Physical and Environmental Geography Commons^™

Late Jurassic Dinosaurs On The Move, Gastroliths And Long-Distance Migration, Josh Malone

Geography: Student Scholarship & Creative Works

The Jurassic Morrison Formation of the Rocky Mountain and Colorado Plateau regions is famous for its dinosaur fossils. The Morrison Formation (150-157 Ma) is comprised mostly of sandstone and mudstone that was deposited in a terrestrial deposition system that included fluvial, paludal, and lacustrine environments. Paleocurrent data indicates that Morrison sediment was transported to the north and east. Within the Morrison Formation, we find exotic pebble and cobble-size durable clasts of quartzite, chert and vein quartz weathering out of the mudstone paleosols. We interpret these exotic clasts as gastroliths, carried within the gastric mills of dinosaurs. For this study, we …