The musk duck (Biziura lobata) is a highly aquatic, stiff-tailed duck native to southern Australia. It is the only living member of the genus Biziura. An extinct relative, the New Zealand musk duck or de Lautour's duck (B. delautouri), once occurred on New Zealand, but is only known from prehistoric subfossil bones. It was about 8% longer than the living species, with a particularly large head.