Reseña paleobiogeográfica de los Xenarthra (Mammalia) del Pleistoceno tardío de la región Mesopotámica (Argentina).

CARLINI A.A., A.E. ZURITA, A. MIÑO BOILINI

INSUGEO

INSUGEO

Año: 2008 vol. 17 p. 259 - 270

1514-4836

Abstract: PALAEOBIOGEOGRAPHIC REVIEW OF THE XENARTHRA (MAMMALIA) FROM THE LATE PLEISTOCENE OF THE MESOPOTAMIAN REGION (ARGENTINA).- The palaeontological evidence coming from the late Pleistocene of the Mesopotamian region of Argentina suggest (based mainly in the mammal faunas) that this area is somewhat different to that of the Pampean region and middle-north of Argentina, and shows some palaeofaunistic similitude to that proceeding from the southern Brazil and western Uruguay. In this context, we make a comparative analysis of the Xenarthra palaeofauna of the late Pleistocene of the Argentinean Mesopotamia. The Xenarthra are well represented, with “tropical” and “pampean” taxa. In this palaeobiogeographic context, it is remarkable some probable cases of endemic species, especially among the Cingulata Glyptodontidae Neuryurini and the Tardigrada Scelidotheriinae and Mylodontinae. In addition, two of best represented Xenarthra in the pampean region (that is Megatherium Cuvier and Neosclerocalyptus Paula Couto) are almost absent in the fossil record of the Argentinean Mesopotamia. Finally (and compared with that observed in the Pampean region) the Pleistocene Glyptodontidae are mainly characterized by the genus Panochthus Burmeister and Glyptodon Owen, whose are also common in southern Brazil and western Uruguay. To conclude, it is important to remark that the Xenarthra palaeofauna is an important element to support the biogeographic differentiation of this region during, at least, the late Quaternary. The hypothetical coexistence of two great groups of taxa (“pampeans” and “brasilic”) can be explained by migratory process (mainly retractions and expansions) of the biota stimulated by the frequent cyclic climatic fluctuations occurred in the Pleistocene.