Description[]
Bone Shards can be found within Fossil Ore, as a potential drop.
Crafting[]
Bone Shards are almost solely used to produce Arrows within the Erebus. They can be turned into Bonemeal with the recipe on the right, but it's not efficient and is a waste of potential Arrows, especially with the amount of Fly Wings available.

This shapeless recipe crafts into 1 Bonemeal.

This is the recipe for 4 Arrows. Note that you can replace the Fly Wing/Bone Shard with their vanilla counterparts.