The purpose of this report is to provide a preliminary inventory of the paleontological resources within the newly created Grand Staircase-Escalante National Monument for two principal reasons. First, in establishing the monument, President Clinton proclaimed the opportunities for scientific study, expounding at length on the paleontological resources and sites. He directed the U.S. Bureau of Land Management to develop a management plan for the monument within three years. Information on the location, extent, and importance of paleontological resources needs to be available to the monument planners, to paleontologists and other scientists, and to the interested public to help determine how these resources will be incorporated into the management plan. Will scientists be allowed to excavate specimens or sites? Can a sample be removed for additional study or curation? Are there sites that should be exposed in place and protected for public appreciation? These and many other questions will have to be answered in the management plan. The more information that can be provided to the BLM, the better they should be able to anticipate the location and size of potential impacts from scientific research.

Grand Staircase-Escalante National Monument contains abundant fossil material in most formations within its borders. These formations range in age from Permian to Cretaceous. More than 800 individual fossil localities are known so far, and almost all areas of the monument that were examined contain at least some fossil material. Important new findings of this survey include: several partial dinosaur skeletons in the Kaiparowits Formation; a ceratopsian skull in the Wahweap Formation; the previously unreported presence of many ammonoid and bivalve genera in the monument in the Dakota, Tropic, and Straight Cliffs Formations; the first fossils of any kind from the Entrada Sandstone within the monument, including a dinosaur tracksite containing more than 250 tracks of at least 30 individuals; previously unrecognized sites and abundances of vertebrate ichnogenera in the Navajo, Kayenta, Moenave, and Chinle Formations; the first ichnofossil material from the Wingate Sandstone in the monument; and a previously unreported sponge genus from the Kaibab Limestone. The Cretaceous rocks exposed within the monument contain one of the best and most continuous records of Late Cretaceous terrestrial life in the world. Research on these strata is still in its earliest stages.

The Grand Staircase-Escalante National Monument is the location of one of the best-known terrestrial records for the late Cretaceous. Prior fieldwork confirmed the richness of the area, but a major effort begun in the new century has documented over 2,000 new vertebrate fossil sites, provided new radiometric dates, and identified five new genera of ceratopsids, two new species of hadrosaur, a probable new genus of hypsilophodontid, new pachycephalosaurs and ankylosaurs, several kinds of theropods (including a new genus of oviraptor and a new tyrannosaur), plus the most complete specimen of a Late Cretaceous therizinosaur ever collected from North America, and much more. The research documented in this book is rewriting our understanding of Late Cretaceous paleobiogeography and dinosaur phyletics. At the Top of the Grand Staircase: The Late Cretaceous of Southern Utah is a major stepping stone toward a total synthesis of the ecology and evolution of the Late Cretaceous ecosystems of western North America.