Person: Fernández López, Sixto Rafael
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First Name
Sixto Rafael
Last Name
Fernández López
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Geológicas
Department
Geodinámica, Estratigrafía y Paleontología
Area
Paleontología
Identifiers
55 results
Search Results
Now showing 1 - 10 of 55
Item Itinerario paleontológico por el Cerro de la Cruz (Sierra del Reclot).(Geología de Alicante: [libro guía de las excursiones del XIII Simposio sobre Enseñanza de la Geología, Alicante, 5-10 de julio de 2004], 2004) Caracuel Martín, Jesús E.; Fernández López, Sixto Rafael; Tent-Manclús, J.E.; Yébenes, A.; Alfaro , Pedro; Andreu Rodríguez, José Manuel; Estévez, A.; Tent-Manclús, J.E.; Yébenes, A.Item Taphonomy, facies and palaeoenvironmental analysis.(Abstracts and Programs. 6th International Symposium on the Jurassic System, 2002) Fernández López, Sixto Rafael; Martire, LucaItem Early Jurassic carbonate evolution in the Lusitanian Basin (Portugal): facies, sequence stratigraphy and cyclicity(23rd IAS Meeting of Sedimentology : Coimbra 2004, Sedimentology and society. Field trip guidebook. Volume 1, Carboniferous and Jurassic carbonate platforms of Iberia, 2004) Duarte, Luís Vitor; Wright, V.P.; Fernández López, Sixto Rafael; Elmi, Serge; Krautter, Manfred; Azeredo, Ana; Henriques, María Helena Paiva; Rodrigues, René; Perilli, Nicola; Duarte, Luís Vitor; Henriques, María Helena PaivaItem La naturaleza del registro fósil y el análisis de las extinciones(Coloquios de paleontología, 2000) Fernández López, Sixto RafaelEl registro fósil es parcial, está sesgado y presenta desorden estratigráfico. Sin embargo, estas propiedades del registro fósil no disminuyen la utilidad de los datos paleontológicos para identificar e interpretar los sucesivos eventos de extinción. La información del registro fósil es la única información disponible sobre los taxones extinguidos y su orden de sucesión. Tanto la validez de los datos paleontológicos respecto a la información disponible en el registro fósil, como la parcialidad y el sesgo del registro fósil respecto a la información paleobiológica original, son susceptibles de contrastación con criterios independientes. La continuidad del registro fósil, al igual que la continuidad del registro estratigráfico, es de naturaleza operatoria y susceptible de contrastación. Las reducciones de diversidad taxonómica en el registro fósil, y la falta de registro de una o más especies, debidas a procesos de extinción biológica pueden ser distinguidas de las que se deben a otras causas como por ejemplo: las características del muestreo, los cambios en la conservación diferencial de los fósiles, la presencia de lagunas en el registro estratigráfico o las debidas a otros cambios paleobiológicos. El registro fósil contiene la información más relevante para formular hipótesis fundamentadas y contrastables respecto a los eventos de extinción biológica ocurridos en la biosfera durante la historia de la Tierra.Item Bathonian Working Group(Newsletter (International Subcommission on Jurassic Stratigraphy), 2006) Fernández López, Sixto RafaelItem Jurásico Medio(Geología de España, 2004) Gómez Fernández, Juan José; Fernández López, Sixto Rafael; Vera, J.A.Item Accumulation: taphonomic concept and other palaeontological uses(Current Topics on Taphonomy and Fossilization, 2002) Fernández López, Sixto Rafael; Fernández Jalvo, Yolanda; Alcalá, Luis; Renzi, Miguel de; Pardo Alonso, Miguel V.; Belinchón, Margarita; Peñalver, Enrique; Montoya, Plinio; Márquez Aliaga, AnaItem New Early Bathonian Bigotitinae and Zigzagiceratinae (Ammonoidea,Middle Jurassic)(Rivista italiana di paleontologia e stratigrafia, 2007) Fernández López, Sixto RafaelSeveral tens of Lower Bathonian Bigotites from Digne-Castellane region (SE France) and Cabo Mondego area (Portugal) have been reviewed. Three species have been distinguished in the lowermost subzone of the Zigzag Zone (Parvum Subzone) just above the boundary Bajocian to Bathonian: B. diniensis Sturani [M+m], B. sturanii sp. nov. [M+m] and B. mondegoensis sp. nov. [M+m]. In the Bas Auran area, a chronocline from evolute, strongly ribbed and constricted forms (including B. sturanii and B. diniensis) to involute forms with blunt, moderately prominent ribbing and weak constrictions (including B. mondegoensis) can be recognized. The shared taxa B. mondegoensis sp. nov. and possibly B. diniensis Sturani permit detailed subdivision and correlation to be established between ammonite fossil assemblages of Parvum Subzone in the Lusitanian and Alpine basins. A separate genus of Zigzagiceratinae, Protozigzagiceras g. nov., is proposed to encompass P. torrensi (Sturani) as type species. These new palaeontological data about the youngest members of Bigotitinae and the oldest members of Zigzagiceratinae are of biochronostratigraphic importance for the subdivision and correlation of the basal Bathonian Zigzag Zone. Three successive biohorizons can be identified at the Parvum Subzone in Bas Auran (French Alpine Basin) and Cabo Mondego (Lusitanian Basin): Diniensis, Mondegoensis and Protozigzagiceras biohorizons.Item Alteración tafonómica y tafonomía evolutiva(Boletín de la Real Sociedad Española de Historia Natural. Sección geológica, 2005) Fernández López, Sixto RafaelItem Ammonoid taphonomy, palaeoenvironments and sequence stratigraphy at the Bajocian/Bathonian boundary on the Bas Auran area (Subalpine Basin, south-eastern France)(Lethaia, 2007) Fernández López, Sixto RafaelBas Auran, in south-eastern France, is the candidate area for Global Boundary Stratotype Section and Point (GSSP) of the base of the Bathonian Stage (Middle Jurassic). In the Bas Auran area, upper Bajocian and lower Bathonian deposits are made up of limestone beds alternating with marls that correspond to the ‘Marno-calcaires à Cancellophycus’, below the ‘Terres Noires’ Formation. Taphonomic analyses of the successive ammonoid fossil assemblages provide new and complementary data for biostratigraphic completeness, palaeoenvironmental setting and sequence stratigraphy. Lithologic differentiation between limestone and marl intervals resulted from alternating episodes of carbonate input and starvation. Both lithologic phases may contain evidence for sedimentary and taphonomic reworking, associated with scours, that reflects low rates of sedimentation and stratigraphic condensation. Three successive types of elementary cycles resulted from increasing rates of stratigraphic condensation, sedimentary condensation and substrate stabilization during early Bathonian. The occurrence of reelaborated ammonoids (i.e. exhumed and displaced before their final burial) implies that tractive current flows or winnowing affected the burial of concretionary internal moulds. In the lower Bathonian strata, the dominance of homogeneous concretionary internal moulds of phragmocones, completely filled with sediment, is indicative of low rates of sedimentation and sediment accumulation, respectively associated with low degrees of stratigraphic and sedimentary condensation. However, at the Bajocian/ Bathonian transition, hemipelagic, bed-scale limestone–marl alternations show a maximum value of biostratigraphic completeness and there is no evidence for taphonomic condensation in the ammonoid fossil assemblages. Taphonomic analyses of the successive ammonoid fossil assemblages and taphofacies confirm the development of a deepening phase associated with sedimentary starvation, which characterizes the last episode within the deepening half-cycle of third and second order cycles, in the Bas Auran area of French Subalpine Basin during early Bathonian.