The vertebrate-bearing beds of the Laño quarry (Condado de Treviño) are among the most relevant sites from the Late Cretaceous of Europe. Geologically, Laño and the adjacent region are set on the southern limb of the South-Cantabrian Synclinorium (SE Basque-Cantabrian Region, northern Iberian Peninsula). The Laño sites were discovered in 1984; thousands of bones and teeth, including microfossils, have been collected during the prospection in the field and excavation campaigns. The vertebrate remains occur at two different stratigraphic horizons within a continental to shallow marine succession of Late Campanian-Maastrichtian age. The lower horizon contains the Laño 1 and Laño 2 sites, whereas the upper horizon contains the Albaina site. In the Laño sites, three fossiliferous beds (called L1A, L1B and L2) are known within an alluvial system composed mainly of fluvial sands and silts. The sedimentary structures are consistent with channel areas within an extensive braided river system. Based mainly on stratigraphic correlations, the fluvial beds of Laño are regarded as Late Campanian to Early Maastrichtian in age. These deposits have yielded a very diverse vertebrate assemblage, which consists of nearly 40 species, including actinopterygians, lissamphibians, lepidosaurs, turtles, crocodyliforms, dinosaurs, pterosaurs, and mammals. Seven genera and ten species have been erected to date in Laño. With reference to the marine vertebrate association of Albaina, it consists of at least 37 species, including sharks and rays, actinopterygians, mosasaurids, and plesiosaurs. Two genera and species of rhinobatoids (family indet.) and two new species of rhinobatids have been erected in Albaina. The fossil association indicates a Late (but not latest) Maastrichtian age. Recently, isolated turtle and dinosaur fossils have been discovered in the sublittoral beds of Albaina. The Laño quarry is one of the most noteworthy Campanian-Maastrichtian vertebrate localities of Europe by its taxonomic diversity, and provides useful information about the composition and affinities of both continental and marine vertebrate faunas from the latest Cretaceous of southwestern Europe.
Sirenian vertebrae and ribs have been recently discovered from two Middle Eocene localities of the Pamplona Basin, Navarre (western Pyrenees). These outcrops correspond to different lower Bartonian lithostratigraphic units: the lower part of the Pamplona Marl Formation (Uztarrotz site) and the upper part of the Ardanatz Sandstone (Ardanatz site). The former represents a deep and low-energy sea floor far away from a deltaic slope; the Ardanatz environment probably corresponds to a semi-closed deltaic bay periodically affected by catastrophic floods (i.e., fluvial hyperpycnal flows). The presence of epibiontic activity suggests that the bones were exposed for a while prior to the burial. The histological structures are well preserved except in the peripheral region, where tubular-like microstructures filled by pyrite and iron oxides probably correspond to microbial bioerosion. The major mineral component of the fossil bones is francolite (carbonate fluorapatite). In the Ardanatz samples there is evidence of secondary francolite due to the late replacement of original carbonate fluorapatite through internal fractures. The Ardanatz and Uztarrotz sirenian fossils do not show any evidence of reelaboration. They have similar sum of rare earth elements (REE) concentrations relative to the host rock, but comparatively lower than in other vertebrate fossil bones. This feature may be due to the dense compact structure of pachyosteosclerotic sirenian bones.
Fossil associations from the middle and upper Eocene (Bartonian and Priabonian) sedimentary succession of the Pamplona Basin are described. This succession was accumulated in the western part of the South Pyrenean peripheral foreland basin and extends from deep-marine turbiditic (Ezkaba Sandstone Formation) to deltaic (Pamplona Marl, Ardanatz Sandstone and Ilundain Marl formations) and marginal marine deposits (Gendulain Formation). The micropalaeontological content is high. It is dominated by foraminifera, and common ostracods and other microfossils are also present. The fossil ichnoasssemblages include at least 23 ichnogenera and 28 ichnospecies indicative of Nereites, Cruziana, and ?Scoyenia-Mermia ichnofacies. Body macrofossils of about 80 taxa corresponding to macroforaminifera, sponges, corals, bryozoans, brachiopods, annelids, molluscs, arthropods, echinoderms and vertebrates have been identified. Both the number of ichnotaxa and of species (e. g. bryozoans, molluscs and condrichthyans) may be considerably higher. Body fossil assemblages are comparable to those from the Eocene of the Nord Pyrenean area (Basque Coast), and also to those from the Eocene of the west-central and eastern part of South Pyrenean area (Aragon and Catalonia). At the European scale, the molluscs assemblages seem endemic from the Pyrenean area, although several Tethyan (Italy and Alps) and Northern elements (Paris Basin and Normandy) have been recorded. Palaeontological data of studied sedimentary units fit well with the shallowing process that throughout the middle and late Eocene occurs in the area, according to the sedimentological and stratigraphical data.Se describen las asociaciones fósiles del Eoceno medio y superior (Bartoniense y Priaboniense) de la sucesión sedimentaria de la Cuenca de Pamplona. Esta sucesión se acumuló en la parte oeste de la Cuenca de antepaís periférica surpirenaica y comprende desde turbiditas marinas profundas (Formación Areniscas de Ezkaba) hasta depósitos deltaicos (Formaciones Margas de Pamplona, Areniscas de Ardanatz y Margas de Ilundain) y marinos marginales (Formación Gendulain). El contenido micropaleontológico es alto y está dominado por los foraminíferos. Los fósiles de ostrácodos y otros organismos son también abundantes. Las asociaciones de icnofósiles incluyen al menos 23 icnogéneros y 28 ichnoespecies, indicativas de las icnofacies de Nereites, Cruziana, y ?Scoyenia-Mermia. Se han identificado fósiles corporales de unos 80 taxones, correspondientes a macroforaminíferos, esponjas, corales, briozoos, braquiópodos, anélidos, moluscos, artrópodos, equinodermos y vertebrados. El número de icnotaxones y de especies (p. e. briozoos, moluscos gasterópodos, bivalvos y peces condríctios) puede ser considerablemente mayor. Las asociaciones de fósiles corporales son comparables a las del Eoceno del Área norpirenaica (Costa vasca) y de las partes central y este del Área surpirenaica (Aragón y Cataluña). A escala europea, la asociación de moluscos parece endémica del Área pirenaica,...
A non‐destructive quantitative analysis method was developed using energy‐dispersive x‐ray fluorescence (µ‐EDXRF) in combination with partial least‐squares regression (PLSR) to determine major, minor and some trace elements in vertebrate fossil bones and sediments. This method was compared with the obtained results by traditional destructive analytical methods such as inductively coupled plasma/optical emission spectroscopy (ICP/OES) and inductively coupled plasma/mass spectrometry (ICP/MS) in a large range of concentrations (from 10 µg/g to 100 mg/g). A mixture design was conducted in order to build a calibration model by mixing up four different geological reference material with similar matrix components. The collected spectra was pre‐processed following different treatments (log and squared root transformations, derivatization, and sample‐wise normalization) and the best regression models were obtained with the first derivative and with the squared root transformation. The full cross‐validated models were satisfactorily validated with samples prepared in the same way as the calibration set samples, and they were applied to study the composition of several fossil bones. In spite of the goodness of the obtained results working with reference materials and homogeneous samples, in the case of fossils, which were not pretreated, the results show significantly higher uncertainties. Copyright © 2008 John Wiley & Sons, Ltd.
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