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

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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Late-Glacial Cooling in Amazonia Inferred from Pollen at Lagoa do Caçó, Northern Brazil

Quaternary Research ◽

10.1006/qres.2000.2187 ◽

2001 ◽

Vol 55 (1) ◽

pp. 47-56 ◽

Cited By ~ 60

Author(s):

Marie-Pierre Ledru ◽

Renato Campello Cordeiro ◽

José Maria Landim Dominguez ◽

Louis Martin ◽

Philippe Mourguiart ◽

...

Keyword(s):

Amazon Basin ◽

Ice Core ◽

Late Glacial ◽

Climatic Conditions ◽

Convective Precipitation ◽

Pollen Data ◽

Moisture Source ◽

Northern Latitudes ◽

Low Latitudes ◽

Northern Brazil

AbstractNew pollen data from a core at Lagoa do Caçó, Maranhão state, Brazil (2°58′S 43°25′W; 120 m elevation), show higher frequencies of Podocarpus at the end of the Pleistocene than today. The increase in Podocarpus, which follows the successive increase of various pioneer species such as Didymopanax, Melastomataceae/Combretaceae, and Cecropia, implies a progressive late-glacial increase of moist and cool climatic conditions. A comparable increase in Podocarpus is found in other lowland records in Amazonia. A review of published pollen data from Amazonia suggests that the moisture source was from the southeast. By contrast, present-day moisture comes from the tropical Atlantic and from the Amazon basin, with its convective precipitation. The likely cause for the southeastern moisture source between ca. 15,000 and 14,500 cal yr B.P. was enhanced polar (Antarctic) advection that reached low latitudes and maintained year-round the meteorological equator in its austral-winter position at northern latitudes or reduced drastically its southward summer displacement. This hypothesis is consistent with marine and ice core records.

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

Geological Magazine ◽

10.1017/s0016756813000393 ◽

2013 ◽

Vol 151 (3) ◽

pp. 472-490 ◽

Cited By ~ 7

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.

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Lateral variation of crustal properties from aerogeophysical data in northern Brazil

Geophysics ◽

10.1190/geo2016-0206.1 ◽

2017 ◽

Vol 82 (5) ◽

pp. J39-J60

Author(s):

João Willy Corrêa Rosa ◽

José Wilson Corrêa Rosa ◽

Götz Bokelmann

Keyword(s):

High Resolution ◽

Radon Transform ◽

Large Scale ◽

Amazon Basin ◽

Seismic Anisotropy ◽

Sedimentary Cover ◽

Azimuthal Anisotropy ◽

Lateral Variation ◽

Data Set ◽

Northern Brazil

A new method is proposed for the study of crustal azimuthal anisotropy, and the lateral variation of other crustal aerogeophysical parameters, using a quantitative approach. The processing of a large, newly acquired, high-resolution set of aerogeophysical data is considered using the existing Radon transform and the geostatistical analysis approaches. The data set includes an area of the Guyana shield, in northern Brazil, which was not included in previous surveys. The area is covered by dense rain forest vegetation and thick soil layers. Parameterization was performed considering the possible anisotropic character of the geophysical 2D data. Application of the newly proposed geostatistical data processing yielded high-resolution images of the lateral variation of quantitative geophysical parameters, which indicate good correlation with previously determined seismic anisotropy in the area. Average anisotropy as measured by the Radon transform and variogram analysis is scale dependent. At scales greater than [Formula: see text], the results seem to match those of the previous seismic studies. Images of the derived quantitative parameters from magnetic and radiometric data in the shield area indicate sharp changes that follow the known geologic changes observable in the survey area. Observed large-scale anisotropy in the area seems to be autocorrelated with two different geochronological provinces of the Amazonian craton. Application of the new technique to two other lower resolution aeromagnetic surveys located on the Amazon basin has produced two different results, including one successful data treatment of the aeromagnetic survey. The results obtained for this area indicate that the sedimentary cover seems to play almost no role in the observed magnetic anomaly anisotropy in the middle Amazon basin area. Most of the observed magnetic anomalies appear to be controlled by the continuing geologic features of the cratonic basement.

