[1] UFJF, SBPr, Programa Posgrad, BR-36036900 Juiz De Fora, MG, Brazil
[2] IANIGLA, CONICET, CRICYT, RA-5500 Mendoza, Argentina
[3] Univ Nacl Nordeste, Fac Ciencias Exactas & Nat & Agrimensura, RA-3400 Corrientes, Argentina
[4] Consejo Nacl Invest Cient & Tecn, Ctr Ecol Aplicada Litoral, Area Paleontol, RA-3400 Corrientes, Argentina