Palynomorphs from abra límite, zenta range, Eastern Cordillera, Northwestern Argentina

This study presents the first Devonian palynological record in the Zenta Range in Eastern Cordillera, Argentina. Two associations were recognized on the basis of differences in palynomorphs and palynofacies. The palynoassemblage AL1, from the lower part of the outcrop, is characterized by chitinozoans, such as Cingulochitina sp. cf. C. serrata and Hoegisphaera sp. cf. H. glabra, accompanied by a few species of phytoplankton, which suggests the Lochkovian s. l., and palynofacies indicate a marine paleoenvironment. The appearance of Diboliporites farraginis in the palynoassemblage AL2 suggests a Middle Devonian. The concurrence of some fresh or brackish water taxa, sporomorphs and very few acritarchs, denotes littoral conditions in this part of the succession. The transgression for the Early Devonian is recorded in AL1.Apresenta-se o primeiro registro palinológico devoniano da Faixa Zenta, Cordilheira Oriental, Argentina. Com base nas diferenças qualitativas e palinofácies duas associações foram reconhecidas. A associação palinológica AL1, ocorrente na parte inferior do afloramento, é caracterizada principalmente por quitinozoários, como Cingulochitina sp. cf. C. serrata e Hoegisphaera sp. cf. H. glabra, com o registro subordinado de táxons fitoplanctônicos permite posicionamento no Lochkoviano s. l, com características palinofaciológicas de ambiente marinho. O registro de Diboliporites farraginis na associação palinológica AL2 sugere correspondência com o Devoniano Médio. A ocorrência de determinados táxons de água doce ou salgada juntamente com esporomorfos e acritarcos, denota condições ambientais costeiras para a parte superior da sucessão. O marco transgressivo proposto para o Devoniano inicial, relacionado à origem da expansão da bacia sedimentar, está registado na associação palinológica AL1.Fil: Noetinger, Maria Sol. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Geología; ArgentinaFil: Di Pasquo Lartigue, Maria. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Geología; Argentina. Provincia de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Universidad Autónoma de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción; Argentin

First record of Early Devonian (Lochkovian) flora from the Santa Rosa Formation - Alarache, Southern Bolivia

New information on plants and palynomorphs from Angosto de Alarache, South Bolivia, is presented. The plant remains appear at the base of the section. Dichotomizing sterile forms are assigned to Hostinella sp. and scarce stems terminated in spherical structures are interpreted as indetermined sporangia. The palynological association 1 recovered from this level contains abundant phytodebris, trilete spores, few cryptospores, algae, very poorly preserved chitinozoans, and other elements (fungi, ?lichens). Trilete spores assignable to Apiculiretusispora sp., Punctatisporites sp. and Retusotriletes sp., are obtained from the maceration of some isolated sporangia. The dichotomous branching of the stems and the trilete spores recovered from the isolated sporangia support its tracheophyte affinity. The palynological assemblage 2, obtained three metres above, contains abundant phytodebris and more diverse palynomorphs. Two new species (Retusotriletes albarinii n. sp., Acinosporites macgregorii n. sp.) are described. Based on the presence of the trilete spores Dictyotriletes emsiensis (ALLEN) MCGREGOR, Retusotriletes maculatus MCGREGOR and CAMFIELD, Apiculiretusispora plicata (ALLEN) STREEL and the absence, mainly of Verrucosisporites polygonalis LANNINGER and Urochitina loboi VOLKHEIMER et al., we propose a Lochkovian age but restricted up to the Late not latest Lochkovian, and the correlation with the lower part of the Emsiensis Zone of the Amazon Basin and the MN Zone of Western Europe. The abundance of fragmented stems of varied size and parallel to bedding planes, along with the isolated sporangia in the plant assemblage suggests a short distance transportation under low energy conditions, probably from marginal palaeoenvironments to low energy marine settings

