RT Journal Article
T1 Paleoenvironment and paleoecology associated with the early phases of the Great American Biotic Interchange based on stable isotope analysis of fossil mammals and new U–Pb ages from the Pampas of Argentina
A1 Sanz Pérez, Danae
A1 Montalvo, Claudia
A1 Mehl, Adriana
A1 Tomassini, Rodrigo
A1 Hernández Fernández, Manuel
A1 Domingo Martínez, Laura
AB The analysis of stable isotopes in fossil mammals is useful for reconstructing paleoenvironmental and paleoecological conditions, but has been rarely applied to the Neogene of South America. In this study, we perform an integrative analysis (including U–Pb zircon dates and mammalian stable isotopes data) for the Late Miocene–Early Pliocene of central Argentina. We provide radioisotopic ages for some classic fossiliferous localities in this region, including an age of 9.7 ± 0.3 Ma for Arroyo Chasicó and 4.5 ± 0.2 Ma for Farola Monte Hermoso, and address the interval covering the Chasicoan (Late Miocene), Huayquerian (Late Miocene–Early Pliocene), and Montehermosan (Early Pliocene) stages/ages. In the Chasicoan Stage/Age, taxa with mixed C3–C4 diets are recorded, suggesting the existence of favorable conditions for the C4 photosynthetic pathway before its full expansion. However, taxa represented across most of the Huayquerian Stage/Age show a preference for C3–based diets, which changes in the latest Huayquerian–Montehermosan stages/ages when an increase in the percentage of C4 plants in the diet of notoungulates, rodents, and xenarthrans is recorded, coinciding with the global expansion of C4 plants. For the first time, the dietary behavior of two South American endemic sparassodont metatherians (Lycopsis and Thylacosmilus) has been evaluated from using stable isotope; analysis of these hypercarnivores show differences in δ13C values, suggesting prey partitioning, partly due to the difference in body size. The fossiliferous sites studied, and the new isotopic and chronological information obtained, provide more detailed paleoecological and paleoenvironmental contexts for the Argentine Pampas during the last stages of the isolation of South America and the first pulses of the Great Biotic American Interchange. In addition, the new ages allow to better adjust the arrival of the first Holarctic immigrants in the region.
PB Elsevier
SN 0031-0182
YR 2024
FD 2024
LK https://hdl.handle.net/20.500.14352/91635
UL https://hdl.handle.net/20.500.14352/91635
LA eng
NO Sanz-Pérez, Dánae, et al. «Paleoenvironment and Paleoecology Associated with the Early Phases of the Great American Biotic Interchange Based on Stable Isotope Analysis of Fossil Mammals and New U–Pb Ages from the Pampas of Argentina». Palaeogeography, Palaeoclimatology, Palaeoecology, vol. 634, enero de 2024, p. 111917. https://doi.org/10.1016/j.palaeo.2023.111917.
NO Ministerio de Ciencia e Innovación (España)
NO Universidad Nacional de La Pampa (Argentina)
NO Universidad Nacional del Sur (Argentina)
NO Waitt Foundation
NO Santander Universidades
NO Universidad Complutense de Madrid
DS Docta Complutense
RD 16 dic 2025