9317943 Flynn This proposal requests funding to extend the PIs' study of fossil land mammal faunas of the Andes mountain chain in central Chile. During most of the last 80 million years South America drifted as an island continent. The highly peculiar land mammals that arose as a result of this isolation have captured the interest of biologists for more than two centuries. The PIs have recently discovered two new and highly unexpected fossil mammal assemblages in volcanic sediments of the Chilean Andes. These assemblages help to fill in what was previously a very poorly understood interval in the history of South American mammals. In addition, occurrence of these fossils in volcanic deposits enables the application of various "absolute" geologic dating techniques, providing a precise calibration for at least the younger of the two assemblages. The project will focus on three areas in continuation of the PIs' study in this region. First, field collecting and reconnaissance efforts will be extended to discover new localities and assemblages of different ages. Second, the PIs will establish an integrated geological time framework for known and newly identified assemblages. Third, preparation, description, and analysis of these diverse, well preserved fossils will be completed. This will help clarify biotic, environmental, and geologic events during crucial intervals of South American land mammal history.
