Endemism and regionalization of Neotropical mammals: a multi-taxon analysis.

This article focuses on identifying areas of endemism and biogeographic regionalization of Neotropical mammals using raw occurrence data for 361 species across Placentalia and Marsupialia taxa. Employing endemicity analysis via the NDM/VNDM software and hierarchical cluster analysis based on Simpson's beta dissimilarity metric (βsim), the study reveals 116 consensus areas grouped into 24 endemic area groups (AEGs) and three main biogeographic clusters, highlighting spatially congruent regions such as the Atlantic Forest, Mexican transition zone (MTZ), Amazon, and South American transition zone. The analyses identified 172 endemic species, including 125 newly proposed endemics, exceeding previous estimates based on range maps, and suggest more spatially restricted areas of endemism than earlier studies. Results underscore the importance of using updated raw occurrence data and multiple analytical approaches to refine the delimitation of Neotropical biogeographic regions and transition zones, while acknowledging limitations due to sampling biases and taxonomic uncertainties.