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Trichomycterus anhanga, a new species of miniature catfish related to T. hasemani and T. johnsoni (Siluriformes: Trichomycteridae) from the Amazon basin, Brazil

Neotropical Ichthyology ◽

10.1590/s1679-62252012000200001 ◽

2012 ◽

Vol 10 (2) ◽

pp. 225-231 ◽

Cited By ~ 9

Author(s):

Guilherme M. Dutra ◽

Wolmar B. Wosiacki ◽

Mario C. C. de Pinna

Keyword(s):

New Species ◽

Amazon Basin ◽

Sensory System ◽

Ventral Surface ◽

Dark Spot ◽

Single Pair ◽

Mandibular Symphysis ◽

Dorsal Fin ◽

Northern Brazil ◽

A New Species

Trichomycterus anhanga is described from the Amazon basin, northern Brazil. The species is diagnosed by the latero-sensory system which is restricted to LL1 and LL2, the pectoral fin with two branched rays, the absence of pelvic fins and girdle, the reduced jaws and pharyngeal dentition, the presence of six to seven interopercular odontodes, the absence of a lateral series of spots, the presence of a small dark spot on the ventral surface of the mandibular symphysis, the narrow comma-shaped palatine, the absence of procurrent rays anterior to the dorsal and anal fins, the position of insertion of the first dorsal-fin pterygiophore and the presence of a single pair of pleural ribs. Trichomycterus anhanga shares with T. hasemani and T. johnsoni a wide cranial fontanel which occupies most of the skull roof. Miniaturization as well as synapomorphies for the T. hasemani group are discussed.

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Devonian–Early Carboniferous miospore biostratigraphy of the Amazon Basin, Northern Brazil

Review of Palaeobotany and Palynology ◽

10.1016/s0034-6667(02)00184-7 ◽

2003 ◽

Vol 124 (3-4) ◽

pp. 131-202 ◽

Cited By ~ 75

Author(s):

José Henrique G. Melo ◽

Stanislas Loboziak

Keyword(s):

Amazon Basin ◽

Early Carboniferous ◽

Northern Brazil

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Taxonomic validity of Mesoclemmys heliostemma (McCord, Joseph-Ouni & Lamar, 2001) (Testudines, Chelidae) inferred from morphological analysis

Zootaxa ◽

10.11646/zootaxa.3575.1.4 ◽

2012 ◽

Vol 3575 (1) ◽

pp. 63 ◽

Cited By ~ 4

Author(s):

FLAVIO B. MOLINA ◽

FABIO A. MACHADO ◽

HUSSAM ZAHER

Keyword(s):

Amazon Basin ◽

Morphological Analysis ◽

Morphological Characters ◽

Statistical Analyses ◽

Descriptive Statistics ◽

Valid Species ◽

Group Differences ◽

Multivariate Statistical Analyses ◽

Multivariate Statistical ◽

Northern Brazil

Mesoclemmys heliostemma (Testudines: Chelidae) was described based on five vouchered specimens and nine live spec-imens from the western Amazon basin. Some authors questioned its status as a valid species, suggesting that it representsa junior synonym of M. raniceps. Here, we report on eight additional specimens from eastern Peru and northern Brazil,and provide descriptive statistics of morphological characters for hatchlings, juveniles, and adults of M. heliostemma, M.raniceps, and M. gibba. We also test for group differences through univariate and multivariate statistical analyses, anddiscuss some advantages of this methodology. Our data suggest that all three taxa are morphologically divergent, and that M. heliostemma is a valid species.

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Preliminary survey of avifauna of the Estação Ecológica do Cuniã in Porto Velho, northern Brazil

Check List ◽

10.15560/17.1.289 ◽

2021 ◽

Vol 17 (1) ◽

pp. 289-310

Author(s):

Tatiana Lemos da Silva Machado ◽

Uéslei Marques de Oliveira ◽

Sheiliane Santos do Nascimento ◽

Marcos Pérsio Dantas Santos ◽

Angelo Gilberto Manzatto

Keyword(s):

Amazon Basin ◽

Migratory Birds ◽

Bird Species ◽

The State ◽

Camera Trapping ◽

Preliminary Survey ◽

Endemic Birds ◽

Northern Brazil ◽

Porto Velho

We present a preliminary list of the avifauna found at the Estação Ecológica do Cuniã (ESEC Cuniã) in Porto Velho, northern Rondônia, Brazil. This inventory is based on systematic records obtained by mist-netting and camera trapping and non-systematic visual and audio records collected within the study area in 2017 and 2019. The combined dataset includes 135 bird species representing 37 families. Among these species are endemic birds and migratory birds. Four of the species are described in the last decade, and the records represent expansions of these species’ known ranges to the state of Rondônia. Overall, the data show that the ESEC Cuniã has a considerable diversity of bird species and is important for the conservation of the fauna of the floodplains of the Amazon basin.

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