You can get it from Giaprey's after the quest ends.
Good Luck Finding it...
CeroNueve09™
You could just fight a monster from the Upper Rank missions in the Guild Hall.
You get a large monster bone from the large monsters like the kut-ku.
4*+ Elder quests. If I recall correctly, the Green Plesioth awarded Monster Bone+.
You can get them by killing monsters with shells in the dessert.
By hunting a khezu, rathalos, rathian etc... The first time I got any monster bone +, it was when I got 3 of them from one run of the 5* village quest "Small Shadow over the Swamp".
Just keep hunting monsters. You get really weird monster bones near the end.
Kill the things with spicky tails in the desert
combine bone and machalite ore. :)
in the desert, look for a large monster with a spiked tail. kill these!!! ---- they are not hard and you can carve them twice.
This isn't a question but a incomplete sentence, and there is no such item, bone, or weapon called big bone.
Most medium sized monsters drop them, but I think the best way is to kill apcerpos in the desert or volcano.
Killing monster will give you monster bone by chance. Since you did not mention the size of the bone. It is very hard to answer. If you mean monster bone+, you will needs to get it from G-rank quests, or trade Sm blue YKK ears from forest and Hill elders for it. Look in Gamefaqs.com for more information.