On the Occurrence of the Gastropod Genus Cassis in the Esmeraldas Fauna, Northwestern Ecuador

Abstract

In his seminal treatment of the Panama Land Bridge as a sea barrier, Woodring (1966) coined the now-familiar term "paciphile" for those molluscan genera and/or species that, during the Tertiary, lived on both sides of the Tropical American landmass, but today are living only on the Pacific side. At that time he listed 43 genera or subgenera classified as paciphiles; predicting, however, that some would be eliminated from the list as living representatives were discovered in the western Atlantic. In contrast, he cited only four "caribphile" genera, those that survive in the Caribbean but are extinct in the eastern Pacific. Time has proved his prediction correct and perhaps five of the formerly paciphile genera have been eliminated from his list, nevertheless the overwhelming number of paciphile genera, in contrast to caribphile genera, remains intact.