227 research outputs found

    Atopidae (Trilobita) in the upper Marianian (Cambrian Series 2, Stage 4) of Iberia

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    New atopid trilobites are described from the early Cambrian Cumbres beds and Herreriás shale of northern Huelva Province (Andalusia, Spain) and are dated as middle-late Marianian (Cambrian Series 2, Stage 4). New specimens of Atops calanus Richter and Richter, 1941 are described and the Laurentian species Pseudatops reticulatus (Walcott, 1890b) is recognized for the first time in the Mediterranean subprovince. The associated trilobite assemblage studied herein suggests an age close to the base of Cambrian Stage 4

    The distribution of Paradoxides (Acadoparadoxzdes) mureroensis SDZUY, 1958 (earliest Middle Cambrian) and its palaeobiogeographical consequences

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    [Resumen] El norte de España contiene los mejores afloramientos conocidos para estudiar la transición del Cámbrico Inferior al Cámbrico Medio en la región mediterránea debido, sobre todo, al excelente registro paleontológico presente en la Región Cantábrica y en las Cadenas Ibéricas. LOTZE (1961) YSDZUY (1971b) propusieron situar este límite en la aparición de Paradoxides (Acadoparadoxides) mureroensis pero esta especie solo era conocida entonces en la localidad de Murero (Zaragoza), y en Tuva (Siberia: REPINA, 1969). Su cita posterior en varias localidades de las Cadenas Ibéricas permitió establecer la biozona de Paradoxides (Acadoparadoxides) mureroensis como la primera del Cámbrico Medio en esta área. Los nuevos hallazgos de estas especie en las localidades de Valdoré y Porma (Zona Cantábrica) y Ounein (Marruecos) permiten reconocer dicha biozona en estas regiones. Esta biozona se sitúa, en su localidad de definición, por encima de un evento estratigráfico denominado Geoevento Valdemiedes, que caracteriza un fenómeno de extinción que afectó total o parcialmente a diferentes grupos de trilobites como los Neoredlíchidos y Hamatolénidos, y probablemente a los Arqueociatos. De algún modo fue también responsable de la subsecuente aparición de los Paradoxídidos y del mayor desarrollo de los Agnóstidos que tienen lugar en la base del Cámbrico Medio. Para analizar las características de esta transición se han estudiado seis secciones en las Cadenas Ibéricas y dos en la región cantábrica. La distribución geográfica de Paradoxides (Acadoparadoxides) mureroensis es bordada en el contexto de las reconstrucciones paleogeográficas de esta época. Los nuevos especímenes de Paradoxides (Acadoparadoxides) mureroensis studiados sugieren la conveniencia de revisar la diagnosis original de esta especie, para incluir un morfotipo caracterizado por tres surcos glabelares, que se interpreta como una fase evolutiva previa a la probable aparición del subgénero Eccaparadoxz ·des en las Cadenas Ibéricas.[Abstract] The northern Spain contains the best known outcrops to study the Lower-Middle Cambrian transition in the Mediterranean region. It is due to the excellent palaeontological record found in the Cantabrian Mountains and the Iberian Chains. Since the works ofLOTZE (1961) and SDZUY (1971b) it has been proposed the horizon with the first record of Paradoxides (Acadoparadoxides) mureroensis as the Lower-Middle Cambrian boundary but this species was only recorded at Murero (Zaragoza), its type locality, and Tuva (Siberia) by REPINA (1969). In other localities of the Iberian Chains by VALENWELA et al. (1990), GOZALO et al. (1993), ALVARO et al. (1993), its finging has made possible the definition of the Paradoxicles (Acadoparadoxides) mureroensis biozone as the first biozone of the Middle Cambrian in this region. Now, this species is also found at Borobia (Iberia Chains), Porma and Valdoré (Cantabrian Mountains), and Ounein (Morocco) which permet us an accurate correlation between aH these regions. In its locality, the mencioned biozone is placed aboye the Valdemiedes Geoevent which characterize an extinction phenomenon concerning to the faunas of Neoredlichiids, Hamatolenids and probable Archaeocyaths. To a certain extend this event also favoured the subsequent record of Paradoxidids and Agnostoids during the lowermost Middle Cambrian. To understand the characteristics of the Lower-Middle Cambrian transition, we .studyed six sections from the Iberian Chains and other two from the Cantabrian region. This distribution of Paradoxides (Acadoparadoxides) mureroensis is analized in a palaeobiogeographical contexto The new specimens of Paradoxides (Acadoparadoxides) mureroensis studied now, suggest the convenience to revise the original diagnosis of this species, to include a morphotype characterized by three glabelar furrows, which is interpreted as an evolutive phase, previous to the probable appearence of Eccaparadoxides subgenus in the Iberian Chains

