A blue land crab guarding its burrow in Costa Rica
Dudarev Mikhail/Shutterstock
Crabs have a habit of evolving to live away from the ocean. The crustaceans have clambered out of the sea and made homes in land-based habitats between seven and 17 different times since they arose about 230 million years ago.
The findings highlight crabs’ extreme evolutionary flexibility, as they have repeatedly used beaches, estuaries, rivers and mangroves to colonise terrestrial habitats. Determining how they have done so may give insights into understanding how other animals may have broken their bond with …