87 resultados para Leptostraca, Fossil


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Un muestreo intensivo del clasico yacimiento de mamíferos fósles de Santpedor ha dado como resultado la presencia de Theridomys aff. aquatilis, Gliravus aff. priscus, Eucricetodon atavus y Pseudoltinomys gaillardi. Esta asociacin permite atribuir 1os niveles del yacimiento al Oligoceno inferior mas bajo (nivel de Hoogbutsel)

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Macroalgae is the dominant trophic group on Mediterranean infralittoral rocky bottoms, whereas zooxanthellate corals are extremely rare. However, in recent years, the invasive coral Oculina patagonica appears to be increasing its abundance through unknown means. Here we examine the pattern of variation of this species at a marine reserve between 2002 and 2010 and contribute to the understanding of the mechanisms that allow its current increase. Because indirect interactions between species can play a relevant role in the establishment of species, a parallel assessment of the sea urchin Paracentrotus lividus, the main herbivorous invertebrate in this habitat and thus a key species, was conducted. O. patagonica has shown a 3-fold increase in abundance over the last 8 years and has become the most abundant invertebrate in the shallow waters of the marine reserve, matching some dominant erect macroalgae in abundance. High recruitment played an important role in this increasing coral abundance. The results from this study provide compelling evidence that the increase in sea urchin abundance may be one of the main drivers of the observed increase in coral abundance. Sea urchins overgraze macroalgae and create barren patches in the space-limited macroalgal community that subsequently facilitate coral recruitment. This study indicates that trophic interactions contributed to the success of an invasive coral in the Mediterranean because sea urchins grazing activity indirectly facilitated expansion of the coral. Current coral abundance at the marine reserve has ended the monopolization of algae in rocky infralittoral assemblages, an event that could greatly modify both the underwater seascape and the sources of primary production in the ecosystem.

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En el presente trabajo se describen las principales características estratigráficas y sedimentológicas del relleno de la fosa de la Cerdanya. A partir de éstas se han diferenciado dos unidades: la Unidad Neógena Inferior y la Unidad Neógena Superior que reflejan dos situaciones tectónicas diferentes. La Unidad Inferior corresponde al período de formación y posterior evolución de la fosa bajo el movimiento direccional de la falla NE-SW de la Tet, mientras que la Unidad Superior refleja una situación extensional generalizada. La revisión de los numerosos yacimientos de Mamíferos fósiles de la Unidad Neógena Inferior, expuesta en esta nota, permiten concluir que esta se sedimentó en el Vallesiense. Por contra, el hallazgo del nuevo yacimiento de Can Vilella, indican que la sedimentación de la Unidad Superior se inició en el Turoliense superior (MN 13)

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In the southeastern Ebro Foreland Basin, the marine deposits of Lutetian and Bartonian age show excellent outcrop conditions, with a great lateral and horizontal continuity of lithostratigraphic units. In addition, the rich fossil record -mainly larger foraminifers-, provides biostratigraphic data of regional relevance for the whole Paleogene Pyrenean Basin, that can be used for the Middle Eocene biocorrelation of the western Tethys. This contribution is a sedimentary and biostratigraphic synthesis of the basic outcrops and sections of the Lutetian andBartonian marine and transitional deposits in the southeastern sector of the Ebro Foreland Basin.

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In this study we analyze and explain the formation of the constructive micrite envelope in the vadose continental environment. This constructive micrite envelope shows a wide variety of textural components. The principal textural components are: microorganisms, micritic and microspar LMC cement, whisker crystals, microfibres and aggregates of LMC acicular crystals. The main microorganisms are hyphae fungi, although actynomicetes and bacteries also occur. The constructive micrite envelope is due to the action of calcified filaments (hyphae fungi) which collapse and coalesce forming an intertwined mesh as well as due to the precipitation of micritic and microspar cement. The whisker crystals, microfibres and aggregates of LMC acicular crystals are secondary microtextures. Constructive micrite envelopes does not indicate a specific diagenetic environment. The constructive micrite envelopes present irregularities or bumps at the outer surface of the grains, and the destructive micrite envelopes present irregularities towards the grain interior. This morphologic criterion is useful to differenciate the micrite envelope origin, constructive or destructive, in the fossil record.

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Over the last decades, there has been an increasing interest on the chronology, distribution and mammal taxonomy (including hominins) related with the faunal turnovers that took place around the Pliocene-Pleistocene transition [ca. 1.8 mega-annum (Ma)] in Europe. However, these turnovers are not fully understood due to: the precarious nature of the period's fossil record; the"non-coexistence" in this record of many of the species involved; and the enormous geographical area encompassed. This palaeontological information gap can now be in part bridged with data from the Fonelas P-1 site (Granada, Spain), whose faunal composition and late Upper Pliocene date shed light on some of the problems concerning the timing and geography of the dispersals.

