124 research outputs found

    Re-evaluation of Cerebropollenites thiergartii Eberh.Schulz 1967 and related taxa: priority of Sciadopityspollenites and nomenclatural novelties

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    The important marker species for the base of the Jurassic, Cerebropollenites thiergartii, occurs contemporaneously with at least nine related taxa. However, their distinction is difficult and has been confused in the past. In addition, a long history of numerous recombinations with different genus names (e.g. Tsugaepollenites and Sciadopityspollenites), and inconsistent classifications or synonymisations, further complicate the taxonomic framework of Cerebropollenites thiergartii. A comprehensive study of these ten taxa, summarising their crucial distinctive characteristics and potential synonymy, is currently missing. This limits the stratigraphic value of Cerebropollenites thiergartii and associated taxa relevant to the Triassic–Jurassic transition. Here, we revisit relevant holotype material, related taxa and investigated new material for potential interspecific and intraspecific morphological variation. Based on an empirical analysis of name use and an extensive literature review, we identified previous sources of confusion, re-evaluated the distinctive characteristics and stratigraphic value of these taxa, and their relevance for the Triassic–Jurassic transition. Finally, we argue that the recombination as Sciadopityspollenites thiergartii is taxonomically and nomenclaturally imperative, not only due to priority, but also because it unifies previous disjunct use of Cerebropollenites for Mesozoic and Sciadopityspollenites for Cenozoic taxa, or Mesozoic species in many Russian studies. Thus, we propose a series of nomenclatural novelties: Sciadopityspollenites emend., Sciadopityspollenites thiergartii comb. nov. et emend., S. thiergartii ssp. nov. thiergartii, S. thiergartii ssp. multiverrucosus stat. nov., S. megaorbicularius sp. nov., S. carlylensis comb. nov. et emend., S. serratus emend., S. macroverrucosus emend., S. mesozoicus emend., Cryptopalynites gen. nov., Cryptopalynites pseudomassulae comb. nov. et emend

    Re-evaluation of Cerebropollenites thiergartii Eberh.Schulz 1967 and related taxa: priority of Sciadopityspollenites and nomenclatural novelties

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    The important marker species for the base of the Jurassic, Cerebropollenites thiergartii, occurs contemporaneously with at least nine related taxa. However, their distinction is difficult and has been confused in the past. In addition, a long history of numerous recombinations with different genus names (e.g. Tsugaepollenites and Sciadopityspollenites), and inconsistent classifications or synonymisations, further complicate the taxonomic framework of Cerebropollenites thiergartii. A comprehensive study of these ten taxa, summarising their crucial distinctive characteristics and potential synonymy, is currently missing. This limits the stratigraphic value of Cerebropollenites thiergartii and associated taxa relevant to the Triassic–Jurassic transition. Here, we revisit relevant holotype material, related taxa and investigated new material for potential interspecific and intraspecific morphological variation. Based on an empirical analysis of name use and an extensive literature review, we identified previous sources of confusion, re-evaluated the distinctive characteristics and stratigraphic value of these taxa, and their relevance for the Triassic–Jurassic transition. Finally, we argue that the recombination as Sciadopityspollenites thiergartii is taxonomically and nomenclaturally imperative, not only due to priority, but also because it unifies previous disjunct use of Cerebropollenites for Mesozoic and Sciadopityspollenites for Cenozoic taxa, or Mesozoic species in many Russian studies. Thus, we propose a series of nomenclatural novelties: Sciadopityspollenites emend., Sciadopityspollenites thiergartii comb. nov. et emend., S. thiergartii ssp. nov. thiergartii, S. thiergartii ssp. multiverrucosus stat. nov., S. megaorbicularius sp. nov., S. carlylensis comb. nov. et emend., S. serratus emend., S. macroverrucosus emend., S. mesozoicus emend., Cryptopalynites gen. nov., Cryptopalynites pseudomassulae comb. nov. et emend

