When decimal currency was introduced in New Zealand on 10 July 1967, there was no new circulating denomination with the size and specifications of the old one crown piece, in which only commemorative coins had been issued; the new (large) fifty cents were equivalent in value but not in size. New Zealand issued crown-sized commemoratives with the specifications of the old crown, based on the British pre-decimal Crown. Until the introduction of the smaller circulating dollar coin in 1990, these coins had a one dollar denomination; later issues were denominated as five dollars.
These coins are legal tender but are not intended for circulation.
In 1980 the large one dollar coin depicted a "fantail" bird. It is remarkable in that the obverse features an effigy of Queen Elizabeth II by a New Zealand artist, James Berry. | 
Search for New Zealand: One Dollar 1980 Fantail on eBay 