    The Cambrian of the Iberian Peninsula : an overview

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    This work is a brief overview of the Cambrian in the Iberian Peninsula, along with an updated review of lithostratigraphic and biostratigraphic data. A Cambrian correlation chart between the different stratigraphical units that have been established in the Iberian Peninsula is given. We also reappraise the Lower and Middle Cambrian regional stages in the light of new palaeontological data, and the different biozonations proposed with several palaeontological groups

    A new occurence of the genus Tonkinella in northern Spain and the Middle Cambrian intercontinental correlation

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    The genus Tonkinella is a typical polimeroid trilobite in lower Middle Cambrian rocks from Vietnam, Canada, U.S.A., India, Korea, Siberia, China and Argentina. It has recently been found in the Mediterranean region (Iberian Chain, northeastern Spain). In this paper we refer the finding of Tonkinella aff. breviceps in the Leonian (lower Middle Cambrian) of the Cantabrian Mountains (northern Spain), analysing its stratigraphical position, fossil assemblages, biochronology and utility for intercontinental correlation. The presence of this taxon allows us to make a more accurate correlation between the Middle Cambrian biochronological scales of Laurentia, the Mediterranean area and China

    First report of Crumillospongia (Demospongea) from the Cambrian of Europe (Murero biota, Spain)

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    The demosponge genus Crumillospongia, originally described from the Burgess Shale (middle Cambrian of Canada), has only been cited from lower and middle Cambrian localities of North America and China. The taxon is now also described from uppermost lower Cambrian rocks of the Murero Lagerstätte (Zaragoza Province, NE Spain). Crumillospongia mureroensis sp. nov. is a small to medium sized sack-shaped to elongate demosponge characterized by the presence of densely packed pores of three sizes, considerably larger than those in any other species of the genus. The Spanish material represents a link in the chronostratigraphical gap between the Chinese and North American material.Peer reviewe

    Cambrian bioestratigraphy and environmental evolution of the Borobia area (Province of Soria, Oriental Iberian Chain, Spain)

