Small densely furred aquatic monotreme of Australia and Tasmania having a broad bill and tail and webbed feet,only species in the family Ornithorhynchidae.

• 澳大利亚和塔斯马尼亚的体毛浓密、水生小哺乳动物，嘴和尾宽阔，脚有蹼，鸭嘴兽科的唯一种类。