Euconnus

Jałoszyński, Paweł & Perkovsky, Evgeny, 2016, Diversity of Scydmaeninae (Coleoptera: Staphylinidae) in Upper Eocene Rovno amber, Zootaxa 4157 (1), pp. 1-85 : 60

Euconnus (incertae sedis) sp. 1

( Figs 26 , 182–188 )

Material studied. Late Eocene of Europe , Rovno amber: sex unknown; inclusion in elongate, rectangular prism of amber 11.5 mm long ( Fig. 26 ), collection number K-9126 ( SIZK).

Description. Body ( Figs 182–188 ) elongate, relatively stout and strongly convex, dark brown; BL 1.50 mm.

Head ( Figs 182–188 ) broadest at eyes, HL 0.33 mm, HW 0.35 mm; shape of vertex and frons difficult to assess; tempora seem shorter than eyes. Punctures on frons and vertex ( Figs 186–187 ) fine, separated by spaces 3– 4 × as wide as diameters of punctures; setae ( Figs 186–187 ) sparse, short, suberect. Antennae ( Figs 182–188 ) much shorter than half BL, AnL 0.55 mm, shapes of antennomeres difficult to assess, but antennae seem to be gradually thickened distally and compactly assembled, with at least some of flagellomeres transverse.

Pronotum ( Figs 182 , 186 ) slightly broader than long, broadest site difficult to define, but most likely in front of middle; PL 0.35 mm, PW 0.38 mm; anterior margin arcuate; posterior margin shallowly bisinuate, shapes of pronotal corners and lateral margins difficult to assess; base of pronotum with short but distinct sublateral carinae ( Fig. 186 ; slc) and one (inner) pair of antebasal pits ( Fig. 186 ; abp). Punctures on pronotal disc ( Fig. 186 ) small but distinct, separated by spaces 3–4 × as wide as diameters of punctures; setae ( Fig. 186 ) short, sparse, suberect; sides of pronotum with thick bristles ( Figs 186–188 ).

Elytra ( Figs 182, 184–186, 188 ) elongate oval, strongly convex, broadest anterior to middle, EL 0.83 mm, EW 0.60 mm, EI 1.38; punctures and setae similar to those on pronotum but slightly sparser ( Fig. 186 ). Scutellum not visible between elytral bases.

Legs ( Figs 183 , 187–188 ) moderately long, slender, unmodified.

Remarks. This species can be placed in Euconnus on the basis of the carinate and elevated mesoventral intercoxal process ( Fig. 187 ; msvp) the metaventral intercoxal process ( Fig. 187 ; mtvp) short and very broad, broadly separating metacoxae, the scutellum not exposed between elytral bases ( Fig. 186 ), the subtriangular inner (adcoxal) part of prothoracic hypomeron ( Fig. 187 ; hy) demarcated laterally by complete hypomeral ridge ( Fig. 187 ; hyr), and two basal elytral foveae ( Fig. 186 ; bef) on each elytron. Additionally, the lateral bristles on the pronotum and sublateral pronotal carinae ( Fig. 186 ; slc) accompanied by small antebasal pits ( Fig. 186 ; abp) can be found in many extant species of Euconnus , but these characters are not restricted to this genus. This fossil does not show any conspicuous characters that could be used to reliably define a new species; also it was not possible to determine whether this species belongs to any of the extant subgenera or not.

Figures

FIGURES 21 – 34. Specimens of Rovno amber with inclusions of Scydmaeninae. K- 8972, Rovnoscydmus sp. specimen 8 (21); K- 3322, Rovnoscydmus sp. specimen 9 (22); K- 15548,? Rovnoscydmus sp. specimen 10 (23); K- 8971,? Rovnoscydmus sp. specimen 11 (24); K- 6045, Euconnus palaeogenus sp. n. (25); K- 9126, Euconnus sp. 1 (26); K- 24859,? Euconnus sp. 2 (27); K- 24302, Stenichnus proavus sp. n. (28); UA- 2216, Microscydmus sp. 1 (29); K- 6943,? Microscydmus sp. 2 (30); K- 3657 a,? Microscydmus sp. 3 (31); K- 6764,? Scydmoraphes sp. 1 (32); K- 6274, Glandulariini gen. & sp. indet. 1 (33); K- 7089, Glandulariini gen. & sp. indet. 2 (34).

FIGURES 182 – 185. Euconnus sp. 1 (K- 9126). Dorsal (182), ventral (183), right lateral (184) and left lateral (185) views.

FIGURES 186 – 188. Euconnus sp. 1 (K- 9126). Nearly dorsal (186), ventral (187) and lateral (188) views. Abbreviations: abp, antebasal pit; bef, basal elytral fovea; bst, basisternal part of prosternum; cl, clypeus; fr, frons; hy, hypomeron; hyr, hypomeral ridge; lbr, labrum; lp, labial palp; md, mandible; msvp, mesoventral intercoxal process; mtvp, metaventral intercoxal process; mxp 3 – 4, maxillary palpomere III – IV; pg, pygidium; slc, sublateral carina; st 3 – 8, abdominal sternite III – VIII; v 3, metaventrite.