The Morrison Formation is a distinctive sequence of Upper Jurassic sedimentary rock found in the western United States which has been the most fertile source of dinosaur fossils in North America. It is composed of mudstone, sandstone, siltstone, and limestone and is light gray, greenish gray, or red. Most of the fossils occur in the green siltstone beds and lower sandstones, relics of the rivers and floodplains of the Jurassic period.
The distinctive banding of the Morrison Formation, a group of rock layers that occur throughout Dinosaur National Monument and the source of fossils like those found at the Dinosaur Quarry
Stratotypes for members of the Morrison Formation
Brushy Basin Member showing the purple and red colors of paleosols (ancient soils). East side of the San Rafael Swell, Emery County, Utah.
Gypsiferous facies of the Ralston Creek Member exposed in a road cut, Fremont County, Colorado.
The Bone Wars, also known as the Great Dinosaur Rush, was a period of intense and ruthlessly competitive fossil hunting and discovery during the Gilded Age of American history, marked by a heated rivalry between Edward Drinker Cope and Othniel Charles Marsh. Each of the two paleontologists used underhanded methods to try to outdo the other in the field, resorting to bribery, theft, and the destruction of bones. Each scientist also sought to ruin his rival's reputation and cut off his funding, using attacks in scientific publications.
The rivalry between Othniel Charles Marsh (left) and Edward Drinker Cope (right) sparked the Bone Wars.
Marsh (back row and center), surrounded by armed assistants for his 1872 expedition. Marsh spent little time in the field himself, generally delegating these tasks to his agents.
Marsh and Lakota Chief Red Cloud in New Haven, Connecticut, c. 1880
The Morrison Formation at Como Bluff, Wyoming