Cephennomicrus

Jałoszyński, Paweł & Perkovsky, Evgeny, 2016, Diversity of Scydmaeninae (Coleoptera: Staphylinidae) in Upper Eocene Rovno amber, Zootaxa 4157 (1), pp. 1-85 : 25

Cephennomicrus sp. 1

( Figs 6 , 71–74 )

Material studied. Late Eocene of Europe , Rovno amber: sex unknown; inclusion in elongate prism of amber 18 mm long ( Fig. 6 ), collection number K-8289 ( SIZK).

Description. Body ( Figs 75–80 ) elongate and moderately strongly convex, dark brown; BL 0.70 mm.

Head ( Figs 76–77, 79–80 ) broadest at eyes, HL 0.10 mm, HW 0.15 mm; head structures poorly visible, compound eyes large and strongly convex, finely faceted. Antennae ( Figs 76, 79 ) much shorter than half BL, AnL about 0.25 mm, antennomeres I–V elongate, the shape of VI–VIII difficult to assess in the studied specimen, IX about as long as broad, X transverse, XI about as long as IX–X combined, slightly broader than X, about twice as long as broad, slightly asymmetrical.

Pronotum ( Figs 75–76, 78–79 ) nearly semioval; PL 0.20 mm, PW 0.25 mm; pronotal disc broadest near base, sides strongly rounded in anterior half and weakly so in posterior third; posterior pronotal corners obtuse-angled; posterior margin arcuate and slightly flattened in front of scutellum; base with two pairs of small and shallow but distinct antebasal pits ( Fig. 78 ; abp) connected by narrow transverse antebasal groove ( Fig. 78 ; abg). Punctures on pronotal disc fine but distinct, separated by spaces 1.5–2 times as wide as diameters of punctures; setae short, moderately dense, suberect ( Figs 75–78 ).

Elytra ( Figs 75–80 ) elongate oval, moderately convex and broadest anterior to middle, EL 0.40 mm, EW 0.31 mm, EI 1.28; punctures slightly larger and sparser than those on pronotal disc; setae similar to those on pronotum ( Figs 75–78 ).

Legs ( Figs 76–77, 80 ) moderately long, slender, unmodified; all tibiae straight or weakly curved near base.

Remarks. This is the smallest adult of Cephennomicrus found in Rovno amber; the key characters of this genus are clearly visible in the dorsal and ventral view in Figs 78, 80 . Judging from the body length, proportions of body parts and the shape of pronotum, this species is almost certainly different from all remaining specimens of Cephennomicrus treated in this paper. However, as all congeneric specimens described below, it is an unremarkable species that could be properly defined only by male genital characters.

Figures

FIGURES 1 – 20. Specimens of Rovno amber with inclusions of Scydmaeninae. K- 27418, Rovnoleptochromus ableptonoides sp. n. (1); K- 243, Vertheia quadrisetosa sp. n. (2); UA- 442, Vertheia sp. 1 (3); K- 800, Cephennodes sp. 1 (4); K- 6011, Cephennomicrus giganteus sp. n. (5); K- 8289, Cephennomicrus sp. 1 (6); K- 7010, Cephennomicrus sp. 2 (7); K- 27565, Cephennomicrus sp. 3 (8); K- 8912, Cephennomicrus sp. 4 (9); DU- 32, Cephennomicrus sp. 5 (10); K- 5770, Glaesoconnus unicus sp. n. (11); K- 9579, Rovnoscydmus frontalis sp. n. (12); K- 347, Rovnoscydmus microscopicus sp. n. (13); K- 25702, Rovnoscydmus sp. specimen 1 (14); K- 26348, Rovnoscydmus sp. specimen 2 (15); UA- 1556, Rovnoscydmus sp. specimen 3 (16); K- 8970, Rovnoscydmus sp. specimen 4 (17); K- 8968, Rovnoscydmus sp. specimen 5 (18); K- 7350, Rovnoscydmus sp. specimen 6 (19); K- 3037, Rovnoscydmus sp. specimen 7 (20).

FIGURES 71 – 74. Holotype of Cephennomicrus giganteus sp. n. (K- 6011). Habitus in dorsolateral (71, 73) and lateral (72, 74) view. Abbreviations: abg, antebasal groove; abp, antebasal pit; bef, basal elytral foveae; bst, basisternal part of prosternum; hy, hypomeron,; hyr, hypomeral ridge; lpc, lateral pronotal carina; mcp, mesocoxal projection; msvp, mesoventral intercoxal process; mtvp, metaventral intercoxal process; mxp 2 – 3, maxillary palpomere II – III; pg, pygidium; psp, prosternal process; st 3 – 8, abdominal sternite III – VIII; v 3, metaventrite.

FIGURES 75 – 80. Cephennomicrus sp. 1 (K- 8289). Dorsolateral (75, 78), lateral (76, 79) and ventral (77, 80) view. Abbreviations: abg, antebasal groove; abp, antebasal pit; bst, basisternal part of prosternum; hy, hypomeron; hyr, hypomeral ridge; lpc, lateral pronotal carina; msvp, mesoventral intercoxal process; mtvp, metaventral intercoxal process; pg, pygidium; psp, prosternal process; st 3 – 8, abdominal sternite III – VIII; v 3, metaventrite.