When I made my dragon I used paper spikes to add texture to its skin, and when I'd finished I had a bunch of them left over.  I think they look a lot like the papillae inside a leatherback turtle's mouth, and that gives me an idea.

Picture from the always excellent Science-Based Life blog.

I had a bit of a play with the spikes, making some papillae.  I think I need a few more spikes, but the basic idea is very interesting and I think I can develop it into something cool.