USING GPR, GPS AND CLOSE-RANGE PHOTOGRAPHY TO MAP AND CHARACTERIZE DINOSAUR TRACKS IN THE CONNECTICUT RIVER VALLEY

Fossil trackways can provide information about environmental conditions, group behavior, as well as body size and speed, though the connections between track-size-to-body size and stride-to-speed has recently been challenged (Bobo and Rainforth, 2010). Much of this information can be extracted from photographs and maps of trackways. By georeferencing the data within a digital database, we can extract more information and ask new questions about animal behavior and environment. Our efforts aim to move studies of fossil trackways toward such a digitized georeferenced environment.

While dinosaur skeletal remains are rare, numerous trackways exist in the eastern United States. We chose a well-exposed set of trackways on sedimentary bedding planes in the Connecticut River valley, previously mapped by Ostrom (1972). We used differential GPS to record the location of each track. We took close range oriented photographs to determine the orientation, size and morphology of individual tracks. We precisely located an oriented scale object in each photograph with a reflectorless total station, and used this data to georeference the photographs in GIS software (Global Mapper). We measured dinosaur track characteristics within this georeferenced environment, including size, shape, and bearing. The trackways occur in thinly bedded ripple-marked sandstone, so we suspected that additional tracks existed in the subsurface. We explored the ability of ground penetrating radar (GPR) to identify buried trackways.

We present here our initial results. We found it difficult to compare our trackways with Ostrom (1972). We found many more tracks. In addition, GPR revealed disruptions in the subsurface of the same scale as exposed tracks, leading us to conclude that radar could detect the buried tracks. A major goal of our effort aims at integrating a variety of spatial data and sharing this data with the scientific community for further investigation. Our study highlights the value of combining GPS, GPR, and digital images in the study of dinosaur tracks.