Upper Silurian miospores from the Precordillera Basin, Argentina: biostratigraphic, palaeonvironmental and palaeogeographic implications

2013 ◽  
Vol 151 (3) ◽  
pp. 472-490 ◽  
Author(s):  
V. J. GARCÍA MURO ◽  
C. V. RUBINSTEIN ◽  
P. STEEMANS
Keyword(s):  
South America ◽  
North Africa ◽  
Environmental Conditions ◽  
Amazon Basin ◽  
Northern Spain ◽  
Cantabrian Mountains ◽  
Northern Brazil ◽  
Upper Silurian ◽  
Local Ecology ◽  
New Synonymy

AbstractThis study is concentrated on Ludlow (to Pridoli?) miospores from the Los Espejos Formation at the Quebrada Ancha locality, Central Precordillera, San Juan Province, Argentina. The Ludlow age is in agreement with the age based on acritarchs. The assemblage of continental palynomorphs is composed of 43 miospore species (29 trilete spores and 14 cryptospores). A new synonymy is proposed: Chelinospora poecilomorpha is here considered a junior synonym of Clivosispora verrucata. In addition, specimens belonging to C. verrucata var. verrucata and C. verrucata var. convoluta are included in a new morphon. This study represents the second Late Silurian miospore assemblage described from South America; the first was from the Urubu River, Amazon Basin, northern Brazil. The Quebrada Ancha assemblages allow a reasonably good correlation with biozones established for the Upper Silurian from the Cantabrian Mountains, northern Spain. The dendrogram analysis between coeval miospore assemblages from different localities shows a strong palaeogeographic affinity with the miospores recovered from northern Brazil and North Africa. Miospore assemblages from Spain show influences from Baltica and North Africa, demonstrating their intermediate position between these two continental plates. Conversely, dissimilarities recognized between Libya and Tunisia are most probably owing to local ecology and/or environmental conditions.

scholarly journals Amazonia as the Origin and Diversification Area of Didelphidae (Mammalia: Metatheria), and a Review of the Fossil Record of the Clade

2021 ◽  
Author(s):  
Mariela C. Castro ◽  
Murilo J. Dahur ◽  
Gabriel S. Ferreira
Keyword(s):  
South America ◽  
Amazon Basin ◽  
Parametric Models ◽  
Isthmus Of Panama ◽  
Biogeographic History ◽  
Early Diversification ◽  
Northern Portion ◽  
History Of ◽  
Environmental Events ◽  
Fossil Records

AbstractDidelphidae is the largest New World radiation of marsupials, and is mostly represented by arboreal, small- to medium-sized taxa that inhabit tropical and/or subtropical forests. The group originated and remained isolated in South America for millions of years, until the formation of the Isthmus of Panama. In this study, we present the first reconstruction of the biogeographic history of Didelphidae including all major clades, based on parametric models and stratified analyses over time. We also compiled all the pre-Quaternary fossil records of the group, and contrasted these data to our biogeographic inferences, as well as to major environmental events that occurred in the South American Cenozoic. Our results indicate the relevance of Amazonia in the early diversification of Didelphidae, including the divergence of the major clades traditionally ranked as subfamilies and tribes. Cladogeneses in other areas started in the late Miocene, an interval of intense shifts, especially in the northern portion of Andes and Amazon Basin. Occupation of other areas continued through the Pliocene, but few were only colonized in Quaternary times. The comparison between the biogeographic inference and the fossil records highlights some further steps towards better understanding the spatiotemporal evolution of the clade. Finally, our results stress that the early history of didelphids is obscured by the lack of Paleogene fossils, which are still to be unearthed from low-latitude deposits of South America.

scholarly journals Coupling between the JULES land-surface scheme and the CCATT-BRAMS atmospheric chemistry model (JULES-CCATT-BRAMS1.0): applications to numerical weather forecasting and the CO<sub>2</sub> budget in South America

2013 ◽  
Vol 6 (1) ◽  
pp. 453-494 ◽  
Author(s):  
D. S. Moreira ◽  
S. R. Freitas ◽  
J. P. Bonatti ◽  
L. M. Mercado ◽  
N. M. É. Rosário ◽  
...  
Keyword(s):  
South America ◽  
Atmospheric Chemistry ◽  
Land Surface ◽  
Amazon Basin ◽  
Mean Squared Error ◽  
Weather Forecasting ◽  
Dew Point ◽  
Surface Model ◽  
Co2 Concentrations ◽  
Wide Range

