Last Glacial mammals in South America: a new scenario from the Tarija Basin (Bolivia)

Abstract

The chronology, sedimentary history, and paleoecology of the Tarija Basin (Bolivia), one of the richest Pleistocene mammalian sites in South America, are revised here based on a multidisciplinary study, including stratigraphy, sedimentology, geomorphology, paleontology, isotope geochemistry, and (14)C geochronology. Previous studies have indicated a Middle Pleistocene age for this classic locality. We have been able to obtain a series of (14)C dates encompassing all the fossil-bearing sequences previously studied in the Tarija Basin. The dated layers range in age from about 44,000 to 21,000 radiocarbon years before present (BP), indicating that the Tarija fauna is much younger than previously thought. Glacial advances correlated to marine isotopic stages (MIS) 4 and 2 (ca. 62 and 20 ka BP, respectively) are also documented at the base and at the very top of the Tarija-Padcaya succession, respectively, indicating that the Bolivian Altiplano was not dry but sustained an ice cap during the Last Glacial Maximum. The results of this multidisciplinary study enable us to redefine the chronological limits of the Tarija sequence and of its faunal assemblage and to shift this paleontological, paleoclimatological, and paleoecological framework to the time interval from MIS 4 to MIS 2.

Ñuagapua (Chaco, Bolivia): Evidence for the latest occurrence of megafauna in association with human remains in South America

“…These were recently reattributed to the final part of the Marine Isotope Stage (MIS) 4, to the MIS 3 and to the earlier part of the MIS 2 (Coltorti et al, 2007(Coltorti et al, , 2010b, when humans apparently still had not reached the continent. In Tarija, no artefacts have been found associated with megafauna.…”

A taxonomic and biogeographic review of the fossil tapirs from Bolivia

“…1 in Soibelzon et al 2009) or to the "Ensenadan Land Mammal Age" (Marshall et al 1984;MacFadden 2000), although Marshall et al (1984: 33) mentioned the possibility "that some fossils from this locality are younger". By contrast, radiocarbon dating of organic levels from several different localities suggests a Late Pleistocene age (between 27180 and 39000 14 C BP) for the fossiliferous strata (Coltorti et al 2007 Description.-The lectotype comprises a partial left mandible bearing pm2-pm4 (Figs. 2A, 3A; SOM: table S1).…”

Chronological Distribution of Brazilian Glyptodon SP. Remains: A Direct 14C Date for a Specimen from Iporanga, São Paulo, Brazil

“…Elsewhere in South America, Glyptodon sp. chronology is scarce, imprecise, and often open to dispute (Rossello et al 1999(Rossello et al , 2001Cione et al 2001;Suárez 2003;Jull et al 2004;Coltorti et al 2007;Chávez-Aponte et al 2008;Rincón et al 2008). …”