This version of the tree was made by Don Rosa in hope of settling the genealogy questions once and for all. He based himself on Carl Barks's two previous Duck family trees (about which you may read here and here), Mark Worden's version and personal ideas, to which he added other characters mentioned in Carl Barks's stories as well as Fethry Duck, to his chief editor's bold insistence. This official version is, however, not exactly like what Don Rosa had intended: the face of Huey, Dewey and Louie Duck's father is hidden and Ludwig von Drake is not included in the tree, despite Don Rosa's wish to include both of them. He later made a slightly altered version including Ludwig and the father's faces.This version is considered the most "canonical" tree of all, rendering the three previous versions non-canonical. It is however not perfect, because of Rosa's will to include only Barks-created characters, excluding for instance Gideon McDuck or Moby Duck. Even then, he actually missed one, Cousin Mehitabel Mudhen, mentioned in Barks's 1946 "Collection Crisis", whom some theorize may be a relative of Lulubelle Loon. Moreover, Rosa wisely chose the name of Della Duck for Donald Duck's sister, as per earlier sources, rather than following Barks's idea of calling her Thelma.