The Holocene and Pleistocene specimens, between 7,000 and 110,000 years-old, had been exposed by beach erosion. Biologic or geologic processes easily destroy the crabs' thin exoskeletons. They have been preserved, most likely because they died in their burrows, possibly from winterkill, and were not exposed to the wind, sea, or predators.
Such whole-body deposits of fossilized ghost crabs are rare on the east coast of the U.S., down to Brazil. That some of the fossils are as "young" as they are is also significant. Poor fossilization normally occurs in pure, clean sand exposed to tidal actions. The same process that produced the coquina ledges found along the shoreline and offshore of Brevard County probably formed the fossil crabs.
Dunes kept the specimens hidden. As a result of beach erosion, possibly because of the building of Port Canaveral, the fossils were exposed.