Cephennomicrus

Jałoszyński, Paweł & Perkovsky, Evgeny, 2016, Diversity of Scydmaeninae (Coleoptera: Staphylinidae) in Upper Eocene Rovno amber, Zootaxa 4157 (1), pp. 1-85 : 25-28

Cephennomicrus sp. 2

( Figs 7 , 71–74 )

Material studied. Late Eocene of Europe , Rovno amber: sex unknown; inclusion in rectangular prism of amber 10 mm long ( Fig. 7 ), collection number K-7010 ( SIZK).

Description. Body ( Figs 81–84 ) elongate and strongly convex, very dark brown; BL 0.94 mm.

Head ( Figs 81–84 ) broadest at eyes, HL 0.13 mm, HW 0.23 mm; vertex ( Fig. 83 ; vt) weakly convex and strongly transverse; frons ( Fig. 83 ; fr) subtrapezoidal, flattened and posteriorly confluent with vertex; supraantennal tubercles weakly marked; eyes large, strongly convex, moderately coarsely faceted. Antennae ( Figs 81–83 ) about as long as half BL, AnL about 0.45 mm, all antennomeres distinctly elongate, IX–XI forming indistinctly demarcated club, antennomere XI slightly shorter than IX–X combined, slightly broader than X and slightly more than twice as long as broad, nearly symmetrical.

Pronotum ( Figs 81, 83 ) subrectangular; PL 0.29 mm, PW 0.33 mm; pronotal disc broadest near anterior fourth, sides rounded in anterior half and straight or weakly concave in posterior third (the shape of lateral margin difficult to assess due to orientation of specimen); posterior pronotal corners obtuse-angled and blunt; posterior margin very shallowly bisinuate and slightly flattened in front of scutellum; base with two pairs of small and shallow but distinct antebasal pits ( Fig. 83 ; abp) connected by narrow transverse antebasal groove ( Fig. 83 ; abg). Punctures on pronotal disc very fine but distinct, separated by spaces 1.5–2 times as wide as diameters of punctures; setae very short, dense, nearly recumbent ( Figs 81, 83 ).

Elytra ( Figs 81, 83 ) elongate oval, strongly convex, EL 0.53 mm, EW 0.43 mm, EI 1.24; punctures and setae similar to those on pronotal disc ( Figs 81, 83 ).

Legs ( Figs 81–84 ) moderately long, slender, unmodified; all tibiae very weakly curved.

Remarks. This specimen is of moderate length and among all studied fossils of Cephennomicrus its generic characters are best exposed, including the characteristic scale-like microsculpture of some ventral structures ( Figs 82, 84 ). It is most similar to the specimen K-8912, described below as Cephennomicrus sp. 4, but proportions of body parts indicate that these two specimens may not be conspecific. However, as the specimen K-8912 is poorly preserved, this conclusion is not well supported. Certainly Cephennomicrus sp. 2 and sp. 4 are not conspecific with any other Cephennomicrus found in the studied material.

The medium body length, general body form and fine, short vestiture of setae of Cephennomicrus sp. 2 resemble some Asian species (e.g., Jałoszyński 2009a, b, 2015e). However, lack of any conspicuous modifications and unremarkable appearance do not allow for defining this species as new.

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 81 – 84. Cephennomicrus sp. 2 (K- 7010). Dorsal (81, 83) and ventral (82, 84) view. Abbreviations: abg, antebasal groove; abp, antebasal pit; bef, basal elytral fovea; bst, basisternal part of prosternum; bsti, basistipes; fr, frons; gp, gular plate; hy, hypomeron; hyr, hypomeral ridge; lpc, lateral pronotal carina; mcp, mesocoxal projection; mn, mentum; msvp, mesoventral intercoxal process; mtvp, metaventral intercoxal process; mxp 2 – 3, maxillary palpomere II – III; psp, prosternal process; smn, submentum; st 3 – 8, abdominal sternite III – VIII; v 3, metaventrite; vt, vertex.