New Cretaceous and Cenozoic Decapoda (Crustacea: Thalassinidea, Brachyura) from Puerto Rico, United States Territory

A large number of recently collected specimens from Puerto Rico has yielded two new species including Palaeoxanthopsis tylotus and Eurytium granulosum, the oldest known occurrence of the latter genus. Cretaceous decapods are reported from Puerto Rico for the first time, and the Cretaceous fauna is similar to that of southern Mexico. Herein is included the first report of Pleistocene decapods from Puerto Rico, which were previously known from other Caribbean localities. The Pleistocene Cardisoma guanhumi is a freshwater crab of the family Gecarcinidae. The freshwater crab families have a poor fossil record; thus, the occurrence is noteworthy and may document dispersal of the crab by humans.