Conclusion
Despite considerable phylogenetic uncertainty in the data, we found an influence of ecotone on the rates and timing of diet transitions for sigmodontine rodents. This result is especially noteworthy as there may be only subtle differences in the rates of transition and time of diet evolution between ecotone and core species, owing to lagged responses to environmental changes. The spatial analysis of diet evolution shed light on the evolutionary pathways that sigmodontine rodents tracked to achieve such an impressive diversity, and expand and survive into the large range of habitats in which they occur today. Our approach provides a formal link between macroecology and macroevolution, and can be incorporated in more sophisticated approaches integrating reconstruction of ancestral areas and ecological traits.