Bioluminescence evolved 540 million years ago

An ancient group of glowing corals pushes back the origin of bioluminescence in animals to more than half a billion years ago. Tiny crustaceans that lived around 270 million years ago were previously thought to be the earliest glowing animals. Genetic analysis and computer modelling revealed that octocorals probably evolved the ability to make light much earlier, around the time when the first animals developed eyes.