Cygnus paloregonus
Cygnus paloregonus is a fossil swan. It is an ancestor of, and distantly allied to, the mute swan. It is known from the Pleistocene from Fossil [Lake, Oregon], Froman's [Ferry, Idaho], and from Arizona. It is referred to by Hildegarde Howard in Delacour's The Waterfowl of the World as "probably the mute type swan".