Bacanius kirejtshuki Sokolov et Perkovsky, 2020

Sokolov, Alexander V. & Perkovsky, Evgeny E., 2020, The first Eocene species of Bacanius (Coleoptera: Histeridae: Dendrophilinae) from Rovno amber, Russian Entomological Journal 29 (2), pp. 157-160 : 159

Bacanius kirejtshuki Sokolov et Perkovsky , sp.n.

Figs 1–5 .

MATERIAL. Holotype SIZK UA-28067 .

DESCRIPTION. Habitus as illustrated ( Figs 1–5 ). PEL = 1.2 mm. H = 0.6 mm. Colour dark brown. Dorsal surface without microsculpture. Broadly oval, moderately convex. Widest at elytral humeri. Head retracted in thorax, relatively big, form typical for the tribe Bacaniini ( Figs 2 , 4 ). Frons and epistoma with uniform punctures coarse and sparse (2–3). Frons separate from epistoma by distinct stria, arcuate inwardly to vertex. First antennal segment poorly distinguishable, rest parts of antenna retracted in thorax.

PL = 0.38 mm. PPW = 0.9 mm. APW = 0.8 mm. PPW = 0.9 mm. Small part of pronotum visible only, impossible define features of punctures on the disc ( Figs 2 , 4 ). Lateral surface with fine and sparse (2–4) punctures. Marginal pronotal stria complete laterally and anteriorly. Antescutellar stria absent. Scutellum not visible.

EW = 1.0 mm. Elytral punctures fine and sparse (2–4), distinguishable partly from middle to apex. Impossible to descern punctures in basal part of elytra and along suture. Outer subhumeral stria well impressed, complete, prolong to base. Epipleural stria distinct, situated closer to subhumeral striae. Prosternal lobe broad and prominent, with conspicuous sparse punctures ( Figs 1 , 5 ). Mesometasternal suture looks like line of coarse punctures. Punctures of meso- and metasternum invisible mostly. Lateral parts of metasternum with various punctures, relatively dense (1.0–1.5). Hind edge of metaventrite arcuate to abdomen. There are outer and inner striae of 1st abdominal ventrite. Its surface coarsely punctured laterally and along anterior margin, rest part finely punctured. Probably pygidium smooth or with very weak punctures.

Legs of typical form for Bacaniini . Foretibia broadened with unique tooth near distal angle. Mesotibia and metatibia narrowed, not strongly broadened apically, mesotibia only with several fine spurs on the apex.

COMPARATIVE REMARKS. The described species belongs to Bacaniini by not truncate elytra that covered exposed tergites, dorsal striae absent. Generic system of Bacanius is developed not so good now, many extant genera of Bacaniini consist with species of former Bacanius sensu stricto. Nonetheless new species has all key characters for attribute it to genus Bacanius . In 1984 Slawomir Mazur established subgenus Gomyister Mazur, 1984 , distributed mostly in tropical areas of the Old and New World [ Mazur, 1984]. They can be recognized by complete subhumeral stria and absence of antescutellar stria. Bacanius kirejtshuki has that features, so we suppose to place it close to recent Gomyister .

ETYMOLOGY. The new species is dedicated to coleopterist Dr. Sc. Alexander G. Kirejtshuk.

Figures

Figs 1–3. Bacanius kirejtshuki sp.n.: 1, 3 — habitus, ventral and dorsal view; 2 — head, lateral view. Рис. 1–3. Bacanius kirejtshuki sp.n.: 1, 3 — габитус, сниЗу и сверху; 2 — голова, сбоку.

Figs 4–5. Bacanius kirejtshuki sp.n., habitus: 4 — dorsal view; 5 — ventral view. Рис. 4–5. Bacanius kirejtshuki sp.n., габитус: 4 — сверху; 5 — сниЗу.