User:Ashorocetus/sandbox/Dinosaur size

Size has been one of the most interesting aspects of dinosaur science to the general public. In addition to public interest, size is important for paleontologists because it is correlated with ecological roles, physiology, and biomechanics of dinosaurs.

Estimating Size
Since dinosaurs are often known from fragmentary remains, it is impossible to tell exactly how big they were.

Mass
Mass is estimated either by using models or by taking advantage of scaling relationships between skeletal dimensions (like combined circumference of the humerus and femur) and body mass. For example, Argentinosaurus, one of the largest dinosaurs known, was estimated to be roughly 73 tonnes by using several regression equations relating limb bone dimensions to body mass. Measuring the volume of a computer generated model of Argentinosaurus yielded an estimated 83 tonnes, and an estimate based on the circumference of the femur and reconstructed humeral circumference gave approximately 90 t.

Length
Length is usually easier to estimate than mass in dinosaurs. If a species is know from fairly good remains, one can simply measure the head-to-tail length of the skeleton. In the case of less complete remains, typically the dinosaur can be reconstructed and length estimated from the reconstruction, but occasionally isometry or allometry are used to estimate length.