scholarly journals Late Miocene potamarchine rodents (Caviomorpha: Dinomyidae) from southwestern Amazonia, Brazil (northern South America): with description of new taxa

2014 ◽  
Author(s):  
Leonardo Kerber ◽  
Francisco Negri ◽  
Ana Ribeiro ◽  
Maria Vucetich ◽  
Jonas Souza Filho
Keyword(s):  
South America ◽  
New Taxa ◽  
Late Miocene ◽  
Northern South America ◽  
Southwestern Amazonia

scholarly journals A new enigmatic Late Miocene mylodontoid sloth from northern South America

2015 ◽  
Vol 2 (4) ◽  
pp. 150138 ◽  
Author(s):  
Ascanio D. Rincón ◽  
H. Gregory McDonald ◽  
Andrés Solórzano ◽  
Mónica Núñez Flores ◽  
Damián Ruiz-Ramoni
Keyword(s):  
South America ◽  
Late Miocene ◽  
Northern South America

scholarly journals A new enigmatic Late Miocene mylodontoid sloth from northern South America

2015 ◽  
Vol 2 (2) ◽  
pp. 140256 ◽  
Author(s):  
Ascanio D. Rincón ◽  
H. Gregory McDonald ◽  
Andrés Solórzano ◽  
Mónica Núñez Flores ◽  
Damián Ruiz-Ramoni
Keyword(s):  
South America ◽  
Late Miocene ◽  
Preliminary Analysis ◽  
New Genus ◽  
New Taxon ◽  
New Genus And Species ◽  
Consensus Tree ◽  
Discriminate Analysis ◽  
Northern South America ◽  
Phylogenetic Affinities

A new genus and species of sloth ( Eionaletherium tanycnemius gen. et sp. nov.) recently collected from the Late Miocene Urumaco Formation, Venezuela (northern South America) is herein described based on a partial skeleton including associated femora and tibiae. In order to make a preliminary analysis of the phylogenetic affinities of this new sloth we performed a discriminate analysis based on several characters of the femur and tibia of selected Mylodontoidea and Megatherioidea sloths. The consensus tree produced indicates that the new sloth, E. tanycnemius , is a member of the Mylodontoidea. Surprisingly, the new taxon shows some enigmatic features among Neogene mylodontoid sloths, e.g. femur with a robust lesser trochanter that projects medially and the straight distinctly elongated tibia. The discovery of E. tanycnemius increases the diversity of sloths present in the Urumaco sequence to ten taxa. This taxon supports previous studies of the sloth assemblage from the Urumaco sequence as it further indicates that there are several sloth lineages present that are unknown from the better sampled areas of southern South America.

Late Miocene crocodylians from northeast Argentina: new approaches about the austral components of the Neogene South American crocodylian fauna

2012 ◽  
Vol 103 (3-4) ◽  
pp. 551-570 ◽  
Author(s):  
Paula Bona ◽  
Douglas Riff ◽  
Zulma Brandoni de Gasparini
Keyword(s):  
South America ◽  
Late Miocene ◽  
South American ◽  
Drainage Basins ◽  
New Approaches ◽  
Northern South America

ABSTRACTThe richest and more explored regions concerning Miocene crocodylians in South America are the basins surrounding the areas of Urumaco (Venezuela), La Venta (Colombia), Acre (Northwest Brazil) and Paraná (Northeast Argentina). Fossils from the late Miocene in the Paraná area were recovered from the “Conglomerado Osífero” (Ituzaingó Formation) and assigned to several taxa of Caimaninae (Alligatoroidea) and to a taxon of Gavialoidea. The late Miocene “fauna” of crocodylians recorded in northeast Argentina differs from coeval ones of northern South America by the absence of crocodyloids, some alligatorid genera (such as Purussaurus, Melanosuchus, and Paleosuchus) and by the scarce gavialoid species. Giant forms, conspicuous in the northern South American deposits, are also absent in southern latitudes. Despite this, the austral South American crocodylian fauna exhibits strong affinities with the northern, contemporary forms, sharing taxa at generic (i.e. Caiman and Gryposuchus) and even specific levels (i.e. Mourasuchus nativus). The sharing of such freshwater taxa in the Miocene indicates partial connections of drainage basins through swamp areas on their boundaries, and is evidence against the assumption of an intracontinental coeval seaway link in this continent proposed by several authors.

