Is there a creature currently published that has the abilities that would enable it to;
find and collect the bones of multiple bodies
able to separate them so each group of bones belong to the individual creature it was
interrogate the dead/learn who the bones belong to and other basic personal details
bones would be from over a hundred bodies ranging from new to up to about 100 years old scattered over an area of roughly 600 x 600 feet
Was thinking there might be a Pychopomp from somewhere that could be useful.
You could also just invent a spell that does this exceptionally specific thing. Billy McWizardSticks the Necromancer wizard might know it, but refuse to teach it to anyone and have the feat that makes it so he can cast it without it being in his spellbook. He's gotta protect his shtick.
The object reading spell or psychometry skill unlock would work well. Munavri get the first available at-will.