The new species, called Johngarthia Cocoensis, was discovered on the island by researchers Robert Perger and Rita Vargas of the University of Costa Rica and Adam Wall of the LA County Natural History Museum. The crabs have been identified as being "giant", and at 40 cm, or just shy of half a meter, these guys definitely live up to their nickname.
If you are curious, as to how this species wound up at Cocos, researchers may have an idea. It appears that the Giant Crab, Johngarthia Cocoensis, is similar to another crab species in the western Pacific. Perger believes that larvae could have washed ashore and, over time, the crab evolved and adapted to its new environment.