Three-dimensionally preserved graptolites from the Silurian of the Central Iberian Zone (Spain and Portugal)

[ES] Los graptolitos silúricos de la Zona Centroibérica suelen conservarse aplastados en pizarras negras, pero en algunos yacimientos los rabdosomas pueden retener parte de su relieve original o conservarse incluso en tres dimensiones. La mayoría de las veces existe una piritización temprana de los rabdosomas por la acción de bacterias sulforreductoras en ambiente anóxico, a la que se suma la génesis de nódulos. La alteración posterior de la pirita deja los graptolitos en forma de moldes, que pueden ser estudiados mediante vaciados en látex. Otros fenómenos de piritización multifásica en sedimentos gruesos conducen a la formación de nódulos de pirita que incluyen en su interior graptolitos huecos y en tres dimensiones, con el peridermo replicado delicadamente en óxidos de hierro. En otras ocasiones, los graptolitos preservados en nódulos generados en sedimentos pelágicos incluyen el recrecimiento de fosfatos sobre el peridermo de los graptolitos, que llegan a conservarse huecos y con estructuras de rellenos geopetales. Finalmente, se presenta el único caso de calizas con graptolitos conocido en el Silúrico centroibérico.[EN] Silurian graptolites form the Central-Iberian Zone are often preserved as flattened moulds in black shales, but in some cases rhabdosomes can maintain a part of its original relief, and even can appear three-dimensionally preserved. The majority of these cases can be related to an early pyritisation of the periderm favoured by bacterial activity under anoxic conditions, which also led to the genesis of nodules on the same beds. Further oxidation and dissapearance of iron minerals limited the preservation of graptolites to external moulds, that can be studied through latex casts. A different way of preservation of 3-D graptolites occurs in coarse sandstone that enhanced multiphase pyritisation fenomena, where ferruginous nodules enclosing rhabdosomes reveal that the framboidal pyrite that mineralized the periderm during very early diagenesis was remarkably resilient not only to subsequent deformation, but also to the differential weathering of the massive overpyrite that constitute the nodules. The pyritised graptolite periderm was finally replicated by iron-oxides with a minor proportion of phyllosilicates. The occurrence of “hollow” graptolites is also known from silico-phosphatic nodules, where the organic periderm was finely replicated by phosphatic overgrowths that coated the inner and outer surfaces of the rhabdosome. Occasional pseudostalactites of phosphatic minerals and colloidal silica partially occupied the empty spaces. Graptolite internal moulds occurring in limestone are very rare and are restricted to a single locality within the studied region.Peer reviewe

El patrimonio paleontológico del Paleozoico marino de la región de Almadén (Ciudad Real)

La región de Almadén se integra en la Paleontología mundial del Paleozoico a mediados del siglo XIX, tras el descubrimiento de importantes yacimientos fosilíferos de los sistemas Ordovícico, Silúrico y Devónico, que permitieron establecer correlaciones con el Macizo Armoricano francés y la región de Bohemia (República Checa). Se trata de un área de referencia para la geología española, consagrada por más de siglo y medio de estudios, que alberga las localidades tipo de más de medio centenar de especies paleontológicas entre braquiópodos, trilobites, moluscos, equinodermos, graptolitos, corales e icnofósiles, descubiertos y nombrados por vez primera en la región de Almadén. Desde el punto de vista del patrimonio paleontológico de relevancia nacional e internacional, destacan los yacimientos tipo de muchos fósiles, a veces únicos a nivel mundial, y también el gran número de colecciones paleontológicas de Almadén depositadas en museos e instituciones de España y otros países europeos

A first insight into mercury distribution and speciation in soils from the Almadén mining district, Spain

Almost no environmental data on mercury distribution and speciation in soils have been published so far for the Almadén mining district (central Spain), despite its huge size and historic importance. The mercury distribution in soils of the district reveals the existence of high and extremely high mercury values (up to f9000 ppm Hg). The Hg-thermodesorption curves for soils from a decommissioned metallurgical precinct (Almadenejos) and a phytoremediation site show that mercury occurs in the forms of cinnabar and as mercury bound to organic matter. The TEM-EDX study of the highly contaminated anthrosols from Almadenejos (samples with Hg >5000 ppm) shows the existence of cinnabar particles adsorbed to the surface of chlorite grains. Given the generally pyrite-poor character of the ores, and the presence of carbonates in the host rocks, cinnabar solubilization is limited, which in turn mitigates environmental hazards in the district. The only by-product of cinnabar leaching in the mineral dumps is schuetteite (Hg3SO4O2). Preliminary results on local plants (Asparagus acutifolius, Dittrichia graveolens, Marrubium vulgare) show that mercury gets incorporated to roots, stems and leaves, with values of up to about 300 ppm Hg.Depto. de Mineralogía y PetrologíaFac. de Ciencias GeológicasTRUEEuropean Union FEDERUniversity of Castilla-La Manchapu

