Ancient fish with human-like hearing stuns scientists

Long ago, some saltwater fish adapted to freshwater — and in doing so, developed an extraordinary sense of hearing rivaling our own. By examining a 67-million-year-old fossil, researchers from UC Berkeley discovered that these “otophysan” fish didn’t evolve their sensitive Weberian ear system in rivers, as long thought, but rather began developing it in the ocean before migrating inland. This new timeline suggests two separate invasions of freshwater, explaining why so many freshwater species exist today.