Most terrestrial plants and animals left the ocean a single time in their evolutionary history to live ashore. But crabs have seemingly scuttled out of the sea more ... tree of life has been ...

These unusual critters found nowhere else in the world underscore the importance of efforts to understand life ... sea creatures that had never been seen before, including a kind of hairy ...

But few animals appreciate the spiny edges of sea urchins more than the carrier crabs that use them like a shield. The carrier crab is uniquely built with two back legs that are especially adapted ...