scholarly journals South American giant short-faced bear (Arctotherium angustidens) diet: evidence from pathology, morphology, stable isotopes, and biomechanics

2014 ◽  
Vol 88 (6) ◽  
pp. 1240-1250 ◽  
Author(s):  
Leopoldo H. Soibelzon ◽  
Gustavo A. Grinspan ◽  
Hervé Bocherens ◽  
Walter G. Acosta ◽  
Washington Jones ◽  
...  
Keyword(s):  
Stable Isotopes ◽  
South America ◽  
Body Mass ◽  
Great Power ◽  
Middle Pleistocene ◽  
South American ◽  
Geometric Morphometric ◽  
Large Size ◽  
Dental Pathology ◽  
Great American Biotic Interchange

Arctotherium angustidensGervais and Ameghino, 1880 (the South American giant short-faced bear) is known for being the earliest (Ensenadan Age, early to middle Pleistocene) and largest (body mass over 1 ton) of five describedArctotheriumspecies endemic to South America. Here we assess the diet of this bear from multiple proxies: morphology, biomechanics, dental pathology, stable isotopes and a previous study using geometric morphometric methodology. Results favor the idea of animal matter consumption, probably from large vertebrates in addition to vegetable matter consumption. Most probably, active hunting was not the unique strategy of this bear for feeding, since its large size and great power may have allowed him to fight for the prey hunted by other Pleistocene carnivores. However, scavenging over mega mammal carcasses was probably another frequent way of feeding. South American short-faced bears adjusted their size and modified their diet through Pleistocene times, probably as a response to the diversification of the carnivore guild (from the few precursory taxa that crossed the Panamanian Isthmus during the Great American Biotic Interchange).

The largest known bear, Arctotherium angustidens, from the early Pleistocene Pampean region of Argentina: with a discussion of size and diet trends in bears

2011 ◽  
Vol 85 (1) ◽  
pp. 69-75 ◽  
Author(s):  
Leopoldo H. Soibelzon ◽  
Blaine W. Schubert
Keyword(s):  
South America ◽  
Early Pleistocene ◽  
Middle Pleistocene ◽  
Buenos Aires Province ◽  
South American ◽  
Pampean Region ◽  
Great American Biotic Interchange ◽  
Epiphyseal Fusion ◽  
Evolutionary Trajectories ◽  
Serious Injuries

The South American giant short-faced bear (Arctotherium angustidens Gervais and Ameghino, 1880) is one of five described Arctotherium species endemic to South America and it is known for being the earliest, largest, and most carnivorous member of the genus. Here we report an extraordinarily large A. angustidens individual exhumed from Ensenadan sediments (early to middle Pleistocene) at Buenos Aires Province, Argentina. Based on overall size, degree of epiphyseal fusion, and pathologies, this bear was an old-aged male that sustained serious injuries during life. Body mass of the bear is estimated and compared to other ursid species based on a series of allometric equations. To our knowledge, this specimen now represents the largest bear ever recorded. In light of this discovery, we discuss the evolution of body size in Arctotherium (from large-to-small) and compare this to bears that exhibited different evolutionary trajectories. We suggest that the larger size and more carnivorous nature of A. angustidens, compared to later members of the genus, may reflect the relative lack of other large carnivores and abundance of herbivores in South America just after the Great American Biotic Interchange.

Middle Pleistocene age of the fossiliferous sedimentary sequence from Tarija, Bolivia

2013 ◽  
Vol 79 (2) ◽  
pp. 268-273 ◽  
Author(s):  
Bruce J. MacFadden ◽  
Peter K. Zeitler ◽  
Federico Anaya ◽  
John M. Cottle
Keyword(s):  
South America ◽  
New Age ◽  
Middle Pleistocene ◽  
South American ◽  
Sedimentary Sequence ◽  
The Past ◽  
Reference Sections ◽  
Great American Biotic Interchange ◽  
New Interpretation ◽  
Land Mammal

AbstractThe highly fossiliferous sediments of the Tolomosa Formation from Tarija, southern Bolivia, represent one of the most important localities in South America that documents the Great American Biotic Interchange. Over the past several decades, chronostratigraphic studies have indicated a middle Pleistocene age for the Tolomosa Formation from ~ 1.1 to 0.7 Ma. This interval correlates to the Ensenadan South American Land Mammal Age as it is characterized from classic localities in Argentina. Recently, however, a new interpretation based on AMS 14C ages indicates that the fossiliferous sediments from Tarija are latest Pleistocene, i.e., < 44 ka, and thus of Lujanian age. Here we report a new age of 0.76 ± 0.03 Ma (2σ) based on 11 U–Th/Pb and U–Th/He individual determinations from the Tolomosa Formation. This is indistinguishable from the age published from the same ash in 1983, and was originally used to calibrate the magnetostratigraphic section at Tarija. The new age confirms that the age of the Tolomosa Formation is middle Pleistocene, and not latest Pleistocene. The age of the Tarija Fauna has significant implications with regard to the stage of evolution biochronology for Pleistocene fossil mammals in South America, and in particular, the classic and important reference sections in Argentina.

