Brant (goose) the "Agreement on the Conservation of African-Eurasian Migratory Waterbirds" applies. "Branta" is a Latinised form of Old Norse "brandgás", "burnt (black) goose", and "bernicla" is the medieval Latin name for the barnacle. The brant and the similar barnacle goose were previously considered one species, formerly believed to be the same creature as the crustacean. That myth can be dated back to at least the 12th century. Gerald of Wales claimed to have seen these birds hanging down from pieces of timber, William Turner accepted the theory, and John Gerard claimed to have seen the birds emerging from their shells. The
Branta thessaliensis Mammal Neogene stage MN12, 7.5-6.8 million years ago) deposit at Perivolaki in Thessaly, after which region the species was named. Both near-shore freshwater bodies and open grassland habitat were found in the Perivolaki area during MN12. The species provides further support for the distinctness of "Branta" from the "Anser" grey geese by that time. It also suggests that the present biogeography of Eurasian "Branta" - breeding at Arctic and wintering at Mediterranean latitudes - is a product of post-Miocene times, possibly due to range shifts during the ice age era. In this aspect it is notable that such a breeding-wintering