Out of the Antilles: Fossil phylogenies support reverse colonization of bats to South America

Abstract

AbstractAimPrevious phylogenies of extant short‐faced bats (Chiroptera: Stenodermatina) supported either two colonization events from the mainland to the Antilles, or reverse colonization, but lacked both fossil data and statistical modelling of biogeography. Recent multi‐locus phylogenies of noctilionoid bats and likelihood modelling of ancestral ranges support a continental origin for the clade. We include all known extinct and extant stenodermatina species and apply statistical modelling to test competing biogeographical hypotheses.LocationThe Neotropics, including the Antilles.MethodsWe combined mitochondrial and nuclear sequences with 302 new morphological characters to infer phylogenies. Bayesian tip‐dating analyses applied codon models to protein‐coding genes, with relaxed molecular clocks fitting a compound Poisson process. The combined maximum clade credibility tree was used in comparisons of alternative biogeographical models.ResultsThe new phylogenies support the fossil Cubanycteris silvai as sister to all extant species of short‐faced bats. Among Artibeus (the sister group to short‐faced bats), the Antillean fossil A. anthonyi has distinctive characters and is nested within the subgenus Artibeus. The common ancestor of all short‐faced bats is inferred to be Antillean, as a mainland origin is unlikely. Founder‐event speciation is the most probable process explaining the distribution of these highly divergent fossil lineages.Main conclusionsDated, character‐based phylogenies of fossil species are indispensable for biogeographical inference: without fossils, biogeographical analyses find a mainland origin for short‐faced bats. The rate of founder speciation in this clade is twice as high as the estimate from noctilionoids in general, highlighting the role of founder events in the diversification of island taxa. Although rare, reverse colonization contributes key species to continental communities. Short‐faced bats, including Cubanycteris, share biomechanical adaptations for a strong bite conferring access to harder figs. We hypothesize these adaptations and characters related to roosting ecology enabled ancestral lineages to successfully establish and diversify on the mainland.