What is a Black Valdano?

[henmad]

I was reading about the origin of Anconas and came across a reference to
Black Valdano's. :

"They (Anconas) probably originated from a cross between the Black Valdano and the common fowl
of Italy" , H. Cecil Sheppard

I can't find any reference to "Black Valdanos' anywhere else. Has anyone ever heard anything about such a bird?

Thanks