Supersaurus << SOO pur `sawr` uhs >> was one of the largest dinosaurs that ever lived. It measured from 100 to 130 feet (30 to 40 meters) long, stood about 27 feet (8.2 meters) tall at the hips, and may have weighed more than 40 tons (36 metric tons). This enormous reptile lived about 150 million years ago, near the end of the Jurassic Period. It inhabited what is now the western United States.
Supersaurus belonged to a group of gigantic, long-necked dinosaurs called sauropods. The animal’s slender neck may have stretched as long as 40 feet (12 meters). Its huge, whiplike tail probably extended about 50 feet (15 meters). Because of its large size, Supersaurus moved slowly on its four short, thick legs.
Supersaurus ate plants. Its mouth probably had peg-shaped teeth for stripping bark and leaves from trees. Such a huge animal would have eaten tons of plant material every day.
The American paleontologist James A. Jensen discovered Supersaurus in 1972. Jensen found a fossilized shoulder blade in Colorado that measured about 8 feet (2.4 meters) long. Few fossils of Supersaurus exist, and no complete skeleton has been assembled. Most of what scientists know about the dinosaur comes from comparing its fossils with those of better-known sauropods, such as Apatosaurus. 
See also Dinosaur (Kinds of dinosaurs); Sauropod.