A Middle Devonian benthic graptolite from the Cantabrian Zone, NW Spain

Se presenta la primera cita de un graptolito dendroideo en el Devónico de la Cordillera Cantábrica, que a su vez constituye el primer hallazgo de graptolitos bentónicos en materiales de este periodo del suroeste de Europa. El horizonte estudiado se sitúa cerca del techo de la Formación Moniello-Santa Lucía y se asigna al Eifeliense inferior por medio de conodontos y braquiópodos. Los graptolitos conservan parte de su peridermo orgánico y relieve original, fosilizados en margas, pero se hallan fragmentados. El estudio taxonómico permite adscribirlos a la nueva especie Dictyonema georgii sp. nov., caracterizada por una malla de aspecto desmográptido marcada por el desarrollo irregular de algunos estipes a partir de las dicotomías y, sobre todo, por la existencia de puentes tecales con distintas orientaciones y grosores, parte de los cuales son tan anchos como los estipes e implican transferencias de grupos tecales entre estipes adyacentes. Además, la nueva especie se diferencia de las escasas formas comparables por sus estipes más finos y numerososThe first record of a Devonian graptolite from the Paleozoic of the Cantabrian Mountains is here reported, also being the first occurrence of benthic graptolites for this period in southwestern Europe. The studied horizon is located near the top of the Moniello-Santa Lucía Formation and has been assigned to the lower Eifelian by means of conodonts and brachiopods. The graptolites retain part of their organic periderm and partial relief, being fragmented and preserved in marls. The taxonomic study revealed a new species Dictyonema georgii sp. nov., characterized by a desmograptid-like mesh (without pseudoanastomosis) marked by the irregular development of some stipes from dichotomies and, above all, by the existence of irregularly oriented thecal bridges; these have different thicknesses, some being as wide as the stipes, and implying thecal transfer between adjacent stipes. Furthermore, the new species differs from the few comparable forms by its thinner and relatively more numerous stipe

Search for Mutations in a Segment of the Exon 28 of the Human Von Willebrand Factor Gene. New Mutations, R1315C and R1341W, Associated with Type 2M and 2B Variants

[EN] von Willebrand Disease (vWD) is the most frequently inherited bleeding disorder in humans, and is caused by a qualitative and/or quantitative abnormality of the von Willebrand factor (vWF), A large number of defects that cause qualitative variants have been located in the Al domain of the vWF, which contains sites for interaction with platelet glycoprotein Ib (GPIb). We have developed a new approach to detect mutations based on Ddel digestion and single-strand conformation polymorphism analysis. A segment of 487 nucleotides, extending from intron 27 to codon 1368 of the pre-pro vWF was amplified from genomic DNA, The cleavage with Ddel yields two fragments of appropriate size for this kind of analysis and confirms that the gene, rather than the pseudogene, is being investigated, Six families with type 2B vWD: one type 2M vWD family, and one another type 2A vWD family were studied. After sequencing the fragments with an altered electrophoretic pattern, we found four mutations previously described-R1308C, V1316M, P1337L, and R1306W-in patients with 2B vWD, The last one arose de novo in the patient. In addition, two new candidate mutations were observed: R1315C and R1341W. The first one was associated to type 2M vWD, whereas the one second cosegregated with type 2B vWD. The fact that these new mutations were not found in 100 normal alleles screened further supports their causal relationship with the disease, These mutations, which induce either a gain or a loss of function, further show an important regulatory role of this region in the binding of vWF to GPIb and its implications in causing disease.We wish to thank J.M. Montoro for performing multimeric assays and R. Curats for his technical assistance.Casaña, P.; Martínez, F.; Espinós-Armero, CÁ.; Haya, S.; Lorenzo, JI.; Aznar, JA. (1998). Search for Mutations in a Segment of the Exon 28 of the Human Von Willebrand Factor Gene. New Mutations, R1315C and R1341W, Associated with Type 2M and 2B Variants. American Journal of Hematology. 59(1):57-63. https://doi.org/10.1002/(sici)1096-8652(199809)59:13.0.co;2-z576359

