Illustration of hypothetical model of how thrust and lift may be generated.

<p>Using the tail-membrane fanning motions (black arrow indicates direction of travel) of a long-eared myotis (<i>Myotis evotis</i>), we illustrate a hypothetical duel-use of the tail-wing wherein dorsal extension and downstoke above the body plane delivers thrust, whereas ventral flexion generates thrust and also lift when held in a curved position below the body axis. This positioning would be analogous to an airplane extending its flaps to increase air-speed above a flight surface.