Abstract. This article presents the development of a new numerical system denominated JULES-CCATT-BRAMS, which resulted from the coupling of the JULES surface model to the CCATT-BRAMS atmospheric chemistry model. The performance of this system in relation to several meteorological variables (wind speed at 10 m, air temperature at 2 m, dew point temperature at 2 m, pressure reduced to mean sea level and 6 h accumulated precipitation) and the CO2 concentration above an extensive area of South America is also presented, focusing on the Amazon basin. The evaluations were conducted for two periods, the wet (March) and dry (September) seasons of 2010. The statistics used to perform the evaluation included bias (BIAS) and root mean squared error (RMSE). The errors were calculated in relation to observations at conventional stations in airports and automatic stations. In addition, CO2 concentrations in the first model level were compared with meteorological tower measurements and vertical CO2 profiles were compared with aircraft data. The results of this study show that the JULES model coupled to CCATT-BRAMS provided a significant gain in performance in the evaluated atmospheric fields relative to those simulated by the LEAF (version 3) surface model originally utilized by CCATT-BRAMS. Simulations of CO2 concentrations in Amazonia and a comparison with observations are also discussed and show that the system presents a gain in performance relative to previous studies. Finally, we discuss a wide range of numerical studies integrating coupled atmospheric, land surface and chemistry processes that could be produced with the system described here. Therefore, this work presents to the scientific community a free tool, with good performance in relation to the observed data and re-analyses, able to produce atmospheric simulations/forecasts at different resolutions, for any period of time and in any region of the globe.

scholarly journals Two new long-rostrum cranefly species from the Cretaceous Iberian amber (Diptera, Limoniidae, Helius)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Iwona Kania-Kłosok ◽  
Wiesław Krzemiński ◽  
Antonio Arillo
Keyword(s):  
Environmental Conditions ◽  
Lower Cretaceous ◽  
Fossil Record ◽  
First Record ◽  
Northern Spain ◽  
Fossil Species ◽  
Body Morphology ◽  
Cretaceous Period ◽  
Basque Cantabrian Basin

AbstractFirst record of the genus Helius—long-rostrum cranefly from Maestrazgo Basin (eastern Spain, Iberian Penisula) is documented. Two new fossil species of the genus Helius are described from Cretaceous Spanish amber and compared with other species of the genus known from fossil record with particular references to these known from Cretaceous period. Helius turolensis sp. nov. is described from San Just amber (Lower Cretaceous, upper Albian) Maestrazgo Basin, eastern Spain, and Helius hispanicus sp. nov. is described from Álava amber (Lower Cretaceous, upper Albian), Basque-Cantabrian Basin, northern Spain. The specific body morphology of representatives of the genus Helius preserved in Spanish amber was discussed in relation to the environmental conditions of the Maestrazgo Basin and Basque-Cantabrian Basin in Cretaceous.

scholarly journals Reassessment of Viséan miospore biostratigraphy in the Amazon Basin, northern Brazil

1998 ◽  
Vol 104 (2) ◽  
pp. 143-155 ◽  
Author(s):  
Stanislas Loboziak ◽  
José Henrique G. Melo ◽  
Maurice Streel
Keyword(s):  
Amazon Basin ◽  
Northern Brazil

New Middle Cambrian palaeoscolecid sclerites of Hadimopanella oezgueli from the Cantabrian Mountains, northern Spain

GFF ◽  
2014 ◽  
Vol 136 (1) ◽  
pp. 22-25 ◽  
Author(s):  
Tania Barragán ◽  
Jorge Esteve ◽  
Diego C. García-Bellido ◽  
Samuel Zamora ◽  
J. Javier Álvaro
Keyword(s):  
Northern Spain ◽  
Cantabrian Mountains ◽  
Middle Cambrian

Kuehneola loeseneriana.

2021 ◽  
Author(s):  
Keyword(s):  
South America ◽  
Environmental Conditions ◽  
Pathogenic Fungus ◽  
North Central ◽  
Plant Pathogenic Fungus ◽  
The World ◽  
Agricultural Plants

Abstract There is little published information on this plant pathogenic fungus, which is limited to parts of North, Central and South America. It infects Rubus spp., which exist in other regions of the world with similar environmental conditions, therefore this species may pose a threat to native or agricultural plants if introduced.

