Brontosaurus or Apatosaurus?

by AMNH on

On Exhibit posts

It’s one of the most recognizable dinosaur species, yet most people know it by a name most paleontologists stopped using more than a century ago: brontosaurus.

One of the most iconic specimens of this massive animal is on display in the Hall of Saurischian Dinosaurs, the first sauropod—a species belonging to the group of massive, herbivorous, long-tailed dinosaurs—to be mounted and displayed at the Museum.

Museum preparators work on a mount of a dinosaur, then known as Brontosaurus, in 1904.
©AMNH Library/Image no. 17506

By the time that Museum paleontologist Walter Granger discovered a large set of fossilized bones at Wyoming’s Como Bluff in 1898, O. C. Marsh of Yale University had already characterized what he believed to be two distinct sauropod species: Apatosaurus and Brontosaurus. Granger believed his findings, catalogued as AMNH 460, to be Brontosaurus.  

The Museum’s “Brontosaurus” took six years to mount and used four different specimens collected from Como Bluff by Granger and other Museum paleontologists. Casts from Marsh’s Apatosaurus were used to fill in the missing bones, and since Granger and his team did not find a head with their specimen, they gave it a sculpted head of another sauropod, Camarasaurus. Figuring out how to support the large skeleton was another challenge, since no specialized materials existed for this purpose. The mount was later revised to be more anatomically accurate, but the original framework—which consists of repurposed pipes and plumbing fixtures—still supports the dinosaur’s torso.

By the time the mount was complete in 1905, the dinosaur’s name had been officially changed. In 1903, Elmer Riggs, a paleontologist from the Chicago’s Field Museum of Natural History made the case that Apatosaurus was actually a juvenile Brontosaurus, and that the two names actually referred to the same species. The name given to the first specimen of the species to be discovered, Apatosaurus, became the accepted scientific name; Brontosaurus became invalid, or, at best, considered a redundancy—even though for most people, Brontosaurus remained the best-known name for the popular dinosaur.

Nearly a century after it was first mounted, the Museum’s Apatosaurus underwent another major revision. During the renovation of the fossil halls in the 1990s, in a project that took three preparators a year to complete, four neck vertebrae were added and the tail was extended and lifted off the ground to reflect the lack of evidence for a dragging tail in preserved sauropod tracks.

The Apatosaurus also received a new head to replace the Camarasaurus skull used by Granger in 1905. Earl Douglass, of Pittsburgh’s Carnegie Museum found an Apatosaurus skeleton with a detached skull nearby a few years after the Apatosaurus was first mounted, but for decades paleontologists disagreed over whether the skull belonged with the body. During the renovation of the fossil halls, the Museum replaced the Camarasaurus head with a cast of the skull from the Carnegie Museum.