scholarly journals Fossil horses from the Late Pleistocene of Tapalqué Creek (Buenos Aires Province, Argentina)

2019 ◽  
Vol 294 (3) ◽  
pp. 285-305
Author(s):  
José L. Prado ◽  
Ricardo Bonini ◽  
Cristian Favier-Dubois ◽  
Gustavo N. Gómez ◽  
Pamela Steffan ◽  
...  
Keyword(s):  
South America ◽  
Buenos Aires ◽  
Buenos Aires Province ◽  
South American ◽  
Fluvial Deposits ◽  
Sedimentary Deposits ◽  
Diagenetic Processes ◽  
Taphonomic Analysis ◽  
Land Mammal ◽  
New Evidence

A comparative study was made with the known record of equids species in South America, identifying the remains as Equus neogeus, Hippidion devillei, and Hippidion principale. These data increase the record of Equidae in South America and provide new evidence about the chronological and geographical distribution. The sedimentary deposits of the Lujan Formation outcropping at Tapalqué creek (4 to 120 ky) were accumulated through fluvial processes. This Formation comprises a rich vertebrate fauna corresponding to the Lujanian South American Land Mammal Age, which includes numerous and diverse vertebrate remains. The taphonomic analysis indicates that the faunistic assemblage was formed and was subject to diagenetic processes without distinction of its action in the fossiliferous levels, that can be recognized as fluvial deposits.

Chronostratigraphy and “Land-Mammal Ages” in the Cenozoic of southern South America: principles, practices, and the “Uquian” problem

1995 ◽  
Vol 69 (1) ◽  
pp. 135-159 ◽  
Author(s):  
Alberto L. Cione ◽  
Eduardo P. Tonni
Keyword(s):  
South America ◽  
Buenos Aires ◽  
New South ◽  
Lower Boundary ◽  
Buenos Aires Province ◽  
South American ◽  
Southern South America ◽  
Matuyama Chron ◽  
Study Case ◽  
Land Mammal

The concept of “land-mammal age” as developed in South America is examined. The “Uquian Land-mammal age” is used as a study case. “Land-mammal age” parataxonomy is here considered methodologically but not conceptually different from chronostratigraphic taxonomy. “Land-mammal ages” in South America are based on stages. However, we consider that accurate biostratigraphic studies must be done in South America for establishing the biostratigraphy and precise boundary stratotypes of most stages-ages. The Uquia outcrops are here considered inadequate as a stratotype. A new South American continental stage-age is proposed. This stage is based on a biostratigraphic scheme. The stratotypes of the stage and biozones are located in the fossiliferous southeastern Buenos Aires Province marine cliffs. The lower boundary stratotype is proposed. The stage-age is probably correlated with the Gauss Chron and the lower Matuyama Chron. Additionally, some major units of Ameghino are validated and a different timing for the arrival of North American mammals to southern South America is presented.

DIFFUSE TERMITINAE NESTS SHED LIGHT ON THE AFFINITIES OF LAETOLICHNUS KWEKAI (KRAUSICHNIDAE)

Palaios ◽  
2021 ◽  
Vol 36 (3) ◽  
pp. 122-127
Author(s):  
LILIANA F. CANTIL ◽  
JORGE F. GENISE ◽  
JUAN L. FARINA ◽  
SEBASTIÁN LUPO ◽  
DARÍO PORRINI ◽  
...  
Keyword(s):  
Buenos Aires ◽  
Complex Structure ◽  
Coastal Dunes ◽  
Field Studies ◽  
Buenos Aires Province ◽  
South American ◽  
First Time ◽  
New Evidence ◽  
Semiarid Shrublands ◽  
Shed Light

