Euconnus (Cladoconnus) nathani, Jałoszyński & Perkovsky, 2021

Jałoszyński, Paweł & Perkovsky, Evgeny E., 2021, A new bizarre species of Euconnus (Cladoconnus) in Upper Eocene Rovno amber (Coleoptera: Staphylinidae: Scydmaeninae), Zootaxa 5004 (2), pp. 395-400 : 396-397

† Euconnus (Cladoconnus) nathani sp. n.

( Figs 1–5 )

Type material. Holotype: Late Eocene of Europe , Rovno amber: male; inclusion in irregular piece of amber ~30 × 15 × 10 mm, collection number SIZK L-983, collected 10 km north of Voronki village , Vladimirets District, Rovno Region, Ukraine ( SIZK).

Diagnosis. Antennomeres 7–9 conspicuously modified: 7 small, with short mesal projection; 8 enormously enlarged, crescent-shaped, with long, curved and pointed mesal projection and the widest place situated just behind distal articulation; 9 with mesal margin concave, lateral margin convex, broadest near distal fourth.

Description. Body ( Figs 1–5 ) elongate but not slender, dark brown, nearly black, glossy, BL 2.03 mm; vestiture as dark as cuticle.

Head weakly elongate, exposed only in left lateral and anteroventral views, HL 0.43 mm, HW 0.38 mm; eyes small and oval, weakly convex, adjacent to large antennal fossae. Maxillary palp typical of Stenichnini, with slender subconical palpomere 4. Vertex in anterior view ( Fig. 5 ) strongly convex, slightly bulging dorsad; frons between antennal fossae narrow, with concave sides, broadening anterad, towards broad and convex clypeus ( Fig. 5 ; cl); tempora in lateral view about as long as eyes; labrum ( Fig. 5 ; lbr) large and with evenly rounded anterior margin, with long erect setae. Punctures on frons and vertex not discernible; setae sparse, short and suberect; tempora with sparse thick bristles, well-visible near occipital constriction. Antennae ( Fig. 2 ) much shorter than body, AnL 0.98 mm; scape and pedicel each about twice as long as broad, antennomeres 3–6 each slightly or indistinctly elongate, 7 strongly asymmetrical, about as long as 6 but much broader, with mesal (in Fig. 2 anterior) projection, 8 strongly enlarged and monstrously modified, crescent-shaped, with long, curved and pointed mesal (in Fig. 2 anterior) projection, its mesal margin strongly concave and outer lateral margin strongly rounded, widest site of antennomere 8 situated just behind distal articulation, antennomere 9 strongly modified, with mesal margin concave and outer lateral margin convex, widest near distal fourth, with small subtriangular distomesal projection, antennomere 10 unmodified, about as long as broad, antennomere 11 unmodified, about 1.8 × as long as broad, about as long as 9 but much longer than 10.

Pronotum largely obscured by air bubble, PL 0.48 mm, PW 0.45; only left hypomeron visible, including clearly marked hypomeral ridge ( Fig. 4 ; hyr) demarcating glabrous inner region from outer area densely covered with thick, straight bristles.

Elytra dorsally not exposed (obscured by air bubble) much broader than pronotum, strongly convex, broadest apparently in front of middle, with evenly rounded sides, EL 1.13 mm, EW 0.75 mm, EI 1.5; punctures not discernible, elytral surface covered with moderately dense and long suberect setae.

Hind wings not exposed.

Lateral area on mesoventrite with dense, thick bristles; mesoventral intercoxal process ( Fig. 4 ; msvp) keel-like, narrow and strongly elevated, extending anteriorly far beyond mesocoxae.

Metaventrite unmodified, evenly and weakly convex on median region, uniformly covered with setae similar to those on sides of elytra; metaventral intercoxal process ( Fig. 4 ; mtvp) broad, with weakly concave posterior margin.

Legs long and slender, unmodified, except for slightly recurved metatibiae.

Female. unknown.

Etymology. This remarkable species is dedicated to Nathan Perkovsky, a prematurely deceased son of the second author.

Figures

FIGURES 1–3. Euconnus (Cladoconnus) nathani sp. n. Habitus in lateroventral view (1); head and antennae in lateroventral view (2); anteroventral habitus (3). Roman numbers indicate antennomeres.

FIGURES 4–5. Euconnus (Cladoconnus) nathani sp. n. Habitus in lateroventral (4) and anteroventral (5) views. Roman num- bers indicate antennomeres; abbreviations: cl, clypeus; hyr, hypomeral ridge; lbr, labrum; msvp, mesoventral process; mtvp, metaventral process.