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

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approximately corresponds to the base of the Barranca de los Lobos “Formation” of Kraglievich (1952) and a new (unpublished) unconformity bounded unit (Zárate, 1989).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.

1995 ◽  
Vol 69 (1) ◽  
pp. 135-159 ◽  
Author(s):  
Alberto L. Cione ◽  
Eduardo P. Tonni

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.


2019 ◽  
Vol 294 (3) ◽  
pp. 285-305
Author(s):  
José L. Prado ◽  
Ricardo Bonini ◽  
Cristian Favier-Dubois ◽  
Gustavo N. Gómez ◽  
Pamela Steffan ◽  
...  

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.


Check List ◽  
2014 ◽  
Vol 10 (1) ◽  
pp. 187
Author(s):  
Javier Muzón ◽  
Alejandro Del Palacio ◽  
Lía Ramos

Ischnura ultima Ris, 1908 is recorded for the first time from Buenos Aires Province, Argentina, 750 km southeast from the southernmost previous known localities (Córdoba Province). This finding supports a stronger biogeographical relationship between the southern hills of Buenos Aires (surrounded by the Pampas lowlands) and the Monte province. In addition, this record supports the odonate endemic areas scheme previously proposed for Argentina.


2019 ◽  
Vol 93 (06) ◽  
pp. 1088-1104
Author(s):  
María B. Santelli ◽  
Claudia J. del Río

AbstractThe Chilean species traditionally assigned to the genera Chlamys Röding, 1798 or Zygochlamys Ihering, 1907 are now placed in two new endemic South American taxa: Dietotenhosen n. gen. (middle Miocene–early middle Pliocene), to include the southeastern Pacific Ocean species D. hupeanus (Philippi, 1887) n. comb. and D. remondi (Philippi, 1887) n. comb., and Ckaraosippur n. gen. (earliest middle Miocene–Pliocene), for C. calderensis (Möricke, 1896) n. comb. (Chile) and C. camachoi n. sp. (Argentina). Both genera are the youngest survivors of the tribe Chlamydini in southern South America. None of them is related to the circumpolar genus Psychrochlamys Jonkers, 2003, and the previous proposal of the dispersal through the Antarctic Circumpolar Current for the species included herein in Dietotenhosen is rejected.UUID: http://zoobank.org/61b4bb50-321f-4b78-9069-609178ef0817


Radiocarbon ◽  
2001 ◽  
Vol 43 (1) ◽  
pp. 77-81 ◽  
Author(s):  
Eduardo A Rossello ◽  
Bor-ming Jahn ◽  
Tsung-Kwei Liu ◽  
Jorge L Petrocelli

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.


Check List ◽  
2011 ◽  
Vol 7 (3) ◽  
pp. 388 ◽  
Author(s):  
Jorge Williams ◽  
Federico Kacoliris

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. 


Phytotaxa ◽  
2015 ◽  
Vol 208 (4) ◽  
pp. 296
Author(s):  
GÉSSICA A. GOMES-COSTA ◽  
MICHAEL H. NEE ◽  
MARIA REGINA DE V. BARBOSA

During the analysis of European and American herbaria collections for a taxonomic review of the Brazilian species of Gurania, two new South American species were found.  Gurania jeffreyi occurs in Ecuador and Colombia and Gurania calathina is found only in Colombia. Descriptions and illustrations of the new species are presented with comments on affinities and differences between them and related species.


Check List ◽  
2011 ◽  
Vol 7 (6) ◽  
pp. 809 ◽  
Author(s):  
Pier Cacciali ◽  
Daniel Espínola ◽  
Silvia Centrón Viñales ◽  
Irene Gauto Espínola ◽  
Hugo Cabral

Micrurus silviae is a coralsnake with a triadal pattern, and is one of the eight species found in southern South America. In Paraguay there are six taxa recorded: M. altirostris, M. baliocoryphus, M. frontalis, M. pyrrhocryptus, M. corallinus, and M. lemniscatus carvalhoi. Here we present a record of M. silviae, an additional and seventh species for the country. Previously M. silviae was known only from Rio Grande do Sul state, in southern Brazil. The specimen was found in South American Mesopotamian Grasslands ecoregion, with natural grassland in the Department of Itapúa.


Parasite ◽  
2021 ◽  
Vol 28 ◽  
pp. 80
Author(s):  
Paula Carolina Serrano ◽  
María Celina Digiani ◽  
María de los Angeles Gómez-Muñoz ◽  
Juliana Notarnicola ◽  
María del Rosario Robles ◽  
...  

Hassalstrongylus dollfusi (Díaz-Ungría, 1963) Durette-Desset, 1971 was described in a wild house mouse, Mus musculus, from Venezuela and, since then, has never been reported again in the type host or in any other host. In this work, specimens assignable to H. dollfusi were found at 10 localities in Northeast Argentina, in five species of sigmodontine rodents. The nematodes were attributed to H. dollfusi based on diagnostic characters such as: synlophe with 22–31 subequal ridges; in males, hypertrophy of right ray 4 of the male bursa, thickening of the dorsal ray and bases of rays 8, distal tip of the spicules bent and spoon shaped; and, in females, presence of subventral postvulvar alae supported by hypertrophied struts. The new host recorded are: Oligoryzomys fornesi, O. flavescens, O. nigripes, Holochilus chacarius and Akodon azarae. The parasite showed a strong preference for host species of Oligoryzomys, which appear to act as primary hosts. The parasite could be present, parasitizing different species of Oligoryzomys, in a geographic area from the type locality in Venezuela southward to north Corrientes in Argentina. It has not been reported from populations of Oligoryzomys spp. of the Argentinean and Brazilian Atlantic Forest, nor south of 28° S, which may be explained by constraints in the environmental conditions required by the free-living stages of the parasite. This study provides the first identification and redescription of H. dollfusi in southern South America, from autochthonous hosts, six decades after its description.


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