PTEROSAUR TRACKS, PHOTOGRAMMETRIC ICHNOLOGY, AND MANAGING ICHNOLOGICAL RESOURCES ON FEDERAL PUBLIC LANDS

The ichnological record of pterosaurs provides valuable insight into the enigmatic locomotion, habitat, feeding patterns, and community dynamics of this unique group of vertebrates. Unfortunately, taphonomic and preservational biases, as well as small sample sizes have led to poor ichnotaxonomic naming and misidentifications. As it is likely that variation in track data is partially due to differing measurement and documentation techniques, more refined and standardized measuring methods are required. Fortunately, properly collected and processed close-range photogrammetric (CRP) projects can assist in the documentation, preservation, and assessment of the subtle, low relief, and often small size of many pterosaur ichnites. CRP image collection is ideal for pterosaur tracksites of various extents, exposures, and orientations; and allows for a more objective understanding of ichnotaxomic variations, as well as the recordation of novel ichnites that may reflect the kinetics of a diversity of pterosaur movements and activities.

In the 1970s, abundant Late Jurassic pterosaur tracksites discovered in central Wyoming on Federal Public Lands were some of the first pterosaur tracksites to be recorded following Stokes’ initial documentation (1957) of a pterosaur trackway in Arizona. In particular, the exposures of the Sundance and Morrison formations around Alcova and Seminoe reservoirs contain hundreds of tracks and trackways of the ichnogenus Pteraichnus and may represent some of the highest concentrations of pterosaur tracks anywhere in the world. The Paleontological Resources Preservation Act (PRPA) mandates the protection and interpretation of these scientifically significant paleontological resources. PRPA requires the management of paleontological resources on public lands using scientific principles and expertise and authorization is required for any scientific study of ichnological material, as well as for molding and casting. BLM is actively developing plans for inventorying, monitoring, and scientific and educational use of ichnological resources. Photogrammetric ichnology not only supports PRPA, but also is being used to help unravel ichnological complexities to provide a unique glimpse of the paleoecology, paleobiology, and paleoethology of these pterosaur communities.