3.1 Clumped isotope analyses on Arctica islandica
\begin{equation} \Delta_{47}\left(I-CDES\right)=0.0280\pm 0.0042*\frac{10^{6}}{T^{2}}+0.304\pm 0.0524\ (T\ in\ K,\ \pm 1\sigma;\sigma_{\text{res}}=0.047\%0)\nonumber \\ \end{equation}
A regression through all aragonitic mollusk data (including data from Caldarescu et al., 2021) is indistinguishable from the unified clumped isotope calibration (Anderson et al., 2021):
\begin{equation} \Delta_{47}\left(I-CDES\right)=0.0449\pm 0.0024*\frac{10^{6}}{T^{2}}+0.089\pm 0.0291\ (T\ in\ K,\ \pm 1\sigma;\sigma_{\text{res}}=0.043\%0)\nonumber \\ \end{equation}