Late Pleistocene mammals from northeastern Brazil caves: Taxonomy, radiocarbon dating, isotopic paleoecology (δ13C), and paleoenvironment reconstruction (δ13C, δ18O)

Abstract

In this paper, we described fossils from six mammal taxa (Coendou magnus Cuvier, 1823; Nothrotherium maquinense (Lund, 1839); Tamandua tetradactyla (Linnaeus, 1758); Leopardus wiedii (Schinz, 1821); Didelphis sp.; and Dicotyles tajacu (Linnaeus, 1758)) found in Toca da Barriguda cave (Campo Formoso, Bahia, Brazil). To better understand the isotopic paleoecology of these taxa, AMS radiocarbon dating and carbon and oxygen isotopic analyses were performed. The radiocarbon ages indicate the occurrence of Condou magnus at 33,171–33,765 Cal yr BP, Tamandua tetradactyla at 43,944–44,496 Cal yr BP, Leopardus wiedii at 45,475–46,157 Cal yr BP, and Didelphis sp. at ∼50,227 cal yr BP. Of these taxa, five were carnivorous/omnivorous, only Coendou magnus was herbivorous and lived in low-density forest and arboreal savanna habitats (δ13C = −12.8‰ to −8.4‰; piC3 = 80–90%) during the late Pleistocene. An increase in a dry climate in the region between 50 cal kyr BP (δ18O = 27.1‰) and 27 cal kyr BP (δ18O = 34.0‰) was suggested based on the oxygen isotopic values found in the mammalian bone fossils, which presents similarity and good correlation with the oxygen isotopic values recorded in stalagmites from two caves in Brazil.