A Costa Rican Biological Puzzle—The Geological, Landscape, and Vicariance History as a Conditioning of the Past and Present Biogeography

The high biological diversity and endemicity for Costa Rica are aspects that have always intrigued naturalists in the past and today. Lamentably, not very much is known about the possible processes that have been active in the past. To understand the highly complex problem of Costa Rica’s biodiversity and endemicity and its feasible generation mechanisms, simple proposals or models are established integrating geological and biological lines of evidence that could have favored changes that generated biodiversity and endemicity. This study adduces models integrating geological, paleogeographical, and biological lines of evidence to explain different biodiversity processes operating in Costa Rica. An updated compilation and synthesis of primary information is presented trying to explain the present high levels of organismal biodiversity, distribution, and endemismEndemism mechanisms. These possible mechanisms are based on available stratigraphical, radiometric dating, paleontological, paleotectonic and paleogeographical evidence spanning the last 24 Ma to 24 ka. This study amalgamates auspiciously geological and biological processes with very interesting and novel results regarding the coupled evolution and inter-relation between life, geology, and landscape.