Metoisops michalskii Kim, Taszakowski, and Herczek sp. nov.

Figs. 1A, 2.

Zoobank LCID: urn:lsid:zoobank.org:act: D378FF45-A830-4D05-B346- 6FAAC446208A

Etymology: Named after Artur Michalski, a collector of the new fossil; a noun in the genitive case.

Holotype: DZUS HE44-451 - 1-001, male in 23×14 × 4 mm in piece of Baltic amber, with the curatorial museum code.

Type locality: Vistula Spit, Gdańsk Bay, Poland.

Type horizon: Baltic amber, mid-Eocene (ca. 44.1±1.1 Ma according to Wappler 2005).

Material.— Holotype only.

Diagnosis.—Differs from other congeners by the following combination of characters: body relatively small, deeply punctate, covered with densely golden pubescence (Fig. 2A 1); head extremely transverse, wider than 3× longitudinal length; vertex distinctly narrow; compound eye wide, single compound eye as wide as 3× vertex; second antennal segment thick, slightly clavate; third segment shorter than fourth segment; fourth segment subdivided (Fig. 2A 3); second labial segment shortest; third labial segment longest; posterior pronotal width shorter than 2 times longitudinal length; embolium impunctate; basal and apical parts of femur dark brown.

Description.—Male body elongate-oval, length 2.69 mm. Coloration mostly dark brown, partly pale brown. Head mostly dark brown; vertex and frons dark; clypeus and juga dark brown; antennae mostly dark brown; apical part of first segment, second segment and apical part of first subdivision of fourth segment somewhat paler; labium mostly pale brown, apex of fourth labial segment dark brown. Thorax pronotum entirely dark brown; scutellum pale brown; hemelytron mostly dark brown; embolial margin paler; membrane grayish, subhyaline; legs pale brown with dark bands; basal and apical parts of femur dark brown. Abdomen entirely dark brown.

Body generally glossy, mostly punctate, densely covered with golden pubescence; frons and clypeus impunctate, covered with relatively short pubescence; antennae with short and dense erect setae; pronotum with large and dense punctures except for calli region, densely covered with golden pubescence; scutellum with small punctures and with somewhat short pubescence; mesoscutum impunctate; hemelytra with large punctures, covered with dense golden pubescence; embolial area impunctate; cuneus impunctate.

Head hypognathous, elongate in lateral view, anterior margin almost straight in dorsal view, less than pronotum height in lateral view; vertex narrow, approximately 3 times as wide as single compound eye; compound eye slightly prominent in frontal view; ocelli large, almost touching compound eye, not close to each other; fovea antennalis positioned below compound eyes; antennae shorter than the body, four segmented including subdivided fourth segment, cylindrical; first segment slightly longer than the third segment; second segment longest and thickest, longer than the third and fourth segments combined; third segment shorter than fourth segment; proportion of first to fourth antennal segments 0.20: 0.81: 0.26: 0.39 (first subsegment: 0.20; second subsegment 0.19); frontal-clypeal part rather elongate; labium somewhat thick, exceeding hind coxae, reaching third abdominal segment. Thorax pronotum trapezoid, midline length longer than anterior width and 1/2 posterior width respectively, posterior margin weakly convex in middle, lateral margin straight, posterior angle slightly carinate; pronotal collar thin; calli region weakly swollen; scutellum large, midline as same as pronotal midline length, width more than anterior pronotal width; mesoscutum narrowly developed; lateral margin of hemelytra rounded; commissure as long as scutellum length; cuneus broad, inner margin straight, cuneal fracture weakly developed; membrane with two cells (large and very small); legs moderately long; hindfemur not reaching the apex of abdomen; tarsus two segmented (Fig. 2A 5). Abdomen elongate, exceeding apex of cuneus. Genital capsule with a pair of relatively large parameres, left paramere subequal to right paramere in length; left paramere scythe-shaped, hypophysis broad; right paramere elongate and curved, hypophysis tapered to apex (Fig. 2A 6).

Measurements (in mm).—Body length 2.69; head length 0.18; head width including compound eyes 0.54; vertex width 0.08; first antennal segment 0.20; second antennal segment 0.81; third antennal segment 0.26; fourth antennal segment 0.39 (subsegments; first 0.20; second 0.19); first labial segment 0.27; second labial segment 0.32; third labial segment 0.29; fourth labial segment 0.34; pronotal midline length 0.48; basal pronotal maximal width (straight) 0.90; anterior scutellar width 0.52; scutellar midline length 0.37; commissure length 0.46; outer embolial margin length (straight) 1.24; maximal width across hemelytron 0.42; hindleg (femur: tibia: tarsus) 0.92: 1.20: 0.33.

Remarks.—The subequal parameres in length and the structure of apices of parameres (broad hypophysis in left paramere and tapered hypophysis in right paramere) are similar to those found in Gigantometopini. The paramere morphology of fossil in Isometopinae is the first finding.

Stratigraphic and geographic range. — Type horizon and locality only.