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Revision of Triplicatella (Orthothecida, Hyolitha) with preserved digestive tracts from the early Cambrian Chengjiang Lagerstätte, South China
No full textThe cap-shaped shells of Triplicatella are known almost exclusively from small shelly fossil assemblages with articulated specimens showing unequivocally that they represent the operculum of a hyolith. Abundant specimens of Triplicatella opimus from the fine-grained shales of the Chengjiang Lagerstätte of South China with soft-part preservation are documented herein. The soft tissues, including the feeding apparatus and complex digestive system, in T. opimus strongly suggest that Triplicatella was a deposit feeder. The digestive tract of T. opimus consists of two limbs, a spiral loop folded into a chevron-like structure and a slightly recurved to straight anal tube, which are preserved as reddish-black traces enriched in iron. The new anatomical information obtained from T. opimus in the Chengjiang Biota suggests an intermediate stage in the development of the characteristic folded gut of orthothecid hyoliths. The new anatomical information reported here shows that Triplicatella is one of the best-preserved early members of the Orthothecida and promotes our understanding of the general anatomy and evolution of the Hyolitha
Temporal and Geographical Variation of Intestinal Ulcers in Grey Seals (Halichoerus grypus) and Environmental Contaminants in Baltic Biota during Four Decades
No full textCorals and mollusks from a Miocene carbonate-rich deposit of Madruga, western Cuba
No full textHere is reported fauna from a Middle Miocene limestone deposit of the Cojímar Formation near the town of Aguacate in the Province of Mayabeque, western Cuba. The fossils are preserved only as internal or external molds, but we identified members of at least eight bivalves and six gastropod families and one solitary coral. The most common taxon is a lucinid bivalve probably belonging to the genus Anodontia, which may likely represent a new taxon. This species in particular, and the fauna and facies in general, suggest that the Aguacate limestone may represent an ancient seagrass meadow environment. The fauna of the Aguacate quarry shows biogeographic relationships mainly to the Miocene of Panama and Florida, but also some links to the subtropical Atlantic coast of North America, and the Miocene of northern Ecuador.Aquí se registra la fauna presente en un depósito de calizas del Mioceno Medio de la Formación Cojímar que aflorancerca del pueblo de Aguacate, en la provincia de Mayabeque, occidente de Cuba. Los fósilesse conservan solo como moldes internos o externos, peroidentificamosmiembros de al menos ocho familias debivalvos y seis de gasterópodos, y un coral solitario. El taxón más común es un bivalvo lucínido que probablemente pertenezca al género Anodontia, y que pudiera representar un nuevo taxón para la ciencia. Estaespecie en particular, y la fauna en general, sugieren que la caliza Aguacate puede representar un antiguoambiente de pradera de pastos marinos. La fauna de la cantera de Aguacate muestra relaciones biogeográficas principalmente con el Mioceno de Panamá y Florida, pero también algunos vínculos con la costa atlántica subtropical de América del Norte y con el Mioceno del norte de Ecuador
The importance of adjusting contaminant concentrations using environmental data: a retrospective study of 25 years data in Baltic blue mussels
No full textAge and paleoenvironmental significance of the Frazer Beach Member—A new lithostratigraphic unit overlying the end-Permian extinction horizon in the Sydney Basin, Australia
No full textThe newly defined Frazer Beach Member of the Moon Island Beach Formation is identified widely across the Sydney Basin in both outcrop and exploration wells. This thin unit was deposited immediately after extinction of the Glossopteris flora (defining the terrestrial end-Permian extinction event). The unit rests conformably on the uppermost Permian coal seam in most places. A distinctive granule-microbreccia bed is locally represented at the base of the member. The unit otherwise consists of dark gray to black siltstone, shale, mudstone and, locally, thin lenses of fine-grained sandstone and tuff. The member represents the topmost unit of the Newcastle Coal Measures and is overlain gradationally by the Dooralong Shale or with a scoured (disconformable) contact by coarse-grained sandstones to conglomerates of the Coal Cliff Sandstone, Munmorah Conglomerate and laterally equivalent units. The member is characterized by a palynological “dead zone” represented by a high proportion of degraded wood fragments, charcoal, amorphous organic matter and fungal spores. Abundant freshwater algal remains and the initial stages of a terrestrial vascular plant recovery flora are represented by low-diversity spore-pollen suites in the upper part of the unit in some areas. These assemblages are referable to the Playfordiaspora crenulata Palynozone interpreted as latest Permian in age on the basis of high precision Chemical Abrasion Isotope Dilution Thermal Ionization Mass Spectrometry (CA-IDTIMS) dating of thin volcanic ash beds within and stratigraphically bracketing the unit. Plant macrofossils recovered from the upper Frazer Beach Member and immediately succeeding strata are dominated by Lepidopteris (Peltaspermaceae) and Voltziopsis (Voltziales) with subsidiary pleuromeian lycopsids, sphenophytes, and ferns. Sparse vertebrate and invertebrate ichnofossils are also represented in the Frazer Beach Member or in beds immediately overlying this unit. The Frazer Beach Member is correlative, in part, with a thin interval of organic-rich mudrocks, commonly known as the “marker mudstone” capping the Permian succession further to the north in the Bowen, Galilee and Cooper basins. The broad geographic distribution of this generally <5-m-thick mudrock unit highlights the development in eastern Gondwana of extensive, short-lived, shallow lacustrine systems with impoverished biotas in alluvial plain settings in the immediate aftermath of the end-Permian biotic crisis.The authors also acknowledge the support of a collaborative research grant from the National Science Foundation (EAR-1636625 to CF and TF). </p
Övervakning av metaller och organiska miljögifter i limnisk biota (fram till 2019 års data)
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Genomic signatures of host adaptation in group B Salmonella enterica ST416/ST417 from harbour porpoises
No full textPlant mesofossils from the Late Cretaceous Klikov Formation, the CzechRepublic
No full textLate Cretaceous mesofossils are described from the Zliv-Řídká Blana locality in the South Bohemian Basins, the Czech Republic. Angiosperm remains dominate the fossil assemblage both in terms of taxonomic diversity and quantitatively, with about 65 different species based on about 1,000 specimens of flowers, fruits and seeds. There are surprisingly few nonangiosperm species in the flora, with only four specimens assigned to bryophytes, ferns and conifers. There are no megaspores of Selaginellales or Salviniales, which are otherwise common in many Cretaceous mesofossil floras. Among angiosperms, flowers and fruits assigned to the Normapolles group (Fagales) and to the Ericales are particularly prominent. In systematic composition as well as general organization and size of the angiosperm reproductive organs, the Zliv-Řídká Blana mesofossil flora is comparable to other Late Cretaceous mesofossil floras collected from various regions of Laurasia. In addition to the plant remains, the fossil assemblage also includes insect eggs and coprolites.Financial support was received from the Ministry of Culture of the Czech Republic (IP DKRVO 2019–20232.I.c., National Museum, 00023272)</p
