High Resolution Climatic Record Entombed in Fossil Hominid Dental Enamel

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.