VERTEBRATE PALEONTOLOGY IN THE CRETACEOUS SEQUENCE OF BRYCE CANYON NATIONAL PARK, PAUNSAUGUNT PLATEAU, UTAH

Bryce Canyon National Park contains a sequence of Upper Cretaceous strata including the Dakota Formation (Cenomanian-Turonian), Tropic Shale (Turonian), Tibbet Canyon (Turonian), Smoky Hollow (Turonian), John Henry (Coniacian-Santonian – earliest Campanian?), Drip Tank (Campanian?) members of the Straight Cliffs Formation, and the Wahweap Formation (lower Campanian), and possibly the Kaiparowits Formation (upper Campanian). Vertebrate fossils have been relatively rare in Bryce Canyon National Park, and until two years ago only two reasonably good microvertebrate localities were known in the Wahweap Formation, and a single locality in the upper part of the Straight Cliffs Formation. In the past two field seasons (2003-2004), we have taken a different approach and have “blind washed” horizons that looked promising (mudstones preserving organics) but showed little or no bone at the surface. This has resulted in a series of new localities in the John Henry Member including a locality low in the member and several in the upper part of the member. Many of these localities are very rich with one producing delicate bones of frogs and lizards and another producing diverse mammals including marsupials, symmetrodonts, and multituberculates. This is significant as in the adjacent Kaiparowits Plateau there is only one microvertebrate site that has yielded diverse mammals from the John Henry Member. As such, our knowledge of Coniacian-Santonian nonmarine vertebrates is poor in North America. The excellent preservation and richness of these new localities indicates there is considerable potential for microvertebrate studies in Bryce Canyon National Park.