Its exact size is unclear because of the incompleteness of the fossils. Estimates have been based on skull, teeth, and limb bone measurements. However, the known bone elements are from individuals of different sizes. All skeletal reconstructions are composite extrapolations. This resulted in weight estimates from 11 to 20 tonnes. Its shoulder height has been estimated as . Its length was about from front to back. As explained, such figure are only approximations. These figures are for the largest of the three species in the genus.