Environmental change and seasonal behavior of mastodons in the Great Lakes region inferred from stable isotope analysis
2014; Cambridge University Press; Volume: 82; Issue: 2 Linguagem: Inglês
10.1016/j.yqres.2014.07.002
ISSN1096-0287
AutoresJessica Z. Metcalfe, Fred J. Longstaffe,
Tópico(s)Forensic Anthropology and Bioarchaeology Studies
ResumoAbstract We investigate seasonal variations in the diet and drinking water of four Great Lakes mastodon ( Mammut americanum ) specimens using stable isotope analysis of serially sampled inner-enamel bioapatite structural carbonate (δ 13 C sc , δ 18 O sc ), and previously published bulk analyses. Isotopic analyses and thin section measurements showed that mastodon tooth enamel extension rates (~ 12–4 mm/yr, decreasing toward the cervix) were lower than those of mammoths or modern elephants. Mastodons had distinct and highly regular seasonal variations in δ 13 C sc and δ 18 O sc , which we interpret in the context of local glacial history and vegetation changes. Seasonal variations in δ 18 O were large but variations in δ 13 C were small, and may have been obscured if coarser sampling methods than our inner-enamel sampling approach were used. Thus, our approach may be particularly useful for understanding relatively small seasonal changes in δ 13 C within C 3 environments. The seasonal patterns, though not entirely conclusive, suggest that the Ontario mastodons did not migrate over very long distances. Rather, the climate and seasonal dietary patterns of mastodons within the region changed over time, from ~ 12,400 to 10,400 14 C yr BP (~ 15,000 – 12,000 cal yr BP). Insights gained using these methods can contribute to a better understanding of megafaunal extinctions and Paleoamerican lifeways.
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