Caracterización del género Acer Linné (Magnoliophyta) en el Vallesiense (Neógeno) de la comarca de la Cerdaña (Lérida, España).

Se realiza un estudio sistemático de los restos fósiles asignables al género Acer L., que se han colectado en los yacimientos de la cuenca lacustre del Vallesiense de la Cerdaña (Lérida, España), tras el cual se identifican y describen tres especies: A. mtegemmum (VIVIANI) MASSALONGO, A. pyrenaicum REROLLE y A. subcampestre GOEPPERT, a partir de restos macroscópicos. Además, se describen otros restos asignables a Acer entre los que se encuentran: sámaras, una flor y palinomorfos

Estudio tafonómico y análisis paleoecológico de la macro y microflora miocena de la Cuenca de la Cerdaña

Tesis de la Universidad Complutense de Madrid, Facultad de Ciencias Biológicas, Departamento de Biología Vegetal I (Botánica y Fisiología Vegetal), leída el 09-02-1996Fac. de Ciencias BiológicasTRUEpu

New palynological and isotopic data for the Triassic of the western Cantabrian Mountains (Spain)

Triassic carbonate rocks of the western Cantabrian Mountains, northern Spain, have long been attributed to the Muschelkalk facies, and as such have been correlated with other Middle Triassic carbonate units of the Iberian Peninsula. Data on palynological assemblages here presented, point to a Ladinian-lower Carnian age of the upper part of the Buntsandstein facies in this area. In addition, the 87Sr/86Sr ratio of the limestones formerly attributed to the Muschelkalk facies indicates a Norian or Norian-Rhaetian boundary age. These findings also imply that the position of the marine coast during the Middle Triassic Tethys transgression should be moved to a more easterly position, in the Basque Country.Las rocas carbonatadas triásicas que afloran en la zona occidental de la Cordillera Cantábrica en el norte de España, han sido tradicionalmente atribuidas al Muschelkalk por correlación con las unidades carbonatadas del Triásico Medio de otras áreas de la Península Ibérica. Las asociaciones palinológicas encontradas en la parte superior de las facies Buntsandstein que afloran en esta área, indican una edad Ladiniense-Carniense inferior. La relación 87Sr/86Sr de los niveles de calizas atribuidos anteriormente al Muschelkalk, son propios de los carbonatos de edad Noriense o Noriense-Rhetiense. Estos datos implican, además, que la posición de la línea de máximo avance del mar del Tethys hacia occidente durante el Triásico Medio se situó en una posición más oriental y dentro del País Vasco.Peer reviewe

Events around the Triassic–Jurassic boundary in northern and eastern Spain: A review

More than 20 successions containing the Triassic–Jurassic (T–J) boundary were studied in five of the major geological units of Spain. The data are from outcrop, cored boreholes, and interpreted well-logs. A consistent −3.4‰ δ13Corg isotope excursion, starting in the Rhaetian and continuing in the Hettangian, was recorded in Asturias. Climate changes in the T–J transition show a warming episode in the early Hettangian. Other climate changes are indicated by an increase in hygrophytic miospores above the T–J boundary; this reflects a more humid episode at the beginning of the Hettangian. The Messejana Dyke in southeastern Iberia is part of the Central Atlantic Magmatic Province (CAMP). CO2 outgassing related to extensive magmatic activity in the CAMP is thought to be one of the possible factors responsible for the end-Triassic mass extinction. No major sea-level changes or unconformities were recorded at the T–J boundary. Only in the Asturias area was there a well-defined shallow carbonate platform during the T–J transition. The other areas of eastern and northern Spain were occupied by coastal playas and sabkhas that developed in arid climatic conditions. The biotic crisis around the T–J boundary is reflected in the palynomorph record. In Asturias, seven species do not persist beyond the late Rhaetian, and only six appeared in the Triassic–Jurassic transition. However, 22 taxa appeared in the early Hettangian

Sucessão de palinomorfos ao longo do Pliensbaquiano superior – Toarciano inferior no perfil de Peniche (Portugal

The Peniche section in the Lusitanian Basin (western Portugal) provides an exceptional, continuous record of the Portuguese Lower Jurassic, and is the candidate for the Global Boundary Stratotype Section and Point for the base of the Toarcian. This paper reports a palynological study of the Margaritatus, Spinatum, Polymorphum and Levisoni zones. Forty eight levels yielded representative and well preserved palynomorph assemblages. Fifty seven palynomorph taxa were recorded: 19 spore taxa, 20 pollen taxa, 11 acanthomorph acritarchs, 4 prasinophytes and 3 dinocyst taxa. The Pliensbachian levels show a characteristic predominance of Classopollis and a wide diversity of aquatic palynomorphs. The Toarcian levels are characterised by the pollen grains of Spheripollenites and a progressive reduction in the diversity of aquatic palynomorphs.O perfil de Peniche, localizado na Bacia Lusitânica (Oeste de Portugal), mostra um registo contínuo e exceptional no contexto do Jurássico Inferior português, que inclui o candidato a estratotipo do limite Pliensbaquiano–Toarciano. Neste âmbito foi desenvolvido um estudo palinológico envolvendo as zonas Margaritatus, Spinatum, Polymorphum e Levisoni, tendo sido analisados 48 níveis com associações representativas e bem preservadas de palinomorfos. Foram identificados 57 taxa de palinomorfos: 19 de esporos, 20 de pólenes, 11 de acritarcas Acanthomorpha, 4 de prasinófitas e 3 de dinocistos. Os níveis do Pliensbaquiano são caracterizados pela larga predominância de Classopollis e pela diversidade de palinomorfos aquáticos. Os grãos de pólen Spheripollenites e a diminuição progressiva da diversidade de palinomorfos aquáticos caracterizam os níveis do Toarciano.Depto. de Geodinámica, Estratigrafía y PaleontologíaFac. de Ciencias GeológicasTRUEpu

