The Pterosaur: The take-off
The pterosaur wing was supported from an enormously extended fourth digit (finger) on the front limb. From this the wing was extended, in somewhat batlike fashion, a great wing membrane. Manipulation of a wing of this sort would appear to have been an awkward matter, and flight was originally considered to be mostly achieved by soaring rather than flapping. Further since there are no intermediate fingers extending into the wing membrane, it was originally thought to have been very fragile. The hind legs of pterosaurs, in stark contrast to most birds, were feeble structures, and it is difficult to see how these creatures could have stood up, let alone get a running take-off as birds do today.