Fossils in the Smithsonian’s National Museum of Natural History research collection in its Department of Paleobiology.
Before this study, a reliable temperature curve for the Phanerozoic did not yet exist. This is largely due to the fragmentary nature of the fossil record. Fossil specimens offer some clues about ancient temperatures, but these are only isolated snapshots of one region at a single time. This makes it difficult to decipher what ancient temperatures looked like on a global scale.
To create an accurate curve, the research team used data assimilation. Meteorologists use data assimilation to combine observations of various factors like temperature, humidity and wind speed with weather models to create more accurate forecasts. In a similar vein, the team reconstructed climatic snapshots of the world at various points across the Phanerozoic by integrating data related to ancient ocean temperatures from different parts of the planet with computer simulations of past climates.