‘Penis Worms’ May Have Been the First Hermits

Consider this evolutionary dilemma, faced by the aquatic and squishy: How do you survive in hostile, predator-filled oceans? Squid rely on speed or camouflage. Snails develop complex shells. Hermit crabs borrow those complex shells when other animals aren’t using them, trading them out for bigger models as they grow. This sheltering strategy was believed to have emerged 180 million years ago in the Jurassic Period, when hermit crabs’ ancestors appeared in oceans, said Martin Smith, a paleontologist at the University of Durham in England. But in a study published Monday…