Unrestricted.2016-11-142011-02-182016-11-142000-08http://hdl.handle.net/2346/10338This thesis is comprised of two separate studies. The first investigated the intrageneric relationships within Noctilio by examining variation in the mitochondrial cytochrome b gene and the nuclear Recombination Activating Gene-2 (RAG-2). Gene sequences were analyzed to assess the time frame when piscivory evolved in this genus, concluding that piscivory is the derived state within Noctilio. A significant dichotomy was present within A. albiventris indicating that the taxon might consist of two biological species. The second study evaluated intrageneric and intraspecific relationships within the family Mormoopidae based on cytochrome b and RAG-2 gene sequences. Resuhs suggested that: (1) P. personatus is basal to P. davyi, P. gymnonotus, P. quadridens, and P. macleayii, (2) P. parnellii is the most divergent species within Pteronotus, (3) there is a new, unnamed subgenus in Pteronotus, (4) there seems to be two biological species existing within P. davyi and P parnellii, (5) and the genus Mormoops was monophyletic.application/pdfengPteronotusBatsMormoopsNoctilioThesis