Paleoenvironmental proxies in echinoid spines ( Eucidaris galapagensis , Döderlein 1887) along a natural water temperature gradient

The use of paleoenvironmental proxies such as oxygen isotopes in echinoderm skeletons has been a matter of controversial debate. Many previous studies showed a variety of environmental as well as biological processes causing deviations from equilibrium incorporation of geochemical proxies during the formation of echinoderm skeletons. However, given the global distribution of echinoids, their fast spine growth and their occurrence throughout the entire Phanerozoic, species-specific calibrations of geochemical proxies in echinoid spines can disclose a valuable bio-archive for reconstructing ancient environmental conditions throughout Earth's history if samples are adequately preserved in the sedimentary record.