Half-Billion-Year-Old Fossils Reveal Our Four-Eyed, Noodle-Like Ancestor from the Cambrian Ocean | #four-eyed ancestor # Cambrian fossils # early vertebrate evolution # half-billion-year-old fossils # myllokunmingids # Chengjiang fossil beds # Haikouichthys ercaicunensis # pineal gland evolution # jawless fish fossils # origins of vertebrate vision