Figure 1. The Yale specimen of Rhamphorhynchus phyllurus with preserved wingtip ungual highlighted. See figure 2 for closeup.
The Yale specimen of Rhamphorhynchus phyllurus (Figs. 1, 2; VP 1001778) has one painted wing tip and one that may include another wingtip ungual.
Figure 2. Closeup of Rhamphorhynchus phyllurus in figure 1 focusing on the preserved wingtip ungual. Was this carved in? Or is it real? Note the cylindrical tip of the penultimate wing phalanx (m4.4). The wingtip was buried deep within the matrix and had to be exposed.
The wingtip
was buried deep within the matrix and had to be exposed. So the question is: was it carved? Or is it real? If it was carved, why was it carved? Traditionally pterosaurs are not supposed to have wing tip unguals, but I’ve found them in several specimens.
You might remember
we looked at this wing tip earlier with a different provided image. The present one appears to offer more clues.
The Pterosaur Heresies 
It’s neither carved nor real. It’s a combination of preparation scratches around the wingtip and, well, your usual pareidolia. Get a better photo (or *gasp* visit the specimen).