Mammal and adult bird joints have highly finished or ossified bone surfaces covered by a thin veneer of cartilage. Animatronic Dinosaur joint bone surfaces are mgose and pitted, showing they were capped by thick cartilage joint surfaces. You can see cartilage joints of this type next time you have poultry for dinner. Birds become fully grown in size before their joints are fully ossifiedthat is, before their bone structure is completely mature. Because it wastes money to feed fowl after they have reached their maximum weight, slaughter houses do them in at this stage. When examining the knee of your meal, notice that the cartilage articular surfaces are very precisely sculpted. animatronic dinosaur costume Adult bird knees look just the sarne,’but the cartilage has turned into bone. Crocodilians also have complex cartilagenous limb joints, but they retain them into full adulthood. Theropods followed much the same pattern of development.
Predatory dinosaur hind limbs were running legs that worked like those of birds. Because the hip socket, knee, and ankle were rylinders that worked only fore and aft, and the shank bones were locked together, the limb was “stiff.” It could not rotate much about its long axis, and its action was always close to vertical. It could not splay outward, despite drawings that show otherwise.2o Recently, Archaeopterw was accused of having a more lizard-like sprawling gait, in part because the hip socket is closed off to a degree on the inside.2t Actually, a number of bird hip sockets are partly closed, and it is even a little so in the protobird Velociraptor antirrhopus. Animatronic dinosaur for sale Overall, the hip joint of Archaeopteryx is of the erect theropod-avian t54le, and it worked that way. The theropod femur and knee were bowed out a little, especially as they swung forward and had to clear the belly. The ankle is also bowed a little, in its case inward. Such bowed-knee, knock-ankled limbs can be seen in birds, in horses, and in antelope. Fossil footprints confirm that predatory dinosaur feet paced along a nanow-gauge trail or trackway-the faster the gait, the nanower the trackway tended to be. Trackways also show that theropods were sometimes a little pigeon-toed, rarely did the feet splay outwards instead. Some have attributed this to a ducklike waddle. Theropods probabty did waddle a little, but these longlimbed, naruow-hipped animals moved smoothly, more like the big ground birds than like fat-hipped ducks. Most of the pigeontoing was inherent to the foot itself.