Corals as climate archives
View inside the collection drawers: 40-million-year-old tropical reef corals from present-day France. Photo: Stefan Krüger - Unusually well-preserved reef corals from the Geological and Palaeontological Collection at Leip-zig University hold a great secret: they allow us to travel far into the past and reconstruct climatic conditions in our latitudes. Researchers from Leipzig University, the Universities of Bremen and Greifswald, and UniLaSalle in Beauvais have now succeeded in doing just this. Using chemical analyses, they were able to model seasonal temperature fluctuations of this period and show for the first time that corals already lived in symbiosis with algae 40 million years ago. Their results, which may also serve to improve current climate forecasts, have been published in the renowned journal Science Advances. In the Middle Eocene, some 40 million years ago, a tropical climate prevailed in our latitudes: it was warm and humid, as evidenced by fossils from Lake Geiseltal near Halle, for example. It was so warm, in fact, that coral reefs extended far to the north - to about the 45th degree of latitude, roughly the level of present-day southern France.
