Tabulate corals across the Frasnian/Famennian boundary: architectural turnover and its possible relation to ancient photosymbiosis

The Frasnian-Famennian biodiversity crisis has traditionally been considered one of the “Big Five” mass extinctions; among deep changes in the biosphere, it almost completely erased shallow-water marine ecosystems like coral-stromatoporoid reefs, which were widespread on the carbonate platforms in the Devonian. The high biodiversity of bioconstructors during the Givetian-Frasnian acme of Palaeozoic reef development contrasts sharply with very...