User:Tom Radulovich/Caribbean paleohistory

The Greater Antilles and Bahamas are made up of rocks of continental and volcanic origin as well as marine limestone. The Lesser Antilles are generally younger, and of volcanic rock and marine limestone.

R.D.E. MacPhee and M. A. Iturralde-Vinent developed a schematic biogeographic history of the Caribbean Region. Fossil evidence shows that the Caribbean islands have continuously existed for 35 million years. Islands may have existed before then, but and episode of subsidence and sea level rise drowned all existing land. During the Eocene-Oligocene transition, 35 and 33 mya, a period of tectonic uplift coincided with a worldwide drop in sea level, exposing what they call the "GAARlandia landspan." GAARlandia stands for Greater Antilles - Aves Ridge, and included at portions of at least three of present-day Greater Antilles (Cuba, Hispaniola, and Puerto Rico), connected to the South American Continent by the Aves Ridge, a north-south running marine ridge lying west of the Windward Islands. In their hypothesis, the Aves Ridge was then above sea level, and formed a continuous land mass with South America, allowing South American flora and fauna to colonize the Greater Antilles.

Megalonychid sloth fossils have been found on the Greater Antilles and Curacao. A recent excavation of a lahar on Grenada dated 2.6–3.7 mya found fossils of an extinct capybara, Hydrochaeris gaylordi, as well as a Megalonychid sloth, the first to be found in the Lesser Antilles.