Jellyfish undergo an amazing metamorphosis, from tiny polyps growing on the seafloor to swimming medusae with stinging tentacles. This shape-shifting has served them well, shepherding jellyfish through more than 500 million years of mass extinctions on Earth.
“Whatever they’re doing has really worked for them,” said David Gold, an assistant professor of paleobiology in the University of California, Davis, College of Letters and Science.
