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
Jurassic epochs: Early, Middle, and Late. Similarly, in stratigraphy, the Jurassic is divided into the Lower Jurassic, Middle Jurassic, and Upper Jurassic series of rock formations, also known as "Lias", "Dogger" and "Malm" in Europe. The separation of the term Jurassic into three sections originated with Leopold von Buch. The faunal stages from youngest to oldest are: During the early Jurassic period, the supercontinent Pangaea broke up into the northern supercontinent Laurasia and the southern supercontinent Gondwana; the Gulf of Mexico opened in the new rift between North America and what is now Mexico's Yucatan Peninsula. The Jurassic North Atlantic Ocean