This week I have part of a specimen that needs to be reassociated with the rest of its skeleton:
Which skeleton should I be looking for? Put your suggestions below and I’ll do my best to reply. Good luck!
Zygoma
Adventures in natural history collections
Zygoma 
My first thought was bat wing. Then I thought maybe a bird. Both have long, slender bones. But also, both tend to have a humerus shorter than the radius/ulna, which this does not have. On balance, the curved humerus is more bat-like.
Like your thinking – it is a wing, but not from a bat
The length of that long bone is bothering me. So, perhaps it is not the humerus, but the ulna (minus radius & carpus) with the metacarpus & phalanges?
it is definitively not from a bat: those have all the fingers and those are really long: the opposite of what you are seeing here. Like RH I am more thinking of a flightless bird, still not sure which one though.
I believe you are looking for a small flightless bird, that inhabits antipodean islands. Clues- the bowed humerus, the small size, the odd fusing of the carpals, which may end in a claw.
Following your clues I’ve checked one antipodean bird in particular and agree with your identification; quite characteristic now that I’ve seen it, though the morphology was new to me. I saw bird of this genus (a southern brown, I think) feeding on a beach at midnight; not sure which species this is though.
Definitely a wing. The end is very strange.
It’s from a very strange animal 😉
I did a search on birds with what that end might be and I ended up with Op. ho. ?
But as it’s Christmas is should probably be Op. ho. ho. ho.
Good punnage! Not a Hoatzin though.
Thanks to commenters pointing me to the right part of the world and to google image search, I would put my money on one of the A****yx.
I thought that one was extinct. (sorry, couldn’t resist 😉 )