Scientists have shown that the most complete giant, 26 metres long sauropod dinosaur, Dreadnoughtus, discovered in South America in 2014, was not as large as previously thought.
To estimate the mass of Dreadnoughtus scientists originally used a scaling equation that predicts body mass based on the size of thigh and arm bones. This method produced a range of estimates with the average being a colossal 60 tonnes.
Now another group of scientists have used a three-dimensional skeletal modelling technique to examine body mass more directly and found that the mass of the Dreadnoughtus was more likely to be between 30 and 40 tonnes, considerably less than originally thought.
Ah yes, the 'digitally dunking a toy model in water to measure displacement' method of estimating mass. I'll stick to the 'mass estimation' technique of Campione, et. al., 2014.