8 research outputs found

    Investigaciones radiográficas sobre el desarrollo del esqueleto de la mano : memoria de doctorado

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    El verso de las h. en blanco. Tesis de doctorado leída en la Universidad Central el 29 de junio de 1902.Universidad Central (Madrid)TRUEProQuestpu

    TAPHONOMY OF AMMONITE ASSEMBLAGES FROM THE MIDDLE-UPPER OXFORDIAN (TRANSVERSARIUM? - BIFURCATUS ZONES) IN THE INTERNAL PREBETIC (BETIC CORDILLERA, SOUTHERN SPAIN): TAPHONIC POPULATIONS AND TAPHOFACIES TO SUPPORT ECOSTRATIGRAPHIC INTERPRETATIONS

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    The taphonomic analysis conducted on ammonoid assemblages has proven useful for palaeobiological and palaeoenvironmental reconstructions in upper Middle-to-lower Upper Oxfordian epicontinental deposits of the Internal Prebetic (southern Spain). Taphonic populations close to type I indicate the proximity, even coincidence, of life areas for neritic ammonites (i.e. parautochthonous assemblages). The relationships among preservation mode, shell size, within-bed position, corrasion, fragmentation, and epibionts (encrustment included), with lumpy-oncolitic and condensed & bioclasts-rich lumpy-oncolitic limestones allows us to typify two taphofacies. Taphofacies I shows higher values of mean shell size, corrasion, epibionts and encrustments, as well as a high number of specimens in quasi-horizontal settlement. The opposite characteristics serve to identify Taphofacies II. Taphonomic features, taphofacies and lithofacies combine in coherence with progressing third-order transgressive-to-highstand system-tract conditions and the resulting ecostratigraphic trends, which are registered by fluctuations in ammonite assemblages

    UPPER KIMMERIDGIAN AND TITHONIAN AMMONITES FROM THE TUNISIAN "DORSALE" (NE TUNISIA): UPDATED BIOSTRATIGRAPHY FROM THE JEBEL OUST

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    In the context of updating biostratigraphic analysis in the Upper Kimmeridgian-lowermost Berriasian from the whole of the Tunisian Dorsale (NE Tunisia), new results obtained from the Jebel Oust reference section are presented. The bed-by-bed-sampling of a rather rich ammonite fauna gathered in the two most favourable profiles in the area allowed to propose, for the first time, a biozonation for Upper Kimmeridgian to Tithonian limestones. Calpionellids relayed or completed ammonite assemblages, and were also useful for biostratigraphy in beds close to the Jurassic-Cretaceous boundary. The composition of ammonite assemblages, as well as the known ranges for genera and species, is in accordance with the available information from epioceanic areas in West-Mediterranean Tethys. The recognized biozones fit the standard proposal given by Groupe Français D'Etude du Jurassique in 1997. Age-interpretation for turbiditic horizons in the Jebel Oust is made for the first time. In spite of some limitations, the biostratigraphic results obtained in Jebel Oust sections provide a valuable tool for potential correlations with poorly known sections in northern Tunisia, as well as with other Tethyan areas.

    Historia del conocimiento de los ammonites (moluscos fósiles) del Jurásico de España

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    La Paleontología como ciencia tiene su inicio con los trabajos de Georges Cuvier sobre anatomía comparada, la aceptación de los modelos actualistas geológicos de Charles Lyell y el paradigma evolucionista de Charles Darwin. Sin embargo, son escasas las aportaciones de naturalistas españoles a la historia de la paleontología. Con ocasión del tercer centenario del nacimiento del naturalista español José Torrubia (1698-1761) autor de uno de los primeros libros paleontológicos españoles (el Aparato para la Historia Natural Española) publicado en 1754, se presenta aquí una panorámica general de la historia del conocimiento e interpretación de uno de los grupos de organismos fósiles más interesantes de España: los Ammonites, moluscos exclusivamente fósiles del grupo de los cefalópodos
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