Researchers report evidence that the flexible diet of mammoth-like gomphotheres may have enabled adaptation to resource availability and survival in various climates in Chile. Paleontologists infer extinct animals' diets by examining tooth fossils for pits or scratches consistent with particular feeding patterns. However, relying on dental evidence alone could obscure changes in an individual's feeding behavior over its lifetime. Erwin González-Guarda and colleagues used three proxies for diet in examining tooth fossils from gomphotheres: dental microwear, stable isotope analysis, and microfossils of plants preserved in dental tartar. The authors applied the techniques to gomphothere molars from 30 sites in Chile with ages ranging from 30,000 to 12,000 years ago, encompassing the end of the last glacial period. Both early-life and late-life dental evidence supported a diet dominated by tree browsing, with some herb grazing. The findings support a hypothesis that the gomphotheres' diet was not limited to species-specific diversity, but was flexible according to resource availability. The findings also expand the gomphothere's possible habitat to include closed-canopy forests. According to the authors, the results, including isotopic evidence of latitudinal climate gradients in Chile, suggest that further paleontological study in Chile may yield insight into ecosystem dynamics in both glacial and interglacial periods.
###
Article #18-04642: "Multiproxy evidence for leaf-browsing and closed habitats in extinct proboscideans (Mammalia, Proboscidea) from Central Chile," by Erwin González-Guarda, et al .
MEDIA CONTACT: Erwin González-Guarda, Institut Català de Paleoecologia Humana i Evolucio Social, Tarragona, SPAIN; e-mail: erwingonzalezguarda@gmail.com
Proceedings of the National Academy of Sciences