Serpukhovian coral assemblages from Idmarrach and Tirhela Formations (Adarouch, Morocco)

The Serpukhovian coral assemblages from Idmarrach and Tirhela formations (Adarouch, Morocco) have been studied. They yielded quite diverse assemblages with a total of 32 rugose and 1 tabulate species. The distribution of corals in the sections Idmarrach 1, 2, 3, and 4 and Tirhela 1 and 2 has been established, which include Serpukhovian and Bashkirian rocks. The Serpukhovian assemblages are composed mostly of species that have their higher abundance in the upper Viséan. However, most of the recorded taxa in Adarouch have been already mentioned in Serpukhovian rocks from Britain, Moscow Basin, Urals, Donets Basin and other North African regions such as Tindouf and Béchar. Thus, their stratigraphic range is not expanded. The coral diversity is mainly concentrated in biostromes from the Idmarrach 1 section. However, the high total diversity is due to the combination of favourable depositional settings and a mixture in different beds of several ecological environments, such as coral shoals, protected lagoons and microbial mounds. Most Serpukhovian species have been recorded in areas from the western Palaeotethys previously mentioned. The total assemblage can be considered as typical for the late Mississippian in the western Palaeotethys. However, a small degree of isolation is registered by the absence in the Serpukhovian from Adarouch of the genera Lonsdaleia, Actinocyathus, Tizraia and Kizilia that have been recorded in other North African basins. That fact may be explained by the incipient rising of some areas as ‘highs’ due to the start of the collision between Gondwana and Laurasia.Research project CGL2012-30922BTE of the Spanish Ministry of Research and InnovationPeer reviewe

Biomineralización: cuando los organismos crean minerales

Sección: Baúl de la ciencia[ES] Los sistemas bióticos y abióticos se entrelazan, en su máxima expresión, durante la formación de biominerales. Estos son minerales producidos por los organismos, ayudados de macromoléculas orgánicas, los cuales forman esqueletos y estructuras esqueléticas (como dientes, huesos, conchas, espículas…) de una manera precisa, que involucra una maquinaria celular sincronizada y que tienen una función biológica muy específica. El estudio de la biomineralización es multidisciplinar y tiene un enfoque diverso: ingeniería, biología, química, paleontología. Este artículo resume qué es la biomineralización, cuándo aparece en la historia de la Tierra, tipos de biomineralización, el papel de la matriz orgánica en la biomineralización, los controles (genéticos y ambientales) de la biomineralización, así como el papel de los estudios sobre biomineralización empleando fósiles

Reconstructing a Carboniferous inferred coral–alcyonarian association using a biomineralogical approach

The taxonomic assignation and ecological implications of the genus Syringoalcyon Termier & Termier, 1945 have been a palaeontological problem for a long time. Carboniferous material from Morocco and Spain has been studied using a biomineralogical approach by means of petrographic microscopy, SEM, AFM, EMPA and CIP microscopy analysis. Detailed morphological, structural, chemical composition and crystallographic data enable a deeper understanding of the nature of Syringoalcyon. The coral walls and the so-called epithecal scales exhibit conspicuous differences in microstructure (lamellae and holacanthine fibres in the coral vs. single crystal in scales), nanostructure (pill-shaped vs. granule-shaped nanocrystals), composition (LMC vs. HMC) and crystallographic orientation. The results of these analyses imply that Syringoalcyon is an association between the tabulate coral Syringopora and an epibiont. They also suggest that the epibiont was an alcyonarian (a rare occurrence in the fossil record) that was attached to the syringoporoid. This work highlights the utility of the biomineralizational approaches for solving palaeontological problems, such as systematic affinities, and for advancing knowledge of the evolution of biocrystallization processes.Financial support through the Spanish Ministerio de Economía y Competitividad (research project CGL2012-30922BTE) and Complutense University Research Group (910231). Ismael Coronado acknowledges financial support through a FPI-UCM grant and the Synthesys grant FR-TAF-2397 developed in MNHN (Paris, France).Peer reviewe