Floristic changes in the Iberian Peninsula and Balearic Islands (south-west Europe) during the Cenozoic

AIM  The aim of this work was to identify the main changes in the flora and vegetation of the Iberian Peninsula over the Cenozoic Era, to record the disappearance of taxa associated with these changes and to determine the influence of climate and human activity on these events. Location  The Iberian Peninsula and Balearic Islands. METHODS  A critical review was made of the palaeobotanical literature with the aims of detecting patterns of floristic change and extracting information on the disappearance of different taxa over the Cenozoic. These data are viewed alongside the most recent data for the climate of this period. A critical analysis is made of the role of Palaeotropical and Arctotertiary taxa in the forest communities of the Iberian Peninsula throughout the Cenozoic. RESULTS  Although the Eocene–Oligocene transition was a time when many taxa disappeared, the most outstanding events occurred between the end of the Oligocene and throughout the Miocene. Substantial floristic changes took place over this period, including the disappearance of 177 Palaeotropical taxa. This was probably related to acute cooling and aridification; no evidence exists that the Messinian Salinity Crisis had any important effect in the Iberian Peninsula. The last great disappearance of Palaeotropical taxa (36 in total) ended in the Middle–Late Piacenzian; Arctotertiary taxa were most affected during the Pleistocene. The Lower–Middle Pleistocene transition, best represented by marine isotopic stages (MIS) 36–34 and 20–18 and characterized by a change in glacial cyclicity, was the time of the last notable disappearance of taxa. MAIN CONCLUSIONS  This work provides the first chronogram of extinctions for the Iberian flora, and records the disappearance of 277 taxa during the Cenozoic. A clear relationship was detected between the main climatic events and the latest appearances of the different taxa

The Heritage Interest of the Cretaceous Amber Outcrops in the Iberian Peninsula, and Their Management and Protection

All the amber outcrops of the Iberian Peninsula are Lower Cretaceous in age and, in the case of Spain, some of them have provided important arthropod specimens preserved as bioinclusions. These Spanish localities are rich in fossil taxa of phylogenetic relevance and evidence of both paleoecological interactions and paleobehaviors are also abundant. Despite their high heritage interest, the actions conducted to their protection and management have been very unequal. In some cases, only the generic laws of national or autonomous scopes protect this heritage. In this paper, the state of the art of the Iberian Peninsula amber outcrops and a review of the major Cretaceous amber outcrops worldwide for comparison are presented. That comparison shows, in general, that the best protection, both legal and physical, occurs in Spain and that the case of Portugal is very different. In addition, some actions aimed at a more effective protection and management of the amber outcrops in Spain and Portugal are proposed, for example the proposal to consider the San Just outcrop, located in the Aragonese Community, under a protection designation as is the so called Bien de Interés Cultural

Biodiversity of ecosystems in an arid setting: The late Albian plant communities and associated biota from eastern Iberia

Deserts are stressful environments where the living beings must acquire different strategies to survive due to the water stress conditions. From the late Albian to the early Cenomanian, the northern and eastern parts of Iberia were the location of the desert system represented by deposits assigned to the Utrillas Group, which bear abundant amber with numerous bioinclusions, including diverse arthropods and vertebrate remains. In the Maestrazgo Basin (E Spain), the late Albian to early Cenomanian sedimentary succession represents the most distal part of the desert system (fore-erg) that was characterised by an alternation of aeolian and shallow marine sedimentary environments in the proximity of the Western Tethys palaeo-coast, with rare to frequent dinoflagellate cysts. The terrestrial ecosystems from this area were biodiverse, and comprised plant communities whose fossils are associated with sedimentological indicators of aridity. The palynoflora dominated by wind-transported conifer pollen is interpreted to reflect various types of xerophytic woodlands from the hinterlands and the coastal settings. Therefore, fern and angiosperm communities abundantly grew in wet interdunes and coastal wetlands (temporary to semi-permanent freshwater/salt marshes and water bodies). In addition, the occurrence of low-diversity megafloral assemblages reflects the existence of coastal salt-influenced settings. The palaeobotanical study carried out in this paper which is an integrative work on palynology and palaeobotany, does not only allow the reconstruction of the vegetation that developed in the mid-Cretaceous fore-erg from the eastern Iberia, in addition, provides new biostratigraphic and palaeogeographic data considering the context of angiosperm radiation as well as the biota inferred in the amber-bearing outcrops of San Just, Arroyo de la Pascueta and La Hoya (within Cortes de Arenoso succesion). Importantly, the studied assemblages include Afropollis, Dichastopollenites, Cretacaeiporites together with pollen produced by Ephedraceae (known for its tolerance to arid conditions). The presence of these pollen grains, typical for northern Gondwana, associates the Iberian ecosystems with those characterising the mentioned region.Depto. de Geodinámica, Estratigrafía y PaleontologíaFac. de Ciencias GeológicasTRUEMinisterio de Ciencia, Innovacio ́n y UniversidadesIGME-CSICSecretaria d’Universitats i Recerca de la Generalitat de CataloniaEuropean Social Fundpu