Research Article |
Corresponding author: Dmitry Telnov ( anthicus@gmail.com ) Academic editor: Chen‑Yang Cai
© 2021 Dmitry Telnov, Evgeny E. Perkovsky, Dmitry V. Vasilenko, Shûhei Yamamoto.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Telnov D, Perkovsky EE, Vasilenko DV, Yamamoto S (2021) The first fossil Coleoptera record from the Volyn Region, Ukraine, with description of a new Glesoconomorphus (Coleoptera, Mycteridae) in syninclusion with Winterschmidtiidae (Acari) and a key to species. ZooKeys 1068: 189-201. https://doi.org/10.3897/zookeys.1068.75391
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Glesoconomorphus ekaterinae sp. nov. (Coleoptera, Mycteridae), representing the first ever fossil species of Coleoptera from the Volyn Region of Ukraine and the first mycterid from late Eocene Rovno amber, is described and illustrated. A key to species of the fossil mycterid genus Glesoconomorphus Alekseev, Pollock & Bukejs, 2019 is presented. The systematic position of Glesoconomorphus within Eurypinae J. Thomson, 1860 is briefly discussed. The oldest finding of phoretic Winterschmidtiidae Oudemans, 1923 mites, found on the type specimen of the new beetle species, is reported.
Eurypinae, identification, morphology, phoresy, Priabonian, Rovno amber, taxonomy
Glesoconomorphus Alekseev, Pollock & Bukejs, 2019 was erected recently to hold the sole species G. nachzehrer Alekseev, Pollock & Bukejs, 2019 (
As discussed by
Glesoconomorphus appears close to the extant Conomorphus Champion, 1889 and Stilpnonotus Gray, 1832 due to the presence of a distinct ocular groove narrowly separated from the eyes (
Rovno amber is considered the southern coeval of Baltic amber (
The aims of the present paper are to describe and illustrate Glesoconomorphus ekaterinae sp. nov., the first known Coleoptera species from Priabonian amber from the Volyn Region of Ukraine, to supplement the definition of the genus, and to provide a key to Glesoconomorphus species. The presence of an abdominal setal patch in Glesoconomorphus ekaterinae sp. nov. confirms placement of the genus in the subfamily Eurypinae. The closure of the procoxal cavities and the presence of an apicoventral binding patch on each elytron, two other common features of Eurypinae (
Lisove is a new amber mine in the Volyn Region of NW Ukraine, 9 km east of Manevichi (the former Manevichi district, now Kamen-Kashirsky district).
Paired morphological structures are generally treated as singular in the text.
The specimen was studied and digital images were made using a Leica Z16 APO stereomicroscope equipped with Leica DFC450 Digital Camera at the I. I. Schmalhausen Institute of Zoology of the National Academy of Sciences of Ukraine (Kiev), and subsequently processed with the LAS Core 3.8 and Adobe Photoshop CS5 software.
The holotype is deposited at the Schmalhausen Institute of Zoology of the National Academy of Sciences of Ukraine, Kiev (
Family Mycteridae Oken, 1843
Subfamily Eurypinae J.Thomson, 1860
Holotype
♂
Lisove, Volyn Region, NW Ukraine.
Patronymic. The new species is named in honour of Ekaterina A. Sidorchuk (1981–2019), who was a renowned acarologist and our helpful colleague.
Holotype ♂, total body length 2.95 mm; head length 0.29 mm, head width across compound eyes 0.67 mm, pronotal length 0.59 mm, maximum pronotal width 0.66 mm, elytral length 2.17 mm, combined maximum elytral width across postmedian area 1.15 mm.
♂, body cylindrical, slightly convex in dorsal aspect. Dorsum and venter uniformly dark brown with weak metallic coppery lustre, compound eyes reddish brown. Head flattened dorsally, glossy. Labrum transverse, moderately densely punctate, anterior margin broadly emarginate. Frontoclypeal suture not present. Anterolateral margin of frons slightly prominent laterodorsad, not concealing insertion of antenna. Broad, shallow paired frontal furrow present. Minimum interocular distance 1.6× the dorsal eye length. Ocular (suborbital) groove present, distinct, traceable from frontal canthus to posterolateral extent of compound eye, narrowly separated from eye in anterior part, becoming more distant from it in posterior part. Compound eye large, entire, hemispherical, strongly prominent laterally in dorsal view. Interfacetal setae not present. Tempora slightly constricted posteriad, 0.34× dorsal eye length. Head dorsal punctures circular to slightly elliptical, rather large, moderately deep and dense. Intervening spaces glossy, glabrous, on frons generally as wide as to 1.5× wider than punctures. Punctures generally smaller on head base. Inconspicuous, appressed, anteriad-directed setae rising from centre of each puncture, generally not or slightly surpassing length of adjoining puncture. Antenna moniliform, rather short, in male extending towards base of pronotum. Basal antennomere cylindrical, about 1.1× longer than antennomere two. Antennomere three of about same length as preceding antennomere. Antennomeres 8–10 subtriangular, widened distally. Antennomeres 9–10 slightly transverse. Terminal antennomere elliptical, about 1.2× longer than penultimate antennomere. Terminal maxillary palpomere subsecuriform. Pronotum flattened dorsally, widest in anterior half, slightly constricted laterally towards base. Anterior and posterior margins truncate to subtruncate. Anterior bead not observed, posterior bead well-defined, broad. Anterolateral angles obsolete, broadly rounded. Posterolateral angles obtuse angulate. Lateral margin of pronotum modified into an obtuse carina delimiting pronotal disc from pronotal hypomeron (observed in lateral view). Pronotal disc with paired, moderately large, shallow, longitudinal, elliptical postmedian impression. Pronotum densely and roughly punctate dorsally and laterally, punctures nearly