Dinosaurs may not have been as monstrously heavy as previously thought, because of flaws in the statistical model to calculate their weight, researchers reported on Sunday.

Widely cited estimates for the mass of Apatosaurus louisae, one of the largest of the dinosaurs, may be double that of its actual mass, the researcher said in the Zoological Society of London's Journal of Zoology.

Apatosaurus was said to have weighted 38 tons but its actual mass may be only 18 tons, they claimed.

"Paleontologists have for 25 years used a published statistical model to estimate body weight of giant dinosaurs and other extraordinarily large animals in extinct lineages, " lead researcher Gary Packard from Colorado State University said in a statement.

"By re-examining data in the original reference sample, we show that the statistical model is seriously flawed and that the giant dinosaurs probably were only about half as heavy as is generally believed."


Visitors look at one of the dinosaur, during the Dinosaurs of Argentina exhibition in Belgrade, Serbia, Friday, June 19, 2009. Among the most attractive exhibits are the complete skeletons of seven dinosaurs, including a 14-meter-long gigantosaurus from the Cretaceous period and a 17-meter long rebbachisaurus, a herbivore from the same period. [China Daily/Agencies]
The new predictions have implications for numerous theories about the biology of dinosaurs, ranging from their energy metabolism to their food requirements and to their modes of locomotion, the researchers said.

Source: China Daily/Agencies