Quill knobs will only appear where feathers need to be firmly anchored to
resist external pressure; so when you see them on the forelimbs they
normally indicate flight feathers. So you won't see evidence of feather
attachment elsewhere on the skeleton, although a nicely preserved
Microraptor himblimb could be interesting...
It's been a while since I did anything on this subject, but IIRC the
feathers don't actually reach the bone; the roughness / ridge/ knobs on
the
bone are caused by the tendons and muscles used to anchor the quills.
This Velociraptor specimen seems like good evidence for GSP's secondary
flighlessness thing - unless there's another reason for large, strongly
attached forelimb feathers.
Regards,
Michael Lovejoy