The Ferris Formation is a Late Cretaceous to Paleocene, fluvial-deltaic geological formation in southern Wyoming. It contains a variety of trace and body fossils, preserved in sandy fluvial channel deposits and overbank units. Dinosaur remains are fragmentary, but include Triceratops, Tyrannosaurus, dromaeosaurids, Paronychodon, Richardoestesia, Edmontosaurus, Edmontonia, Ankylosaurus, and Pachycephalosaurus.