Scientists Find Fossilized Brains From 500-Million-Year-Old Arthropods

During Earth’s Cambrian period 500 million years ago, the seas teemed with weird and fabulous critters. One of them, the radiodont, had a predatory appendage, toothy circular mouth and a segmented body with swimming legs. It's an ancient relative of today’s arthropods, which include insects and spiders. In a new study, researchers report several hundred radiodont fossils with exquisitely preserved brains and nerves. The finding sheds light on how arthropods evolved their segmented body plans.