A LATEST PLEISTOCENE-EARLY HOLOCENE PALAEOFAUNAL ASSOCIATION IN NORTHERN ARGENTINA

ZURITA, A. E.; RODRIGUEZ-BUALÓ, S.; BOGAN, S.; MIÑO-BOILINI, A.R.; ALCARAZ, M. A.; LUTZ, A. I; FRIEDRICH, J

San Juan

Congreso; IV Congreso Latinoamericano de Paleontología de Vertebrados; 2011

One of the most important palaeofaunistic associations from northern Argentina has been recovered from the cliff of the Bermejo River, Formosa province, Argentina (Zurita et al., 2009). All the recorded taxa constitute typical Pleistocene Pampean megafauna, except for the intertropical cingulate Holmesina paulacoutoi (Cartelle and Bohorquez, 1985). This fossiliferous level has approximately six meters and it belongs to the Río Bermejo Formation. The recorded taxa are Xenarthra, Proboscidea, Carnivora, Artiodacyla, Notoungulata, including in total more than 14 genera. A Recent C14 dating taken from material recovered in the middle section of this fossiliferous level indicates an age of 9570±90 BP (LP-2389). If this dating is correct, this site represents the first early Holocene palaeofaunistic association from northern Argentina. Most of the taxa suggest the presence of open palaeoenvironments. Among the remarkable aspects of this paleofaunistic association it could be mentioned that within the Cingulata Glyptodontidae, the only two recorded genus are Glyptodon Owen, 1839 and Neosclerocalyptus Paula Couto, 1957, while it is noteworthy the absence of the others typical Pampean Pleistocene genera, especially Panochthus Burmeister, 1866. In addition, the presence of the intertropical Xenarthra H. paulacoutoi, apparently coeval with the Pampean taxa (including the other pampatheriid species, Pampatherium typum), raises some questions about the ecological tolerance of this taxon. Furthermore, we provide for this association the first latest Pleistocene-early Holocene records of the teleostei cf. Synbranchus marmoratus (Synbranchiformes, Synbranchidae), represented by several well preserved precaudal vertebrae. Previous records of this taxon correspond to the early-late Pleistocene (“Belgranense”) of the Quequén Salado river, Buenos Aires province (Cione and Barla, 1997; Pardiñas et al., 1996). Nowadays, Synbranchus marmoratus has a very wide distribution in South America, which includes the Bermejo river basin.