Ancient Sumerians developed astounding advances in writing, mathematics, medicine, astronomy and more. They credited these achievements to the Anunnaki—giant, winged gods, who are only found in ancient texts. Could these gods be more than legend?Ancient Sumerians developed astounding advances in writing, mathematics, medicine, astronomy and more. They credited these achievements to the Anunnaki—giant, winged gods, who are only found in ancient texts. Could these gods be more than legend?