Isotopic insight on paleodiet of extinct Pleistocene megafaunal Xenarthrans from Argentina

BONINI, R; SOIBELZON, L.H.; BOCHERENS, H; COTTE, M; STRACCIA, P; SCIAN, D; PREVOSTI, F.

GONDWANA RESEARCH

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2017 vol. 48 p. 7 - 14

1342-937X

The diet of extinct giant Xenarthrans is a debated topic, especially for ground sloths, for which herbivory,insectivory, and carnivory through scavenging or active hunting have been suggested. In this study, stable carbonisotopic composition of collagen and carbonate fraction ofwell-preserved fossil boneswas used as a tracer of trophiclevel. N200 modern mammal bones of species with a variety of diets were used as a reference dataset. Thegood preservation of the carbonate isotopic composition was checked using different diagenetic indicators andby using fossil carnivorous and herbivorous taxa from the same sites as test-taxa. The results on modern mammalsindicate a clear distinction in the difference between the carbon isotopic composition of carbonate and collagenbetween faunivores (carnivores, insectivores, piscivores, omnivores) and herbivores. Using thisframework, the results on the fossil megafaunal Xenarthrans indicate a herbivorous diet for both Glyptodontidsand are also consistent with a herbivorous diet for giant ground sloths, including Megatherium. The hypothesisthat Megatherium could be a cryptic meat-eater or an insectivore is not supported by the results obtained inthe present study.