Here Be Monsters

Life on earth began in the oceans.  And it used to be simpler. For the first few billion years, life consisted of microbes that didn’t really swim or hunt; they mostly floated and, if they were lucky, bumped into something they could engulf and digest. But that changed during the Cambrian period. Over a relatively short period of time known as the Cambrian Explosion, organisms started becoming larger and more complex. For the first time they grew limbs and exoskeletons; intestines and eyes. Animals from this period developed strange body plans that look almost alien to the modern eye. It was an unprecedented surge of biodiversity.  But many of the animal groups that emerged during the Cambrian Period died soon after during an extinction event, their bizarre body plans perishing along with them. To paraphrase the evolutionary biologist and paleontologist Stephen Jay Gould, these were “early experiments in life’s history.” Among the survivors of the Cambrian extinction event was metaspriggina, a