Caribbean biodiversity shaped by subduction zone processes along the Lesser Antilles arch

Abstract

Biodiversity hotspots often coincide with regions along subduction zones where tectonic activity continuously make and break geographic connections promoting biological diversification and speciation. A puzzling biodiversity hotspot is the northern Caribbean islands that contain endemic terrestrial and freshwater biotas mainly evolved from South American colonizers that dispersed during the Cenozoic. However, tectonic reconstructions have always assumed a mostly inactive and coherent eastern Caribbean plate, such that migration routes must either have been overwater, or through an inner-plate land bridge. Nevertheless, recent studies revealed that the northeastern Caribbean region underwent tectonically induced uplift, subsidence and large-scale block rotations questioning the assumed plate coherency. Here we present a plate reconstruction including these novel constraints and reveals how tectonic and volcanic activity along the Lesser Antilles subduction zone have established a transient land corridor connecting South America and the Greater Antilles from ~45 to 25 Ma ago offering a new avenue to explain Caribbean biotic interchanges and diversification.