Brachiosaurus is known from all parts of the skeleton except for the important neural arches of the caudal cervical and cranial dorsal vertebrae and much of the pes. It was one of the largest sauropods and the one in which the lengthening of the forelimb relative to the hindlimb reached its extreme. 

B. althithorax was present in the Late Jurassic of  North America, B. brancai in eastern Africa, and B.atalaiensis in Europe. The skull is relativily large, of the general camarasaur type but broader and with a more elongate snout. The jaws are robust with broad subspatulate teeth, the crowns convex laterally, concave medially, many with a median ridge.