From the Composite Bow quest introduced in the Paths of Destruction event.

Dark Revenant Thighbone
Value: 0
10 Burden Units
The thighbone of a departed Dark Revenant.


This has no apparent use.

Notes

You give Ivory Crafter Dark Revenant Thighbone.
Ivory Crafter tells you, "Aha! A Dark Revenant thighbone, quite exceptional!"
You've earned 7,500 experience.
Ivory Crafter gives you Trade Note (50,000).
Ivory Crafter tells you, "A fine reward for your formidable deed."