scholarly journals Fossil freshwater fishes and the biogeography of northern South America

Author(s):  
Gustavo Adolfo Ballen Chaparro
Zootaxa ◽  
2019 ◽  
Vol 4671 (4) ◽  
pp. 527-540
Author(s):  
AUGUSTO FROTA ◽  
CARLA SIMONE PAVANELLI ◽  
WEFERSON JÚNIO DA GRAÇA

Knowledge on the hydrological evolution of the Neotropical region was used along with the current distribution of the anablepid species to investigate the historical biogeography of this family. Areas of endemism were delimited by endemicity analysis resulting in seven individual areas of endemism and three consensus areas located in northwestern Argentina, southern Brazil, and northern South America. These areas were discussed in the context of anablepid species diversification, especially for the genus Anableps and the subgenera Jenynsia and Plesiojenynsia. The existence of areas of endemism for the family analyzed reveals an intimate association with historical events that occurred in the geological evolution of South America, which can be associated with the main diversification patterns and historical hypotheses in the context of Neotropical freshwater fishes biogeography. 


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

2021 ◽  
pp. 875529302110275
Author(s):  
Carlos A Arteta ◽  
Cesar A Pajaro ◽  
Vicente Mercado ◽  
Julián Montejo ◽  
Mónica Arcila ◽  
...  

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.


1940 ◽  
Vol 18d (5) ◽  
pp. 173-190 ◽  
Author(s):  
Henry J. Griffiths

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.


2017 ◽  
Vol 51 (5-6) ◽  
pp. 1901-1914 ◽  
Author(s):  
Armineh Barkhordarian ◽  
Hans von Storch ◽  
Eduardo Zorita ◽  
Paul C. Loikith ◽  
Carlos R. Mechoso

1944 ◽  
Vol 34 (4) ◽  
pp. 101 ◽  
Author(s):  
Oscar Haught

Phytotaxa ◽  
2013 ◽  
Vol 93 (1) ◽  
pp. 25 ◽  
Author(s):  
TEUVO AHTI ◽  
HARRIE J. M. SIPMAN

The diversity of the lichen family Cladoniaceae in the Neotropics is apparently underestimated. A revision of the family for the Flora of the Guianas resulted in the description of 10 species new to science from Northern South America: Cladonia cayennensis; Cladonia flavocrispata; Cladonia isidiifera; Cladonia maasii; Cladonia mollis; Cladonia persphacelata; Cladonia recta; Cladonia rupununii; Cladonia subsphacelata; Cladonia termitarum.


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