New species of the genus Trixagus Kugelann, 1794 (Coleoptera ...

Proceedings of the Zoological Institute RASVol. 316, No. 1, 2012, рр. 83–88УДК 595.765NEW SPECIES OF THE GENUS TRIXAGUS KUGELANN, 1794 (COLEOPTERA:THROSCIDAE) FROM THE LOWERMOST EOCENE AMBER OF OISE (FRANCE)A.V. Kovalev 1 , A.G. Kirejtshuk 1, 2 * and A. Nel 21Zoological Institute of the Russian Academy of Sciences, Universitetskaya emb., 1, 199034 St. Petersbug, Russia;e-mails: fornax13@list.ru, kirejtshuk@gmail.com, agk@zin.ru2CNRS UMR 7205, Muséum National d’Histoire Naturelle, CP 50, Entomologie, 45, rue Buffon, F-75005 Paris, France;e-mails: kirejtshuk@gmail.com, agk@zin.ru, anel@mnhn.frABSTRACTTrixagus majusculus sp. nov., the third fossil representative of the genus of the elaterioid family Throscidae:Throscinae is described from the Lowermost Eocene amber of Oise (France). The new species is compared withboth extinct and extant species of the genus. “Throscus (?)” peritulus Cockerell, 1925 is excluded from the familyThroscidae and a review of the available fossil representatives of this family is given.Key words: amber, Coleoptera, Insecta, France, Lowermost Eocene, new species, Throscidae, TrixagusНОВЫЙ ВИД РОДА TRIXAGUS KUGELANN, 1794 (COLEOPTERA:THROSCIDAE)ИЗ НИЖНЕЭОЦЕНОВОГО ЯНТАРЯ УАЗЕ (ФРАНЦИЯ)А.В. Ковалев 1 , А.Г. Кирейчук 1, 2 * и А. Нель 21Зоолологический институт Российской академии наук, Университетская наб., 1, 199034 Санкт-Петербург, Россия;e-mail: fornax13@list.ru, kirejtshuk@gmail.com, agk@zin.ru2CNRS UMR 7205, Muséum National d’Histoire Naturelle, CP 50, Entomologie, 45, rue Buffon, F-75005 Paris, France;e-mails: kirejtshuk@gmail.com, agk@zin.ru, anel@mnhn.frРЕЗЮМЕИз нижнеэоценового янтаря Уазе (Франция) описан Trixagus majusculus sp. nov., третий представитель родаэлатероидного семейства Throscidae: Throscinae. Новый вид сравнивается как с вымершими, так и современнымивидами. “Throscus (?)” peritulus Cockerell, 1925 выведен из состава семейства Throscidae и дан обзоримеющихся ископаемых представителей этого семейства.Key words: янтарь, Coleoptera, Insecta, Франция, нижний эоцен, новый вид, Throscidae, TrixagusINTRODUCTIONThe family Throscidae Laporte, 1840 representsa comparably not numerous group in both recentand previous faunas. The most fossils of this family*Corresponding author / Автор-корреспондентremain undescribed. Nevertheless, they are knownfrom the Miocene Dominican amber, Eocene Baltic,Bitterfeld and Fushun amber, Upper CretaceousSakhalin amber, Lower Cretaceous Lebanese andBurmese amber, and also from compression depositsof Khetana River (Lower Cretaceous), London Clay(Upper Paleocene-Lower Eocene), Messel (Middle

