This week I have a mystery object for you, that I stumbled across when preparing a talk for the Natural Sciences Collections Association’s Bone Day last week:
It’s a bit of an odd one, so I’d love to hear what you think it might be. As usual, if you recognise what it is please give everyone else a chance by sharing your knowledge below in the guise of a rhyme or cryptic clue.
Have fun!
Zygoma 
think I know this- something that hasn’t been used for much in a LONG time. Fish and bicycle springs to mind.
I think our friend Pinnie Pete might cross the circle for this. Maybe even Gracie will.
it’s a radius… from a pinniped?
So definitely a lobefin then?