The vagaries of preservation in fossils means that different specimens provide different things. Some have exceptional bones, some have bits or even lots of soft tissue, some preserve unusual features or things seen in odd angles, or just have parts that are often missing like gastralia. Taken in combination of course there is often a lot of information available and far more can be said about a set of fossils than from a single specimen. Ultimately some however just look really nice.
This I think is a near perfect example. It’s actually a privately owned specimen of Pterodactylus, but it is on public display in the Solnhofen Museum. There are better specimens for some details of the skeleton, certainly there are those which show off more unusual angles, and many have soft tissue where this has none. But it is a striking example of a fossil pterosaur with every bone well preserved and in about as ‘natural’ and undisturbed position as you can hope to see.
As long as this remains privately owned and not formally owned by a museum, no one is ever going to describe this (or they shouldn’t really). But that’s perhaps not much of an issue. Obviously as a researcher, I want every specimen in a museum, but at least in this case Pterodactylus is so studied and well known from lots of excellent specimens that, excellent example though this is, little to no scientific knowledge is actually being lost or skipped in this one specimen. Still, if the owner would like to give it to the museum, or me for that matter, I’d not be complaining. As this is a private specimen and not in the literature I rather assume that few readers have seen it and so it seemed too good not to show it off here.
Dave Hone's Archosaur Musings 
Gorgeous.
I spent quite a bit of time photographing an amazing Rhamphorhynchus briefly held on display at a museum filled with privately held fossils and books of historical note. Not certain I’ll ever get a chance to see it’s like again, so I snapped plenty of photos. (At one point, I was told to get out from behind the display, where I was adjusting the camera for a dorsal view of the skull.) The info-placard they had for it was terrible, though.
Why can’t someone write a paper on a privately owned fossil?
The answer is that if it is privately owned, then the museum does not have control over it. The owner could take it back or sell it or whatever. That means that researchers do not have guaranteed access to the material. That means that people can’t check what you have done or said about the material. There’s no guarantee of verification, and so the material is, in theory, off limits. Exceptions do occur and there are fights about this, but for example societies like SVP specifically state that members should not publish on private material, and most journals won’t accept papers on private material.
Good question. Chris Bennett (sp?) described those crested Nyctosaurus specimens and they were privately owned…
That’s not quite true though. Chris actually only describes the crests, not the specimens as a whole. And he did so once he had got casts / photos that were archived in a museum. SO he was bending the rules a bit for 1 detail, rather than just describing a whole new and privately owned specimen.