But there are problems with this idea too. (Realistic dinosaur costume)The worst is that powered flrght is most effrcient at moderate speeds, much less so at slow speeds. Since interbranch leaps are rather slow, developlng powered fhght at this stage could be difficult. Interbranch glides are faster, well within the range for efficient flapping fltght. Perhaps it was a combination of developing controls for leaping and landings plus the speed of gliding that contains the answer, but I wouldn’t be surprised if somone ctune up with an aerodynamic criticism of this scenario as well.
Actually, much of this theorizing may be redundant. It is possible that theropods had developed long arm display feathers well before they tried anything aerodynamic with them, as the supposed Triassic feather prints mentioned in Chapter 4 may indicate. (walking dinosaur costume)In this case, small theropods were preadapted for fltght, and we would not need to explain the intitial evolution of wing feathers in aerodynamic terms.s
How well Archaeoptery< flew-and when good, powered fhght was first achieved-is a bone of much contention. I am sure thatArchaeopterSm was a good power-flyer, not just a glider as often thought. It was certainly not the sort of fine-tuned flyer modern birds are, but it is hardly likely that it could have developed all the anatomical refinements of high-performance flight before it could power-fly. It would make more sense that the basics of powered flight would have been achieved before fhght was refined. (Dinosaur costume)In Archaeopteryx the wing feathers are fully aerodynamic, being the asymmetrical winglike airfoils found in modern flyrng birds.6 In a fltght posture, ArchaeopterSx looks reasonably streamlined and aerodSmamic (Animatronic dinosaur for sale). Figure 9-5 shows that the wing’s surface/total weight ratio was well within the flyng bird range, about equal to a crow’s. The -ing bones are also as strong as flyrng birds. The big furcula, created by fusing the clavicles into one unit, helped lock together and immobilize the shoulder girdle. This is disadvantageous in most animals, who need as much arm reach as they can get. But it is a classically avian way of strengthening the shoulder for flight. And not just flight, but powered flight, since flytng squirrels and other gliding mammals do have furculas. Although AtchoeoprerJ ‘s theropod-like shoulder joint is not specifically adapted for flight, I have found that the upper arm of even early theropods such as Coelophysls can be manipulated in the basic flapping pattern of powered fhght ( such experiments cannot be done with Archoeopteryx itself since all the bones are still set in the original slabs).