High levels of damaging ultraviolet-B (UV-B) radiation collapsed forest ecosystems and killed off many species of fish and tetrapods at the end of the Devonian period, 359 million years ago, according to new research from the University of Southampton and the Sedgwick Museum of Earth Sciences. Devonian-period seafloor. Image credit: University of Michigan Museum of Natural History. “Our ozone shield vanished for a short time in this ancient period,...