Half-Billion-Year-Old Brains Preserved in Fool's Gold

A set of incredible fossils from southwest China reveals something amazing: 520 million-year-old brains, some preserved in fool's gold. Researchers led by Nicholas Strausfeld, a neuroscientist at the University of Arizona, first discovered fossilized brains this old in 2012, but only reported on one specimen. Now, Strausfeld and his colleagues have analyzed seven more fossils and discovered bits of brain in each.