environment with distinct wet and dry seasons. The Morrison Basin, where dinosaurs lived, stretched from New Mexico to Alberta and Saskatchewan, and was formed when the precursors to the Front Range of the Rocky Mountains started pushing up to the west. The deposits from their east-facing drainage basins were carried by streams and rivers and deposited in swampy lowlands, lakes, river channels, and floodplains. This formation is similar in age to the Lourinha Formation in Portugal and the Tendaguru Formation in Tanzania. Brontosaurus may have been a more solitary animal than other Morrison Formation dinosaurs. As a genus, Brontosaurus existed for a long span of time, and have been found in most levels of the Morrison. B. excelsus fossils have been reported from the upper Salt Wash Member to the upper Brushy Basin Member, ranging from the middle to late Kimmeridgian age, about 154–151 Mya. Additional remains are known from even younger rocks, but they have not been identified as any particular species. Older Brontosaurus remains have also been identified from the middle Kimmeridgian, and are assigned to B. parvus. Fossils of these animals have been found in Nine Mile Quarry and Bone Cabin Quarry in Wyoming and at sites in Colorado, Oklahoma, and Utah, present in stratigraphic zones 2–6. The Morrison Formation records an environment and time dominated by gigantic sauropod dinosaurs. Dinosaurs known from the Morrison include the theropods Ceratosaurus, Ornitholestes, and Allosaurus, the sauropods Apatosaurus, Brachiosaurus, Camarasaurus, and Diplodocus, and the ornithischians Camptosaurus, Dryosaurus, and Stegosaurus. Other vertebrates that shared this paleoenvironment included ray-finned fishes, frogs, salamanders, turtles, sphenodonts, lizards, terrestrial and aquatic crocodylomorphans, and several species of pterosaurs. Shells of bivalves and aquatic snails are also common. The flora of the period has been revealed by fossils of green algae, fungi, mosses, horsetails, cycads, ginkgoes, and several families of conifers. Vegetation varied from river-lining forests of tree ferns, and ferns (gallery forests), to fern savannas with occasional trees such as the Araucaria-like conifer Brachyphyllum. In popular culture The length of time taken for Riggs's 1903 reclassification of Brontosaurus as Apatosaurus to be brought to public notice, as well as Osborn's insistence that the Brontosaurus name be retained despite Riggs's paper, meant that Brontosaurus became one of the most famous dinosaurs. Brontosaurus has often been depicted in cinema, beginning with Winsor McCay's 1914 classic Gertie the Dinosaur, one of the first animated films. McCay based his unidentified