PIs: Scott D. Sampson, Kirk R. Johnson Co-PIs: Eric M. Roberts, Patrick M. O?Connor, Mark A. Loewen
The Late Cretaceous was a period of elevated sea levels and hothouse climates. Shallow seas flooded many continental landmasses, including North America. For about 25 million years, the Late Cretaceous Interior Seaway extended from the Arctic Ocean to the Gulf of Mexico, effectively dividing the North American continent into two landmasses. On the western landmass, sandwiched between the seaway to the east and rising mountains to the west, dinosaurs underwent dramatic diversification, achieving perhaps the acme of their evolutionary history. This project seeks to continue and expand the Kaiparowits Basin Project, designed to explore Late Cretaceous (approximately 75 million year old) ecosystems preserved in the Kaiparowits Basin, Grand Staircase-Escalante National Monument, southern Utah. More specifically, two geologic units will be targeted?the Kaiparowits and Wahweap formations?with findings placed into phylogenetic, stratigraphic, paleoenvironmental, and biogeographic context. Results to date have been spectacular, highlighted by a new dinosaur fauna that includes ceratopsians (horned dinosaurs), hadrosaurs (duckbill dinosaurs), ankylosaurs (armored dinosaurs), pachycephalosaurs (dome-headed dinosaurs) hypsilophodont ornithopods (small-boded, bipedal forms), large-boded tyrannosaur theropods (carnivorous dinosaurs), and a variety of smaller-bodied theropods. Many forms are represented by exceptional materials, including mostly complete skulls and skeletons, as well as footprints and skin impressions. Yet the majority of vertebrate (back-boned) species are presently known only from fragmentary remains, and vast expanses of badlands remain unexplored, suggesting that we have only begun to realize the potential of these units. We propose to expand upon earlier efforts through an integrative, multi-disciplinary project that encompasses vertebrate and invertebrate paleontology, paleobotany, and geology. The principle project goal is to reconstruct the Late Cretaceous terrestrial faunas preserved within the Kaiparowits and Wahweap formations, and to compare these with penecontemporaneous examples north and south within the Western Interior Basin (WIB). Plant diversity will also be a major target of study, in an attempt to better understand the nature of these dinosaur-rich ecosystems. The discovery and rigorous phylogenetic analysis of additional and more complete fossils from Upper Cretaceous horizons in the Kaiparowits Basin of Utah, and their placement into geological context, will shed significant new light on the mode and tempo of evolution within terrestrial ecosystems in Cretaceous North America. In particular, we will test hypotheses relating to evolutionary turnover and putative north-south biogeographic zonation of species. With continued work, we are confident that the vertebrate fauna from the Kaiparowits Formation in particular will become one of the best known examples of Late Cretaceous age, and the most comprehensively documented fauna from the southern portion of the WIB. As in the past, this project is firmly committed to providing a training ground for graduate and undergraduate students, including women and minorities. Also as in the past, results of this project will be disseminated to both the scientific community and the general public through a variety of outlets, including original publication, media exposure, the internet, museum displays, and lectures/seminars. Outreach highlights include permanent exhibits planned for a new, $100 million Utah Museum of Natural History facility in Salt Lake City, which will portray a detailed reconstruction of the Kaiparowits Formation ecosystem in order to convey the workings of natural systems generally, and to compare this Late Cretaceous example with modern habitats.