circular. Intervening spaces glossy, glabrous, generally narrower than punctures except in median part of pronotal disc, where intervening spaces are from as large as to twice as large as punctures. Dorsal pronotal setae similar to those on head. Scutellar shield small, widened posteriad, subtruncate at posterior margin, roughly punctate. Elytron moderately strongly elongate, slightly widened in apical third, slightly convex dorsally. Humerus broadly rounded. Humeral callosity not present. Postbasal transverse impression not indicated. Apical sutural angle broadly rounded. Epipleura rather broad in basal half of elytra. Sutural stria narrow, present in apical fourth of elytra. Elytral punctures rather large, deep and dense, intervening spaces glossy and glabrous, from as large as to narrower than punctures. Each puncture with an inconspicuous, appressed, moderately long, posteriad-directed seta. Metathoracic wings fully developed (functional), long, visible veins darkly pigmented. Radial cell present, fully closed. Legs moderately long, rather robust, finely and sparsely pubescent. Femora thickened but not clavate, glossy, sparsely punctate, subequal in length to tibiae. Ventral side of tarsomeres densely setose. Male basal metatarsomere 1.5× shorter than combined length of remaining metatarsomeres. Metasternum slightly convex in ventral aspect, glossy, sparsely punctate. Abdominal ventrites rather densely and roughly punctured laterally. Intercoxal process of abdominal ventrite I with particularly large and dense, shallow punctures. Male abdominal ventrite II modified, with an elliptically grouped median group of dense, elongate, scale-like setae comprising a sex patch. Setae of sex patch reaching neither anterior nor posterior margin of male abdominal ventrite II. Male tergite VII broadly rounded at posterior margin, densely punctate-corrugate dorsally. Male genital organs and remaining terminalia not exposed and not studied.
Female unknown.
The new species is generally close to G. nachzehrer but specifically different in the comparatively less slender body, the dorsal outline of the pronotum, which is constricted towards the base (lateral margins of pronotum subparallel in G. nachzehrer), the transverse pronotum (pronotum subquadrate to slightly wider than broad in G. nachzehrer), the pronotal disc delimited from the pronotal hypomeron by an obtuse carinate lateral margin in lateral view (lateral margin of pronotum not carinate in lateral view in G. nachzehrer), the presence of frontal furrows (not observed in G. nachzehrer), the comparatively less densely punctured frons with some of the intervening spaces twice as wide as the generally circular to slightly elliptical punctures (frons somewhat denser punctured, with punctures generally elongate, in G. nachzehrer), the labrum broadly emarginate at the anterior margin (labrum broadly rounded in G. nachzehrer), the comparatively stronger elytral punctures (punctures on elytra comparatively smaller in G. nachzehrer). The holotype of G. ekaterinae sp. nov. is also significantly smaller than the holotype of G. nachzehrer (total body length 2.95 mm vs 3.6 mm), which should not be considered as an important comparative feature. Indeed, the males of some Eurypinae (for instance, Omineus Lewis, 1895) are known to be smaller than the females (
Glesoconomorphus ekaterinae sp. nov., holotype ♂ A abdomen in ventral view (arrow indicates a setal patch) B pro-, meso-, and metathorax in right lateral view C sexual setal patch on ventrite II, enlarged. Abbreviations: pm = phoretic mite (Acari: Winterschmidtiidae), v1–v5 = ventrites I-V.
The present key excludes sexual features, since both sexes remain unknown for each of the two known species.
1 | Pronotum distinctly transverse, lateral margins broadly rounded, constricted prebasally; pronotal disc delimited from hypomeron by obtuse carinate lateral margin (lateral view); frontal furrows present; ratio of elytral length to combined width of elytra 1.89; labrum broadly emarginate at anterior margin | G. ekaterinae sp. nov. |
– | Pronotum nearly as long as wide, lateral margins subparallel, not or vaguely constricted prebasally; transition of pronotal disc to hypomeron even, lateral margin of pronotum not carinate in lateral view; ratio of elytral length to combined width of elytra 2.12; labrum broadly rounded at anterior margin | G. nachzehrer Alekseev, Pollock & Bukejs, 2019 |
The composition of fossil Mycteridae was discussed recently in
The presence of a sex patch on abdominal ventrite II in male Glesoconomorphus ekaterinae sp. nov. and the presence of distinct frontal furrows provide additional support for the placement of Glesoconomorphus in the subfamily Eurypinae of Mycteridae. The structure of the procoxal cavities and the presence or absence of an apicoventral binding patch on each elytron remain unknown in this genus.
Nearly all studied Rovno amber inclusions from the Rovno Region (reported inclusions from Zhitomir Region listed in
The type species of Glesoconomorphus from Baltic amber is named after “Nachzehrer”, a mystical vampire from the folklore of Germany and Poland that, according to the legend, first persecutes and then murders its natural relatives (
Kirill V. Makarov (Moscow State Pedagogical University, Russia) is thanked for pointing our attention to this peculiar syninclusion. We also are grateful to Nikolai R. Khomich (Rovno, Ukraine) for his help in obtaining the specimen, to Anatoly P. Vlaskin (
This research was supported by the Grant-in-Aid for JSPS (Japan Society for the Promotion of Science, Tokyo, Japan) Fellows (20J00159) given to S.Y. We thank the reviewer Darren A. Pollock (Eastern New Mexico University, Portales, USA) and the editor for improving the paper.