Rovnoscydmus

Jałoszyński, Paweł & Perkovsky, Evgeny, 2016, Diversity of Scydmaeninae (Coleoptera: Staphylinidae) in Upper Eocene Rovno amber, Zootaxa 4157 (1), pp. 1-85 : 52-53

† Rovnoscydmus sp. specimen 9

( Figs 22 , 161–164 )

Material studied. Late Eocene of Europe , Rovno amber: male; inclusion in elongate, subtriangular prism of amber 23.5 mm long ( Fig. 22 ), collection number K-3322 ( SIZK).

Description. Body ( Figs 161–164 ) elongate, slender and relatively strongly convex, brown; BL 1.10 mm.

Head ( Figs 161–164 ) visible only in lateral view, HL 0.23 mm; only sides of vertex and frons visible; compound eyes large, strongly convex, bean-shaped; tempora slightly shorter than eyes. Punctures on frons and vertex not visible; setae ( Fig. 163 ) sparse, short and suberect. Antennae ( Figs 161–164 ) slightly shorter than half BL, AnL 0.53 mm, antennal club not demarcated; antennomeres I–II strongly elongate, III–VII elongate (III only slightly), VIII–X about as long as broad or slightly transverse, XI much shorter than IX–X combined, about 1.6 × as long as broad, with rounded apex.

Pronotum ( Figs 161–164 ) visible only in lateral view, broadest site not possible to define; PL 0.28 mm, punctures and setae poorly visible.

Elytra (161–164) elongate oval, strongly convex, broadest site not possible to define, EL 0.60 mm, punctures and setae poorly visible.

Legs ( Figs 161–164 ) moderately long, slender, unmodified.

Remarks. This specimen is visible only in lateral view, but its measurements and proportions are similar to those of Rovnoscydmus species, the metacoxae are clearly separated from sides of metaventrite ( Fig. 164 ), and the antennae are very similar to those of Rovnoscydmus frontalis . Examination in slightly lateroventral view revealed that the metaventral intercoxal process does not differ from that of Rovnoscydmus frontalis . Taking into account the shape of the head in lateral view very similar to that illustrated in Figs 124 , 138 and 150 , determination of the inclusion K-3322 as congeneric with Rovnoscydmus seems strongly supported.

A unique feature of this specimen is the aedeagus (AeL 0.30 mm) protruding from the abdomen ( Figs 161– 164 ). It demonstrates that Rovnoscydmus has the male copulatory organ typical for most Glandulariini , i.e., with slender parameres visible at both sides of the median lobe; it also seems to be symmetrical. Moreover, as this is the only unambiguously identified male of this genus, it also demonstrates that at least in this species of Rovnoscydmus no peculiar external secondary sexual characters exist.

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 161 – 164. Rovnoscydmus sp. specimen 9 (K- 3322). Right lateral (161, 163) and left lateral (162, 164) views. Abbreviations: aed, aedeagus.

FIGURES 123 – 125. Rovnoscydmus sp. specimen 1 (K- 25702). Dorsolateral (123), ventrolateral (123) and ventral (125) view. Abbreviations: abg, antebasal groove; bef, basal elytral fovea; bst, basisternal part of prosternum; fr, frons; hy, hypomeron; mn, mentum; lbr, labrum; lp, labial palp; mcp, mesocoxal projection; md, mandible; mn, mentum; mtvp, metaventral intercoxal process; mxp 2 – 4, maxillary palpomere II – IV; nr, ' neck' region; pcr, procoxal rest; st 3 – 8, abdominal sternite III – VIII; tm, temple; v 3, metaventrite; vt, vertex.

FIGURES 135 – 138. Rovnoscydmus sp. specimen 4 (K- 8970). Ventrolateral (135, 137) and dorsolateral (136, 138) views. Abbreviations: abg, antebasal groove; bef, basal elytral fovea; hw, hind wing; hy, hypomeron; hyr, hypomeral ridge; lbr, labrum; mcp, mesocoxal projection; md, mandible; mtvp, metaventral intercoxal process; mxp 3 – 4, maxillary palpomere III – IV; nr, ' neck' region; st 3 – 8, abdominal sternite III – VIII; tm, temple; v 3, metaventrite.

FIGURES 145 – 150. Rovnoscydmus sp. specimen 6 (K- 7350). Dorsal (145, 148), dorsolateral (146, 149) and lateral (147, 150) views. Abbreviations: bef, basal elytral fovea; fr, frons; hw, hind wing; mcp, mesocoxal projection; nr, ' neck' region; tm, temple; vt, vertex.