Brachiosaurus was a large sauropod dinosaur that lived during the Late Jurassic (155-150 million years ago) in what is now western North America.
The first Brachiosaurs skeleton was discovered in 1900 in Colorado bya collecting crew from the Field Museum of Natural History inChicago, and was described and named in 1903 by Elmer Riggs. Theskeleton was incomplete, so Riggs wasn't sure exactly what Brachiosaurus looked like. Unfortunately, Brachiosaurus is a rare dinosaur. Very few additional boneshave been found over the years, so the picture remains incomplete.Fortunately, skeletons of a closely related sauropod called Giraffatitan from Africa had the missing bones, so thesewere copied and added to the incomplete skeleton of Brachiosaurus, completing the puzzle. This compositeskeleton was exhibited at the Field Museum of Natural history untilit was moved to O'Hare International Airport to make room for'SUE', the famous Tyrannosaurus rex skeleton.