Elemental distribution and speciation in dinosaur teeth and bones to understand fossilization processes

During fossilization, the skeleton undergoes numerous chemical modifications: the mineral fraction, bio-apatite, is modified by the inclusion of exogenous elements. Consequently, fossilized bio-apatites are made up with elements acquired de vivo and elements acquired post-mortem. While the geochemistry of de vivo elements represents powerful tool to make paleo-inferences, elements acquired during the fossilization obliterate these pristine records. Thus, this proposal aims to analyze the elemental distribution of de vivo and principally acquired post-mortem elements using µ-SXRF mapping. Then, coupled XANES and EXAFS of both Sr and Y K-edges, which are respectively proxies for de vivo and post-mortem elements will be performed on contrasted areas to fathom their speciation. Such information will improve our understanding of bio-apatite fossilization and present an integrative methodology to assess the degree of preservation of de vivo elements in bio-apatite in various samples.