GLOBETROTTING WITH THEROPODS: A PHOTOGRAMMETRIC, SPATIAL, AND MORPHOLOGICAL COMPARISON OF MIDDLE JURASSIC DINOSAUR TRACKS FROM NORTH AMERICA AND THE UNITED KINGDOM

The Middle Jurassic is an important time in the evolutionary history of dinosaurs. Fortunately, there are a number of significant dinosaur tracksites from this time period that provide valuable information about the trackmakers, their environments, behaviors, and global distribution. A key to more fully understanding the animals of this time is consistent, detailed 3D documentation from sites worldwide. Close-range photogrammetry is an excellent method for the 3D documentation of fossil footprints. Dramatic technological advancements have resulted in a simplification of the process for capturing overlapping stereoscopic photographs. Affordable, quality digital cameras, high performance laptops, and cost effective software allow for the production of dense, accurate point clouds in the field. As these point clouds are generated from photographs, image textures can be registered with the quality, reliability, and authenticity necessary for scientific use. These data can be exported into a variety of visualization softwares, where vertical exaggeration and scale can be manipulated to enhance features difficult to see or measure in the field, and can be used to produce solid models. Digital ichnology data, along with digital spatial data utilized in Geographic Information Systems (GIS) provide excellent tools for capturing the incredible wealth of information provided at dinosaur tracksites. These tools can aid in unraveling numerous ichnological complexities, such as variations in footprint morphology related to trackmaker, substrate, and preservational level (e.g., underprints). In particular, important, Middle Jurassic tracksites in Wyoming and Utah can now be easily compared with similar data from other localities. Digital track data for the United Kingdom (also known for significant Middle Jurassic dinosaur track localities) can be compared to those from North America. This comparison will provide a unique glimpse of the paleoecology, paleobiology, and behavioral complexities of Middle Jurassic theropod dinosaur communities in the Northern Hemisphere.