Rubiacearum Americanarum Magna Hama Pars XLVI: New Species and Taxonomic Changes in Faramea of Central and South America (Rubiaceae, Coussareeae)

2020 ◽  
Vol 28 (2) ◽  
pp. 108-142
Author(s):  
Charlotte M. Taylor ◽  
Jomar G. Jardim
Keyword(s):  
New Species ◽  
South America ◽  
Central America ◽  
New Taxa ◽  
New Subspecies ◽  
Taxonomic Changes ◽  
New Nomenclatural Combinations

Review of specimens and names of Faramea Aubl. (Rubiaceae, Coussareeae) has required new nomenclatural combinations, clarified the identities of some previously described species, and discovered some new taxa. Here we transfer two Faramea names, F. suaveolens Duchass. and F. panurensis Müll. Arg., to Coussarea Aubl.; review the identities of F. cuencana Standl., F. multiflora A. Rich., F. oblongifolia Standl., F. parvibractea Steyerm., F. spathacea Müll. Arg. ex Standl., and F. suerrensis (Donn. Sm.) Donn. Sm.; lectotypify F. multiflora and F. panurensis; transfer to Faramea and lectotypify Rudgea scandens K. Krause; and describe 13 new species and two new subspecies: F. camposiana C. M. Taylor of Ecuador and Peru, F. foreroana C. M. Taylor of Colombia, F. fosteri C. M. Taylor of western South America, F. galerasana C. M. Taylor of Ecuador, F. grayumiana C. M. Taylor of Central America, F. kampauicola C. M. Taylor of Ecuador and Peru, F. neilliana C. M. Taylor of western South America, F. premontana C. M. Taylor of Ecuador, F. quijosana C. M. Taylor of Ecuador, F. ramosiana C. M. Taylor of Colombia, F. reyneliana C. M. Taylor of Peru, F. stoneana C. M. Taylor with two subspecies from Central and western South America, F. suerrensis subsp. miryamiae C. M. Taylor from Colombia, and F. vernicosa C. M. Taylor of Ecuador and Peru.

scholarly journals Air quality variations in Northern South America during the COVID-19 lockdown

2020 ◽  
Vol 749 ◽  
pp. 141621 ◽  
Author(s):  
Juan F. Mendez-Espinosa ◽  
Nestor Y. Rojas ◽  
Jorge Vargas ◽  
Jorge E. Pachón ◽  
Luis C. Belalcazar ◽  
...  
Keyword(s):  
Air Quality ◽  
South America ◽  
Northern South America

Ground-motion model for subduction earthquakes in northern South America

2021 ◽  
pp. 875529302110275
Author(s):  
Carlos A Arteta ◽  
Cesar A Pajaro ◽  
Vicente Mercado ◽  
Julián Montejo ◽  
Mónica Arcila ◽  
...  
Keyword(s):  
South America ◽  
Ground Motion ◽  
Ground Motions ◽  
Strong Motion ◽  
Motion Prediction ◽  
Depth Range ◽  
Ground Motion Prediction ◽  
Natural Period ◽  
Nazca Plate ◽  
Northern South America

Subduction ground motions in northern South America are about a factor of 2 smaller than the ground motions for similar events in other regions. Nevertheless, historical and recent large-interface and intermediate-depth slab earthquakes of moment magnitudes Mw = 7.8 (Ecuador, 2016) and 7.2 (Colombia, 2012) evidenced the vast potential damage that vulnerable populations close to earthquake epicenters could experience. This article proposes a new empirical ground-motion prediction model for subduction events in northern South America, a regionalization of the global AG2020 ground-motion prediction equations. An updated ground-motion database curated by the Colombian Geological Survey is employed. It comprises recordings from earthquakes associated with the subduction of the Nazca plate gathered by the National Strong Motion Network in Colombia and by the Institute of Geophysics at Escuela Politécnica Nacional in Ecuador. The regional terms of our model are estimated with 539 records from 60 subduction events in Colombia and Ecuador with epicenters in the range of −0.6° to 7.6°N and 75.5° to 79.6°W, with Mw≥4.5, hypocentral depth range of 4 ≤  Zhypo ≤ 210 km, for distances up to 350 km. The model includes forearc and backarc terms to account for larger attenuation at backarc sites for slab events and site categorization based on natural period. The proposed model corrects the median AG2020 global model to better account for the larger attenuation of local ground motions and includes a partially non-ergodic variance model.

STUDIES ON STRONGYLOIDES AGOUTII SP. NOV. FROM THE AGOUTI (DASYPROCTA AGOUTI)

1940 ◽  
Vol 18d (5) ◽  
pp. 173-190 ◽  
Author(s):  
Henry J. Griffiths
Keyword(s):  
Seasonal Variation ◽  
South America ◽  
Biological Study ◽  
Free Living ◽  
Classical Studies ◽  
Group A ◽  
Northern South America

A morphological and biological study is presented of a hitherto unrecorded member of the genus Strongyloides from the golden-rumped agouti (Dasyprocta agouti), a rodent native to Trinidad, B.W.I., and northern South America. The name Strongyloides agoutii sp. nov. is proposed for this species.Observations on the free-living development over a period of three years showed the indirect type to prevail; no seasonal variation was observed. Continuous propagation of the free-living generation of this species was not observed in faecal cultures or on artificial media.A brief résumé of the classical studies on species of the genus Strongyloides is included, together with a summary of existing hypotheses and theories on the biology of this group. A list of species and hosts for this genus is given.

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