scholarly journals Distributional patterns of herbivore megamammals during the Late Pleistocene of South America

2013 ◽  
Vol 85 (2) ◽  
pp. 533-546 ◽  
Author(s):  
VALERIA GALLO ◽  
LEONARDO S. AVILLA ◽  
RODRIGO C.L. PEREIRA ◽  
BRUNO A. ABSOLON

The geographic distribution of 27 species of the South American megafauna of herbivore mammals during the Late Pleistocene was analyzed in order to identify their distributional patterns. The distribution of the species was studied using the panbiogeographical method of track analysis. Six generalized tracks (GTs) and two biogeographic nodes were obtained. The GTs did not completely superpose with the areas of open savanna present in Pleistocene, nor with the biotic tracks of some arthropods typical of arid climate, indicating that these animals avoided arid environment. Overall, the GTs coincided with some biogeographic provinces defined on the basis of living taxa, indicating that certain current distributional patterns already existed in Pleistocene. The biogeographic nodes coincided with the borders between the main vegetal formations of the Pleistocene, showing that the type of vegetation had great influence in the distribution of the mammalian megafauna. The node 1 confirmed the existence of contact zones between paleobiogeographic regions near Argentina-Uruguay border. The node 2 connects the Brazilian Intertropical regions.

2016 ◽  
Vol 88 (2) ◽  
pp. 829-845 ◽  
Author(s):  
THAIS M.F. FERREIRA ◽  
ADRIANA ITATI OLIVARES ◽  
LEONARDO KERBER ◽  
RODRIGO P. DUTRA ◽  
LEONARDO S. AVILLA

ABSTRACT Echimyidae (spiny rats, tree rats and the coypu) is the most diverse family of extant South American hystricognath rodents (caviomorphs). Today, they live in tropical forests (Amazonian, coastal and Andean forests), occasionally in more open xeric habitats in the Cerrado and Caatinga of northern South America, and open areas across the southern portion of the continent (Myocastor). The Quaternary fossil record of this family remains poorly studied. Here, we describe the fossil echimyids found in karst deposits from southern Tocantins, northern Brazil. The analyzed specimens are assigned to Thrichomys sp., Makalata cf. didelphoides and Proechimys sp. This is the first time that a fossil of Makalata is reported. The Pleistocene record of echimyids from this area is represented by fragmentary remains, which hinders their determination at specific levels. The data reported here contributes to the understanding of the ancient diversity of rodents of this region, evidenced until now in other groups, such as the artiodactyls, cingulates, carnivores, marsupials, and squamate reptiles.


Zootaxa ◽  
2020 ◽  
Vol 4751 (1) ◽  
pp. 75-104
Author(s):  
MAURICIO M. ROCHA ◽  
ELIANA M. CANCELLO

In this contribution we present updates on the taxonomy and morphology of the South American species of Amitermes. Two new species are described: Amitermes bandeirai, sp. n., from Brazil, and Amitermes lilloi, sp. n., from Argentina. Amitermes nordestinus is a junior synonym of Amitermes aporema. The imago of A. aporema is described for the first time. Detailed comparative gut anatomy of the eight species is presented for the first time. The geographic distribution of Amitermes in South America is expanded and the distribution patterns of some species are discussed. 


Zootaxa ◽  
2021 ◽  
Vol 4964 (3) ◽  
pp. 401-442
Author(s):  
MARYSOL TRUJANO-ORTEGA ◽  
CURTIS J. CALLAGHAN ◽  
ARTURO ARELLANO-COVARRUBIAS ◽  
ARMANDO LUIS-MARTÍNEZ ◽  
OMAR ÁVALOS-HERNÁNDEZ ◽  
...  

We present a synthesis of the existing information on the genus Emesis Fabricius in Mexico concerning biogeographical patterns and taxonomical aspects. Emesis is the most diverse genus of Emesidini with 57 species and subspecies, with Mexico as the northern limit of this Neotropical genus. We analyzed 5434 specimens of the Lepidoptera Collection of the MZFC, UNAM and compared them with specimens from collections of Mexico, Central and South America. Taxonomic determination and corroboration were made by analysis of wing patterns and genitalia. Geographic distribution and phenology were obtained from the database MARIPOSA. We present an updated list of Emesis of Mexico, with 17 species and subspecies. For each species, we provide information on phenology, geographic, altitudinal, and vegetation distributions. We discuss taxonomic and undersampling concerns for some species, as well as spatial and temporal patterns with special reference to vegetation types and biogeographic provinces in Mexico. 


Paleobiology ◽  
1976 ◽  
Vol 2 (3) ◽  
pp. 220-234 ◽  
Author(s):  
S. David Webb

The American interchange of land mammals reached its acme during the late Blancan and early Irvingtonian in North America and during the Chapadmalalan and Uquian in South America. It lasted about two million years and included taxa adapted to diverse habitats. It was preceded in the early Hemphillian in North America and the Huayquerian in South America by the interchange of a few heralding genera. The MacArthur-Wilson faunal equilibrium hypothesis correctly predicts a marked increase in originations, number of genera, and turnover rate for the South American fauna during the peak of the interchange. Subsequent further increases were not so predicted but closely resemble patterns also observed in late Pleistocene land mammals of Europe and North America. The continued increase in South American land mammal genera after the interchange had largely ceased resulted principally from autochthonous evolution of northern immigrant stocks. A marked decrease in South American ungulate genera (from thirteen to three) coincided with the appearance of fourteen northern ungulate genera and therefore appears to be a replacement phenomenon. The area/diversity relationship predicts no important change in generic diversity if a maximum of only nine percent of North America is occupied by the interamerican mingled fauna. At the family level, however, diversity is seriously overestimated due to the nomenclatural artifact of increased relative diversity by filtering.


