STRATIGRAPHIC AND TAPHONOMIC INTERPRETATIONS OF THE LOWER BONE-BEARING QUARRY OF THE RED CANYON RANCH DINOSAUR SITE IN THE UPPER JURASSIC MORRISON FORMATION, SHELL, WYOMING

We studied a site at Red Canyon Ranch near Shell, Wyoming, in order to understand the local paleoenvironments preserved in the Upper Jurassic Morrison Formation. Abundant dinosaur material occurs at this site at two intervals. We concentrated on the lower of the two bone-bearing intervals. Layers at this horizon are typically crossbedded, very fine to fine sandstones that preserve moderately large, disarticulated dinosaur vertebral elements. These are topped by a mud pebble conglomerate layer that preserves fragmentary dinosaur bones and teeth. The stratigraphic and taphonomic interpretation of this bone bearing interval shows strong evidence of a high sinuosity fluvial paleoenvironment. This is also shown by the overall rounded surfaces and scattered distribution of the bones and teeth found in the quarry. We mapped each bone before removal using high resolution differential GPS and entered the data into Arc GIS. We took pictures of each bone and used these to replace the GPS point in order to reconstruct the distribution of bones in the quarry. The project has helped us to better understand the paleoenvironment of the area, as well as, aided better visualization of the quarry.