Where do I get fossilized bone?

[Falonious]

I am only lvl 4 flame. Thx.

[Storm Elemental]

out toward desert, something that looks like a giant ribcage upturned. you can glide to it from a tower a dig all you like. :)

[Aigle1705]

once you reach the savana or desert area. there are huge rip cage like structures of a brown texture. mine those with yea pickaxe.

so yes its a soil just like dirt, n stone. :D