PhyloPic

You don't know about PhyloPic?  Shame on you.  PhyloPic is an open database of life form silhouettes, and includes plenty of flying creatures, both living and fossil.  The fantastic silhouette of Archaeopteryx that current graces the header of the Aero Evo page comes from PhyloPic, and was rendered by the site's creator, T. Michael Keesey.  The equally impressive Tupandactylus imperator is by Evan Boucher, and the fantastic little Drosophila (obviously not to scale) is by Ramiro Morales-Hojas.  Check out their work on PhyloPic. All three of those vector images are freely available.  There are hundreds more on the site.

Go check it out using the link above or clicking here.