Yes, dinosaur bones have been rearranged after they were mounted. This is because the field of dinosaur study is constantly changing as more bones are found, or more studies are completed. For example, in early 1999, scientists used a computer model of sauropod dinosaurs—dinosaurs with a neck up to 40 feet (12 meters) in length. Most of these animals were posed by museums with long S-shaped necks that would allow them to reach high into the tall trees to gather leaves. But the computer model indicated that the animals could not lift their heavy necks because the vertebrae were too heavy. These dinosaurs probably kept their necks straight out and may have chewed on lower-lying shrubs. Thus, many museums had to rearrange their sauropod mounts to fit the newest discovery.