Goose barnacle migrate, it was thought that barnacle geese, "Branta leucopsis", developed from this crustacean, since they were never seen to nest in temperate Europe, hence the English names "goose barnacle", "barnacle goose" and the scientific name "Lepas anserifera" (, "goose"). The confusion was prompted by the similarities in colour and shape. Because they were often found on driftwood, it was assumed that the barnacles were attached to branches before they fell in the water. The archdeacon of Brecon, Gerald of Wales, made this claim in his "Topographia Hiberniae". Since barnacle geese were thought to be "neither flesh, nor born of flesh",
Anser (bird) Maltese swan "Cygnus equitum" was occasionally placed into "Anser", and "Anser condoni" is a synonym of "Cygnus paloregonus". A goose fossil from the Early-Middle Pleistocene of El Salvador is highly similar to "Anser". Given its age it is likely to belong to an extant genus, and biogeography indicates "Branta" as other likely candidate. ?"Anser scaldii" (Late Miocene of Antwerp, Belgium) may be a shelduck. Two species in the genus are of major commercial importance, having been domesticated as poultry: European domesticated geese are derived from the greylag goose, and Chinese and some African domesticated geese are derived from the swan