Dreadnoughtus

Dreadnoughtus is a titanosaurian sauropod dinosaur genus with just one species, Dreadnoughtus schrani. D. schrani is known from two fragmentary skeletons recovered in Upper Cretaceous (Campanian to Maastrichtian; roughly 76-70 Ma) rocks of Argentina's Cerro Fortaleza Formation. It is one of the biggest terrestrial vertebrates known, with the juvenile type specimen attaining a total body length of 26 meters (85 feet) and having the highest mass of any land animal that can be computed with fair accuracy. D. schrani has the most complete skeletons of any enormous titanosaurian.

Dreadnoughtus schrani's weight was approximated using Equation 1 of Campione and Evans (2012), which allows the body mass of a quadruped to be determined based only on the circumference of the humerus and femur. Using this scaling equation, they determined that the Dreadnoughtus specimen weighed around 59.3 tonnes (58.4 long tons; 65.4 short tons).

Gregory S Paul responded to Lacovara et al., pointing out that the error margins for calculations based on limb bones are enormous; applying the same equation, the Dreadnoughtus type specimen may have weighed anywhere between 44 and 74 tonnes (43–73 long tons; 49–82 short tons). Paul calculated as low as 26 tonnes using volumetric approaches based on a more realistic skeleton repair (26 long tons; 29 short tons).