PALEOGEOGRAPHY OF THE ANTILLES AND ORIGIN OF WEST INDIAN TERRESTRIAL VERTEBRATES1

Abstract

Abstract The fauna of the West Indies includes more than 1300 native terrestrial vertebrate species and is characterized by high levels of endemism. Several theories have been proposed to explain how these animals arrived to the islands, including dispersal, vicariance, and land bridges. The dispersal theory proposes that most of the West Indian terrestrial biota arrived by flying or by flotsam. The vicariance theory suggests that there was a proto-Antillean land mass, or masses, connecting North and South America in the late Cretaceous that traveled eastward as the Caribbean geologic plate developed and carried an ancient biota with it. One widely discussed land bridge theory proposes that much of the Antillean biota originated by dispersal over an unbroken dry land connection, the Aves Ridge, between South America and the Greater Antilles 35–33 Ma. Geologic evidence cannot unambiguously support or refute any of these models, despite claims to the contrary. Other evidence bearing on these three theories,...