The Sea of Cortes may be a source of valuable biogeographical information about the emergence of the Isthmus of Panama and its effects on the biogeographical history of the Caribbean and the Eastern Pacific marine biota. Fossil molluscan taxa from the Imperial Formation at the head of the Sea of Cortes were closely related to extant and fossil Caribbean taxa. The living fauna of the Sea of Cortes also shows three distributional patterns reported across a diverse array of taxa. One, like that of the fossil fauna of the Imperial Formation, is the disjunct associations of extant taxa between the Sea of Cortes and the Caribbean; another comprises many disjunct distributions with Southern California; and the third is the high level of endemism found in the Sea of Cortes. Two of these patterns suggest that a common biological history has been shared between the Sea of Cortes and both the Caribbean and California. The endemism may be a relictual artifact of range reduction or a result of true endemic origins within the Gulf.

The goal of my research is to reconstruct the biogeographical history of the intertidal Patellogastropods (limpets) from the Eastern Pacific, The Sea of Cortes, and the Caribbean using a phylogenetic biogeographical approach that integrates molecular, morphological, fossil, and tectonic data. The intention is to evaluate the origins of the unique faunal patterns found in the Sea of Cortes, and its historical ties with the closure of the Panamanian Seaway.

75/125 YEARS