Data from: Ontogenetic variability in crystallography and mosaicity of conodont apatite: Implications for microstructure, paleothermometry and geochemistry

<p>X-ray diffraction data from Silurian conodonts belonging to various developmental stages of the species <i>Dapsilodus obliquicostatus </i>demonstrate changes in crystallography and degree of nanocrystallite ordering (mosaicity) in both hyaline and albid crown tissue. The exclusive use of a single species in this study, combined with systematic testing of each element type at multiple locations, provided insight into microstructural and crystallographic differentiation between element position (S_a, S_b-c, M) as well as between juveniles and adults. A relative increase in the unit cell dimensions of the <i>a</i>-axis/<i>c</i>-axis ratio of nanocrystallites during growth was apparent in areas demonstrating single-crystal behavior but no such relationship was seen in dominantly polycrystalline areas. Systematic variations in mosaicity were identified, with mosaicity (as a proxy for disorder) increasing during growth, as well as along elements from tip to base. These results provide potential insight into the integrity of conodont apatite as a recorder of paleoseawater chemistry, as well as demonstrate the need to consider the influence of ontogeny and element position on the use of conodonts in paleothermometry and geochemical investigations.    </p>