Abstract
Land crabs are found in marine and terrestrial sediments and sedimentary rocks from the Pleistocene and Holocene throughout the Caribbean. Field surveys of two widespread and abundant species, Gecarcinus lateralis and Gecarcinus ruricola, were conducted three times a week for 4 weeks along the northern coast of San Salvador Island, the Bahamas, at three localities that varied in vegetation cover, available sediment, and wind and wave energy. A total of 1400 identifiable remains were found and scored for four taphonomic characters: fragmentation, edge modification, surface alteration, and color loss. The majority of specimens exhibited various levels of disarticulation, from complete limbs to only isolated podomeres. Overall, claws are overrepresented, and the distribution of recovered remains differed significantly (p < 0.0001) from that expected based on the anatomy of a single crab (eight legs, two claws, and one carapace per individual). Remains found in direct sunlight and open spaces consistently showed more surface alteration, edge modification, and more loss than those found within vegetation or on the beach. Fragmentation was not significantly different across localities (p = 0.045). This result suggests that the fossil record of land crabs may be biased as a result of their low preservation potential in terrestrial environments. The discovery of eight poorly preserved Holocene chelae on San Salvador Island contrasts starkly with the abundance and preservational quality of surficial remains. Rapid burial is likely required for their preservation but may not ensure the preservation of the cuticle.
