Complex sentence: The Goldcrest ("Regulus regulus") is a very small passerine bird in the kinglet family which has several subspecies breeding across much of Eurasia and on the islands of Macaronesia.
Split into simpler sentences: The Goldcrest ("Regulus regulus") is a very small passerine bird in the kinglet family. It has evolved several subspecies across a very large range that includes much of Eurasia and the islands of Macaronesia.