The proposed research project is designed to recover the historical relationships of pipid frogs of the genera Silurana and Xenopus and their fossil relatives. Whereas living frogs of these genera are only know from sub-Saharan Africa, fossils (dating from the Upper Cretaceous) occur in Africa and South America, thereby suggesting that the ancestors of the Recent and fossil species may have been widespread on these continents before they split. Silurana and Xenopus long have been the subject of biological and biomedical research (e.g., developmental and genetic studies, immunobiology, gene-mapping, etc.), yet we do not know how many species there are or their relationships to one another, nor is there any authority to identify individual species. The goal of this study is to integrate the information that exists for these taxa (e.g., biochemical, cytological, behavioral) with anatomical (e.g., ostelogical , myological, morphometric) data that will be gathered from adults and developing young in order to (1) identify individual species, (2) determine their interrelationships, (3) describe evolutionary pattern of chromosome, nucleic acids, and morphological features, (4) assess levels of differentiation between sister-species, and (5) combine the various data sets of fossil and Recent organisms to reconstruct the evolutionary history of the group.
