The biogeographic and evolutionary history of Leiosauridae lizards reveal the influence of complex environmental and geological past dynamics in the Neotropical biomes

Abstract

The Neotropics have generated the highest levels of biodiversity on Earth, with complex evolutionary histories underlying the distribution of many groups. Here we present the most comprehensive phylogeny of Leiosauridae to date, based on genome-scale ultraconserved element (UCE) data, encompassing all recognized subfamilies and genera and 70% of described species. Our analyses indicate that the diversification of Leiosauridae was likely influenced by major paleoenvironmental changes during the Cenozoic, with distinct biogeographic patterns emerging between the deepest divisions in the family, Leiosaurinae and Enyaliinae. Results suggest a Miocene colonization of northwestern South America from southeastern regions (SE–NW route), rather than a northeastern dispersal as previously proposed. Climatic oscillations during the Plio-Pleistocene appear to have promoted range expansions of Enyalius into dry biomes and facilitated their persistence in mesic gallery forests within the Cerrado and Caatinga. These findings contribute to a broader understanding of how historical climatic and geological processes may have shaped Neotropical biodiversity and offer a possible explanation for the south–north biogeographic discontinuity observed in the Atlantic Forest.