To drive all those pointed tail spikes deep into the body of its adversaries, Stegosaurus required a tail of great power and flexibility, and both qualities were in abundant supply. (animatronic dinosaur costume)To acquire flexibility in the tail, the stegosaurs’ evolution had to dispose of a major feature of their ancestry, the system of stiff tendons. Most beaked dinosaurs featured a latticework of bony tendons running down either side of their backbones from torso to tail. And all the earliest, most primitive beaked dinosaurs possessed such equipment.
As has already been discussed, this latticework-best seen in duckbills and horned dinosaurs—would have provided an advantage for supporting the body weight without muscular effort. (life size dinosaur for sale)But such bony tendons would have stiffened the stegosaur’s tail too much for easy swinging. Evolution therefore eliminated the system of tendons and the stegosaurs were the only beaked dinosaurs to do away with bony tendons entirely. But merely elimi-nating bony tendons wouldn’t have been enough to render the stegosaur’s tail optimally dangerous. Since the spikes stood at the tail’s extreme tip, the bones of the tail had to be both strong and flexible all the way to the end. In most dinosaurs the tail joints grew progressively stiffer toward the end, but not so in stegosaurs. (real size dinosaur)The joints between the successive segments of the tail gave its entire length from rump to tip enough suppleness to flex in a graceful S-shaped curve, and the vertebrae were much stronger than usual near the end.
To achieve the muscular strength necessary to swing its club, the stegosaur evolved enlarged shelves of bone for anchoring its muscles (similar shelves had evolved in the big-tailed brontosaurs, such as Diplodocus). (life like dinosaur)A twenty-foot-long stegosaur would have had more strength in its tail muscles than a large modern elephant has in one of its hind legs. And when the mighty tail muscles contracted, the stegosaur’s caudal club swung with irresistible authority.