Global isotopic proxy records for Ordovician temperature reconstruction

Xaioli Ma , Yiying Deng, Linna Zhang, Terry Isson, Isabel P. Montañez, Junxuan Fan

The Ordovician represents a critical interval in the Phanerozoic, marked by two profound biological events: the Great Ordovician Biodiversification Event (GOBE), with an unprecedented tenfold increase in marine species diversity, which was abruptly terminated by the Late Ordovician Mass Extinction (LOME), one of the most severe extinction events in Earth's history, wiping out approximately 85% of marine species. Paleotemperature reconstructions are crucial for understanding the Ordovician climate change. Here, we develop a transparent multi-criteria quality-control framework integrating stratigraphic, petrographic, sedimentological, and geochemical constraints to evaluate the preservation of individual isotopic proxy values. Applying this framework, we construct OrdoTemp that presents 5,223 high-quality isotopic proxy data, rigorously screened from 15,367 measurements. This dataset contains oxygen isotope (δ18O) data from carbonate bulk rock, brachiopod, and conodont fossils (98.5%), as well as carbonate clumped isotope (Δ47) data (1.5%). This dataset can contribute to investigations of Ordovician climate change at regional or global scales, helping to understand Ordovician climate system change against the background of GOBE and LOME. The dataset is freely available at https://doi.org/10.5061/dryad.2jm63xt6h (Ma et al., 2026).