ABSTRACT The insect trace fossil Laetolichnus kwekai, which is composed of a small chamber extending to slender cylinders at each end, was tentatively included in the ichnofamily Krausichnidae as termite nests. New evidence presented here provides information to validate these inferences. A more complex structure formed by interconnected Laetolichnus was recently found in the same Pliocene deposits (Laetoli, Tanzania) as the isolated specimens reported previously. Our study confirms inclusion of Laetolichnus in Krausichnidae and supports the inference that it represents a nest of a social insect. Neoichnological field studies in the coastal dunes of Buenos Aires Province, Argentina, were undertaken to refine further the nature of these affinities. Survey of the dune surface revealed abundant loose fragments of termite nests of a size and shape comparable to that of L. kwekai. The fragile nests constructed by Onkotermes brevicorniger, which are described here in detail for the first time, enable us to interpret the fossil structures. They consist of connected chambers similar to the interconnected Laetolichnus. These were frequently exposed and broken by wind action resulting in loose fragments similar to the isolated Laetolichnus. The Celliforma ichnofacies represented at Laetoli, which contains L. kwekai, indicates arid or semiarid shrublands and woodlands. The distribution of O. brevicorniger also corresponds to arid and semiarid shrublands and dry woodlands of Argentina. Although the African termite producer of L. kwekai and the South American Onkotermes would be phylogenetically unrelated, the analogous structures probably reflect convergent nesting behaviors as an adaptation to similar arid to semiarid environmental conditions.

scholarly journals A new stage in the Upper Cenozoic of Southern South America

1992 ◽  
Vol 6 ◽  
pp. 56-56
Author(s):  
Alberto L. Cione ◽  
Eduardo P. Tonni
Keyword(s):  
South America ◽  
Buenos Aires ◽  
New South ◽  
Lower Boundary ◽  
Geographic Location ◽  
Buenos Aires Province ◽  
South American ◽  
Southern South America ◽  
Matuyama Chron ◽  
Upper Cenozoic

Former workers developed in South America a chronostratigraphic system not essentially different to that of European stage/age system. However, the authors of this paper believe that accurate biostratigraphic studies have to be done in southern South America for establishing the precise boundary stratotypes of most stage/ages. A new South American Upper Cenozoic continental stage/age is recognized. The stratotype is located in the fossiliferous southeastern Buenos Aires Province marine cliffs between Mar del Plata and Miramar. The outcrops in the area are the best continental representation of Plio-Pleistocene times in South America. It is younger than Chapadmalalan and older than Ensenadan and replaces the “Uquian”. We consider that the “Uquian” actually emcopasses Chapadmalalan and Ensenadan times. The Uquía outcrops are here considered inadequate as stratotype especially by the dearth of micromanmals, the relatively poor fossil record and the comparatively inadequate geographic location. The new stage would be correlated with the Gauss Chron and possibly with the lower Matuyama Chron. The lower boundary is tentatively stated. For so doing, a biostratigraphic scheme is proposed. This lower boundary approximately corresponds to the base of the Barranca de los Lobos “Formation” of Kraglievich (1952) and a new (unpublished) unconformity bounded unit (Zárate, 1989). Some taxa that apparently ranges from the base are candidates to define it after a detailed biostratigraphic study.Additionally, a different timing for the arrival of North American mammals to southern South America is given.

scholarly journals The 4300-yr 14C Age of Glyptodonts at Luján River (Mercedes, Buenos Aires, Argentina) and Comments on ‘Did the Megafauna Range to 4300 BP in South America’ by Cione et al.

Radiocarbon ◽  
2001 ◽  
Vol 43 (1) ◽  
pp. 77-81 ◽  
Author(s):  
Eduardo A Rossello ◽  
Bor-ming Jahn ◽  
Tsung-Kwei Liu ◽  
Jorge L Petrocelli
Keyword(s):  
South America ◽  
Buenos Aires ◽  
Buenos Aires Province ◽  
Hunter Gatherers ◽  
14C Age ◽  
Precise Time

The glyptodont (Glyptodontidae Burmeister 1879, in Ameghino 1889), a giant cousin of the armadillo, has long been thought to have disappeared in South America at least 10,000 years ago at the end of the Pleistocene. There are indications that the glyptodont had some interaction with ancient hunter-gatherers peoples (Politis et al. 1987; Politis 1995), but the precise time of its extinction has never been well established. Most recently, a brief mention of 14C dates of 7500 to 6500 BP (Geotimes 1996) for glyptodont remains discovered at La Moderna (Azul Department, Buenos Aires province, Argentina), has aroused excitement because the new younger dates have changed the traditional idea about the survival and extinction of this beast.

scholarly journals Squamata, Scincidae, Mabuya dorsivittata (Cope, 1862): distribution extension in Buenos Aires province, Argentina

Check List ◽  
2011 ◽  
Vol 7 (3) ◽  
pp. 388 ◽  
Author(s):  
Jorge Williams ◽  
Federico Kacoliris
Keyword(s):  
South America ◽  
Buenos Aires ◽  
New Records ◽  
Wide Distribution ◽  
Buenos Aires Province ◽  
Previous Record ◽  
Northern Sector