scholarly journals Disproportionate extinction of South American mammals drove the asymmetry of the Great American Biotic Interchange

2020 ◽  
Vol 117 (42) ◽  
pp. 26281-26287 ◽  
Author(s):  
Juan D. Carrillo ◽  
Søren Faurby ◽  
Daniele Silvestro ◽  
Alexander Zizka ◽  
Carlos Jaramillo ◽  
...  
Keyword(s):  
South America ◽  
North American ◽  
Biotic Interactions ◽  
South American ◽  
Dispersal Rate ◽  
Great American Biotic Interchange ◽  
Drastic Increase ◽  
The Asymmetry ◽  
North And South America ◽  
North And South

The interchange between the previously disconnected faunas of North and South America was a massive experiment in biological invasion. A major gap in our understanding of this invasion is why there was a drastic increase in the proportion of mammals of North American origin found in South America. Four nonmutually exclusive mechanisms may explain this asymmetry: 1) Higher dispersal rate of North American mammals toward the south, 2) higher origination of North American immigrants in South America, 3) higher extinction of mammals with South American origin, and 4) similar dispersal rate but a larger pool of native taxa in North versus South America. We test among these mechanisms by analyzing ∼20,000 fossil occurrences with Bayesian methods to infer dispersal and diversification rates and taxonomic selectivity of immigrants. We find no differences in the dispersal and origination rates of immigrants. In contrast, native South American mammals show higher extinction. We also find that two clades with North American origin (Carnivora and Artiodactyla) had significantly more immigrants in South America than other clades. Altogether, the asymmetry of the interchange was not due to higher origination of immigrants in South America as previously suggested, but resulted from higher extinction of native taxa in southern South America. These results from one of the greatest biological invasions highlight how biogeographic processes and biotic interactions can shape continental diversity.

A new and most complete pampathere (Mammalia, Xenarthra, Cingulata) from the Quaternary of Bahia, Brazil

Zootaxa ◽  
2019 ◽  
Vol 4661 (3) ◽  
pp. 401-444 ◽  
Author(s):  
JORGE FELIPE MOURA ◽  
FLÁVIO GÓIS ◽  
FERNANDO CARLOS GALLIARI ◽  
MARCELO ADORNA FERNANDES
Keyword(s):  
New Species ◽  
North America ◽  
South America ◽  
Axial Length ◽  
Vertebral Column ◽  
Middle Miocene ◽  
The Other ◽  
South American ◽  
Great American Biotic Interchange ◽  
A New Species

Pampatheriidae is a group of South American native cingulates recorded from the Middle Miocene to the Early Holocene. These animals arrived in North America during the Great American Biotic Interchange. During the Quaternary, at least three genera existed: Tonnicinctus Góis, González Ruiz, Scillato-Yané and Soibelzon, Pampatherium Gervais and Ameghino, and Holmesina Simpson. They are differentiated mainly by craniodental and osteodermal characters. In this paper, we describe a new species of Holmesina from Bahia state, Brazil. Two well-preserved specimens possessing osteoderms associated with their skeletons enabled us to determine the genus and species more reliably. Holmesina cryptae sp. nov. differs from the other Quaternary pampatheres by having the simplest ornamental pattern of osteoderms, sharing characteristics between Pampatherium and Holmesina osteoderms and the most robust skull among the Holmesina species, however preserving the main synapomorphies of the genus. Moreover, the integrity of the remains of H. cryptae sp. nov. enabled us to describe elements of the hyoid apparatus, the clavicle, the entire vertebral column and the pelvis. It was also possible to measure its total axial length (2.2 m) more reliably, which is smaller than previously estimated for other pampatheres. Holmesina cryptae sp. nov. constitutes the sixth species of the genus, and it is the fourth in South America. 

scholarly journals New radiometric 40Ar–39Ar dates and faunistic analyses refine evolutionary dynamics of Neogene vertebrate assemblages in southern South America

