It was a close relative of the Egyptian Goose. Known from one or two subfossil carpometacarpus bones and a few descriptions, this bird was about the size of a Brent Goose. Its appearance is unknown, except that its wings showed the typical color pattern of shelducks.
Newton, Alfred & Gadow, Hans Friedrich (1893): On additional bones of the Dodo and other extinct birds of Mauritius obtained by Mr. Théodore Sauzier. Transactions of the Zoological Society of London 13: 281-302