GIF animation of the Vienna Pterodactylus demonstrating wing extension as reported by Peters (2002). There is no membrane extension possible for the wing membrane posterior to the elbow (the fuselage fillet) to create the deep chord, bat-like wing membrane proposed by Elgin, Hone and Frey (2010) because there is no membrane material there. Neither do the wing membranes attach at the ankle, contra the traditional and imaginary model supported by Elgin, Hone and Frey (2010). There is no "shrinking" of the wing membrane in this fossil either. Wing membranes don't shrink. They tear and fold only due to the imbricating aktinofibrils. This model permits the wing membrane to fold, like a Japanese fan, into the smallest possible area when retracted/folded. A deep chord membrane would droop like a blanket, as demonstrated in various movies improperly featuring deep-chord wing membrane pterosaurs, including those in Jurassic Park III.
Only at full extension do the wings have an aerodynamic shape. If pterosaurs folded their wings in flight, like some birds do, lift would be lost. Also note the relative placements of the elbow, pteroid, wrist and hind limbs. Yes, the hind limbs would have acted like the horizontal stabilizers on a standard airplane, a trait inherited from ancestors as far back as Sharovipteryx. The hind limbs were capable of lateral extension, like those of lizards, not dinosaurs and Scleromochlus. |
