Hawaiian Land Crab (Geograpsus severnsi)
This species was scientifically described in the year 2011.
Subfossil remains of land crabs have been found on the major Hawaiian Islands for many years, but their identity was not clear. Researchers identified the crab as a new species by comparing physical characteristics with specimens from various collections.
The Hawaiian Land Crab is now known to have occured on all of the larger islands in the Hawaiian chain. The species reached a carapace size of about 6 cm and was therefore probably the largest in its genus.
The Hawaiian land crab species vanished at about 1000 A.D., shortly after the arrival of the first Polynesian settlers resp. of the new animals that the Polynesians brought to the islands (chickens, dogs, pigs and rats).
 Gustav Paulay; John Starmer: Evolution, Insular Restriction, and Extinction of Oceanic Land Crabs, Exemplified by the Loss of an Endemic Geograpsus in the Hawaiian Islands. PLoS ONE, 2011; 6(5): e19916 DOI