Platysomus parvulus lived at the beginning of the Pennsylvanian subperiod of the Carboniferous period, 310 million years ago, at a time when a group of fish called ray-finned fish were exploring new ways to make a living. The species had a plate of teeth suspended by a cradle of jointed bones that also supported the gills it used to breathe. As it turns out, this ancient fish was the first to evolve this feeding structure called a tongue bite. Until now, the oldest known fish with such a dental arrangement lived about 150 million years later. Tongue-bite apparatus highlights functional innovation in a 310-million-year-old ray-finned fish.