Decapod crustaceans of the Seroe Domi Formation of Curaçao

Abstract

A new collection of brachyuran decapod crustaceans (crabs) from the Mio-Pliocene Seroe Domi Formation of Curaçao totals 284 specimens. They exhibit excellent preservation of fine details, including fragile spines and delicate surface textures; however, the majority of the specimens are fragmented and disarticulated. Seven genera are identified from six families; Raninidae, Calappidae, Aethridae, Leucosiidae, Mithracidae, and Portunidae. The decapod fauna from the Pliocene portion of the Seroe Domi Formation was compared to coeval Caribbean brachyuran faunas to judge the relative diversity. Jamaica hosts the largest concentration of Pliocene brachyurans in the Bowden Member of the Layton Formation. Other localities, in Costa Rica, Panama, Florida, and the Dominican Republic, were similar in generic diversity to that of the Seroe Domi Formation. Following uplift of the Central American Isthmus and the end of genetic exchange between the Pacific and Atlantic, crab species that previously spanned both oceans evolved into distinct Pacific and Atlantic forms. The Pliocene crabs of the Seroe Domi Formation all belong to species that represent Atlantic forms.