The first record of Cupedidae (Coleoptera: Archostemata) from Eocene Rovno amber: Cupes groehni Kirejtshuk, 2005 examined using X-ray microtomography Author Bukejs, Andris Author Alekseev, Vitalii I. Author Kairišs, Kristaps text Baltic Journal of Coleopterology 2021 2021-12-30 21 2 111 116 journal article 10.5281/zenodo.12520555 1407-8619 12520555 Cupes groehni Kirejtshuk, 2005 ( Figs. 1–3 ) Fig. 1. Photomicrographs of Cupes groehni Kirejtshuk, 2005 , Rovno amber, JDC 8373 [JDC], habitus: A – dorsal view; B – ventral view. Scale bar represents 1.0 mm. Material examined. One specimen with collection number “JDC 8373” [JDC]; adult, sex female. A complete beetle included in a transparent, yellow amber piece with dimensions of 21 mm × 10 mm and a maximum thickness of 6 mm , preserved without supplementary fixation. Syninclusions: a few stellate fagacean trichomes, and numerous small detritus particle. Strata. Rovno amber, Upper Eocene . Locality. Rovno [ Rivne ] Region (without locality), Ukraine . Measurements: body length 6.9 mm ; head length 1.2 mm ; pronotum length 0.8 mm , pronotum maximum width 1.2 mm ; elytra length 4.9 mm , elytra maximum combined width 1.9 mm . Cupes groehni was described from Eocene Baltic amber based on five specimens with certain variability in size and density of scales, shape of posterior tubercles on head, pronotal width, and body length ( Kirejtshuk 2005 ). The specimen JDC 8373 is morphologically similar to C. groehni (according to Kirejtshuk 2005 ) and is identified as a probable female, showing the sexually dimorphic characters of wider pronotum, more subcircular elytral cells and smaller body size. A check-list of the described Coleoptera from Rovno amber has been compiled recently (Bukejs et al. 2020). The importance of studies on the coleopteran assemblage and a special attention to the species common to different Eocene ambers was discussed and pointed out. Taking into account the data from recent papers ( Bukejs & Legalov 2020 ; Sokolov & Perkovsky 2020 ; Kupryjanowicz et al. 2021 ; Legalov et al. 2021) and our record of Cupes groehni , 62 species of 24 families are reported from Rovno amber (as of 21 May 2021 ). Nine coleopteran species common Fig. 2. X-ray micro-CT renderings of Cupes groehni Kirejtshuk, 2005 , Rovno amber, JDC 8373 [JDC], habitus: A – dorsal view; B – ventral view; C – left lateral view; D – right lateral view. Scale bar represents 1.0 mm. The first record of Cupedidae ( Coleoptera : Archostemata ) from Eocene Rovno amber: Cupes groehni ... Fig. 3. X-ray micro-CT renderings of Cupes groehni Kirejtshuk, 2005 , Rovno amber, JDC 8373 [JDC]: A – pronotum and head, dorsal view; B – details of forebody, ventral view. Not to scale. to Baltic and Rovno ambers, including the current finding, are known. The newly reported specimen represents the first documented finding of the archostematan family Cupedidae in Rovno amber, as well a small argument confirming the evident space-time closeness of Baltic and Rovno amber.