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Huntingdon, United Kingdom

The early rudist bivalve Valletia antiqua Favre in Joukowsky & Favre, 1913 is recorded for the first time from the Tithonian to Berriasian Štramberk Limestone (northeastern Czech Republic) and Ernstbrunn Limestone (Lower Austria). The species is re-described and its spatial distribution and stratigraphical range are outlined. Furthermore, the palaeoecology of Valletia antiqua is discussed in the light of novel data on palaeocommunities and microfacies, habitat selection and intraspecific competition for settling space among juveniles. The study is supplemented with a commented list of all nominal species that have been assigned to Valletia, including data on type localities, type strata, and distribution. © 2015, Czech Geological Survey. All rights reserved. Source

Carriol R.-P.,French Natural History Museum | Schneider S.,CASP
Annales de Paleontologie | Year: 2016

Two new species of cirripedes are described from mid Burdigalian (Ottnangian) deposits in Lower Bavaria (Germany) and Upper Austria. A third species, "Arcoscalpellumg" sp., is left in open nomenclature. Scillaelepas danningeri sp. nov. is the seventh extinct species belonging to the genus Scillaelepas. It is characterized by: A tergum with the occludent margin much longer than the upper carinal margin and internally with the apical part raised and marked by growth-lines cut by fine radial striae; a scutum externally with the tergal surface marked by a groove, with or without ridges, radiating from the apex. Conopea bacata sp. nov. is the sixth fossil species belonging to the genus Conopea and one of the oldest. This species is characterized by its shell with growth ridges beaded. In addition, Paractinobalanus moronii Carriol, 2008 is assigned to Conopea Say. © 2016 Elsevier Masson SAS. Source

Le Heron D.P.,Royal Holloway, University of London | Howard J.P.,CASP
Sedimentary Geology | Year: 2012

Field studies in the Jabel az-Zalmah region, at the northern flank of Al Kufrah Basin provide new insights into the stratigraphy and evolving depositional environments of Cambro-Ordovician through Devonian sediments. At the base of the succession, the Hawaz Formation is about 300. m thick and is characterised by frequently Skolithos-burrowed, fine to medium grained sandstones with occasional silty intervals and rare conglomerates deposited in a generally high-energy tidal shelf setting. Bioturbation is pervasive, and includes spectacular Cruziana traces produced by Early to Mid Ordovician trilobites at the bottom and the top of the Hawaz Formation respectively. These strata were incised during the late Ordovician (Hirnantian) glaciation. Ice sheets flowing over Jabel az-Zalmah cut a palaeo-topography of up to 100. m relief. This relief is overlain by a coarsening upward succession of clastic sedimentary rocks, recording re-advance of an ice sheet, which overrode the uppermost sandstones. Ice sheet retreat was accompanied by marine transgression and erosion, which left a thin transgressive lag-conglomerate, capped sharply by siltstones of the Tannezuft Formation. Progradation resumed after post-glacial maximum flooding, depositing tide, storm, and river-influenced parasequences of a major delta complex (200. m thick Acacus Formation). Fluvial incision, and the development of a disconformity, preceded the deposition of the Tadrart Formation (50. m thick), a succession of trough-cross bedded braided river deposits. Transgression, and the re-establishment of shallow or marginal marine systems, is represented by the extensively bioturbated Binem Formation in which Zoophycos burrows offer a tentative Middle Devonian stratigraphic fix. An understanding of the lithological character of the Lower Palaeozoic strata in Jabel az-Zalmah, together with the character of unconformities that punctuate the succession, will be vital for successful hydrocarbon exploration in this frontier basin which has, until now, been unsuccessful. © 2011 Elsevier B.V. Source

Lopez-Mir B.,CASP | Munoz J.A.,University of Barcelona | Garcia-Senz J.,Instituto Geologico Y Minero Of Espana Igme
International Journal of Earth Sciences | Year: 2014

The Cotiella Massif in the south-central Pyrenees hosts upper Cretaceous gravity-driven extensional faults which were developed in the Bay of Biscay–Pyrenean paleorift margin of the Atlantic Ocean. They accommodate up to 6 km of post-rift carbonates above relict upper Triassic salt. Subsequent Pyrenean contractional deformation preserved the main extensional features, but most of the upper Triassic salt was expulsed and then dissolved, leaving little indications of the original salt volume. Nonetheless, several distinctive salt-related features are still recognizable both at outcrop and at basin scale, providing an exposed analogue for salt-floored extensional basins developed on passive margins. Based on field research, we re-interpret the tectonic evolution of the area and suggest that passive diapirs were coeval with gravity-driven extension during the development of the Cotiella basin. The given interpretations are supported with detailed geological maps, original structural data, cross sections and outcrop photographs. The discovery of previously unknown post-rift salt structures in the Cotiella Massif is an extra element to consider in the paleogeographic reconstructions of the upper Cretaceous passive margin of the Bay of Biscay–Pyrenean realm and consequently helps in our understanding of the evolution of current Atlantic-type margins. © 2014, Springer-Verlag Berlin Heidelberg. Source

The Late Jurassic (Late Oxfordian) Diceratidae and Epidiceratidae (Bivalvia: Hippuritida) from the Korallenoolith Formation at Salzhemmendorf south of Hanover (northern Germany) are revised. Due to poor preservation of the material, the species names Diceras koeneni Dubbers, 1888 and Diceras gracile Dubbers, 1888, established on the re-studied material, are regarded as nomina dubia. The specimens are assigned to the genera Diceras, Epidiceras and Plesiodiceras. For all three genera the occurrence at Salzhemmendorf constitutes their northernmost record. The rudist faunal community suggests a largely tropical to subtropical environment. Palaeoclimate and facies are thought to have restricted further expansion of the Diceratidae and Epidiceratidae towards the north. © 2015 E. Schweizerbart'sche Verlagsbuchhandlung, Stuttgart, Germany. Source

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