The dataset contains long‐term means of δ18Oprecipitation values and temperatures from 84 European sites (GNIP database; IAEA/WMO, 2023), which were used to estimate mean annual (palaeo-) temperatures from the measured oxygen isotope data on horse tooth enamel phosphate. Mean temperatures of the warmest (July/August) and coldest (December/January) periods were considered representative for summer and winter temperatures, respectively, using the peak and trough values of the modelled phosphate data for their calculation.
The greenhouse to icehouse climate transition from the Eocene into the Oligocene is well-documented by sea surface temperature records from the southwest Pacific and Antarctic margin that show evidence of pronounced long-term cooling. However, identification of a driving mechanism depends on a better understanding of whether this cooling was also present in terrestrial settings. Here, we present a semi-continuous terrestrial temperature record spanning from the middle Eocene to the early Oligocene (~41-33 Ma), using bacterial molecular fossils (biomarkers) preserved in a sequence of SE Australian lignites from two locations. We reconstruct terrestrial temperatures and compare them to existing sea-surface temperature records from the Southern Hemisphere from the middle Eocene to Early Oligocene.