The oldest opatrine terrestrial darkling beetle (Coleoptera: Tenebrionidae: Tenebrioninae) from the Paleocene of Menat (France) Maxim Nabozhenko & Alexander Kirejtshuk PalZ Paläontologische Zeitschrift ISSN 0031-0220 Volume 91 Number 3 PalZ (2017) 91:307-313 DOI 10.1007/s12542-017-0368-2 1 23 Your article is protected by copyright and all rights are held exclusively by Paläontologische Gesellschaft. This e-offprint is for personal use only and shall not be self- archived in electronic repositories. If you wish to self-archive your article, please use the accepted manuscript version for posting on your own website. You may further deposit the accepted manuscript version in any repository, provided it is only made publicly available 12 months after official publication or later and provided acknowledgement is given to the original source of publication and a link is inserted to the published article on Springer's website. The link must be accompanied by the following text: "The final publication is available at link.springer.com”. 1 23 Author's personal copy PalZ (2017) 91:307–313 DOI 10.1007/s12542-017-0368-2 RESEARCH PAPER The oldest opatrine terrestrial darkling beetle (Coleoptera: Tenebrionidae: Tenebrioninae) from the Paleocene of Menat (France) 1,2 3,4 Maxim Nabozhenko • Alexander Kirejtshuk Received: 8 August 2016 / Accepted: 27 May 2017 / Published online: 7 July 2017 Ó Pala¨ontologische Gesellschaft 2017 Abstract The oldest terrestrial darkling beetle of the sp. nov. (Unterfamilie Tenebrioninae), wird aus dem opatrine lineage, Palaeosclerum pohli gen. et. sp. nov. mittleren Pala¨oza¨n von Menat in Frankreich beschrieben. (subfamily Tenebrioninae) is described from the Middle Verschiedene Charaktermerkmale, einschließlich der Paleocene of Menat (France). The complex of characters, eigentu¨mlichen Form des Ko¨rpers (robust, angepasst an combining the peculiar shape of body (robust, adapted to a eine grabende Lebensweise), der Ausbildung der Grab- fossorial lifestyle), structure of fossorial protibia, 5-seg- Protibia und die fu¨nfgliedrigen Fu¨hler, zeigen eine große mented antennal club demonstrates a considerable simi- A¨ hnlichkeit der neuen Gattung zu rezenten Vertretern der larity of the new genus to the extant representatives of the ‘‘Sclerina’’-Gattungsgruppe des Subtribus Opatrina. ‘sclerina’ generic group of the subtribe Opatrina. Palaeosclerum gen. nov. wird mit den heutigen Gattungen Palaeosclerum gen. nov. is compared with recent genera Sclerum Dejean, 1834, Platynosum Mulsant und Rey, 1859 Sclerum Dejean, 1834, Platynosum Mulsant and Rey, 1859 und Eurycaulus Fairmaire, 1868, verglichen. and Eurycaulus Fairmaire, 1868. Schlu¨sselwo¨rter Coleoptera Á Tenebrionidae Á gen. et sp. Keywords Coleoptera Á Tenebrionidae Á gen. et sp. nov. Á nov. Á Pala¨oza¨n Á Frankreich Paleocene Á France Kurzfassung Der a¨lteste terrestrische Schwarzka¨fer (der Introduction Abstammungslinie Opatrini), Palaeosclerum pohli gen. et Darking beetles (Tenebrionidae Latreille, 1802) are one of the largest families of the order Coleoptera, including Handling editor: Mike Reich. about 20,000 species in the recent world fauna. More than & Maxim Nabozhenko half of the extant members of the family are xerophilous [email protected] and spread in arid and semiarid landscapes of all conti- & Alexander Kirejtshuk nents, including subantarctic islands (but not actually [email protected]; [email protected] Antarctica). Arid-adapted terrestrial species are poorly 1 represented in known fossils for taphonomic reasons. Caspian Institute of Biological Resources of Dagestan Therefore, most extinct species belong to dendrobiontic Scientific Centre of Russian Academy of Sciences, M. Gadzhiev str. 45, Makhachkala 367000, Russia groups (Kirejtshuk et al. 2008). Most extinct tenebrionids are known from Baltic amber (late Eocene), Geiseltal 2 Dagestan State University, M. Gadzhiev str. 43a, Makhachkala 367000, Russia (Middle Eocene) and Dominican amber (early Miocene). The oldest Paleogene Helopini (Tenebrioninae) genus and 3 Zoological Institute of the Russian Academy of Sciences, Universitetskaya emb., 1, St., Petersbug 199034, Russia species was recently described from the Middle Paleocene of Menat (Nabozhenko and Kirejtshuk 2014). Mesozoic 4 CNRS, MNHN, UPMC, EPHE, Muse´um national d’Histoire naturelle, Sorbonne Universite´s, 57 rue Cuvier, CP 50, Tenebrionidae are poorly represented in the fossil record. Entomologie, 45, rue Buffon, 75005 Paris, France At present, we have descriptions of only two Jurassic 123 Author's personal copy 308 M. Nabozhenko, A. Kirejtshuk comb-clawed beetles (Alleculinae), and three early Creta- related to poor preservation of fossils due to peculiar ceous tenebrionids (two species of subfamily Alleculinae taphonomic