Scanned with 123d catch at Field Musuem in Chicago. This is probably a vessel of some kind, used in some kind of sacrificial rite. again i did not make any notes. but i do recall something about "blood" on the wall next ot the piece, and the poor chap depicted is tied up so i'm pretty sure nothing good came of this for the person on the end of it.
post process with the usual: netfabb/meshmixer/meshlabb etc