CHADWICK, Arthur, TURNER, Lawrence, Southwestern Adventist University, Keene, TX, SPENCER, Lee, Earth History Research Center, Keene, TX.
Preserving the record and register of fossils as they occur during quarry development is crucial for careful taphonomic studies. Using data from digital photographs and high-resolution GPS coordinates of the bones, we have recreated precise virtual maps of the distribution of all bones, bone fragments, ossified tendons and teeth from quarries in an extensive Upper Cretaceous (Lance Formation) bone bed in eastern Wyoming.
The bones are field prepared and photographed and GPS data are recorded in situ. The digital images of the bones are then stripped from their background using a "smart edge" feature in Paintshop Pro and converted to TIF files on a white background. The ArcMap module of ArcGIS 8.2 is used to georeference the TIF file of each bone with the GPS data. When the bones have been rectified, they can be imported into the ArcScene 3-D viewer and examined in three space.
Because of limitations in the number of independent images that can be simultaneously displayed in the ArcScene viewer, we have found it convenient to group the bones in clusters by year or by bone type or elevation in the quarry to develop larger georeferenced assemblages of bones that can be treated as single elements. This grouping allows us to display the data by bone type, species, or by distribution in vertical or horizontal space.
As a consequence of applying these techniques, virtually all of the data on location of the bones are preserved intact, and the assemblage can be visualized as it appeared in the ground. Additional data derived from subsequent and previous research on the site can easily be incorporated in the view. The finished views can be exported as image files for use in publications or for field reference. Further analysis can be facilitated by overlaying the bone assemblages with relevant sedimentological and stratigraphical information, greatly enhancing the reconstruction of events related to the bone deposit.