Complex sentence: His name was changed by Fox's founder, Darryl F. Zanuck to the more "bankable" name of Casey Adams, and made his feature film debut in 1949's "Always Leave Them Laughing".
Split into simpler sentences: His name was changed by Fox's founder, Darryl F. Zanuck to the more "bankable" Casey Adams. He made his feature film debut in 1949's "Always Leave Them Laughing".