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Francisco J. Prevosti ◽  
Cristo O. Romano ◽  
Analía M. Forasiepi ◽  
Sidney Hemming ◽  
Ricardo Bonini ◽  
...  
Keyword(s):  
South America ◽  
Evolutionary Dynamics ◽  
Atlantic Coast ◽  
Buenos Aires Province ◽  
South American ◽  
Important Place ◽  
Faunal Turnover ◽  
Great American Biotic Interchange ◽  
Late Neogene ◽  
Main Basis

AbstractThe vertebrate fossil record of the Pampean Region of Argentina occupies an important place in South American vertebrate paleontology. An abundance of localities has long been the main basis for constructing the chronostratigraphical/geochronological scale for the late Neogene–Quaternary of South America, as well as for understanding major patterns of vertebrate evolution, including the Great American Biotic Interchange. However, few independently-derived dates are available for constraining this record. In this contribution, we present new 40Ar/39Ar dates on escorias (likely the product of meteoric impacts) from the Argentinean Atlantic coast and statistically-based biochronological analyses that help to calibrate Late Miocene–Pliocene Pampean faunal successions. For the type areas of the Montehermosan and Chapadmalalan Ages/Stages, our results delimit their age ranges to 4.7–3.7 Ma and ca. 3.74–3.04 Ma, respectively. Additionally, from Buenos Aires Province, dates of 5.17 Ma and 4.33 Ma were recovered for “Huayquerian” and Montehermosan faunas. This information helps to better calibrate important first appearances of allochthonous taxa in South America, including one of the oldest records for procyonids (7.24–5.95 Ma), cricetids (6.95–5.46 Ma), and tayassuids (> 3.74 Ma, oldest high-confidence record). These results also constrain to ca. 3 Ma the last appearances of the autochthonous sparassodonts, as well as terror birds of large/middle body size in South America. South American faunal turnover during the late Neogene, including Late Pliocene extinctions, is interpreted as a consequence of knock-on effects from global climatic changes and initiation of the icehouse climate regime.

scholarly journals Diversity and disparity of sparassodonts (Metatheria) reveal non-analogue nature of ancient South American mammalian carnivore guilds

2018 ◽  
Vol 285 (1870) ◽  
pp. 20172012 ◽  
Author(s):  
Darin A. Croft ◽  
Russell K. Engelman ◽  
Tatiana Dolgushina ◽  
Gina Wesley
Keyword(s):  
South America ◽  
Body Mass ◽  
Morphological Diversity ◽  
South American ◽  
Guild Structure ◽  
Historical Contingency ◽  
Santa Cruz ◽  
Growing Body ◽  
Terrestrial Carnivore ◽  
Do So

This study investigates whether terrestrial mammalian carnivore guilds of ancient South America, which developed in relative isolation, were similar to those of other continents. We do so through analyses of clade diversification, ecomorphology and guild structure in the Sparassodonta, metatherians that were the predominant mammalian carnivores of pre-Pleistocene South America. Body mass and 16 characters of the dentition are used to quantify morphological diversity (disparity) in sparassodonts and to compare them to extant marsupial and placental carnivores and extinct North American carnivoramorphans. We also compare trophic diversity of the Early Miocene terrestrial carnivore guild of Santa Cruz, Argentina to that of 14 modern and fossil guilds from other continents. We find that sparassodonts had comparatively low ecomorphological disparity throughout their history and that South American carnivore palaeoguilds, as represented by that of Santa Cruz, Argentina, were unlike modern or fossil carnivore guilds of other continents in their lack of mesocarnivores and hypocarnivores. Our results add to a growing body of evidence highlighting non-analogue aspects of extinct South American mammals and illustrate the dramatic effects that historical contingency can have on the evolution of mammalian palaeocommunities.

scholarly journals Multiproxy evidence for leaf-browsing and closed habitats in extinct proboscideans (Mammalia, Proboscidea) from Central Chile

2018 ◽  
Vol 115 (37) ◽  
pp. 9258-9263 ◽  
Author(s):  
Erwin González-Guarda ◽  
Alia Petermann-Pichincura ◽  
Carlos Tornero ◽  
Laura Domingo ◽  
Jordi Agustí ◽  
...  
Keyword(s):  
South America ◽  
Late Pleistocene ◽  
Feeding Habits ◽  
South American ◽  
Dental Microwear ◽  
Central Chile ◽  
Great American Biotic Interchange ◽  
History Of ◽  
The Individual

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.

scholarly journals First steps towards assessing the evolutionary history and phylogeography of a widely distributed Neotropical grassland bird (Motacillidae: Anthus correndera)

