Brontosaurus
"Brontosaurus" was a large, long-necked quadrupedal animal with a long, whip-like tail, and forelimbs that were slightly shorter than its hindlimbs. The largest species, "B. excelsus", weighed up to and measured up to long from head to tail. For comparison, the current largest land animal, the average male African bush elephant is 3.20 m (10.5 ft) tall at the shoulder and has a body mass of 6,000 kg (13,228 lb) or 6.6 short tons.
Brontosaurus
The Morrison Formation records an environment and time dominated by gigantic sauropod dinosaurs. Dinosaurs known from the Morrison include the theropods "Ceratosaurus", "Ornitholestes", and "Torvosaurus", 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".