Fossils of just about everything have been unearthed, from ancient feathers to entire dinosaur skeletons preserved in opal, but there is one thing nobody thought could survive hundreds of thousands of years—until now.

Brain matter from a Cambrian arthropod that crawled around 500,000 years ago has proven many paleontologists wrong about brain decay being inevitable. Previous research suggests that no matter what it may be protected by, soft neural matter will break down long before fossilization can even start. Minds have suddenly been changed. Alalcomenaeus may have been a tiny creature, but its exoskeleton was tough enough to ward off decomposition.