Wall of Bones was mentioned in the article as being a spell that could be in the book and originally appeared in Oriental Adventures. It later appeared in 3.5's Complete Arcane. Instead of converting from those versions, this is pretty much just a mash up of 5e's wall of stone and wall of thorns.
As an aside, years ago I toured Rome's Capuchin Crypt. Quite beautiful and definitely creepy.
Ok, I've edited this thing like 5 times trying to take out the weird spacing. Still keeps doing it. Deal with it. LOL.
Wall of Bones
Casting Time: 1 action
Range: 120 feet
Range: 120 feet
Components: V, S, M (a withered peach branch taken from a cemetary)
Duration: Concentration, up to 10 minutes
A nonmagical wall of bones springs into existence at a point you choose within range. The wall is 6 inches thick and is composed of ten 10-foot-by-10-foot panels. Each panel must be contiguous with at least one other panel. Alternatively, you can create 10-foot-by-20-foot panels that are only 3 inches thick. Though solid, the wall has many small openings and gaps, and provides three-quarters cover to attacks from the other side.When the wall appears, each creature within its area must make a Dexterity saving throw. On a failed save, a creature takes 4d8 piercing damage, or half as much damage on a successful save.
A creature can move through the wall, albeit slowly and painfully. For every one foot a creature moves through the wall, it must spend 4 feet of movement. Furthermore, the first time a creature enters the wall on a turn or ends its turn there, the creature must make a Dexterity saving throw. It takes 4d8 slashing damage on a failed save, or half as much damage on a successful one.
The wall is an object made of bones that can be damaged and thus breached. Each panel has AC 15 and 15 hit points per inch of thickness. Reducing a panel to 0 hit points destroys it and might cause connected panels to collapse at the DM’s discretion.
If you maintain your concentration on this spell for its whole duration, the wall becomes permanent and can’t be dispelled. Otherwise, the wall disappears when the spell ends.
At Higher Levels. When you cast this spell using a spell slot of 5th level or higher, both types of damage increase by 1d8 for each spell slot above 4th.