A new approach to evaluate the cursorial ability of the giant theropod Giganotosaurus carolinii

The cursorial capability of the South American giant theropod Giganotosauru s carolinii should have been quite limited taking into account the strength indicator of its femur (approximately 7 GPa(-1)) as well as the risk of ex periencing grave or even lethal injuries involved in the falling of this mu ltitonne animal on a run. However, even at low speeds a fall would have cau sed serious injuries. Thus, in accordance to the approach developed in this study, the maximum speed of Giganotosaurus should be not that which will i mplicate corporal lesions with minimum probability of lethalness. Instead, its maximum speed should be that which would permit the recovery of body eq uilibrium as each step is taken. Taking into consideration this approach, a n indicator of stability is defined for bipedal, cursorial animals. This in dicator is determined by the relationship between the time available for th e movement of hip joint during the retraction of a hindlimb and the time ne eded to move the opposite hindlimb by an angle (in function of the speed) o f sufficient magnitude as to facilitate the recovery of body equilibrium. T his indicator was used to estimate the maximum speed of locomotion of Gigan otosaurus (about 14 m s(-1)) at which, from a kinematic point of view, the danger of falling does not exist.