Europoeurypus inglaeso, Alekseev & Bukejs & Pollock, 2020

Alekseev, Vitalii Igorevich, Bukejs, Andris & Pollock, Darren Andrew, 2020, A new fossil Eurypinae genus and sexual dimorphism in the representatives of Omineus (Coleoptera: Mycteridae) from Tertiary amber of Europe, Zootaxa 4820 (3), pp. 551-562 : 554-556

Europoeurypus inglaeso sp. nov.

( Figs. 1–5 )

Material examined. Holotype: No. 6081 [ MAIG] (No. JD 8112 ex coll. Jonas Damzen), adult, apparently female. Almost complete beetle inclusion (tarsomeres present on right pro- and mesotarsus only, apical parts of all left tibiae missing) included in transparent, flat, oval, orange piece of amber with dimensions 24×14× 4 mm. Syninclusions are represented by detrital particles and a few stellate trichomes of plant origin.

Type strata. Baltic amber from Eocene amber-bearing Blaue Erde deposits (mostly Bartonian age, as interpreted for extinct Central European resin-producing forests according to Bukejs et al. 2019).

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

Diagnosis. As stated above, for the new genus.

Description. Body relatively large-sized, elongate, slightly convex dorsally; dark, unicolorous. Dorsal surface evenly punctured and covered with fine, decumbent, conspicuous pubescence.

Measurements: body length 10.2 mm, maximum body width 3.3 mm (elytra postmedially); head length about 1.0 mm, maximum width of head (across eyes) 1.8 mm; pronotal length 1.7 mm, maximum pronotal width 2.3 mm; elytral length 7.5 mm, maximum elytral width (in humeral area) 2.8 mm.

Head moderately narrowed posterior of eyes. Compound eyes protruding, transverse, without intrafacetal setae, widely separated, with entire and very slightly emarginate anterior margin; ommatidial facets distinct and fine (as large as punctures on head). Frons convex, minimum distance between eyes 2.8× as wide as longitudinal eye diameter measured laterally. Ocular (suborbital) grooves indistinct. Frontal furrows present, straight, subparallel. Labrum with anterior margin almost straight, bearing long setae. Mandibles bidentate apically. Terminal maxillary palpomere broadly triangular. Antennal insertion slightly hidden from above. Antennae 11-segmented, short, reaching posteriorly to near one-third of pronotum, pubescent. Antennomeres 2–10 cylindrical, about 2× as long as wide; scape and antennomere 11 wider than other antennomeres; scape subquadrate; antennomere 11 ovoid, pointed api-cally, about 1.5× as long as antennomere 10.

Thorax. Pronotum transverse, 1.3× as wide as long, widest at middle. Pronotal base distinctly narrower than elytral base. Anterior and lateral margins of pronotum slightly rounded; posterior margin slightly sinuate. Lateral pronotal carina present, discernible in ventral view in two-thirds of pronotal length basally. Anterior and posterior angles rounded, not produced. Pronotal disc slightly convex, uneven, with pair of small symmetrical triangular depressions at base; pronotum densely and finely punctate, distance between punctures equal to 0.2–0.3× diameter of one puncture. Prosternum long anterior of procoxae. Procoxal cavities apparently open posteriorly. Elytra elongate, disc moderately convex; dorsal surface evenly and irregularly punctate and pubescent. Pubescence decumbent, long (equal to 5.0–6.0× distance between punctures); distance between punctures equal to 0.5–1.0× diameter of one puncture. Scutellar shield as long as wide, rounded, densely pubescent, pointed posteriorly. Mesocoxal cavities open. Elytral epipleura narrow, widest in basal part and then gradually narrowed posteriorly, extended to abdominal ventrite 2. Metaventrite convex, densely punctate.

Legs slender. Procoxae subconical, contiguous. Meso- and metacoxae narrowly separated. Femora flattened. Tibiae straight, subequal in length to femora, with two short, equal in length spurs apically. Pro- and mesotarsi pen-tamerous. Penultimate tarsomere distinctly widened distally, flat, non-lobed. Tarsal claws swollen basally, without acute basal tooth, symmetrical. Ratio of mesotarsomere lengths 5: 3: 3: 4: 6.

Abdomen with five visible abdominal ventrites. Ventrites 1–3 connate, ventrites 4–5 free; sutures between ven-trites 1–2 and 2–3 flat, sutures between ventrites 3–4 and 4–5 shelf-like. Anterior (intercoxal) process of ventrite 1 broadly triangular, pointed apically. All ventrites punctate, setose, without discernible sex patch(es). Apical margin of ventrite 5 rounded. Ratio of lengths of ventrites 1–5 3.5: 3.5: 3.5: 3.0: 2.5 (medially).

Etymology. The specific epithet inglaeso is a Latin word combination of “in glaeso” (meaning “in amber”), used as a noun in apposition and created analogously to the widely used biological terms “ in vivo ” and “ in vitro ”.

Remarks. The holotype apparently is female due to the lack of sex patch on abdominal ventrite(s).

Figures

FIGURES 1–2. Europoeurypus inglaeso gen. et sp. nov., holotype, No MAIG 6081: 1—habitus, dorsal view; 2—habitus, ven- tral view. Scale bars represent 4.0 mm.

FIGURE 3–4. Europoeurypus inglaeso gen. et sp. nov., holotype, No MAIG 6081: 3—abdomen, showing ventrites without discernible sex patches; 4—details of forebody, dorsal view. Abbreviations: v1–v5—abdominal ventrites 1–5 respectively; icp—intercoxal process of ventrite 1. Scale bars represent 1.0 mm.

FIGURE 5. Reconstruction of Europoeurypus inglaeso gen. et sp. nov. from Baltic amber: habitus, dorsal view. Body length = 10.2 mm.