2013 ◽  
Vol 317 ◽  
pp. 73-79 ◽  
Author(s):  
Mário André Trindade Dantas ◽  
Márcia Cristina Teles Xavier ◽  
Lucas de Melo França ◽  
Mario Alberto Cozzuol ◽  
Adauto de Souza Ribeiro ◽  
...  

Author(s):  
Michael Deininger ◽  
Brittany Marie Ward ◽  
Valdir F. Novello ◽  
Francisco W. Cruz

Here we present an overview of speleothem δ18O records from South America, which mostly are available in the Speleothem Isotopes Synthesis and Analysis (SISAL_v1) database. South American tropical and subtropical δ18O time series are primarily interpreted as being driven by the amount effect and, consequently show the past history of the convection intensity of convergence zones such as the Intertropical Convergence Zone and the South America Monsoon System. We investigate past hydroclimate scenarios in South America related to the South American Monsoon System in three different time scales: Late Pleistocene, Holocene and the last two millennia. The precession driven insolation is the main driver of convective variability over the continent during the last 250 kyrs, including the Holocene period. However a dipole is observed between the west and east portions of the continent. Records located in the central region of Brazil appear to be weakly affected by insolation driven variability and more susceptible to the South Atlantic Convergence Zone. Cold episodic events in Northern Hemisphere increase the activity of the South American Monsoon System on all time scales, in turn increasing rainfall amounts in South America, as was documented during Heinrich events in the late Pleistocene and Bond events in the Holocene, as well as during the Little Ice Age.


1973 ◽  
Vol 3 (2) ◽  
pp. 237-256 ◽  
Author(s):  
Alan L. Bryan

AbstractAfter a summary assessment of certain selected early man sites in various parts of America, the environment of the Venezuelan coastal plain is discussed in order to evaluate the stratigraphy and radiometric dating of the Taima-Taima site, near Coro, Venezuela, where mammals, many now extinct, were killed by people making El Jobo points about 13,000 years ago.Potentially important areas in Peru, Chile and Brazil are mentioned. Certain problems in the models and interpretation of South American paleoclimates are pointed out.The presence of at least four different bifacially flaked stone projectile point traditions in widely separated and environmentally diverse parts of America between 11,000 and 13,000 yr ago suggests that the immediate cultural antecedents of these traditions were essentially independent of one another. From this it is argued that several early American flaked-stone point traditions developed indigenously in America from technological bases which were present in the Old World Middle Paleolithic.


2015 ◽  
Vol 80 (2) ◽  
pp. 376-386 ◽  
Author(s):  
Michael R. Waters ◽  
Thomas Amorosi ◽  
Thomas W. Stafford

Fell's Cave lies near the Magellan Straits of South America's Southern Cone. This was the first site to provide evidence of a late Pleistocene occupation of South America, and it is the site where the Fishtail projectile point type was defined. Previous radiocarbon ages from Fell's Cave on charcoal samples from three hearths in the late Pleistocene artifact-bearing levels yielded dates ranging from ca. 11,000 to 10,100 radiocarbon years before present. New radiocarbon dates on curated charcoal samples from these same hearths yield revised ages of ca. 10,800 to 10,400 radiocarbon years before present. These new dates from Fell's Cave agree well with ages from other South American sites in the Southern Cone with Fishtail points and show that the Fishtail projectile point was made from ca. 10,850 to 10,300 radiocarbon years before present or ca. 12,800 to 12,100 calibrated years before present.


2018 ◽  
Vol 115 (37) ◽  
pp. 9258-9263 ◽  
Author(s):  
Erwin González-Guarda ◽  
Alia Petermann-Pichincura ◽  
Carlos Tornero ◽  
Laura Domingo ◽  
Jordi Agustí ◽  
...  

Proboscideans are so-called ecosystem engineers and are considered key players in hypotheses about Late Pleistocene megafaunal extinctions. However, knowledge about the autoecology and chronology of the proboscideans in South America is still open to debate and raises controversial views. Here, we used a range of multiproxy approaches and new radiocarbon datings to study the autoecology of Chilean gomphotheres, the only group of proboscideans to reach South America during the Great American Biotic Interchange (∼3.1 to 2.7 million years before present). As part of this study, we analyzed stable isotopes, dental microwear, and dental calculus microfossils on gomphothere molars from 30 Late Pleistocene sites (31° to 42°S). These proxies provided different scales of temporal resolution, which were then combined to assess the dietary and habitat patterns of these proboscideans. The multiproxy study suggests that most foraging took place in relatively closed environments. In Central Chile, there is a positive correlation between lower δ13C values and an increasing consumption of arboreal/scrub elements. Analyses of dental microwear and calculus microfossils have verified these leaf-browsing feeding habits. From a comparative perspective, the dietary pattern of South American gomphotheres appears to be constrained more by resource availability than by the potential dietary range of the individual taxa. This multiproxy study is aimed at increasing knowledge of the life history of gomphotheres and thus follows an issue considered one of the greatest challenges for paleontology in South America, recently pointed out by the need to thoroughly understand the role of ecological engineers before making predictions about the consequences of ecosystem defaunation.


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