The most prominent Western example of a dead language is Latin, which eventually developed into the Romance languages. Akkadian, the earliest attested Semitic language, on the other hand, is an extinct language—from which it follows that there are no known languages that descended from it. The most common explanation for the absence of daughter languages is that Akkadian, the language of the Assyrians and Babylonians, was eclipsed by Aramaic (i.e., Old and Official Aramaic) rather early during the first millennium BCE.For more on the scribal relationship between Akkadian and Aramaic, see here, here, here, and here.
Akkadian may be extinct, but it is not forgotten. Nor should it be! See my long post from 2010, Why we need Akkadian (and the humanities!). And a related post is here.
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