That is quite a interesting question, well Joseph had them swore a oath to take his bones out of Eygpt, yet what I find as a some head scratcher is, when Joseph died they embalmed him and place the body in a coffin.
so in my pondering mind, a embalmed body would take a long time to actually become just bones. and the account kind of just drops off right there about the embalming and the coffin.
My question would be Is there farther verses that actually mentions them carry away the bones?