a huge sauropod dinosaur of the genus Brachiosaurus, having a small head with nostrils on a knob above the eyes, long forelegs, and a sloping, massive body, and reaching a length of about 80 feet (24 meters).
Origin of brachiosaur
< New LatinBrachiosaurus (1903); see brachio-, -saur; so named in allusion to the unusual length of the humerus relative to the femur
(brā'kē-ə-sôr'əs) A very large sauropod dinosaur of the genus Brachiosaurus of the Jurassic and Cretaceous Periods. It had forelegs that were longer than its hind legs, and nostrils on top of its head.