Endemism in Middle Miocene Caribbean Molluscan Faunas

Abstract

The term "middle Miocene Caribbean province" is used for a faunal province that embraced both western Atlantic and eastern Pacific waters. The percentage of endemic species in 13 local faunas in that province is tabulated. In general the largest faunas have the highest percentage of endemic species, but notable exceptions to that generalization are apparent. Many examples of discontinuous distribution of species and genera, which are not relicts, support the conclusion that much of the endemisim is apparent rather than real.