500 million years of errors: Shells of brachiopods record shadow of arms race in ancient oceans

A study of fossils from the Paleozoic Era, collected across the world, reveals that ancient brachiopods were little bothered by predators. However, the rare predation traces left on brachiopod shells by unknown assailants coupled with a subtle increase in their frequency through time may be the shadows on the wall that show killers were in the room and their numbers increased with time.