Brontosaurus << BRON toh `sawr` us >> is one of the most famous dinosaurs of all time. Upon its discovery, Brontosaurus was hailed as a new type of dinosaur. Scholars later concluded that the Brontosaurus fossils actually belonged to a previously discovered dinosaur named Apatosaurus. The name Brontosaurus fell into scientific disuse, but it remained popular in the public imagination. More recent studies have suggested that Brontosaurus is indeed distinct from Apatosaurus. Brontosaurus was a sauropod, a type of gigantic, long-necked, plant-eating dinosaur. Brontosaurus lived about 150 million years ago in what is now the western United States. The name Brontosaurus means thunder lizard. It refers to the sound such a huge animal might have made as it walked.
Brontosaurus may have grown to about 75 feet (23 meters) in length. It reached 15 feet (4.5 meters) high at the hips and weighed about 20 to 30 tons (18 to 27 metric tons). It had a small, narrow head that sat atop a long, thick neck. The neck was narrower but deeper than that of Apatosaurus. The neck was nearly triangular cross-section, being broad across the bottom and narrow on top. Brontosaurus had a short torso (central portion of the body), with its back sloping gently down from hips to shoulders. Its long tail was thick at the base but quickly narrowed, becoming thin and whiplike at the tip. Two massive hind limbs bore most of the animal’s weight, on padded feet with large claws. The forelimbs were relatively short, and each forefoot had only one small claw.
Brontosaurus was named in 1879 by the American paleontologist (scientist who studies prehistoric life) Othniel C. Marsh, based on a fairly complete fossil skeleton. In 1905, the American Museum of Natural History, in New York City, unveiled a mounted skeleton designated Brontosaurus—the first publicly exhibited skeleton of any sauropod. It is not clear whether this specimen was actually Brontosaurus, however. In 1931, Marsh’s original skeleton was mounted, also under the name Brontosaurus, at the Peabody Museum at Yale University in New Haven, Connecticut. These mounted skeletons, together with many illustrations made using them as guides, helped to make Brontosaurus one of the best-known dinosaurs.
Scientists soon realized similarities between Brontosaurus and Apatosaurus, which Marsh had discovered two years earlier. In 1903, the American paleontologist Elmer Riggs proposed that the skeletons were of the same dinosaur, and most other paleontologists agreed. Because Apatosaurus had been described first, that name was kept and Brontosaurus was discarded. But the name remained popular and persisted in advertisements, books, films, and toys. In 2015, a team of paleontologists studied the bones of many sauropods. Their analysis suggested that Brontosaurus is indeed distinct from Apatosaurus.
