainly on carinae. Epipleura narrow, distinct along elytra from base to apex, with row of sparse punctures in middle and distinct microsculpture; edges of epipleura smooth, lacking denticles. Metathoracic wings well developed.

Legs short, simple; femora slightly thickened and evenly flattened; tarsomeres 1–4 strongly compressed, first metatarsomere 2.0× shorter than metatarsomere 2.

Ventral side convex, mat, finely and densely punctate, bare.

Etymology. The specific epithet of the new species tricarinatus (Latin adjective meaning “having three ridges or keels”) refers to the three lateral carinae of pronotum, characteristical for the species.