Brontosaurus excelsus

The Brontosaurus, one of the most iconic sauropods, lived during the Late Jurassic period, roughly 154 to 153 million years ago, and is best known for its long neck, relatively small head, and massive, robust body that could grow up to 72 feet long and weigh around 15 to 20 tons. Once thought to be a misidentified species of Apatosaurus, the Brontosaurus was eventually recognized as distinct, with key differences such as a slightly shorter, more arched neck, and a differently shaped skull, which was still small compared to its body size. Like other large sauropods, the Brontosaurus was a herbivore, likely feeding on a variety of plants, including conifers, cycads, and ferns, using its long neck to reach vegetation high in the trees as well as on the ground. Despite its immense size, it likely had a relatively slow metabolism, and its small, peg-like teeth were adapted for stripping leaves rather than chewing, meaning it likely ingested large quantities of food at once. Fossils suggest Brontosaurus may have lived in herds, which could have provided protection from predators such as the fearsome Allosaurus, and its long tail, capable of swinging like a powerful whip, might have been used both for communication within the herd and as a defensive tool.