Climatic warming played a role in the mass extinction events during the Permian period. By studying well-preserved brachiopod shells from central China, researchers reconstructed a high-resolution temperature record. They found that sea surface temperatures decreased during the middle Capitanian, then gradually increased until just before the Permian-Triassic boundary. These warming events coincided with volcanic activity, suggesting a link between the two. Comparing different records, they found discrepancies in the timing of warming events relative to extinction events. This study confirms that brachiopod shells are valuable for understanding past ocean conditions and their relationship to biological crises.