Note: The red shinies do not despawn after you gather them, but they will not update your quest a second time. You can only interact with the ones you have not yet gathered. Keep looking for ones that do update your quest.
Collect 5 piles of dark bones in the Commonlands across the river far south of the Southern Crossroads Savanna (search along the ruins) ( -542, -45, 393 ) /waypoint -542, -45, 393
See the talk page for known locations in the Commonlands and Jarsath Wastes