Tyrannosaurus was not a fast runner review: Pt. 3

To further back up this claim the authors performed a parameter study to assess the sensitivity of their prediction. Mass was not the only important factor in determining their hypothesis. They also looked into limb orientation, and muscle fiber lengths. Since these data points cannot be determined for sure the authors used conservative assumptions leading to an underestimated value of required muscle mass. They used T as the minimum extensor muscle mass per leg and determined that if T  is 5-25% body mass per leg than the biped could not run fast due to the lack of necessary muscle force. Hutchinson and Garcia’s model predicted that the T value for Tyrannosaurus was between 10-21% per leg which is not adequate enough for it to be considered a fast runner.