 Locomotion abilities are best studied for Tyrannosaurus and there are two main issues concerning this : how well it could turn ; and what its maximum straight @-@ line speed was likely to have <unk> may have been slow to turn , possibly taking one to two seconds to turn only 45 ° – an amount that humans , being vertically oriented and tail @-@ less , can spin in a fraction of a second . The cause of the difficulty is rotational inertia , since much of Tyrannosaurus ’ mass was some distance from its center of gravity , like a human carrying a heavy timber . 