Use of UV-curable acrylates gels as mounting media for palynological samples

UV-curable acrylates are used as an easy, economic and rapid mounting media to mount palynological samples. The aqueous palynological residue is dehydrated with ethanol in order to be set in UV-curable acrylates such as Trabasil ® NR2 and Acrysoft ® urethane acrylates. These mounting medias have advantages over other ones: specimens remain in fixed position, and/or they are not attacked by any organism or modified by any environmental conditions such as humidity and heat. In addition refraction index is similar to that of sporopollenin and glass which provides an excellent interfase to discern fine morphological features.Acrilatos inducidos por la luz UV son usados como un medio simple, fácil y económico para el montaje de muestras palinológicas. El residuo palinológico en medio acuoso es deshidratado con etanol para luego ser fijado en acrilatos inducidos por luz UV, comercializados como, por ejemplo, Trabasil ® NR2 y Acrysoft ®. Estos medios de montaje son más ventajosos que los tradicionalmente conocidos: los especímenes quedan en una posición fija, el medio no es atacado por organismos o modificado por ninguna condición climática, tal como humedad y/o calor. Por otra parte el índice de refracción es similar al de la esporopolenina y al del vidrio, lo que confiere una excelente interfase para discernir los caracteres morfológicos más delicados.Fil: Noetinger, Maria Sol. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Pujana, Roberto Roman. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Burrieza, Alfredo. Acrilab Sa; ArgentinaFil: Burrieza, Hernán Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; Argentin

The Gondwanan heritage of the Eocene–Miocene Patagonian floras

The breakup of Gondwana and the associated climatic changes led to the fragmentation of floras that were once connected across the Southern lands. The diversity of the Gondwanan remnants has long been assumed to have fluctuated in Patagonia across the Cenozoic, although it has never been quantified so far. Here we address when the major floristic members of the Gondwanan legacy (e.g., southern beeches, proteas, podocarps, gumtrees) expanded, contracted, or became extinct during the Patagonian biogeographic isolation (Eocene–Miocene) on the basis of the re-assessment of the fossil record (i.e., woods, leaves, and spore-pollen grains). We found that the Patagonian floras experienced moderate to severe shifts in the diversity of the Gondwanan component —relative to the total flora— with the highest estimates in the late Eocene–early Oligocene (~50%) and the lowest estimates in the late Miocene (~20%) according to the fossil pollen record. The most important floristic changes include two major replacements: 1) tropical Gondwanan taxa (e.g., Akania, Eucalyptus, Gymnostoma) by typically cool-temperate taxa (e.g., Nothofagaceae) in the Eocene, and 2) humid taxa (e.g., Podocarpaceae) by arid-adapted floras, mostly of non-Gondwanan affinity, across the Miocene. The variation in diversity of the Gondwanan component from Patagonia shows a striking resemblance to that from Australia for the same period, probably indicating a global-scale driver of floristic turnover (e.g., global cooling conditions). Today, the Patagonian subantarctic forests harbor only about ~15% of the Gondwanan diversity, representing a three-fold decrease from its climax in the late Eocene–early Oligocene.Fil: Barreda, Viviana Dora. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Palazzesi, Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Pujana, Roberto Roman. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Panti, Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Tapia, Mariano Jesús. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Fernández, Damián Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Noetinger, Maria Sol. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentin

Interventions at the hospital “Torcuato de Alvear”:a multidiciplinary experience under a “ciudad total”

Entendiendo a la ciudad desde un concepto de “Ciudad Total” se buscó abordar las intervenciones realizadas en el Hospital Alvear de una manera multidisciplinaria. De esta forma, desde lo patrimonial, lo arqueológico, lo paleontológico y lo botánico se emprendieron diferentes tipos de acciones tendientes a diagnosticar el complejo hospitalario. Sus obras comenzaron en 1908 y tras más de cien años de existencia, requerían de su estudio para una puesta en valor del conjunto edilicio y diagnóstico de sus espacios verdes, en el sector donde funcionaran una serie de pabellones demolidos en la década de 1970.Compreendendo a cidade a partir de um conceito de “cidade total” procuramos abordar as intervenções realizadas no Hospital Alvear de forma multidisciplinar. Dessa maneira, desde o patrimonial, o arqueológico, o paleontológico e o botânico, diferentes ações serão desenvolvidas com tendencias para diagnosticar o complexo hospitalar. A construção começou em 1908, e depois de mais de cem anos de existencia, necesitava de um estudo para uma valorização do complexo de edificio e diagnostico das suas zonas verdes circundantes, que incluiran um levantamento do potencial arqueologico no setor onde funcionava uma serie de pavilhões demolidos na decada de 1970.Understanding the city from a concept of "Ciudad Total" (Comprehensive City) we sought to address the interventions made at the Alvear Hospital from a multidisciplinary point of view. In this sense, different types of actions were engaged on archaeology, paleontology and heritage tending to diagnose this hospital complex, whose building works started in 1908 and, after more than a hundred years of existence, was in the need of a study for an enhancement of the building complex and a diagnose of its surrounding green spaces, including a survey in order to detect archaeological potential in the sector where there used to be a group of wards that were demolished in the 1970s.Facultad de Ciencias Naturales y Muse

