Jurassic Morrison Marshosaurus Tooth with Allosaurus Tooth VF-JC-24-003Marshosaurus bicentesimus with Allosaurus sp. Morrison Formation Brushy Basin Member Upper Jurassic Moffat County, Colorado Here is an outstanding and large example of the very rare Morrison carnivorous dinosaur Marshosaurus. The tooth is 5. 2 cm long and 2 cm wide at the base. The tooth is slender in cross section and the serrations are smaller than other Morrison carnivorous dinosaurs. The serrations on the mesial carina of the tooth extend one half