Complex sentence: Of mixed origins, the Turmodigi remain a mysterious people--its tribal name is not considered to be Indo-European, and they certainly included many elements of Aquitanian, Indo-Aryan and Illyrian origin.
Split into simpler sentences: Of mixed origins, the Turmodigi remain a mysterious people. Its tribal name is not considered to be Indo-European, and they certainly included many elements of Aquitanian, Indo-Aryan and Illyrian origin.