Spore diversity trends in the Middle Devonian of the Chaco-Salteño Plain, northwestern Argentina

Devonian deposits in northwestern Argentina were historically studied with stratigraphical purposes, since these layers conform the source rocks of the producing basins of the region. A fairly well preserved palynomorph assemblage, from the Tonono Formation, provides an opportunity to perform the first quantitative analysis to study the evolution of diversity in the succession. Two associations are here defined by both, stratigraphic distribution of species and cluster analysis, ranging from the lower Eifelian to the lower Givetian. Rarefaction analysis reveals the existence of a relatively rich miospore population. Species richness increases while there is a drop in diversity and evenness towards the top of the column. The increment of the marine components towards the latter section indicates shifts in the shoreline. The influx of warmer water into higher latitudes, as highlighted by the arrival of the brachiopod Tropidoleptus, could have favored the inception of new spore species in the settled community. These results add to evidence that some groups build up the number of species in disturbed settings, and evenness is reduced with each new species introduced.Fil: Noetinger, Maria Sol. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentin

Studies of devonian micro and megafloristic associations in the southern portion of the Tarija Basin of northwestern Argentina and southern Bolivia: age, correlation and depositional environment

Este trabajo comprende el estudio de asociaciones fósiles, tanto de palino como megaflora, obtenidas de 6 localidades del noroeste argentino y sur de Bolivia, emplazadas en tres Provincias Geológicas: Cordillera Oriental, Sierras Subandinas y Llanura Chacosalteña. Se realizó el análisis morfotaxonómico de las especies presentes en 130 niveles palinológicos fértiles provenientes tanto de secciones aflorantes como de subsuelo, como también su caracterización palinofacial. Se reconocieron 231 especies de las cuales 116 comprenden especies de esporas y criptosporas, 31 quitinozoos y 84 taxones del microplancton incluyendo acritarcas, prasinofitas, clorofitas e incertae sedis. Se reconocieron 4 especies nuevas, una criptospora, Cymbohilates rubinsteinae, y tres esporas trilete, Acinosporites macgregorii di Pasquo y Noetinger 2008a, Retusotriletes albarinii di Pasquo y Noetinger 2008a y Retusotriletes ottonei Noetinger y di Pasquo 2011. A su vez, se estudiaron dos niveles con ejemplares fértiles y estériles de plantas fósiles del sur de Bolivia que permanecen en asignación específica abierta al igual que varias especies de palinomorfos. El análisis cuali-cuantitativo y la distribución vertical de las especies reconocidas en las localidades estudiadas permitió la definición de 14 asociaciones que abarcan un lapso desde el Devónico Temprano al Devónico Tardío (Lochkoviano s.l. al Frasniano temprano). Debido a la baja frecuencia o ausencia de especies clave, en las asociaciones estudiadas, ha sido dificultoso establecer una confiable correlación de muchas de las asociaciones con las biozonas conocidas para este período. A su vez, la comparación detallada a nivel taxonómico y palinofacial de las distintas asociaciones permitió establecer correlaciones entre las localidades estudiadas. Esto indica que hubo un importante endemismo en las floras de esta región principalmente durante el Devónico Temprano, extendiéndose hacia el Devónico Medio. La baja proporción de asociaciones coetáneas recuperadas, sumado a la pobre preservación de los palinomorfos, la ausencia de “especies guía” representadas en más de una asociación y el carácter longevo de un gran número de especies que aparecen en más de una localidad no ha permitido sustentar la propuesta de una biozonación local. La recuperación de sedimentitas que abarcan casi la totalidad de la columna devónica permitió el estudio de la evolución paleoambiental de puntos específicos de la cuenca y contribuir al mejoramiento de la configuración paleogeográfica regional más aceptada. Los resultados alcanzados aquí demuestran que las floras del sudoeste de Gondwana habrían estado representadas por especies endémicas tanto de plantas como especies de palinomorfos, las cuales sustentan la creación del Subreino Afro- Sudamericano (ASA), para el lapso Devónico Medio – Tardío temprano. La aparición de especies euramericanas en este Subreino, apoya una configuración paleogeográfica con un Océano Rheico casi cerrado o al menos no muy extenso, que permitió la conexión de ambos supercontinentes.This work includes the study of fossil assemblages of both palyno and megaflora obtained from 6 localities in three different geographical provinces of northwestern Argentina and southern Bolivia: Cordillera Oriental, Sierras Subandinas and the Chacosalteña Plain. A morphotaxonomical analysis was performed on the species present in 130 fertile levels from both outcrop and subsurface sections, as well as their palynofacial characterization. 231 species were recognized, of which 116 species were spores and cryptospores, 31 chitinozoans, and 84 microplankton taxa, including acritarchs, prasinophytes chlorophytes and incertae sedis. Four new species were recognized: a cryptospore, Cymbohilates rubinsteinae, and three trilete spores: Acinosporites macgregorii di Pasquo and Noetinger 2008a, Retusotriletes albarinii di Pasquo and Noetinger 2008a, and Retusotriletes ottonei Noetinger and di Pasquo 2011. From southern Bolivia, two levels with fertile and sterile specimens of fossil plants that remain in open nomenclature were analyzed, as well as several species of palynomorphs. The qualitative and quantitative analysis and vertical distribution of the species recognized in this study allowed the definition of 14 associations covering a period from the Early Devonian to Late Devonian (Lochkovian s.l. to early Frasnian). It was difficult to establish a reliable correlation of many of the associations with known biozones for this period due to the low frequency or absence of key species in the associations. Nevertheless, the detailed comparison of palynofacial and taxonomical features in the recognized associations allowed for the establishment of correlations between the studied sites. This indicated a significant endemism in the flora of this region, mainly during the Early Devonian extending to the Middle Devonian. The low proportion of recovered contemporary associations, combined with poor preservation, lack of key species represented in more than one association, and the long-range nature of a number of species that appear in more than one location does not support the proposal of a local biozonation. The recovery of sediments that cover almost the entire Devonian column allowed the study of the paleoenvironmental evolution of specific points of the basin and contributed to the improvement of the more acceptable regional palaeogeographical settings. The results obtained here demonstrate that the floras of southwestern Gondwana would have been represented by endemic species of both plants and palynomorphs, which support the creation of the Afro- Southamerican Subrealm (ASA) for the Middle to early Late Devonian. The appearance of euramerican species in this Subrealm supports a palaeogeographical setting with a Rheic Ocean, nearly closed or at least not very extensive, allowing the connection of two supercontinents.Fil:Noetinger, María Sol. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina

