Complex sentence: It featured the first non-comic book portrayals ever of Superboy and Lana Lang and stands as a foreunner of later series Superboy, which lasted 4 seasons and Smallville, currently in its 6th.
Split into simpler sentences: It featured the first non-comic book portrayals ever of Superboy and Lana Lang. It is thus a foreunner of later series Superboy, which lasted 4 seasons and Smallville, currently in its 6th.