In New Mexico, there is a fossil quarry that contains numerous specimens of Coelophysis, which is a small, thin dinosaur with a long neck who lived in the late Triassic. It is thought that it's long tail balanced it's weight whenever it moved.
The bone bed containing these specimens is called Ghost Ranch. It is named after a farm close to it and is east of Petrified Forest National Park in Arizona. Both of these places contain the Chinle Formation. The prehistoric rocks in the formation contain fossils. They were once layers of sediment emitted by rivers. In prehistory, a herd of Coelophysis sank into mud. They stayed there until they were excavated in the late 1940s. Ghost Ranch is located in Chama River Valley and is near Abiquiu, a New Mexican town.
Dr. Edwin Colbert, an American paleontologist who was born in 1905 and died in 2001, discovered more than 500 Coelophysis specimens while he was at Ghost Ranch in 1947.