Indeed, Mesozoic evolution spun the three threads of cephalopod history in wildly different directions: ammonoids followed an action adventure, packed with fast-paced speciation and extinction, death and survival in equal measure. Meanwhile, nautiloids puttered along without much obvious change, characters in a contemplative tale. And coleoids, as we’re about to see, displayed one blockbuster success while quietly cooking up another one in the background.