Q1311X: a novel nonsense mutation of putative ancient origin in the von Willebrand factor gene

[EN] Type 3 von Willebrand disease, a recessive autosomally inherited bleeding disorder, refers to complete deficiency of von Willebrand factor (VWF). The novel Q1311X mutation was detected in the homozygous state in four Spanish patients from two apparently unrelated families of gypsy origin. The lack of specific amplification of platelet VWF cDNA from two of the patients indicates reduced levels of mutated gene expression. The similar haplotype linked to mutated alleles suggests a common origin. On the basis of the two instabilities observed and the estimated mutation rate of the microsatellites of intron 40 of the VWF gene, we can estimate that this mutation could have arisen about 2300 years ago.We wish to thank J.M. Montoro and R. Curats for their technical assistance. This work was supported in part by F1S 99/0633.Casaña, P.; Martínez, F.; Haya, S.; Lorenzo, JI.; Espinós-Armero, CÁ.; Aznar, JA. (2000). Q1311X: a novel nonsense mutation of putative ancient origin in the von Willebrand factor gene. British Journal of Haematology. 111(2):552-555. https://doi.org/10.1046/j.1365-2141.2000.02410.x552555111

New occurrences of Ordovician fossils from the Obejo–Valsequillo Domain (provinces of Badajoz and Córdoba, Southwestern Spain)

Se presentan nuevos trilobites, braquiópodos y moluscos del Ordovícico Medio encontrados en el Dominio de Obejo-Valsequillo (suroeste del Macizo Ibérico), donde las localidades paleontológicas de dicha época son muy raras. Los nuevos datos de fósiles ordovícicos de Campillo de Llerena (Badajoz), identificados en cantos y bloques lutíticos incorporados a una formación carbonífera sinorogénica, permiten asegurar la presencia de horizontes del Oretaniense inferior derivados de un área fuente probablemente cercana. En el yacimiento paleontológico de Peñaladrones (noreste de Belmez, Córdoba), sumamos un bivalvo y dos gasterópodos a las listas precedentes. Entre ellos destaca el bellerofóntido Tritonophon sp., un género restringido en el ámbito del Ordovícico Medio ibero-armoricano a dos localidades del Dominio de Obejo-Valsequillo. Finalmente, en la localidad de Mina Guillermín (sur de Alcaracejos, Córdoba) sumamos también nuevos registros de trilobites y moluscos del Oretaniense superior-Dobrotiviense inferiorLower Paleozoic fossils are scarce in the Obejo–Valsequillo Domain of the southwestern Iberian Massif. In this note we add new records for Middle Ordovician trilobites, brachiopods and molluscs of three rarely cited localities, which expand the paleontological record of the region and clarify the stratigraphy and age of some of the assemblages. The Ordovician fossils of Campillo de Llerena (Badajoz province) occur in lutitic blocks and pebbles originating from a nearby source area within an unnamed synorogenic Carboniferous formation. Based on these new records, the existence of lower Oretanian allochthonous strata is recognized for the first time. The bellerophontid genus Tritonophon was identified in the Peñaladrones fossil site (Belmez, Córdoba), this being the second ever record of this rare gastropod in the Obejo-Valsequillo Domain, unknown in the remaining Ibero-Armorican area. Finally, new occurrences of trilobites and molluscs are presented for the Mina Guillermín locality (Alcaracejos, Córdoba), supporting a late Oretanian to early Dobrotivian ag

Fossil localities from the upper Silurian of Hinojosa del Duque (province of Cordoba, Obejo–Valsequillo Domain, southwestern Spain)