Spilocaea oleaginea. [Distribution map].

1987 ◽  
Author(s):  
Keyword(s):  
South Africa ◽  
North America ◽  
South America ◽  
Geographical Distribution ◽  
North Africa ◽  
New South ◽  
Distribution Map ◽  
South Wales ◽  
Olea Europea ◽  
New Distribution

Abstract A new distribution map is provided for Spilocaea oleaginea (Cast.) Hughes. Hosts: Olive (Olea europea). Information is given on the geographical distribution in Africa, Algeria, Egypt, Ethiopia, Libya, Morocco, North Africa, Somalia, South Africa, Tunisia, Asia, China, Iran, Israel, Jordan, Turkey, USSR, Georgia, Australasia & Oceania, Australia, New South Wales, Europe, Cyprus, France, Greece, Italy, Crete, Sicily, Malta, Portugal, Spain, Yugoslavia, North America, USA, California, South America, Argentina, Chile, Ecuador, Peru.

Impact of strong El Niño events on river discharge in South America

2021 ◽  
Author(s):  
Markus Deppner ◽  
Bedartha Goswami
Keyword(s):  
Machine Learning ◽  
Missing Data ◽  
South America ◽  
River Discharge ◽  
Amazon Basin ◽  
Missing Values ◽  
Southern Oscillation ◽  
Enso Events ◽  
Streamflow Data ◽  
The Impact

&lt;p&gt;The impact of the El Ni&amp;#241;o Southern Oscillation (ENSO) on rivers are well known, but most existing studies involving streamflow data are severely limited by data coverage. Time series of gauging stations fade in and out over time, which makes hydrological large scale and long time analysis or studies of rarely occurring extreme events challenging. Here, we use a machine learning approach to infer missing streamflow data based on temporal correlations of stations with missing values to others with data. By using 346 stations, from the &amp;#8220;Global Streamflow Indices and Metadata archive&amp;#8221; (GSIM), that initially cover the 40 year timespan in conjunction with Gaussian processes we were able to extend our data by estimating missing data for an additional 646 stations, allowing us to include a total of 992 stations. We then investigate the impact of the 6 strongest El Ni&amp;#241;o (EN) events on rivers in South America between 1960 and 2000. Our analysis shows a strong correlation between ENSO events and extreme river dynamics in the southeast of Brazil, Carribean South America and parts of the Amazon basin. Furthermore we see a peak in the number of stations showing maximum river discharge all over Brazil during the EN of 1982/83 which has been linked to severe floods in the east of Brazil, parts of Uruguay and Paraguay. However EN events in other years with similar intensity did not evoke floods with such magnitude and therefore the additional drivers of the 1982/83&amp;#160; floods need further investigation. By using machine learning methods to infer data for gauging stations with missing data we were able to extend our data by almost three-fold, revealing a possible heavier and spatially larger impact of the 1982/83 EN on South America's hydrology than indicated in literature.&lt;/p&gt;

scholarly journals New species of Cyphocharax (Characiformes: Curimatidae) from the upper rio Negro, Amazon basin

2014 ◽  
Vol 12 (2) ◽  
pp. 327-332 ◽  
Author(s):  
Bruno F. Melo ◽  
Richard P. Vari
Keyword(s):  
New Species ◽  
Amazon Basin ◽  
Caudal Peduncle ◽  
Caudal Fin ◽  
Rio Negro ◽  
Fin Rays ◽  
Dark Pigmentation ◽  
Northern Brazil ◽  
Adipose Fin ◽  
A New Species

A new species of Cyphocharax, Curimatidae, apparently endemic to the blackwater upper rio Negro of the Amazon basin in northern Brazil, is described.The new species is readily distinguished from its congeners by the presence of a distinctly longitudinally elongate, posteriorly vertically expanding patch of dark pigmentation along the midlateral surface of the caudal peduncle, with the patch extending from the base of the middle caudal-fin rays anteriorly past the vertical through the posterior terminus of the adipose fin. The new species additionally differs from all congeners in details of body and fin pigmentation and meristic and morphometric ratios. Evidence for the assignment of the species to Cyphocharax and the occurrence of other species of the Curimatidae apparently endemic to the upper rio Negro catchment is discussed.

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