reasons. Among beetles, Buprestidae, Cara- and one of the tribe Alphitobiini, Tenebrioninae) (Kirejt- bidae, Cerambycidae, Elateridae, and Staphylinidae have shuk et al. 2012; Nabozhenko and Kirejtshuk 2014; been described in greater number than other groups (Piton Nabozhenko et al. 2015; Chang et al. 2016). The other 1940). The current studies show a considerable represen- Cretaceous taxa described in the beginning of the twentieth tation of Cupedidae consisting of some genera as remains century, after studies of imprints of beetles represented by of the Mesozoic fauna (for example, members of the separated elytra or very incomplete insect bodies and Cenozoic subgenus Caenomerga Kirejtshuk, Nel and classified as Alleculinae, are doubtful and need further Kirejtshuk, 2016, of the genus Mesocupes Martynov, revision (Nabozhenko et al. 2015). Among all described 1926 and apparently Mesocupes Kirejtshuk, Nel and Jurassic, Cretaceous and Paleocene darkling beetles, till Kirejtshuk, 2016), although at the same time some close now terrestrial arid-adapted species were absent. relatives to the modern fauna were present (at least by probable members of the Cupes Fabricius, 1801). The general composition of beetles in the outcrops of Menat Materials and methods includes a significant proportion of weevils (more than half of beetle remains), many specimens of Buprestidae, Cer- The holotype examined is deposited in Muse´e Lecoq ambycidae, Elateridae, Nitidulidae, and some other arbo- d’Histoire Naturelle in Clermont-Ferrand (France). It was real groups (Balazuc and Descarpentries 1964; studied using a stereomicroscope Olympus SCX9 in Nabozhenko and Kirejtshuk 2014; Kirejtshuk et al. 2016). Muse´um National d’Histoire Naturelle (Paris), and a Before the current studies, Tenebrionidae were known only stereomicroscope Leica MZ 16.0 in the Zoological Institute after one species of the genus Cryptohelops Nabozhenko (St. Petersburg) with different modes of light and color and Kirejtshuk, 2014, which is rather similar to recent filters. The specimen was also examined with a Tescan Stenohelops Reitter, 1922 (Tenebrionidae, Helopini) (Piton Vega LSU scanning electron microscope in MNHN to test 1940; Nabozhenko and Kirejtshuk 2014). This representa- the characters not clearly visible in the usual optic stere- tion of beetles should be associated with forest ecosystems omicroscope (puncturation, outlines of legs, pronotum, around the place of their deposition and it is in accordance elytra, etc.) with the Low Vacuum Secondary Electron with other invertebrate groups (Piton and The´obald 1937; TESCAN Detector (LVSTD). Piton 1940; Stroin´ski and Szwedo 2012; etc.). Geological setting and locality Systematic palaeontology Geological setting and stratigraphy, depositional environ- Phylum Arthropoda von Siebold, 1848 ment as well as maps of Paleocene volcano-sedimentary Class Insecta Linne´, 1758 maar are reviewed and summarized in many works (Piton Order Coleoptera Linne´, 1758 1940; Wappler et al. 2009; Nel and Auvray 2006; etc.). The Family Tenebrionidae Latreille, 1802 Menat Pit fossil site is located France, Department Puy-de- Subfamily Tenebrioninae Latreille, 1802 Doˆme (near Gannat) (46°060N, 02°540E). The age of Menat Tribe Opatrini Brulle´, 1832 according to the pollen, paleomammalian stratigraphic, and Genus Palaeosclerum gen. nov. radiometric K/Ar analyses was estimated as 59 Ma (Ked- ves and Russel 1982; Nel 2008). The estimation based on Etymology. The name of the new genus is formed from the macroflora postulated its age within 60–61 Ma (Wappler Greek ‘‘palaeo’’ (pakaio´1—old, ancient) and generic name et al. 2009). ‘‘Sclerum’’ Gender neutral. Type species. Palaeosclerum pohli sp. nov. Brief information about paleobiota of Menat Diagnosis. Body robust, comparatively small. Head with The paleomacroflora of the Menat locality was very rich, median deep triangular emargination at anterior margin. including diverse coniferous (Pinus, Abies, Sequoia, Thuja, Head and pronotum with coarse and dense puncturation. etc.) and deciduous (many species of Quercus, Populus, Antennae short, with 5-segmented club. Pronotum trans- etc.) trees. Consequently, dendrobiontic insects dominate verse, massive, with shallowly bi-emarginate anterior among insect fossils from this outcrop. Blattodea and margin and slightly projecting anterior angles, which clo- Coleoptera are the most numerous and most diverse insects sely contacted with lateral sides of head. Lateral margins of of Menat (Piton 1940; Nel and Auvray 2006). Most beetles pronotum serrate in basal third. Elytra robust, subparallel are identified only to the family level, which is partly sided, with nine sparsely punctured interstriae and eight 123 Author's personal copy The oldest opatrine terrestrial