284 research outputs found

    Fossil versus molecular datings of major ant subfamilies

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    International audienceDespite the interest the ants (Formicidae) have long generated, the group's evolutionary history has become more clearly established only recently, and yet our understanding of the diversity and phylogeny of these organisms is far from complete. Substantial advances have been made in the last decade by the discoveries of primitive fossil and extant lineages, and by molecular phylogenetic analyses. Recent molecular divergence dating estimates suggest that crown group ants arose some time between 115 and 168 million years ago, depending on the methodology applied (BEAST, penalized likelihood, etc.) and the assignment of fossils as stem group or crown group calibration points. This time interval is devoid of fossil ants, however, and the earliest known fossils are currently reported from mid-Cretaceous (ca. 100 Mya) ambers from France and Myanmar. These included only members of extinct or uncertain subfamilies thus far, but new discoveries presented here have revealed the presence of three of the 'big four' modern subfamilies in this time frame, i.e. Dolichoderinae, Formicinae, and Ponerinae. These findings and an overview of other known Cretaceous ants show that molecular divergence datings proposed respectively for each three subfamilies, which did not exceed 90 Mya in previous studies, were all underestimated. Meanwhile, this argues for an age of crown group ants within the 139-158 Mya as proposed by the most recent study, thus closer to the Jurassic/Cretaceous boundary than previously thought

    Introduction to thematic volume “Fossil arthropods in Late Cretaceous Vendean amber (northwestern France)”

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    There is growing knowledge of the insect and arachnid Cretaceous diversity worldwide, most notably as a result of the discovery, in the past twenty years, of numerous Konservat-LagerstĂ€tten (highly fossiliferous deposits) that provide a plethora of fossil arthropods (Wang & Szwedo, 2014). Early Cretaceous (Berriasian–Aptian) insects are known primarily from imprints in rocks, while fossiliferous amber yielding arthropod inclusions range mostly from the Albian to the Campanian – the sole exception being Hauterivian-Barremian amber of Lebanon and Jordan

    A new species of Baikuris (Hymenoptera: Formicidae: Sphecomyrminae) in mid-Cretaceous amber from France

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    International audienceA new species of the extinct ant genus Baikuris Dlussky, 1987 (Formicidae: Sphecomyrminae) is describedand figured from a male preserved in a piece of w100 Myr amber from Charentes, in southwesternFrance. Baikuris maximus sp. nov., is distinguished from other species notably by its larger size, itsforewing with vein 2MĂŸCu absent and vein 3Cu tubular, and the presence of a subpetiolar process. Thediagnosis of the genus is emended, and its distribution during the Cretaceous is briefly discussed

    Diverse barklice (Psocodea) from Late Cretaceous Vendean amber

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    International audienceThe fossil psocodeans from Late Cretaceous (Cenomanian to Santonian) amber of VendĂ©e, in northwestern France, are studied. Two new genera and three new species are described and illustrated, as Proprionoglaris axioperierga n. sp. (Archaeatropidae), Scocompus atelisus n. gen. and sp. (uncertain family within the Amphientometae), and Mesopsocoides dupei n. gen. and sp. (earliest fossil record of the Mesopsocidae). The new fossils are distinguished from their congeners, and their respective systematic placement is discussed. Other fragmentary fossil psocodeans from the same outcrop are illustrated and discussed.Les psoques fossilisĂ©s dans l’ambre crĂ©tacĂ© supĂ©rieur (CĂ©nomanien Ă  Santonien) de VendĂ©e, dans le nord-ouest de la France, sont Ă©tudiĂ©s. Deux nouveaux genres et trois nouvelles espĂšces sont dĂ©crits et illustrĂ©s: Proprionoglaris axioperierga n. sp. (Archaeatropidae), Scocompus atelisus n. gen. et sp. (famille incertaine au sein des Amphioentometae), et Mesopsocoides dupei n. gen. et sp. (plus ancien Mesopscocidae fossile). Ces nouveaux taxons sont comparĂ©s Ă  leurs congĂ©nĂšres, et leur position systĂ©matique respective est discutĂ©e. D’autres psoques fossiles fragmentaires issus du mĂȘme gisement sont discutĂ©s

    A new genus and species of pemphredonine wasp in Late Cretaceous Vendean amber (Hymenoptera: Crabronidae)

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    International audienceA new genus and species of pemphredonine wasp is described and figured in Late Cretaceous (Cenomanian to Santonian) amber from VendĂ©e, in northwestern France. Menopsila dupeae n. gen. and sp., is based on a partial male preserved in a small sliver of translucent amber. The genus is placed incertae sedis within the Pemphredonini, as it intermingles features, likely plesiomorphies, of various lineages within the tribe. It likely represents a stem group to one or more of the constituent subtribes, yet it is arguably most similar to the Spilomenina.Un nouveau genre et une nouvelle espĂšce de guĂȘpe pemphredonine sont dĂ©crits de l’ambre crĂ©tacĂ© supĂ©rieur (CĂ©nomanien Ă  Santonien) de VendĂ©e, nord-ouest de la France. Menopsila dupeae n. gen. et sp., est basĂ© sur un mĂąle fragmentaire prĂ©servĂ© dans un minuscule morceau d’ambre translucide. Le genre est placĂ© incertae sedis au sein des Pemphredonini, car mĂȘlant des caractĂšres probablement plĂ©siomorphes de plusieurs lignĂ©es de cette tribu. Il reprĂ©sente vraisemblablement un groupe souche de l’une ou plus des sous-tribus constitutives des Pemphredonini, mais il est sans doute plus proche des Spilomenina