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    [Resumen] Se estudian dos secciones estratigráficas en los afloramientos cámbricos más septentrionales de la Cadena Ibérica Oriental, las cuales incluyen a las formaciones Jalón, Ribota, Huérmeda, Daroca, Valdemiedes, Murero y Acón. Los datos estratigráficos, mineralógicos, petrológicos y paleontológicos sugieren la existencia de tres geoventos de tipo eustático. El primero de ellos (Transgresión del Cámbrico inferior) comienza con depósitos litorales en condiciones áridas y ambiente oxidante, para evolucionar a un medio sublitoral carbonatado y posteriormente a otro de plataforma siliciclástica abierta. El segundo geoevento (Regresión Hawke Bay) estaría representado por las areniscas y lutitas de la Formación Daroca. El inicio del tercer geoevento (transgresión generalizada del Cámbrico medio) produce la instauración de una plataforma mixta (terrígeno-carbonatada) con pulsos regresivos asociados, representados por la base de la Formación Acón. La presencia de los trilobites Strenuaeva ineondita, Aeadolenus sp., Asturiaspis inopinatus; Paradoxides (Eeeaparadoxides) suleatus; P. (Eee.) rouvillez: P. (Bee.) barehyrhaehis, Badulesia tenera, Badulesia pasehz: Badulesia granien: Solenopleuropsis verdiagana, Solenopleuropsis truneata y Pardazlhaina sp.; junto a los acritarcos Skiagia ezliosa, Heliosphaen'dium dissimzlare, Arehaeodiseina umbonulata, Cristallinium eambn'ensis, Eliasum Ilaniseum, Timofeevia fosfonOtiea y Timofeevia lanearae sugiere que los pisos Marianiense, Bilbiliense, Leoniense y Caesaraugustiense del Cámbrico inferior-medio están representados. Estos datos paleontológicos permiten una primera comparación entre la biozonación española de trilobites y la de acritarcos, y proceder así a la correlación de los materiales del Cámbrico inferior y medio de la Península Ibérica con los de la Plataforma Oriental Europea.[Abstract] Two stratigraphical sections from the more septentrional Cambrian outcrops of the Oriental Iberian Chain 'are studied, including theJalón, Ribota, Huérmeda, Daroca, Valdemiedes, Murero and Acón formations (Lower-Middle Cambrian). The stratigraphical, mineralogical, petrological and paleontological data suggest the presence of three eustatic geoevents. The first one (Lower Cambrian Transgression) started with litoral deposits on arid and oxidant conditions that changed to sublitoral deposits (carbonate shelf) and posteriorly to an open siliciclastic shelf. The second eustatic geoevent (Hawke Bay Regression) is represented by the sandstones and lutites of the Daroca formation. The third geoevent (Middle Cambrian Transgression) began with the establishment of a mixed shelf (terrigenous- carbonated) and shows sorne regressive pulses represented by the basal leveIs of the Acón Formation. The presence of the trilobites Strenuaeva ineondita, Aeadolenus sp., Asturiaspis inopinatus, Paradoxides (Eceaparadoxides) suleatus, P. (Eee.) rouvillei, P. (Bee.) barehyrhaehis, Badulesia tenera, Badulesia pasehz~ Badulesia granien', Solenopleuropsis verdiagana, Solenopleuropsis truneata and Paradazlhania sp.; and the acritarchs Skiagia ezliosa, Heiosphaen'dium dissimzlare, Arehaeodiseina umbonulata, Cristallinium eambn'ensis, Eliasum Ilaniseum, Timofeevia fosfontiea and timofeevia lanearae suggest a Lower-Middle Cambrian age (Marianian to Caesaraugustian stages). These biostratigraphical data allow a comparison between the trilobite and acritarch biozonations for the first time in Spain as well as the correlation of the Península Ibérica's Lower-Middle Cambrian materials with the East European Platform ones.

    Upper Marianian (Cambrian Series 2) trilobites from the Totanés–Noez area (Central Iberian Zone, Toledo province, Spain): systematics and intercontinental correlation

