Scientists have used an imaging technique, called Laser-Stimulated Fluorescence, which allows them to see fossilized soft tissue that is invisible to the eye.

This technique uses a laser to excite the various minerals and chemicals present within the fossil, making the soft tissues fluoresce and stand out. With this, they have been able to see details of wing membranes, and on several pterosaur specimens, evidence of webbing between the feet and membranes on the tail. [4][5]