Complex sentence: Although of obscure origin, what is known is that the Sheltie is a direct descendant of the Colkie the Sheltie is a descendant of small specimens of the Scottish Collie and the King Charles Spaniel.
Split into simpler sentences: Although of obscure origin, what is known is that the Sheltie is a direct descendant of the Colkie. The Sheltie is a descendant of small specimens of the Scottish Collie and the King Charles Spaniel.