Atlasaurus differs from Brachiosaurus relative to the estimated length of the dorsal vertebral column (assuming 12 vertebrae, 3 meters ), in having a proportionately larger skull, a shorter neck (with at least 13 cervical vertebrae, shorter and more uniform in length than Brachiosaurus), a longer tail and more elongated limbs (humerus to femur ratio: 0.99; ulna to tibia ratio: 1.15).