Mabuya dorsivttata is a lizard with a wide distribution in South America. In Buenos Aires province, Argentina, previous voucher records exist only from its northern sector and from Mar del Plata city. In this work, two new records of M. dorsivittata from Buenos Aires province are presented: (1) Azul city (36°46’50” S, 50°51’10” W) and (2) Mar del Tuyú city (37°20’08” S, 59°07’60” W). These new records are located about 175 km from the nearest previous record. 

scholarly journals The first fossil skull of an anteater (Vermilingua, Myrmecophagidae) from northern South America, a taxonomic reassessment of Neotamandua and a discussion of the myrmecophagid diversification

2019 ◽  
Author(s):  
Kevin Jiménez-Lara ◽  
Jhon González
Keyword(s):  
South America ◽  
Middle Miocene ◽  
Taxonomic Status ◽  
South American ◽  
Ecological Constraints ◽  
History Of ◽  
Northern South America ◽  
New Evidence ◽  
History Of The South ◽  
Species Inquirendae

AbstractThe evolutionary history of the South American anteaters, Vermilingua, is incompletely known as consequence of the fragmentary and geographically biased nature of the fossil record of this group. Neotamandua borealis is the only recorded extinct species from northern South America, specifically from the Middle Miocene of La Venta area, southwestern Colombia. A new genus and species of myrmecophagid for La Venta, Gen. et sp. nov., is here described based on a new partial skull. Additionally, given that the co-occurrent species of Gen. et sp. nov., N. borealis, was originally referred to as Neotamandua, the taxonomic status of this genus is revised. The morphological and taxonomic analyses of these taxa indicate that Gen. et sp. nov. may be related to Tamandua and that the justification of the generic assignments of the species referred to as Neotamandua is weak or insufficient. Two species previously referred to as Neotamandua (N. magna and N.? australis) were designated as species inquirendae and new diagnostic information for the redefined genus and its type species, N. conspicua, is provided. Together, these results suggest that the diversification of Myrmecophagidae was taxonomically and biogeographically more complex than what has been proposed so far. Considering the new evidence, it is proposed a synthetic model on the diversification of these xenartrans during the late Cenozoic based on the probable relationships between their intrinsic ecological constraints and some major abiotic changes in the Americas.

scholarly journals Did the Megafauna Range to 4300 BP in South America?

Radiocarbon ◽  
2001 ◽  
Vol 43 (1) ◽  
pp. 69-75 ◽  
Author(s):  
Alberto L Cione ◽  
Aníbal J Figini ◽  
Eduardo P Tonni
Keyword(s):  
South America ◽  
Buenos Aires ◽  
Bone Sample ◽  
Collagen Content ◽  
Buenos Aires Province ◽  
Radiocarbon Dates ◽  
Fossil Remains ◽  
The Poor ◽  
Bone Preservation ◽  
The City

A date of 4300 ± 90 BP for extinct megafauna in Argentina is discussed. The fossil remains come from the Guerrero Member (area) of the Luján Formation near the city of Luján, Buenos Aires Province. The age of the top of the Guerrero Member is constrained by more than 60 radiocarbon dates obtained from the overlying Río Salado Member of Luján Formation, Las Escobas Formation, and Puesto Callejón Viejo Soil, most of them older than 4300 BP. In view of its low collagen content, the 14C measurement of bone sample from Luján should not be accepted uncritically. Because of the poor bone preservation and the possible introduction of “young” contaminants that were not completely eliminated, the 14C date of 4300 ± 90 BP is not reliable. Both biostratigraphic and 14C dating evidence indicates that the date of 4300 BP for the last representative of extinct megafauna in South America is unsupported.

Stratigraphy of the fluvial deposits of the Salado river basin, Buenos Aires Province: Lithology, chronology and paleoclimate

2015 ◽  
Vol 60 ◽  
pp. 129-139 ◽  
Author(s):  
E. Fucks ◽  
M.F. Pisano ◽  
R.A. Huarte ◽  
C.V. Di Lello ◽  
F. Mari ◽  
...  
Keyword(s):  
River Basin ◽  
Buenos Aires ◽  
Buenos Aires Province ◽  
Fluvial Deposits ◽  
Salado River
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