Se presentan las asociaciones paleontológicas identificadas en dos localidades situadas en el término de Hinojosa del Duque (Córdoba), en afloramientos del Silúrico correspondientes a antiguas explotaciones a cielo abierto. Los fósiles de la mina Las Angosturas están preservados en calizas arcillosas e incluyen variados nautiloideos ortoconos, bivalvos, escifocrinoideos, filocáridos, ostrácodos y raros graptolitos, estos últimos de probable edad Ludfordiense medio (Biozona de Neocucullograptus kozlowskii). Los fósiles de la Mina Luisa proceden de nódulos en pizarras, conteniendo también nautiloideos ortoconos, bivalvos, filocáridos, ostrácodos y raros graptolitos y poríferos, en ausencia de escifocrinoideos o de especies que puedan aportar precisiones dentro del rango Ludlow-Pridoli. Las biofacies presentes en las localidades estudiadas se correlacionan con otras áreas del Dominio Obejo-Valsequillo y con la Zona de Ossa Morena, siendo muy distintas de los materiales y faunas coetáneos de la Zona Centroibérica meridional. Entre los resultados taxonómicos, los ostrácodos Sineruga insolita y Silurocypridina calva se identifican por vez primera en España, así como el nautiloideo Akrosphaerorthoceras gregale o el género Warneticaris (filocárido). Algunos bivalvos atribuidos comúnmente al Pridoli podrían tener su registro más antiguo en horizontes del Ludlow, si bien la confirmación queda supeditada al hallazgo de graptolitos más completos y en mejor estado de conservaciónFossiliferous upper Silurian strata have been identified in two abandoned open-pit mines within the municipality of Hinojosa del Duque (province of Cordoba). The fossils from Las Angosturas mine are preserved in argillaceous limestones and include orthocone nautiloids, bivalves, scyphocrinoids, phyllocarids, ostracods and rare graptolites, the latter of probably middle Ludfordian age (Neocucullograptus kozlowskii Biozone). The fossils from Mina Luisa come from nodules occurring in sericitic shales, and the assemblage also includes orthocone nautiloids, bivalves, phyllocarids, ostracods and rare graptolites and porifera, but no species (scyphocrinoid or other) can provide precision within the Ludlow-Pridoli range. Fossil records are correlatable with other areas of the Obejo-Valsequillo Domain and the Ossa-Morena Zone, being very different from the contemporary materials and faunas of the southern Central Iberian Zone. Among the taxonomic results, the entomozooid ostracods Sineruga insolita and Silurocypridina calva are identified for the first time in Spain, as well as the nautiloid Akrosphaerorthoceras gregale or the phyllocarid genus Warneticaris. Some typical ‘Pridoli’ bivalves of the peri-Gondwanan area may present here their oldest occurrence in Ludlow horizons, although confirmation of this hypothesis requires the finding of more complete and well-preserved graptolite

Three-dimensionally preserved graptolites from the Silurian of the Central Iberian Zone (Spain and Portugal)

Los graptolitos silúricos de la Zona Centroibérica suelen conservarse aplastados en pizarras negras, pero en algunos yacimientos los rabdosomas pueden retener parte de su relieve original o conservarse incluso en tres dimensiones. La mayoría de las veces existe una piritización temprana de los rabdosomas por la acción de bacterias sulforreductoras en ambiente anóxico, a la que se suma la génesis de nódulos. La alteración posterior de la pirita deja los graptolitos en forma de moldes, que pueden ser estudiados mediante vaciados en látex. Otros fenómenos de piritización multifásica en sedimentos gruesos conducen a la formación de nódulos de pirita que incluyen en su interior graptolitos huecos y en tres dimensiones, con el peridermo replicado delicadamente en óxidos de hierro. En otras ocasiones, los graptolitos preservados en nódulos generados en sedimentos pelágicos incluyen el recrecimiento de fosfatos sobre el peridermo de los graptolitos, que llegan a conservarse huecos y con estructuras de rellenos geopetales. Finalmente, se presenta el único caso de calizas con graptolitos conocido en el Silúrico centroibérico.Silurian graptolites form the Central-Iberian Zone are often preserved as flattened moulds in black shales, but in some cases rhabdosomes can maintain a part of its original relief, and even can appear three-dimensionally preserved. The majority of these cases can be related to an early pyritisation of the periderm favoured by bacterial activity under anoxic conditions, which also led to the genesis of nodules on the same beds. Further oxidation and dissapearance of iron minerals limited the preservation of graptolites to external moulds, that can be studied through latex casts. A different way of preservation of 3-D graptolites occurs in coarse sandstone that enhanced multiphase pyritisation fenomena, where ferruginous nodules enclosing rhabdosomes reveal that the framboidal pyrite that mineralized the periderm during very early diagenesis was remarkably resilient not only to subsequent deformation, but also to the differential weathering of the massive overpyrite that constitute the nodules. The pyritised graptolite periderm was finally replicated by iron-oxides with a minor proportion of phyllosilicates. The occurrence of “hollow” graptolites is also known from silico-phosphatic nodules, where the organic periderm was finely replicated by phosphatic overgrowths that coated the inner and outer surfaces of the rhabdosome. Occasional pseudostalactites of phosphatic minerals and colloidal silica partially occupied the empty spaces. Graptolite internal moulds occurring in limestone are very rare and are restricted to a single locality within the studied regionDepto. de Geodinámica, Estratigrafía y PaleontologíaFac. de Ciencias GeológicasFALSEpu