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This paper analyses the international inequalities in CO2 emissions intensity for the period 1971–2009 and assesses explanatory factors. Multiplicative, group and additive methodologies of inequality decomposition are employed. The first allows us to clarify the separated role of the carbonisation index and the energy intensity in the pattern observed for inequalities in CO2 intensities; the second allows us to understand the role of regional groups; and the third allows us to investigate the role of different fossil energy sources (coal, oil and gas). The results show that, first, the reduction in global emissions intensity has coincided with a significant reduction in international inequality. Second, the bulk of this inequality and its reduction are attributed to differences between the groups of countries considered. Third, coal is the main energy source explaining these inequalities, although the growth in the relative contribution of gas is also remarkable. Fourth, the bulk of inequalities between countries and its decline are explained by differences in energy intensities, although there are significant differences in the patterns demonstrated by different groups of countries. JEL codes: D39; Q43; Q56. Key words: CO2 international distribution, inequality decomposition, CO2 emissions intensity

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This paper describes petrologic and morphologic characteristics of fossil beaches submerged in the sector of the Costa Brava located between the Pals Beach and Blanes (Girona). These submerged beaches are composed of large-grain sandstone andconglomerate platforms, situated at a depth between 0.5 and 2.5 meters. These platforms are slightly inclinated towards the open sea. These deposits have been formed very recently, and date from Holocene, as noted by the presence of fragments of roman ceramics inside sandstone

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En aquest article es pretén explicar breument la viabilitat de la futura gestió i utilització de la biomassa forestal de Bellver de Cerdanya mitjançant un district heating al futur barri del Pla de Tomet. Les particularitats per les quals aquest poble és ideal per a aquest projecte són que l'ajuntament és propietari de gairebé un 90% dels boscos situats en aquest municipi; i que alhora ja ha realitzat diverses instal·lacions que utilitzen la biomassa forestal per a calefacció i ACS. La situació econòmica de la comarca és bastant complicada, ja que s'ha basat en el sector turístic i la construcció, però ambdós no passen pel millor moment. El projecte serviria per donar un valor a la biomassa forestal que fins ara no s'ha donat, i alhora s'intenta buscar nous inputs econòmics per a la Cerdanya. En aquest treball també s'analitza quins haurien de ser els futurs tractaments que s'haurien d'aplicar a la forest, tenint en compte les activitats que es realitzen actualment, i evitant en tot moment possibles efectes negatius, com podria ser la sobreexplotació. També es dedica una part del projecte a explicar els sistemes per obtenir i gestionar de forma correcta la biomassa. A continuació es tracta la part més tècnica, realitzant una estimació del possible futur consum energètic del barri del Pla de Tomet, encara no construït; i decidint quins sistema de calderes seria el més adequat, el tipus d’emmagatzematge més apropiat i els passos a seguir per millorar el rendiment del procés de la gestió i extracció de la biomassa. Seguint tots aquests passos s'arriba a la conclusió que aprofitar la biomassa forestal és millor solució que utilitzar combustibles fòssils. A part dels obvis beneficis medi ambientals, també és millor a nivell econòmic, tant pels futurs veïns com per l'ajuntament.

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The fossiliferous beds of the 'Cementerio de Ciurana (Gerona) ', have been studied from Taphonomy and Paleoeco.. logy viewpoints. The mode of formation of the fossil assem.. blages hardly implicates transport and the vertical successiori seems to represent a regressive sequence from former normal marine conditions.

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En base a los moluscos fósiles y a criterios sedimentológicos, se realiza una reconstrucción paleoambiental del sector de Sant Pau d'Ordal y de La Pedrera de Sant Llorenq d'Hortons y se deduce la equivalencia lateral de ambas localidades, a las que se atribuye una edad Langhiense-Serravaliense inferior. La presencia del pterópodo Vaginella austriaca, KITTL citado por primera vez en diversos yacimientos del Penedis, permite afirmar que durante este periodo existió una buena comunicación entre el golfo del Penedes y el mar abierto.

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En la presente nota se da una lista ampliada de la fauna malacológica del yacimiento pliocénico de la Plaça de les Bruixes (Molis de Rei, Barcelona). Los fenómenos de coacción que se describen nos muestran su utilidad a la hora de definir las condiciones ambientales y paleogeográficas del lugar donde habita la fauna.

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This paper addresses the surprising lack of quality control on the analysis and selection on energy policies observable in the last decades. As an example, we discuss the delusional idea that it is possible to replace fossil energy with large scale ethanol production from agricultural crops. But if large scale ethanol production is not practical in energetic terms, why huge amount of money has been invested in it and is it still being invested? In order to answer this question we introduce two concepts useful to frame, in general terms, the predicament of quality control in science: (i) the concept of “granfalloons” proposed by K. Vonnegut (1963) flagging the danger of the formation of “crusades to save the world” void of real meaning. These granfalloons are often used by powerful lobbies to distort policy decisions; and (ii) the concept of Post-Normal science by S. Funtowicz and J. Ravetz (1990) indicating a standard predicament faced by science when producing information for governance. When mixing together uncertainty, multiple-scale and legitimate but contrasting views it becomes impossible to deal with complex issue using the conventional scientific approach based on reductionism. We finally discuss the implications of a different approach to the assessment of alternative energy sources by introducing the concept of Promethean technology.

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En este artículo se dan a conocer las características de una nueva línea de investigación, abierta y desarrollada por el autor, que integra conocimientos provenientes de cuatro disciplinas académicas distintas: Paleontología, Lingüística, Literatura y Etnología. Asimismo se apuntan algunas posibilidades de aplicación educativa y/o de vinculación curricular.

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En aquest treball es recopilen i estudien, des d’una perspectiva etnopaleontològica, les aportacions i influencies exercides pels fòssils en relació al patrimoni onomàstic toponímic relacionat amb cavitats càrstiques de l’àmbit geogràfic de les Illes Balears. Generalment es tracta de microtopònims moderns o recents, en vies de popularització i/o tradicionalització (neotopònims), establerts pels científics que estudien les coves i/o esportistes del món de l’espeleologia (topocultismes). Es poden distingir entre espeleotopònims de primer ordre (quan es refereixen a cavitats completes) i de segon ordre (quan es refereixen a un sector d’una cavitat). També es realitza una primera aproximació als topònims referits a mines d’extracció de carbó fòssil (antracotopònims).