    New biting midges (Diptera: Ceratopogonidae) in Late Cretaceous Vendean amber

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    International audienceThe ceratopogonids from Late Cretaceous (Cenomanian to Santonian) amber of Vendée, in northwestern France, are studied. The new species Leptoconops (Leptoconops) gravesi n. sp., Leptoconops species undetermined, and Culicoides doyeni n. sp., are described, illustrated, and compared with other fossil species known for these two genera

    The earliest occurrence and remarkable stasis of the family Bostrichidae (Coleoptera: Polyphaga)in Cretaceous Charentes amber.

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    A new fossil species of auger beetle (Coleoptera: Bostrichidae), preserved in mid-Cretaceous (Albian-Cenomanian) amber from south-western France, is described as Stephanopachys vetus Peris, DelclĂČs et Perrichot sp. n. The species is the earliest fossil bostrichid discovered to date, but is remarkably similar to Recent species of the genus Stephanopachys, supporting long morphological conservation in wood boring beetles. The specimen is fossilized in fully opaque amber and was imaged in 3D using propagation phase-contrast X-ray synchrotron microtomography. Based on the ecology of extant related species habits, it is suggested that S. vetus sp. n. was a primary succession pioneer following wildfires in mid-Cretaceous forests. The fossil record of the family is reviewed

    Evolutionary and paleobiological implications of Coleoptera (Insecta) from Tethyan-inïŹ‚uenced Cretaceous ambers

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    The intense study of coleopteran inclusions from Spanish (Albian in age) and French (AlbianeSantonian in age) Cretaceous ambers, both of Laurasian origin, has revealed that the majority of samples belong to the Polyphaga suborder and, in contrast to the case of the compression fossils, only one family of Archostemata, one of Adephaga, and no Myxophaga suborders are represented. A total of 30 families from Spain and 16 families from France have been identified (with almost twice bioinclusions identified in Spain than in France); 13 of these families have their most ancient representatives within these ambers. A similar study had previously only been performed on Lebanese ambers (Barremian in age and Gondwanan in origin), recording 36 coleopteran families. Few lists of taxa were available for Myanmar (Burmese) amber (early Cenomanian in age and Laurasian in origin). Coleopteran families found in Cretaceous ambers share with their modern relatives mainly saproxylic and detritivorous habits in the larval or adult stages, rather than wood-boring behavior. Fifteen of the coleopteran families occur in both the Lebanese and Spanish ambers; while only five are present in both Spanish and French. Considering the paleogeographic proximity and similarity of age of the Spanish and French ambers, the small number of taxa found in common at both areas is surprising. The ancient origin for the Lebanese and Spanish ambers, the paleogeography (including some barriers for terrestrial biota) and the local paleohabitats are factors that may explain the dissimilarity with the French specimens. Wildfires are believed to be a more likely cause of resin production during the Cretaceous than infestation by beetles. Current knowledge of the beetle species found in the Cretaceous ambers is introduced

    Cretaceous snakefly larvae

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    11 p. : ill. ; 26 cm.Includes bibliographical references (p. 10-11).Snakefly (Raphidioptera) larvae are newly documented from the early Cretaceous ambers of Lebanon, Myanmar (Burma), and France. Previously only two Cretaceous larvae had been documented, one in late Cretaceous (Turonian) amber from New Jersey and another in early Cretaceous (Albian) amber from Myanmar. The specimens discussed herein are likely representative of the extinct family Mesoraphidiidae, but definitive familial assignment is currently not possible. The new fossil material is described and placed into context with the known larval morphology of modern and fossil species, as well as with the geological history of the order as documented by the remains of adults

    Parasitaxus parasitized: Novel infestation of Parasitaxus usta (Podocarpaceae).

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    The world’s sole ‘parasitic’ gymnosperm Parasitaxus usta (Podocarpaceae) is endemic to the island of Grande Terre, New Caledonia. It is a threatened species because of its limited geographic range and progressing habitat fragmentation. Here, we report a novel scale insect outbreak on a Parasitaxus sub-population from Monts Dzumac in the southern part of Grande Terre. The identity of the scale insect was determined through combining morphological and molecular methods. The field collection of scale insects and their secretions from infested Parasitaxus specimens allowed morphological identification of the superfamily Coccoidea. Subsequent genetic sequencing using CO1 markers allowed phylogenetic placement of the wax scale insects to the genus Ceroplastes (Coccoidea, Coccidae), a widespread pest genus. The identified species, C. pseudoceriferus, has not been previously recorded from New Caledonia. As Parasitaxus is already vulnerable to extinction, this new threat to its long-term survival needs to be monitored. Other New Caledonian endemic plant species are potentially at risk of this new species, although it was not observed on Falcatifolium taxoides, the host of Parasitaxus.Peer reviewe
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