First record of Early Devonian (Lochkovian) flora from the Santa Rosa Formation - Alarache, Southern Bolivia

New information on plants and palynomorphs from Angosto de Alarache, South Bolivia, is presented. The plant remains appear at the base of the section. Dichotomizing sterile forms are assigned to Hostinella sp. and scarce stems terminated in spherical structures are interpreted as indetermined sporangia. The palynological association 1 recovered from this level contains abundant phytodebris, trilete spores, few cryptospores, algae, very poorly preserved chitinozoans, and other elements (fungi, ?lichens). Trilete spores assignable to Apiculiretusispora sp., Punctatisporites sp. and Retusotriletes sp., are obtained from the maceration of some isolated sporangia. The dichotomous branching of the stems and the trilete spores recovered from the isolated sporangia support its tracheophyte affinity. The palynological assemblage 2, obtained three metres above, contains abundant phytodebris and more diverse palynomorphs. Two new species (Retusotriletes albarinii n. sp., Acinosporites macgregorii n. sp.) are described. Based on the presence of the trilete spores Dictyotriletes emsiensis (ALLEN) MCGREGOR, Retusotriletes maculatus MCGREGOR and CAMFIELD, Apiculiretusispora plicata (ALLEN) STREEL and the absence, mainly of Verrucosisporites polygonalis LANNINGER and Urochitina loboi VOLKHEIMER et al., we propose a Lochkovian age but restricted up to the Late not latest Lochkovian, and the correlation with the lower part of the Emsiensis Zone of the Amazon Basin and the MN Zone of Western Europe. The abundance of fragmented stems of varied size and parallel to bedding planes, along with the isolated sporangia in the plant assemblage suggests a short distance transportation under low energy conditions, probably from marginal palaeoenvironments to low energy marine settings