    First evidence of ranunculids in Early Cretaceous tropics

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    Early Cretaceous floras containing angiosperms were described from several geographic areas, nearly from the Arctic to the Antarctic, and are crucial to understand their evolution and radiation. However, most of these records come from northern mid-latitudes whereas those of lower paleolatitude areas, such as the Crato Fossil Lagerstätte in NE Brazil, are less studied. Here, we describe from this region of northern Gondwanan origin, two fossil-species of eudicots belonging to a new extinct genus Santaniella gen. nov. Together with several vegetative axes and leaves, anatomically well-preserved fruits with seeds and persistent perianth-like organs allowed us to reconstruct its potential affinities with ranunculids, and presumably Ranunculaceae. Previous records putatively assigned to Ranunculales are all from mid-latitudes, and their first unequivocal occurrence in a low-latitude area supports further the hypothesis of a widespread radiation of the earliest diverging eudicot lineage by this early age

    Neotropical Anacardiaceae (cashew family)

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    Anacardiaceae is an ecologically and economically important plant family of about 200 species in 32 genera in the Neotropics. The family is particularly diverse in leaf architecture and fruit morphology, making it a model family to study the evolution of structural diversity as it correlates with lineage diversification. This fruit diversity is the primary reason 11 of the Neotropical genera are monotypic and that so many genera are recognized in the Anacardiaceae. The economic value of the family is driven by the global markets for cashews, mangoes, and pistachios, but there is great potential value in its medicinal properties. At least 10 Neotropical genera cause contact dermatitis, which is a rich area for research in the family. Here presented is a review of the systematics and structural diversity of the family. Particular attention is given to the morphology, economic botany, paleobotany, ecology, and taxonomy of native and naturalized genera. Keys to Neotropical Anacardiaceae subfamilies and genera are provided along with descriptions of native genera

    The NIKA instrument: results and perspectives towards a permanent KID based camera for the Pico Veleta observatory

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    The New IRAM KIDs Array (NIKA) is a pathfinder instrument devoted to millimetric astronomy. In 2009 it was the first multiplexed KID camera on the sky; currently it is installed at the focal plane of the IRAM 30-meters telescope at Pico Veleta (Spain). We present preliminary data from the last observational run and the ongoing developments devoted to the next NIKA-2 kilopixels camera, to be commissioned in 2015. We also report on the latest laboratory measurements, and recent improvements in detector cosmetics and read-out electronics. Furthermore, we describe a new acquisition strategy allowing us to improve the photometric accuracy, and the related automatic tuning procedure.Comment: 24th International Symposium on Space Terahertz Technology, ISSTT 2013, April 8 to 10, 2013, Groningen, the Netherland

    Latest NIKA results and the NIKA-2 project

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    NIKA (New IRAM KID Arrays) is a dual-band imaging instrument installed at the IRAM (Institut de RadioAstronomie Millimetrique) 30-meter telescope at Pico Veleta (Spain). Two distinct Kinetic Inductance Detectors (KID) focal planes allow the camera to simultaneously image a field-of-view of about 2 arc-min in the bands 125 to 175 GHz (150 GHz) and 200 to 280 GHz (240 GHz). The sensitivity and stability achieved during the last commissioning Run in June 2013 allows opening the instrument to general observers. We report here the latest results, in particular in terms of sensitivity, now comparable to the state-of-the-art Transition Edge Sensors (TES) bolometers, relative and absolute photometry. We describe briefly the next generation NIKA-2 instrument, selected by IRAM to occupy, from 2015, the continuum imager/polarimeter slot at the 30-m telescope.Comment: Proceedings of Low Temperature Detectors 15 (LTD-15), Pasadena, June 201

    A new remarkable Early Cretaceous nelumbonaceous fossil bridges the gap between herbaceous aquatic and woody protealeans

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    Dating back to the late Early Cretaceous, the macrofossil record of the iconic lotus family (Nelumbonaceae) is one of the oldest of flowering plants and suggests that their unmistakable leaves and nutlets embedded in large pitted receptacular fruits evolved relatively little in the 100 million years since their first known appearance. Here we describe a new fossil from the late Barremian/Aptian Crato Formation flora (NE Brazil) with both vegetative and reproductive structures, Notocyamus hydrophobus gen. nov. et sp. nov., which is now the oldest and most complete fossil record of Nelumbonaceae. In addition, it displays a unique mosaic of ancestral and derived macro- and micromorphological traits that has never been documented before in this family. This new Brazilian fossil-species also provides a rare illustration of the potential morphological and anatomical transitions experienced by Nelumbonaceae prior to a long period of relative stasis. Its potential plesiomorphic and apomorphic features shared with Proteaceae and Platanaceae not only fill a major morphological gap within Proteales but also provide new support for their unexpected relationships first suggested by molecular phylogenies
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