Apatosaurus opponent of Marsh and his taxa, labeled the "Apatosaurus" mount of the American Museum of Natural History "Brontosaurus". Because of this decision the name "Brontosaurus" was commonly used outside of scientific literature for what Riggs considered "Apatosaurus", and the museum's popularity meant that "Brontosaurus" became one of the best known dinosaurs, even though it was invalid throughout nearly all of the 20th and early 21st centuries. It was not until 1909 that an "Apatosaurus" skull was found during the first expedition, led by Earl Douglass, to what would become known as the Carnegie Quarry at Dinosaur National Monument. The skull
Dinosaur Ridge Dinosaur Ridge Dinosaur Ridge is a segment of the Dakota Hogback in the Morrison Fossil Area National Natural Landmark located in Jefferson County, Colorado, near the town of Morrison and just west of Denver. The Dinosaur Ridge area is one of the world's most famous dinosaur fossil localities. In 1877, some of the best-known dinosaurs were found here, including "Stegosaurus", "Apatosaurus", "Diplodocus", and "Allosaurus". In 1973, the area was recognized for its uniqueness as well as its historical and scientific significance when it was designated the Morrison Fossil Area National Natural Landmark by the National Park Service. In 1989, the