Dataset for Ecological Stability Across the K-Pg Mass Extinction: A Comparative Analysis of Marine Ecosystem Function and Community Structure

This study is a compilation-based analysis focused on marine ecosystems experienced by the Cretaceous–Paleogene (K–Pg) mass extinction, using productivity-related bulk geochemical proxies TOC and CaCO3. Figure 2 presents trends derived from Supplementary Material (SM) Table S1a. To further assess molecular-level changes, we compiled data for two molecular proxies: the sterane/hopane ratio (S/(S+H)) and the C28/C29 sterane ratio. These proxies, extracted from the same marine ecosystems that experienced the K-Pg mass extinction, are shown in Figure 3, based on data from SM Table S1b. To extend the scope of these molecular proxies, we examined their patterns across other Paleozoic mass extinction events. The resulting trends are presented in Figure 4, also constructed using SM Table S1b. Finally, Figure 5 shows a 1:1 correlation plot based on pre- and post-extinction average values of both molecular proxies (S/(S+H) and C28/C29 sterane ratios) across multiple events; this figure is also based on data compiled in SM Table S1b.