Orthographic borrowing from Sumerian 𒃻𒅮𒈾 (nig̃₂-bun₂-na /nig̃buna/, “turtle”).
𒃻𒅮𒈾 • (NIG₂.BUN₂.NA)
𒃻𒅮𒈾 • (nig̃₂-bun₂-na /nig̃buna/)