12 Preserving paleontological resources using photo- grammetry and geographic information systems

Introduction The American West is a storehouse of fascinating paleontological resources that include the footprints and skeletal remains of dinosaurs. These important scientific and educational resources are often on lands managed by government agencies for the benefit of the nation’s public. Land management agencies are challenged with providing public access to these resources, as well as preserving them for future generations. Conservation includes the scientific identification, documentation, curation, and monitoring of these national treasures. The natural process of weathering, combined with the effects of public visitation—including those of vandalism, unfortunately—can significantly affect a site. Documentation, collection (when appropriate), and retention of data and associated materials in a suitable public repository, where the information can be preserved into perpetuity, are vital. An excellent documentation tool is three-dimensional (3-D) data capture. Photogrammetry, conventional or global positioning systems (GPS) surveying methods, and ground-based laser imaging are techniques that can provide highly accurate 3-D representations of fossil resources. Vertebrate ichnology at the Red Gulch Dinosaur Tracksite The Red Gulch Dinosaur Tracksite (RGDT) is a newly reported (Breithaupt et al. in press) paleontological resource. Located near Shell, Wyoming, the RGDT is a 1,600-sq-m area of land administered by the Bureau of Land Management (BLM) in the eastern Bighorn Basin of northern Wyoming. This site is unique in North America and represents a significant paleontological resource that is being developed for the educational benefit of the public. In a cooperative partnership with the BLM, investigators have supported development of the site as a unique tool for public education. To that end, the investigators have assisted in the creation of interpretive displays and Web sites, as well as disseminating accurate information to the media. Over the past three years, dinosaur tracks were located, mapped, measured, described, surveyed, photographed, and compared with other previously studied track assemblages. Analysis of this data is providing unique insights into the community structure and habitat of Middle Jurassic dinosaurs in northern Wyoming. Because of the density of tracks, degree of surface exposure, proximity to the road, and BLM development plans, the primary focus of research at the RGDT was an arroyo (“dry wash”) exposing a limestone unit of the lower Sundance Formation. This unit historically has been defined as open water marine in character (Darton 1899). However, this discovery demonstrates an episode of subaerial exposure during regressive phases of the Sundance Sea. Geologic work in the area has assigned the track-bearing unit to the Middle Jurassic Bathonian-age (165 million years old) Canyon Springs Member of the Sundance Formation (Schmude 2000). Any evidence of dinosaur activity from the Middle Jurassic is significant, as this was a period worldwide which