Crystallographic orientations of structural elements in skeletons of Syringoporicae (tabulate corals, Carboniferous): Implications for biomineralization processes in Palaeozoic corals

he crystallographic orientation of structural elements in skeletons of representatives of Carboniferous Syringoporicae (Auloporida) has been analysed by scanning electron microscopy (SEM), petrographic microscopy and electron backscatter diffraction (EBSD) on specimens from the Iberian Peninsula. The skeletons of the tabulate corals of the Syringoporicae consist of biogenic calcite crystals, and their microstructure is composed of lamellae, fibres and granules, or of a combination of these. Independent of the microstructure, the c-axis is oriented towards the lumen, quasi-perpendicular to the growth direction of the skeleton (perpendicular to the morphological axis lamellae, parallel to fibres). Most phaceloid taxa have a turbostratic distribution, as a biogenic response to prevent the cleavage of crystals. Cerioid and some phaceloid corals, whose microstructure is conditioned by wall elements, do not exhibit turbostratic distribution. Wall elements are determined by the biology of each taxon. Holacanth septal spines are composed of fibres arranged in a cone-shape structure, sometimes clamped to the external part of the corallite and show a complex crystallography. Monacanth septal spines are spindle shaped and composed of bundles of fibres. Tabulae are composed of lamellae. Their development and crystallographic orientation depends on the position of the epithelium in each case. Shared walls are formed by a combination of the walls of two independent corallites with a median lamina, composed of granules; these have a crystallographic orientation between that of the two corallites. The growth of the microstructure is derived by a coordinated stepping mode of growth, similar to other groups of organisms such as molluscs and scleractinians. The nucleation and formation of packages of co-oriented microcrystals suggest a growth mode similar to mineral bridges with a competitive growth mode between each crystal. The growth pattern of corallites suggests that the growth direction is divided into two main components: a horizontal growth direction towards the lumen and a vertical direction towards the top

Relación de la Hemoglobina y el hematocrito con la altura en la Parroquia Lita Imbabura 2017

Determinar la relación de la Hemoglobina y el hematocrito con la altura en la Parroquia Lita Imbabura 2017La biometría hemática es el análisis más solicitado para la evaluación del estado de salud de un sujeto. Sus valores de referencia son importantes en poblaciones de altura, dada la disminución de la presión parcial de oxígeno que afecta la concentración de hemoglobina, el hematocrito y los indicadores hematimétricos. el objetivo de este estudio fue Determinar la relación de la Hemoglobina y el hematocrito con la altura en la Parroquia Lita Imbabura 2017. Estudio tiene un diseño cuantitativo y no experimental y de tipo de estudio exploratorio, descriptivo y transversal. Se seleccionó una muestra de 173 pobladores con biometrías hemáticas de sujetos de uno u otro sexo, con edades entre 40 y 60años. Los resultados obtenidos La edad promedio de las personas estudiadas fue de 45 a 55 años, siendo en un mayor porcentaje de sexo masculino. Se encontraron diferencias significativas entre los valores de referencia reportados por otras publicaciones en poblaciones a diferentes altitudes, en todos los parámetros evaluados, persistiendo incluso al compararlos con una población de una altitud similar a la parroquia de Lita presentando una media total de hemoglobina 14,80g/dl y hematocrito 45,10% , a una altura de 571 metros sobre el nivel del mar llegando a la conclusión que no existe enfermedades relacionadas a la altura antes más bien existe datos con personas con anemia

Estudio preliminar de las mineralizaciones de Vanadatos de Uranio asociadas a dientes y huesos fósiles: Implicaciones genéticas y geoquímicas

Depto. de Mineralogía y PetrologíaFac. de Ciencias GeológicasTRUEpu

Impact of ocean acidification on crystallographic vital effect of the coral skeleton

Distinguishing between environmental and species-specific physiological signals, recorded in coral skeletons, is one of the fundamental challenges in their reliable use as (paleo)climate proxies. To date, characteristic biological bias in skeleton-recorded environmental signatures (vital effect) was shown in shifts in geochemical signatures. Herein, for the first time, we have assessed crystallographic parameters of bio-aragonite to study the response of the reefbuilding coral Stylophora pistillata to experimental seawater acidification (pH 8.2, 7.6 and 7.3). Skeletons formed under high pCO2 conditions show systematic crystallographic changes such as better constrained crystal orientation and anisotropic distortions of bio-aragonite lattice parameters due to increased amount of intracrystalline organic matrix and water content. These variations in crystallographic features that seem to reflect physiological adjustments of biomineralizing organisms to environmental change, are herein called crystallographic vital effect (CVE). CVE may register those changes in the biomineralization process that may not yet be perceived at the macromorphological skeletal level. https://doi.org/10.1038/s41467-019-10833-6 OPEN

