Drawing lines, lines in space

I am drawing fox bones - again.  Earlier this year I found a whole fox skeleton on a nearby field.  The bones are perfect, cleaned naturally by the weather.  The skeleton isn't very big - a young fox perhaps, defeated by hunger and the winter snow.  Laboriously, over a couple of days, I picked up every bone I could find, scattered over a couple of square metres.  Tiny teeth and claws were beginning to be subsumed into the mossy grass and only the larger bones were resisting the pull down into the earth.
Since then I have been drawing it almost every day.  The drawings are not realistic in an anatomical sense, but record my observations as I turn the bones round in my hand.
The drawings I'm making for the Frost Museum online residency are done with a goose quill pen - a nice sort of circularity: drawing a dead fox by using a goose quill.  The quill came from the old gander, who indeed fell victim to a fox, but not, I think this one.