tag:blogger.com,1999:blog-3739684561063978507.post8554519158747622162..comments2024-03-22T21:58:18.933+00:00Comments on ShukerNature: FROM DEVILISH GECKO TO DERIVED DRAGONET - YET ANOTHER PHOTO-MANIPULATED METAMORPHOSISAnonymoushttp://www.blogger.com/profile/15628598508836601012noreply@blogger.comBlogger1125tag:blogger.com,1999:blog-3739684561063978507.post-77336893521529445242023-03-03T09:23:04.606+00:002023-03-03T09:23:04.606+00:00The aerodynamics of Sharovipteryx mirabilis puzzle...The aerodynamics of Sharovipteryx mirabilis puzzle me. Putting the center of mass ahead of the center of lift (or rather, drag) is almost essential for stable flight, (compare darts,) but if they're not close together it becomes impossible to keep the nose up. (It can take a bit of thought to understand.) With its torso well ahead of the geometric center of its wing and its skull much further ahead still, Sharovipteryx's centers of mass and lift appear to confine it to suicidal plummeting! Perhaps it dove into water from overhanging tree branches, fishing in a similar manner to certain birds, but diving so close to shore seems terribly risky.<br /><br />The posterior of the wing membrane would have offered a large aerodynamic control surface if the legs were capable of a strong twisting motion, but is that likely? Something more likely is shown in a skeletal reconstruction on Pterosaur Heresies: a tail fin much larger than in Dmitry Bogdanov's reconstruction here. If it was horizontal and the tail was strong enough, such a large fin on the end of such a long tail may very well have given it the ability to lift its nose to glide horizontally.<br /><br />But I'm forgetting its canards -- the control surfaces on the back of its head and its arms. Such anterior control surfaces tend to instability but can be very effective. Perhaps there is no need to speculate about the tail after all.<br /><br />Almost regardless of the canards, having the center of mass so far forward of the center of lift indicates the creature may have needed to glide very fast to maintain control. The canards would have given great maneuverability in the vertical axis, while the webbed toes at the ends of its wings may, at speed, have been used to steer by differential drag. Perhaps the tail was used for control, or perhaps just for stability. A picture thus emerges of a very fast, maneuverable little flyer, perhaps hunting insects, turning sharply to catch them. It would have been a marvelous sight! :)<br /><br />Finally, there's the matter of it looking like a supersonic aircraft. Why? Well, :) if I understand right, it was a very early lizard. (I suppose that's what "basal" means.) Thus, it existed an exceptionally long time ago. We know Earth's atmospheric composition was somewhat different in the time of the dinosaurs; what about Sharovipteryx's time? Supposing the atmosphere back then was much denser than it is today, the speed of sound may have been low enough to make this possible, :) especially at low altitudes I don't think it could have flown much faster than Mach 1 though. (Mach numbers are always relative to the speed of sound in the air surrounding the aircraft.) If it did exceed the speed of sound, differential drag from the toes would have offered extreme lateral maneuverability.Ethan Gardenernoreply@blogger.com