Descripción de los corales rugosos y tabulados del Serpukhoviense de las formaciones Idmarrach y Tirhela (Adarouch, Marruecos)

Se describen los corales rugosos y tabulados de las formaciones Idmarrach y Tirhela, que se localizan en el área de Adarouch, en la Meseta central de Marruecos. Se han identificado 32 especies de corales rugosos pertenecientes a 19 géneros y una especie de coral tabulado. Las asociaciones de edad Serpukhoviense de las formaciones estudiadas están compuestas en su mayoría por especies que tienen su máximo desarrollo en el Viseense superior. Sin embargo, la mayoría de los taxones identificados en Adarouch han sido mencionados previamente en rocas del Serpukhoviense de otras regiones del Paleotethys occidental y las cuencas epicontinentales del norte de África. Las asociaciones de corales están dominadas por corales coloniales pertenecientes a la familia Lithostrotionidae y por corales solitarios pertenecientes a la familia Aulophyllidae. Son también frecuentes los representantes de las familias Axophyllidae, Cyathaxoniidae, Cyathopsidae, Palaeosmiliidae, Stereophrentidae y Zaphrentoididae. El medio de desarrollo de los corales estudiados fue una plataforma carbonatada interna a media con importantes aportes de terrígenos finos.The Serpukhovian coral assemblages from the Idmarrach and Tirhela formations in Central Morocco are described. 32 rugose species belonging to 19 genera and 1 tabulate species have been identified. The Serpukhovian assemblages are composed mostly of species that have their greater abundance in the upper Viséan. However, most recorded taxa in Adarouch have been already mentioned in Serpukhovian rocks from other regions in the Palaeotethys and in North African epicontinental basins. The coral assemblage is dominated by colonial corals belonging to the family Lithostrotionidae and solitary corals belonging to the family Aulophyllidae. In addition, representatives of the families Axophyllidae, Cyathaxoniidae, Cyathopsidae, Palaeosmiliidae, Stereophrentidae and Zaphrentoididae are also present in the assemblages. The environment where the corals lived was mostly an inner to middle carbonate platform with a minor but significant input of terrigenous sediments.Depto. de Geodinámica, Estratigrafía y PaleontologíaFac. de Ciencias GeológicasTRUEMinisterio de Ciencia e Innovación (MICINN)pu

Corals from Asturian substage in Cantabrian Mountains: A review

The subdivision of the Pennsylvanian divided the Namurian, Westphalian and Stephanian regional stages in substages named with letters. During the second half of the 20th Century, some of these substages were more properly defined. Westphalian A, B and C were defined as Langsettian, Duckmantian and Bolsovian. The Stephanian A was renamed as Barruelian and the transition between Westphalian and Stephanian as Cantabrian. The Westphalian D, defined in continental strata from Saar-Lorraine, was proposed to be substituted by the Asturian substage with the stratotype in the Cantabrian Mountains. An extensive documentation with assemblages and stratigraphic distribution of plants, fusulinids, brachiopods, corals, molluscs and ostracods was presented. But a formal definition of the stratotype was never proposed. The Asturian substage in the Cantabrian Mountains comprises both marine and terrestrial strata rich in fossils and allows easy correlations with other areas. Recent studies have improved the stratigraphic data and the knowledge on the coral assemblages, mainly in the eastern area of Asturias and Palencia. The entire coral assemblage from Asturian substage in the Cantabrian Mountains is composed of 48 named species and 20 species described in open nomenclature. The short stratigraphic range of many of them may be the basis for the characterization of the Asturian stage with corals. Although some species are endemic in the Cantabrian Mountains, there are some species that are also present in other regions of the Palaeotethys. At the generic level there are significant similarities that should be the basis for wider correlations with North America and East Asia