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",
Branta material and comparisms with other subfossil bones assigned to the genus "Branta" it was redescribed as "Branta rhuax" in 2013. It was another prehistoric Big Island form and remains known only from some parts of a single bird's skeleton, which were much damaged because the bird apparently died in a volcanic eruption, with the bones being found in an ash-filled depression under a lava flow. A presumed relation to the shelducks proposed by Lester Short in 1970 was generally considered highly unlikely due to that group's biogeography, but more recently, bones of a shelduck-like bird have been found on Kaua‘i.