84Kovalev et al.Eocene), Florissant (Uppermost Eocene-LowermostOligocene), and Amagu River (Miocene). There arenot so many descriptions published which make possibleto discuss the phylogeny. These are Palaeothroscussosnovski Iablokoff-Khnzorian, 1962 and Troscitestschitscherini Iablokoff-Khnzorian, 1962 from Balticamber, although later the first was transferred byCobos (1963) to genus Trixagus Kugelann, 1794and second to Aulonothroscus Horn, 1890; Trixagusperitulus Cockerell, 1925 from Amagu River; Megocephaliteseocenicus Hong, 2001 from Fushun amber;Pactopus americanus Wickham, 1914 from Florissant(Colorado, USA); P. avitus Britton, 1960 from LondonClay (United Kingdom); and the rest from Balticamber: P. fasolti Muona, 1993 and P. fafneri Muona,1993; Jaira bella Muona, 1993; Potergus frochi Muona,1993 and P. logei Muona, 1993. Most mentionson fossil Throscidae are supplied only by indicationof family or at most genus summarized in the catalogueby Ponomarenko and Kirejtshuk (2011).This paper presents the eighth contribution to theknowledge on fauna of Coleoptera from the LowermostEocene French amber collected in Oise falls ofParis Basin (Batelka et al. 2006; Bilý and Kirejtschuk2007; Kirejtshuk and Nel 2008, 2009; Kirejtshuk etal. 2010a, 2010b, 2010c; Moseyko et al. 2010).Note. Throscus (?) peritulus Cockerell, 1925,which according to the current taxonomic interpretationshould be considered with the generic nameTrixagus, was described after the print of beetledorsum from the outcrop in Terneysky District(Primorsky Kray, Russian Far East) from KhutsynskayaFormation. This specimen is deposited in theSmithsonian National Museum of Natural History inWashington. The pronotum as figured the picture inthe original paper shows scarcely projecting posteriorangles and, therefore, the specimen certainly cannotbelong to the family Throscidae and its attribution toany other elateroid family is also rather questionable.MATERIAL AND METHODSThe holotype of the species under considerationas many specimens recovered among inclusions fromthe Lowermost Eocene French amber is deposited inthe Laboratoire de Paléontologie, Muséum Nationald’Histoire Naturelle, Paris. Usual optic equipmentwas used for their study, in particular the stereomicroscopeOlympus SCX9 and inverted microscopeOlympus CK 40 in the Paris museum, and also thestereomicroscope microscope Leica MZ 16.0 in theZoological Institute RAS (Saint Petersburg).Type strata. Lowermost Eocene, in amber, circa –53 Myr, Sparnacian, level MP7 of the mammal faunaof Dormaal (Nel et al. 1999).Type locality. Farm Le Quesnoy, Chevrière, regionof Creil, Oise department (north of France).SYSTEMATICSFamily Throscidae Laporte de Castelnau, 1840Subfamily Throscinae Laporte de Castelnau, 1840Genus Trixagus Kugelann, 1794Type species: Dermestes adstrictor Herbst, 1794(= Elater dermestoides Linnaeus, 1767).Trixagus majusculus sp. nov.(Figs 1–4)Holotype. MNHN.F.A46040 (PA 1673), probablefemale, completely preserved, but the entire undersideis covered with thinner or thicker milky coverintermixed with short hairs and hardly visible; alsowith vertical crevices along left and right lateral sidesof dorsum. The holotype is included in a large irregularamber piece (length 27, width 20, height 5 mm),not completely polished; at both sides of the beetlethere are located four specimens of Brachycera andmany gas bubbles of different size and many piecesof white and dark organic matter of different size(gas bubbles and pieces of organic matter irregularlyspread through the amber piece examined).Etymology. The epithet of the new species means‘rather large’, referred to the body size of the new specieswhich is largest among the congeners.Diagnosis. The new species differs from Palaeothroscussosnovskyi Iablokoff-Khnzorian, 1962described from Baltic amber (transferred by Cobos(1963) to Trixagus) in the subparallel lateral bordersof the prosternal plate, distinctly bisinuate base ofpronotum and larger body size, which is wider andmore tapered posteriorly, and apparently in the finerand sparser dorsal puncturation.Also the new species differs from all recent speciesof Trixagus in the larger body and the combination ofthe following features: deeply incised eyes, weaklyconvex frons without carinae and large, almost flatprosternal plate and very coarse and sparse punctura-

New species of the genus Trixagus from amber of Oise 85Figs. 1–2. Trixagus majusculus sp. nov. (Coleoptera, Throscidae), holotype: 1 – body, dorsal; 2 – idem, ventral. Length – 3.55 mm.tion of elytra. At the same time the new species haveas large body as some recent members of the Aulonothroscuswhich are also characterized by more orless incised eyes and well expressed grooves on metaventriteto receive the mesotarsi. At the current studythe new species should be put in the genus Trixagusbecause it does not demonstrate trace of tarsal grooveson metaventrite. The combination of incised eyes andconvex frons without elongate keels is rather characteristicof Trixagus but not Aulonothroscus, althoughsome members of the latter have not these keels (forinstance Afrotropical A. subtilis Cobos, 1960; A. alluaudiCobos; 1962 and A. stanleyi Cobos, 1962 as wellas Australian A. adonis Cobos, 1963).The new species is similar to the recent WesternPalaearctic T. dermestoides (Linnaeus, 1767) in therelatively wide and almost flat prosternal plate, moderatelyshort and dense pubescence, not masking thesculpture of integument, wide frons and larger body,but differs from the latter in the excision of anterioredge of eyes expanded the middle of eye diameter,larger body and lack of frontal carinae. Also this newspecies can be compared with the Palaearctic membersof species-group related to T. carinifrons Bonvou-