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    Marianian (Cambrian Series 2) trilobites from the area between Totanés and Noez (Central Iberian Zone) are described and their biostratigraphical significance is discussed. The trilobites come from eight localities and can be divided into two main assemblages: the first is characterised by Serrodiscus bellimarginatus, Chelediscus cf. garzoni, Atops calanus, Pseudatops reticulatus and indeterminate polymeroid trilobites. The second assemblage consists of Serrodiscus bellimarginatus, Triangulaspis cf. fusca, Andalusiana palaciosi n. sp., Termierella totanesensis n. sp. and Acanthomicmacca sp. Both fossil associations indicate a late Marianian age in the regional stratigraphic scheme for the Cambrian of the Iberian Peninsula, as Serrodiscus, Chelediscus and Pseudatops have been recorded from the upper Marianian substage, while Triangulaspis, Andalusiana, Termierella and Acanthomicmacca are indicative of the middle to upper Marianian. The taxa considered here have regional and intercontinental correlation potential. The presence of the globally distributed genus Serrodiscus allows correlation in the Cambrian Series 2. The first assemblage, composed of Serrodiscus, Chelediscus, Atops and Pseudatops, has been reported from the Ossa-Morena Zone, Avalonia, Laurentia, Baltica and Siberia, improving the correlation between these regions. The second assemblage of Andalusiana, Termierella, Triangulaspis and Serrodiscus is comparable to other assemblages from the Ossa-Morena Zone, the Iberian Chains and Morocco, with Triangulaspis also reported from Newfoundland and Siberia. In addition, the proposal of the ISCS regarding the co-occurrence of Hebediscus, Calodiscus, Serrodiscus and Triangulaspis as a potential marker for the base of the Cambrian Stage 4 may imply that the upper Marianian of Iberia could be approximately correlated with the base of this stage.Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This is a contribution to the GIUV2017-395 Research Group of the Universitat de València and to the project IGCPs 652 “Reading geologic time in Palaeozoic sedimentary rocks” as well as the Andalusian Government to the Research Group RNM276 and by the Centro Científico-Tecnológico de Huelva (CCTH). Thanks to Ms. Isabel Pérez Urresti (technician of the University of Zaragoza) who assisted us with the photography. L.C. is supported by Portuguese funds by Fundação para a Ciência e a Tecnologia (Portugal) in the frame of UI/ DB/151298/2020 Project.Departamento de Geodinámica y Paleontologí

    Análisis criptopaleontológico del lapidario de Teofrastro (s. III a.C.)

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    La obra"Perì líthon" o"Tratado de Piedras" de Teofrasto, es considerado el texto más antiguo conservado sobre minerales y rocas, aunque haya llegado hasta nosotros incompleto. En este trabajo se analiza su contenido comparándolo con el de otros lapidarios antiguos y se concluye que once de las piedras que refiere y que vienen indicadas con nombres geográficos o crípticos son fósiles de plantas, vertebrados o químicos. Por eso, esta obra debe considerarse también como el tratado más antiguo que conocemos sobre paleontología, pues además de los fósiles que menciona, en ella se alude expresamente al proceso de fosilización. Palabras clave: Criptopaleontología

    Cardiotrophin-1 improves kidney preservation, graft function, and survival in transplanted rats

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    [EN]Background Cold ischemia-reperfusion injury is unavoidable during organ transplantation, and prolonged preservation is associated with poorer function recovery. Cardiotrophin-1 (CT-1) is an IL-6 family cytokine with cytoprotective properties. This preclinical study in rats tested whether CT-1 mitigates cold renal ischemia-reperfusion injury in the context of the transplantation of long-time preserved kidneys. Methods Kidneys were flushed with cold (4 degrees C) University of Wisconsin solution containing 0.2 g/mL CT-1 and stored for several periods of time at 4 degrees C in the same solution. In a second approach, kidneys were first cold-preserved for 6 hours and then were perfused with University of Wisconsin solution containing CT-1 (0, 16, 32, or 64 g/mL) and further cold-preserved. Organ damage markers were measured in the kidneys at the end of the storage period. For renal transplantation, recipient consanguineous Fischer rats underwent bilateral nephrectomy and received a previously cold-preserved (24 hours) kidney as described above. Survival and creatinine clearance were monitored over 30 days. Results Cardiotrophin-1 in perfusion and preservation fluids reduced oxidative stress markers (superoxide anion and inducible nitric oxide synthase), inflammation markers (NF-B and tumor necrosis factor-), and vascular damage (vascular cell adhesion molecule-1) and activated leukemia inhibitory factor receptor and STAT-3 survival signaling. Transplantation of kidneys cold-preserved with CT-1 increased rat survival and renal function (ie, lower plasma creatinine and higher creatinine clearance) and improved kidney damage markers after transplantation (ie, lower superoxide anion, tumor necrosis factor-, intercellular adhesion molecule-1, and vascular cell adhesion molecule-1 and higher NF-B). Conclusions Cardiotrophin-1 represents a novel therapeutic strategy to reduce ischemia-reperfusion and cold preservation injury to rescue suboptimal kidneys and, consequently, to improve the clinical outcomes of renal transplantation
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