Mesozoic mammals from South America: their impact on mammalian evolution, phylogeny, and time calibrations.

点击翻译按钮获取中文摘要

Mesozoic mammals are rare and known mostly from Northern continents. The PI has made a unique collection of Mesozoic and early Tertiary mammals from South America (SA) that includes exquisitely preserved cranial and postcranial material, as well as isolated teeth, mandibles, and ear regions. These fossils represent a dramatic improvement in the quality of specimens and an increase of more than 500% in the total number of known SA Mesozoic mammals. The new materials range in age from the Middle Jurassic (170MY) to the early Paleocene (58MY) from five different localities in Patagonia, Argentina, and include the first record of mammals (with some new groups) for the early Late Cretaceous (Turonian) in Gondwana. This collection represents the best evidence to date for tackling the Mesozoic/early Paleocene diversification of Mammalia in SA and its impact on mammalian evolution. The proposal will produce detailed descriptions of the new specimens and will generate a comprehensive morphological data matrix including all major relevant Mesozoic mammals surveying all major traditional character systems (dental, cranial, and postcranial) in addition to new data such as enamel microstructure and Computer Tomography. The impact of different subsets of fossil data on evolutionary histories will be analyzed and compared with molecular data to explore agreements and discrepancies. The new data will provide additional insight into the early evolution of mammals. This project will have as an important component the training of a graduate student and the participation of undergraduates in research opportunities. Casts of the specimens will be donated to major collections, and an exhibit will be prepared for routing to multiple museums and similar institutions. Information on the results and general popular information will be made available via the web, while more technical data and illustrations will also be accessible on-line via MORPHOBANK. The PI and students plan to participate in science education programs open to students of every level, but with an emphasis on K-12 teachers following the success of recent projects organized by the Kentucky Academy of Sciences.