The origin and evolution of Malagasy bats: Implications of new late Pleistocene fossils and cladistic analyses for reconstructing biogeographic history

Despite decades of research on the origin and evolution of Madagascar's modern fauna, one of the most unique and endemic on the planet, the evolutionary and biogeographic history of Malagasy bats has never been systematically investigated. Madagascar has been fully isolated for more than 80 million years, with most of its modern fauna thought to have arrived on the island post-isolation. As a result, most past biogeographic studies have focused on Madagascar's non-volant species, as researchers have investigated the mechanisms by which these animals might have crossed large marine barriers without the benefits of flight. Flying vertebrates, such as birds and bats, have been largely ignored, as they have been assumed to be relatively unconstrained in their ability to disperse.; This dissertation is the first comprehensive and integrated biogeographic study of Malagasy bats, and seeks to investigate how, when, and from where modern Malagasy bats originated. First, I describe newly discovered bat fossils from Anjohibe Cave, more than three times older than the oldest reported Cenozoic non-aquatic fossil vertebrates from Madagascar. Second, phylogcnetic analyses based on morphological data provide new information regarding the evolutionary history of Malagasy bats within four families (Pteropodidae, Emballonuridae, Hipposideridae and Vespertilionidae (Miniopterinae), and emphasize the importance of species-level phylogenetic analyses. Third, biogeographic analyses examine the number of colonization events, area of origin, timing, and method of colonization of Malagasy bats. This research suggests that Malagasy bats did suffer both local and island-wide extinctions, and describes two newly discovered extinct bat species, Hipposideros besaoka and Triaenops goodmani . Cladistic biogeographic analyses suggest that Madagascar's modern bat fauna was assembled through many independent dispersal events from different geographic areas during the Cenozoic. Biogeographic analyses based on distributional data (Parsimony Analysis of Endemicity: PAE) do not recover comparable signals; PAE appears to have poor resolution within huge taxonomic groups, and is deemed an inappropriate method if dispersal is the purported mechanism driving speciation. This dissertation provides the first glimpse into the fossil record of Malagasy bats, and is the first study to elucidate important details of their colonization history and evolutionary relationships.