It is assumed that all fairies once had wings, and that they are descended from airborne dinosaurs such as pterodactyls. Apparently, the upper body skeletal structure is mostly the same and the argument is reinforced by the nubs of bone on each shoulder blade. The wings are a sprite's biggest organ, with 7 major arteries going through them. This means that geeting a wing injury can be very dangerous for a sprite. One such example is when Chix Verbil became the first casualty of the B'wa Kell goblin revolution by geeting shot in the wing by a battery powered Softnose laser. This one hit and punctured 3 arteries and if Captain Holly Short hadn't disobeyed orders then he would have bled out very quickly.