size are based on a comparison between the four Sauroposeidon vertebrae and the vertebrae of the HM SII specimen of Giraffatitan brancai, located in the Berlin's Natural History Museum. The HM SII is the most complete brachiosaur known, though since it is composed of pieces from different individuals its proportions may not be totally accurate. Comparisons to the other relatives of Sauroposeidon are difficult due to limited remains. The neck length of Sauroposeidon is estimated at , compared to a neck length of for the HM SII Giraffatitan. This is based on the assumption that the rest of the neck has the same proportions as Giraffatitan, which is a reasonably good conjecture.Sauroposeidon was probably able to raise its head above the ground, which is as high as a six-story building. In comparison, Giraffatitan could probably raise its head into the air.Sauroposeidon's shoulder height has been estimated at based on an interpretation of the animal as a brachiosaurid. Estimates of its total possible length have ranged from to .Paul, G.S., 2016, The Princeton Field Guide to Dinosaurs 2nd edition, Princeton University Press p. 230 The mass of Sauroposeidon is estimated at . While the vertebrae of Sauroposeidon are 25–33% longer than Giraffatitan', they are only 10–15% larger in diameter. This means that while Sauroposeidon probably has a larger body than Giraffatitan its body is smaller in comparison to the size of its neck, so it did not weigh as much as a scaled-up Giraffatitan. By comparison, Giraffatitan might have weighed . This estimate of the Giraffatitan is an average of several different methodologies. However, Sauroposeidon has a gracile neck compared to Giraffatitan. If the rest of the body turns out to be similarly slender, the mass estimate may be too high. This could be similar to the way the relatively robust Apatosaurus weighs far more than the longer but much slimmer Diplodocus. In addition, it is possible that sauropods may have had an air sac system, like those in birds, which could reduce all sauropod mass estimates by 20% or more. Paleoecology Sauropods, which include the largest terrestrial animals of all time, were a very wide-ranging and successful group. They first appeared in the Early Jurassic and soon spread across the world. By the time of the late Jurassic, North America and Africa were dominated by the diplodocids and brachiosaurids and, by the end of the Late Cretaceous, titanosaurids were widespread