The evolution of the brain and nervous system in animals has been wound back more than 400 million years, thanks to the examination of fossil remains of ancient lungfish providing a missing link in the emergence of land-living, four-legged animals on Earth.
Five hundred million years ago, jaws didn’t exist. The first vertebrates on Earth were in fact wormlike-fish, the 518 million-year-old Metaspriggina walcotti