High resolution climatic record entombed in fossil hominid dental enamel

Abstract

Global climate has fluctuated drastically since the Late Miocene, causing an overall cooling, drying, fragmentation of rainforests, occurrence of glacial-interglacial cycles, draughts-floods, effecting tropical Africa and Asia. We humans, apes and our extinct ancestors, grouped together in a family called hominidae, have evolved in response to these climatic fluctuations, by continuously adapting to changing ecological conditions. Therefore, like other terrestrial proxies such as tree rings, palaeosols, speleothemes, fluvio-lacustrine sediments, peat deposits, microfossils, magnetic minerals and plant phytoliths, hominid dental enamel is a potential archive for high resolution palaeoclimate studies. Hominid dental enamel grows periodically in a rhythemic manner producing daily increments known as cross striations. Incremental lines of longer duration comprising on an average 7-9 cross striations are termed as Retzius lines.