In biology, dactyly is the arrangement of digits on the hands, feet, or sometimes wings of a tetrapod animal. It comes from the Greek word δακτυλος = "finger".

The emu is a species of flightless bird endemic to Australia, where it is the largest native bird. It is the only extant member of the genus Dromaius and the second-tallest living bird after its African ratite relative, the common ostrich. The emu's native ranges cover most of the Australian mainland. The Tasmanian, Kangaroo Island and King Island subspecies became extinct after the European settlement of Australia in 1788.