Complex sentence: Non-Arabic languages indigenous to the region include several Modern South Arabian languages, such as the Mehri and Soqotri languages, which are not Arabic languages, but members of an independent branch of the Semitic family.
Split into simpler sentences: Non-Arabic languages indigenous to the region include several Modern South Arabian languages ("MSA languages") such as the Mehri and Soqotri languages. The MSA languages are not Arabic languages but members of an independent branch of the Semitic family.