New species of the genus Trixagus from amber of Oise 87with a weak shine. Dorsum withy subuniform, moderatelylong, moderately dense, moderately conspicuousand suberect hairs 4–5 times as long as distancebetween their insertions; underside with somewhatfiner, shorter and sparser hairs.Head with puncturation formed by moderatelycoarse and sparse punctures and interspaces betweenthem with extremely fine and dense punctures. Pronotumwith double puncturation, formed by coarseand sparse punctures interspersed extremely fine anddense punctures. Elytra with nine fine and shallowstriae at bottom of which there are located rows offine and shallow, sparse punctures; intervals betweenthem almost flat, with moderately coarse and verysparse punctures, somewhat finer than on the pronotum,and interspaces between them with extremelyfine and dense punctures.Head comparatively large; frons rather convexand without any trace of frontal carinae, slightlywider than its height. Eye medium-sized, slightlyconvex, excision of their anterior edge as extended assomewhat more than three-quarters of eye diameter.Labrum transverse, about twice as wide as long, trapezoidal,with widely rounded lateral angles. Antennaerelatively short and thin; antennomere 1 large, slightlylonger than its wide; antennomere 2 large, almostas wide as previous and about as long as wide; antennomeres3–8 small (antennomeres 3–5 elongate, antennomeres6–8 almost quadrate; 3-segmented clubrelatively small, elongate-oval; antennomere 9 arcuatelywidening to emarginated apex, antennomere 10nearly transversely quadrangular, antennomere 11strongly transverse and rounded at apex.Pronotum wide and short, 1.85 times as wide aslong along the middle, evenly arcuately wideningto posterior angles. Base of pronotum bisinuate;basal impressions nearly indistinct; median partof posterior edge short projecting, nearly straightat apex. Posterior angles far projecting and muchlonger than projecting median part of posterioredge. Lateral carinae long, reaching anterior thirdof pronotum. Scutellum subpentagonal with widelyrounded sides and subacute apex, slightly wider thanlong. Elytra elongate, widest behind base, about 1.75times as long as wide combined (at anterior fourth),gradually narrowing to apices which are forming aconjoining arc.Prosternal plate and process flat, moderately shortand wide, subparallel-sided; with lateral borders; subangularat the apex. Metaventrite of usual structure,relatively convex. Metacoxal plates of usual shape.Abdomen with shallow indistinct depressions forreceipt of metatarsi on ventrites 1–3. Anal ventriterounded at apex.Legs of same structure (as in recent congeners).ACKNOWLEDGMENTSThe authors thank the company Lafarge-Granulatfor the help with the sampling of the fossil and the familyLanglois-Meurinne for the authorization of workingin their property. A.G. Kirejtshuk has a pleasant duty toexpress his recognition to the Museum national d’Histoirenaturelle provided him a possibility to work in this museumin 2006–2011 as visiting professor. This study was alsosupported by the grants of Russian Foundation of BasicResearch N 09-04-00789-а, Programme of the Presidium ofthe Russian Academy of Sciences “Origin and Evolution ofBiosphere” and Ministry of Education and Science of theRussian Federation.REFERENCESBarthel M. and Hetzer H. 1982. Bernstein-Inklusen ausdem Miozän des Bitterfelder Raumes. Zeitschrift fürAngewandte Geologie, 28: 314–336.Batelka J., Collomb F.-M. and Nel A. 2006. Macrosiagondeuvei n. sp. (Coleoptera: Ripiphoridae) from theFrench Eocene amber. Annales de la Société Entomologiquede France, (N.S.), 42(1): 75–78.Bílý S. and Kirejtschuk A.G. 2007. Philanthaxoides gallicusgen. nov., sp. nov. from the Lowermost EoceneFrench amber (Coleoptera: Buprestidae). Folia Heyrovskyana,A, 14(4): 181–186.Cobos A. 1963. Comentarios criticos sobre algunosSternoxia fósiles del ámbar del Báltico recientementedescrito (Coleoptera). Eos, Revista Española de Entomología,39(3–4): 345–355.Cockerell T.D.A. 1925. Tertiary insects from Kudia River,Maritime Province, Siberia. Proceedings of the UnitedStates National Museum, 66(19): 1–13.Iablokoff-Khnzorian S.M. 1962. Predstaviteli Sternoxiaiz Baltiyskogo Yantarya. Semeystvo Throscidae Bach,1849 (Trixagidae sensu Crowson) [Representatives ofSternoxia (Coleoptera) from the Baltic amber. FamilyThroscidae Bach, 1849 (Trixagidae sensu Crowson)].Paleontologicheskiy Zhurnal, 3: 81–89. [In Russian]Kirejtshuk A.G. and Nel A. 2008. Some new fossils ofthe suborder Polyphaga (Coleoptera (Insecta) fromLowermost Eocene French amber. Annales de la SociétéEntomologique de France, (N.S.), 44(4): 419–442.Kirejtshuk A.G. and Nel A. 2009. New genera and speciesof Cucujiformia (Coleoptera, Polyphaga) from lowermostEocene French amber. Denisia, 26: 103–118.

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