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5886 ◽  
Author(s):  
Heraldo V. Norambuena ◽  
Paul Van Els ◽  
Carlos P. Muñoz-Ramírez ◽  
Pedro F. Victoriano
Keyword(s):  
South America ◽  
Population History ◽  
Middle Pleistocene ◽  
Phylogeographic Structure ◽  
General View ◽  
South American ◽  
Distribution Models ◽  
Grassland Bird ◽  
Southern South America ◽  
History Of

Grasslands in southern South America are extensive ecosystems which harbor a unique biodiversity; however, studies on the evolution of their taxa are scarce. Here we studied the phylogeography and population history of the Correndera Pipit (Anthus correndera), a grassland specialist bird with a large breeding distribution in southern South America, with the goals of investigating its phylogeographic history and relate it to the historical development of South American grasslands. The mitochondrial NADH dehydrogenase subunit II gene (ND2) was sequenced in 66 individuals from 19 localities and the intron 9 of the sex-linked gene for aconitase (ACOI9) was sequenced from a subset of those individuals, including all five subspecies of A. correndera, as well as the closely related A. antarcticus. Phylogenetic analysis revealed two distinct lineages within the complex: the first (A) corresponding to Andean subspecies A. c. calcaratus and A. c. catamarcae and the second (B) including birds traditionally assigned to A. c. correndera, A. c. chilensis, A. c. grayi and some individuals of A. c. catamarcae. A. antarcticus is nested within this second lineage. These results were also supported by evidence of niche divergence for variables associated with precipitation. The oldest split between clade A and B was estimated at c. 0.37 Mya, during the middle Pleistocene. Species distribution models for the present and the Last Glacial Maximum (LGM) suggest that grassland areas in southern South America remained relatively stable, in contrast to the general view of a reduction in grassland cover in South America since the LGM. Recent divergences and low phylogeographic structure (for lowland vs. highland geographic groups, intra-population genetic variance was greater than inter-groups; e.g., for ACOI9: 95.47% and ND2: 51.51% respectively), suggest widespread gene flow between lowland populations.

scholarly journals Pleistocene Mammals from Pampean Region (Argentina). Biostratigraphic, Biogeographic, and Environmental Implications

Quaternary ◽  
2021 ◽  
Vol 4 (2) ◽  
pp. 15
Author(s):  
José Luis Prado ◽  
María Teresa Alberdi ◽  
Jonathan Bellinzoni
Keyword(s):  
South America ◽  
The State ◽  
Historical Study ◽  
South American ◽  
Environmental Implications ◽  
Sedimentary Sequences ◽  
Pampean Region ◽  
Mammalian Faunas ◽  
Pleistocene Mammals ◽  
Fossil Records

The Pampean Region contains sedimentary sequences with abundant mammal fossil records, which constitute the chronological outline of the Plio–Pleistocene of South America. These classic localities have been used for more than a century to correlate with other South American regions. Throughout this time, a series of misinterpretations have appeared. To understand the stratigraphic significance of these localities and the geochronological situation of each unit referring to the Pleistocene, a critical historical study of the antecedents was carried out, evaluating the state of each unit. The biostratigraphic studies of the Pampean Region’s mammalian faunas improved the understanding of biogeographic changes taking into account the environmental fluctuations of the Pleistocene.

scholarly journals An Overview of Equine Influenza in South America

Viruses ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 888
Author(s):  
Cecilia Olguin-Perglione ◽  
María Edith Barrandeguy
Keyword(s):  
South America ◽  
Disease Surveillance ◽  
Economic Losses ◽  
South American ◽  
Respiratory Pathogens ◽  
Equine Influenza Virus ◽  
Equine Influenza ◽  
Vaccine Manufacturer ◽  
Gene Level ◽  
Control Procedures

Equine influenza virus (EIV) is one of the most important respiratory pathogens of horses as outbreaks of the disease lead to significant economic losses worldwide. In this review, we summarize the information available on equine influenza (EI) in South America. In the region, the major events of EI occurred almost in the same period in the different countries, and the EIV isolated showed high genetic identity at the hemagglutinin gene level. It is highly likely that the continuous movement of horses, some of them subclinically infected, among South American countries, facilitated the spread of the virus. Although EI vaccination is mandatory for mobile or congregates equine populations in the region, EI outbreaks continuously threaten the equine industry. Vaccine breakdown could be related to the fact that many of the commercial vaccines available in the region contain out-of-date EIV strains, and some of them even lack reliable information about immunogenicity and efficacy. This review highlights the importance of disease surveillance and reinforces the need to harmonize quarantine and biosecurity protocols, and encourage vaccine manufacturer companies to carry out quality control procedures and update the EIV strains in their products.

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