Four-Eyed Fish: Our Ancestor's Shocking Secret Revealed

• Ancient myllokunmingids, ancestors of humans and all vertebrates, had four eyes, a new study in Nature reveals.
• Fossils from China's Chengjiang Biota show these inch-long fish had two large side eyes and two smaller top eyes.
• Scientists believe four eyes were the ancestral condition for vertebrates, evolving for survival during the Cambrian Explosion.
• The two smaller upper eyes are thought to have evolved into the pineal gland in our brains today.
• This discovery changes our understanding of vertebrate evolution, showing early visual sophistication.